technology focus electronics/computers

Technology Focus

Electronics/Computers

Software

Materials

Mechanics/Machinery

Manufacturing

Bio-Medical

Physical Sciences

Information Sciences

Books and Reports

08-11 August 2011

NASA Tech Briefs, August 2011 1

INTRODUCTIONTech Briefs are short announcements of innovations originating from research and developmentactivities of the National Aeronautics and Space Administration. They emphasize information con-sidered likely to be transferable across industrial, regional, or disciplinary lines and are issued toencourage commercial application.

Additional Information on NASA Tech Briefs and TSPsAdditional information announced herein may be obtained from the NASA Technical Reports Server:http://ntrs.nasa.gov.

Please reference the control numbers appearing at the end of each Tech Brief. Infor mation on NASA’s Innovative Partnerships Program (IPP), its documents, and services is available on the World Wide Webat http://www.ipp.nasa.gov.

Innovative Partnerships Offices are located at NASA field centers to provide technology-transfer access toindustrial users. Inquiries can be made by contacting NASA field centers listed below.

Ames Research CenterMary Walsh(650) [email protected]

Dryden Flight Research CenterRon Young(661) [email protected]

Glenn Research CenterJoe Shaw(216) [email protected]

Goddard Space Flight CenterNona Cheeks(301) [email protected]

Jet Propulsion LaboratoryIndrani Graczyk(818) [email protected]

Johnson Space CenterJohn E. James(281) [email protected]

Kennedy Space CenterDavid R. Makufka(321) [email protected]

Langley Research CenterMichelle Ferebee(757) [email protected]

Marshall Space Flight CenterJim Dowdy(256) [email protected]

Stennis Space CenterRamona Travis(228) [email protected]

NASA Headquarters

Innovative Partnerships OfficeDoug Comstock, Director(202) [email protected]

Daniel Lockney, Technology Transfer Lead(202) [email protected]

Small Business Innovation Research(SBIR) & Small Business TechnologyTransfer (STTR) ProgramsCarl Ray, Program Executive(202) [email protected]

NASA Field Centers and Program Offices


5 Technology Focus: Mechanical Components

5 Miniature, Variable-Speed Control MomentGyroscope

5 NBL Pistol Grip Tool for Underwater Training of Astronauts

5 HEXPANDO Expanding Head for Fastener-Retention Hexagonal Wrench

6 Diagonal-Axes Stage for Pointing an Optical Communications Transceiver

7 Electronics/Computers7 Improvements in Speed and Functionality of a

670-GHz Imaging Radar

7 IONAC-Lite

8 Large Ka-Band Slot Array for Digital Beam-Forming Applications

8 Development of a 150-GHz MMIC ModulePrototype for Large-Scale CMB Radiation

9 Coupling Between Waveguide-Fed Slot Arrays

9 PCB-Based Break-Out Box

9 Multiple-Beam Detection of Fast Transient Radio Sources

10 Router Agent Technology for Policy-BasedNetwork Management

11 Software11 Remote Asynchronous Message Service Gateway

11 Automatic Tie Pointer for In-Situ Pointing Correction

11 Jitter Correction

12 MSLICE Sequencing

12 EOS MLS Level 2 Data Processing Software Version 3

12 DspaceOgre 3D Graphics Visualization Tool

13 Manufacturing & Prototyping13 Metallization for Yb14MnSb11-Based

Thermoelectric Materials

14 Solvent/Non-Solvent Sintering To MakeMicrosphere Scaffolds

15 Green Design15 Enhanced Fuel-Optimal Trajectory-Generation

Algorithm for Planetary Pinpoint Landing

17 Materials17 Self-Cleaning Coatings and Materials for

Decontaminating Field-Deployable Land andWater-Based Optical Systems

17 Separation of Single-Walled Carbon Nanotubeswith DEP-FFF

18 Li Anode Technology for Improved Performance

19 Bio-Medical19 Post-Fragmentation Whole Genome

Amplification-Based Method

19 Microwave Tissue Soldering for ImmediateWound Closure

20 Principles, Techniques, and Applications of Tissue Microfluidics

21 Robotic Scaffolds for Tissue Engineering andOrgan Growth

21 Stress-Driven Selection of Novel Phenotypes

23 Physical Sciences23 Method for Accurately Calibrating a

Spectrometer Using Broadband Light

23 Catalytic Microtube Rocket Igniter

24 Stage Cylindrical Immersive Display

25 Vacuum Camera Cooler

25 Atomic Oxygen Fluence Monitor

27 Information Sciences27 Thermal Management Tools for Propulsion

System Trade Studies and Analysis

27 Introduction to Physical Intelligence

27 Technique for Solving Electrically Small to LargeStructures for Broadband Applications

28 Accelerated Adaptive MGS Phase Retrieval

28 Large Eddy Simulation Study for FluidDisintegration and Mixing

29 Tropospheric Correction for InSAR Using InterpolatedECMWF Data and GPS Zenith Total Delay

30 Technique for Calculating Solution Derivatives WithRespect to Geometry Parameters in a CFD Code

30 Acute Radiation Risk and BRYNTRN Organ DoseProjection Graphical User Interface

31 Probabilistic Path Planning of MontgolfierBalloons in Strong, Uncertain Wind Fields

33 Books & Reports33 Flight Simulation of ARES in the Mars Environment

33 Low-Outgassing Photogrammetry Targets for Usein Outer Space

33 Planning the FUSE Mission Using the SOVA Algorithm

33 Monitoring Spacecraft Telemetry Via Optical or RF Link

34 Robust Thermal Control of Propulsion Lines forSpace Missions

08-11 August 2011

This document was prepared under the sponsorship of the National Aeronautics and Space Administration. Neither the United States Govern-ment nor any person acting on behalf of the United States Government assumes any liability resulting from the use of the information containedin this document, or warrants that such use will be free from privately owned rights.


Technology Focus: Mechanical Components

The Miniature Variable-Speed Con -trol Moment Gyroscope (MVS-CMG)was designed for small satellites (massfrom less than 1 kg up to 500 kg). Cur-rently available CMGs are too large andheavy, and available miniature CMGs donot provide sufficient control authorityfor use on practical satellites. This pri-marily results from the need to greatlyincrease the speed of rotation of the fly-wheel in order to reduce the flywheelsize and mass. This goal was achieved bymaking use of a proprietary, space-quali-fied, high-speed (100,000 rpm) motortechnology to spin the flywheel at aspeed ten times faster than other knownminiature CMGs under development.

NASA is supporting innovations inpropulsion, power, and guidance andnavigation systems for low-cost smallspacecraft. One of the key enablingtechnologies is attitude control mecha-nisms. CMGs are particularly attractivefor spacecraft attitude control sincethey can achieve higher torques withlower mass and power than reactionwheels, and they provide continuoustorque capability that enables precisionpointing (in contrast to on-off thrustercontrol).The aim of this work was to develop a

miniature, variable-speed CMG that issized for use on small satellites. Toachieve improved agility, these space-

craft must be able to slew at high rate,which requires attitude control actua-tors that can apply torques on the orderof 5 N·m. The MVS-CMG is specificallydesigned to achieve a high-torque out-put with a minimum flywheel and sys-tem mass. The flywheel can be run overa wide range of speeds, which is impor-tant to help reduce/eliminate potentialgimbal lock, and can be used to opti-mize the operational envelope of theCMG.This work was done by Steve Bilski, Robert

Kline-Schoder, and Paul Sorensen of CreareInc. for Goddard Space Flight Center. Furtherinformation is contained in a TSP (see page 1).GSC-15887-1

Miniature, Variable-Speed Control Moment GyroscopeGoddard Space Flight Center, Greenbelt, Maryland

A document discusses a lightweight,functional mockup of the Pistol GripTool for use during underwater astronauttraining. Previous training tools havecaused shoulder injuries. This new ver-sion is more than 50 percent lighter [inwater, weight is 2.4 lb (≈1.1 kg)], and canoperate for a six-hour training sessionafter 30 minutes of prep for submersion.

Innovations in the design include theuse of lightweight materials (aluminumand Delrin®), creating a thinner hous-ing, and the optimization of internalspace with the removal of as much ex-cess material as possible. This reducestool weight and maximizes buoyancy.Another innovation for this tool is theapplication of a vacuum that seats the O-

rings in place and has shown to be reli-able in allowing underwater usage forup to six hours.This work was done by Michael Liszka,

Matthew Ashmore, Mark Behnke, Walter Smith,and Tod Waterman of ATK Spacecraft, Systemsand Services for Goddard Space Flight Center.Further information is contained in a TSP (seepage 1). GSC-16060-1

The HEXPANDO is an expanding-head hexagonal wrench designed to re-tain fasteners and keep them from beingdislodged from the tool. The tool is in-tended to remove or install socket-headcap screws (SHCSs) in remote, hard-to-reach locations or in circumstanceswhen a dropped fastener could causedamage to delicate or sensitive hard-ware. It is not intended for applicationof torque.

This tool is made of two assembledportions. The first portion of the toolcomprises tubing, or a hollow shaft, at alength that gives the user adequatereach to the intended location. At oneend of the tubing is the expandinghexagonal headfitting with six radialslits cut into it (one at each of thepoints of the hexagonal shape), and asmall hole drilled axially through thecenter and the end opposite the hex is

internally and externally threaded. Thisfitting is threaded into the shaft (via ex-ternal threads) and staked or bondedso that it will not loosen. At the otherend of the tubing is a knurled collarwith a through hole into which the tub-ing is threaded. This knob is secured inplace by a stop nut. The second assembled portion of the

tool comprises a length of all thread orsolid rod that is slightly longer than the

NBL Pistol Grip Tool for Underwater Training of AstronautsGoddard Space Flight Center, Greenbelt, Maryland

HEXPANDO Expanding Head for Fastener-Retention Hexagonal WrenchGoddard Space Flight Center, Greenbelt, Maryland

6 NASA Tech Briefs, August 2011

steel tubing. One end has a slightlylarger knurled collar affixed while theother end is tapered/pointed andthreaded. When the two portions are as-sembled, the all thread/rod portionfeeds through the tubing and isthreaded into the expanding hex headfitting. The tapered point allows it to bedriven into the through hole of the hexfitting. While holding the smaller collaron the shaft, the user turns the larger

collar, and as the threads feed into thefitting, the hex head expands and gripsthe SHCS, thus providing a safe way toinstall and remove fasteners. The clamp-ing force retaining the SHCS varies de-pending on how far the tapered end isinserted into the tool head.Initial tests of the prototype tool, de-

signed for a 5 mm or # 10SHCS have re-sulted in up to 8 lb (≈35.6 N) of pullforce to dislodge the SHCS from the

tool. The tool is designed with a lead-inangle from the diameter of the tubing toa diameter the same as the fastenerhead, to prevent the fastener head fromcatching on any obstructions encoun-tered that could dislodge the fastenerduring retrieval. This work was done by John Bishop of Qine-

tiQ for Goddard Space Flight Center. Further in-formation is contained in a TSP (see page 1).GSC-16109-1

Traditional azimuth-elevation (“az-el”)stages are used to point a variety of devicesranging from large optical telescopes totank guns. Such a stage typically has an “el-evation” stage having a horizontal axismounted on an “azimuth” stage with a ver-tical axis. Both stages are often motorized. Optical communications transceivers

often require two-axis motorized control,as when the communications link is be-tween a ground station and an aircraft or

satellite. In such applications, the tradi-tional azimuth-elevation stage has two im-portant drawbacks: a “gimbal lock” exclu-sion zone at zenith and susceptibility topointing errors caused by backlash. Az-elstages in which the azimuth stage cannotrotate a full 360° have the additionaldrawback of an azimuth exclusion zone. The diagonal-axes stage described here

mitigates or eliminates all of these prob-lems. Instead of one vertical axis and one

horizontal axis, a diagonal-axes stage hastwo horizontal axes, both oriented at 45°to the trajectory of the target. For exam-ple, a ground station located on the equa-tor tracking a satellite with an equatorialorbit would have one axis parallel tonortheast and southwest, and the otheraxis parallel to northwest and southeast. The diagonal-axes stage is considerably

less vulnerable to backlash. If it is correctlyoriented, its axes rotate in only one direc-tion during an overhead pass by a satellite.As a result, the effects of backlash may beinherently eliminated. If the gravity-in-duced torque on either axis changes dur-ing the pass, then backlash may become im-portant during the part of the pass wherethe gravity torque, instead of opposing themotion of the stage, pushes the stage in thedirection of motion. This can result in theloss of gear-to-gear contact in one or morestages of the gear reduction mechanism. Inthis case, a preload spring used to eliminatebacklash need only be sufficiently strong toovercome the gravity torque, i.e. it need notovercome friction in the gear train. The diagonal-axes stage is not backlash-

free for arbitrary target trajectories suchas an aircraft might execute. If properlyoriented for any particular satellite, how-ever, it is backlash-free for all passes of thatsatellite, which will trace out parallel pathson the sky, and for all passes of any othersatellite that are perpendicular to the first.It will also be backlash-free for some frac-tion of other satellite trajectories. This work was done by Martin W. Regehr

and Vachik Garkanian of Caltech for NASA’sJet Propulsion Laboratory. Further informationis contained in a TSP (see page 1). NPO-47427

Diagonal-Axes Stage for Pointing an Optical Communications Transceiver Potential applications include steering aircraft-mounted cameras for ground imaging. NASA’s Jet Propulsion Laboratory, Pasadena, California

A design based on the Diagonal-Axes Stage principle. Motors are shown in red, wedge and intermo-tor block are shown in blue, and the payload hub is green. The box at left with three circular aper-tures is an example of an optical payload; the L-bracket at left is a mounting bracket supporting thestage. Direction of travel is right-to-left.


Electronics/Computers

Significant improvements have beenmade in the instrument originally de-scribed in a prior NASA Tech Briefs article:“Improved Speed and Functionality of a580-GHz Imaging Radar” (NPO-45156),Vol. 34, No. 7 (July 2010), p. 51. First, thewideband YIG oscillator has been re-placed with a JPL-designed and builtphase-locked, low-noise chirp source.Second, further refinements to the dataacquisition and signal processing soft-ware have been performed by movingcritical code sections to C code, and com-piling those sections to Windows DLLs,which are then invoked from the mainLabVIEW executive. This system is an active, single-pixel

scanned imager operating at 670 GHz.The actual chirp signals for the RF andLO chains were generated by a pair ofMITEQ 2.5–3.3 GHz chirp sources. Agi-lent benchtop synthesizers operating atfixed frequencies around 13 GHz werethen used to up-convert the chirpsources to 15.5–16.3 GHz. The resultingsignals were then multiplied 36 times by

a combination of off-the-shelf millime-ter-wave components, and JPL-built 200-GHz doublers and 300- and 600-GHztriplers. The power required to drive thesubmillimeter-wave multipliers was pro-vided by JPL-built W-band amplifiers.The receive and transmit signal pathswere combined using a thin, high-resis-tivity silicon wafer as a beam splitter.While the results at present are en-

couraging, the system still lacks suffi-cient speed to be usable for practicalapplications in a contraband detection.Ideally, an image acquisition speed often seconds, or a factor of 30 improve-ment, is desired. However, the systemimprovements to date have resulted ina factor of five increase in signal acqui-sition speed, as well as enhanced signal-processing algorithms, permittingclearer imaging of contraband objectshidden underneath clothing. In partic-ular, advances in three distinct areashave enabled these performance en-hancements: base source phase noisereduction, chirp rate, and signal pro-

cessing. Additionally, a second pixel wasadded, automatically reducing the im-aging time by a factor of two. Althoughadding a second pixel to the systemdoubles the amount of submillimetercomponents required, some savings inmicrowave hardware can be realized byusing a common low-noise source. This work was done by Robert J. Dengler, Ken

B. Cooper, Imran Mehdi, Peter H. Siegel, JanA. Tarsala, and Tomas E. Bryllert of Caltechfor NASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected]. In accordance with Public Law 96-517,

the contractor has elected to retain title to thisinvention. Inquiries concerning rights for itscommercial use should be addressed to:Innovative Technology Assets ManagementJPLMail Stop 202-2334800 Oak Grove DrivePasadena, CA 91109-8099E-mail: [email protected] to NPO-47180, volume and number

of this NASA Tech Briefs issue, and thepage number.

Improvements in Speed and Functionality of a 670-GHz Imaging RadarImage acquisition time has been reduced, enabling clearer images of contraband objects hidden underneath clothing.NASA’s Jet Propulsion Laboratory, Pasadena, California

The Interplanetary Overlay Net -working Protocol Accelerator (IONAC)described previously in “The Inter -planetary Overlay Networking ProtocolAccelerator” (NPO-45584), NASA TechBriefs, Vol. 32, No. 10, (October 2008)p. 106 (http://www.techbriefs.com/compo-nent/content/article/3317) provides func-tions that implement the Delay Toler-ant Networking (DTN) bundleprotocol. New missions that requirehigh-speed downlink-only use of DTNcan now be accommodated by the uni-directional IONAC-Lite to support high

data rate downlink mission applica-tions. Due to constrained energy re-sources, a conventional software imple-mentation of the DTN protocol canprovide only limited throughput forany given reasonable energy consump-tion rate. The IONAC-Lite DTN Proto-col Accelerator is able to reduce this en-ergy consumption by an order ofmagnitude and increase the through-put capability by two orders of magni-tude. In addition, a conventional DTNimplementation requires a bundle data-base with a considerable storage re-

quirement. In very high downlink data-rate missions such as near-Earth radarscience missions, the storage space uti-lization needs to be maximized for sci-ence data and minimized for communi-cations protocol-related storage needs. The IONAC-Lite DTN Protocol Accel-

erator is implemented in a reconfig-urable hardware device to accomplishexactly what’s needed for high-through-put DTN downlink-only scenarios. The following are salient features of

the IONAC-Lite implementation: • An implementation of the Bundle Pro-

IONAC-Lite A combination of energy and performance optimization is attained for high-speed DelayTolerant Networking. NASA’s Jet Propulsion Laboratory, Pasadena, California


tocol for an environment that requiresa very high rate bundle egress datarate. The C&DH (command and datahandling) subsystem is also expectedto be very constrained so the interac-tion with the C&DH processor and thetemporary storage are minimized. • Fully pipelined design so that bundleprocessing database is not required. • Implements a lookup table-based ap-proach to eliminate multi-pass process-

ing requirement imposed by the Bun-dle Protocol header’s length field struc-ture and the SDNV (self-delimiting nu-meric value) data field formatting. • 8-bit parallel datapath to support highdata-rate missions. • Reduced resource utilization imple-mentation for missions that do not re-quire custody transfer features. Therewas no known implementation of theDTN protocol in a field programmable

gate array (FPGA) device prior to thecurrent implementation. The combination of energy and per-

formance optimization that embodiesthis design makes the work novel.This work was done by Jordan L. Torgerson,

Loren P. Clare, and Jackson Pang of Caltechfor NASA’s Jet Propulsion Laboratory. Formore information, contact the JPL InnovativeTechnology Assets Management Office, 1-818-393-3421, and reference NPO-47344.

This work describes the developmentof a large Ka Band Slot Array for the Gla-cier and Land Ice Surface Topography In -terferometer (GLISTIN), a proposedspaceborne interferometric syntheticaperture radar for topographic mappingof ice sheets and glaciers. GLISTIN willcollect ice topography measurement dataover a wide swath with sub-seasonal repeatintervals using a Ka-band digitally beam-formed antenna. For technology demonstration pur-

pose a receive array of size 1×1 m, con-sisting of 160×160 radiating elements,was developed. The array is divided into16 sticks, each stick consisting of 160×10radiating elements, whose outputs arecombined to produce 16 digital beams.A transmit array stick was also devel-oped. The antenna arrays were designedusing Elliott’s design equations with the

use of an infinite-array mutual-couplingmodel. A Floquet wave model was usedto account for external coupling be-tween radiating slots. Because of the useof uniform amplitude and phase distri-bution, the infinite array model yieldedidentical values for all radiating ele-ments but for alternating offsets, andidentical coupling elements but for al-ternating positive and negative tilts. Waveguide-fed slot arrays are finding

many applications in radar, remote sens-ing, and communications applicationsbecause of their desirable propertiessuch as low mass, low volume, and easeof design, manufacture, and deployabil-ity. Although waveguide-fed slot arrayshave been designed, built, and tested inthe past, this work represents several ad-vances to the state of the art. The use ofthe infinite array model for the radiating

slots yielded a simple design process forradiating and coupling slots. Method ofmoments solution to the integral equa-tions for alternating offset radiating slotsin an infinite array environment was de-veloped and validated using the com-mercial finite element code HFSS. Forthe analysis purpose, a method of mo-ments code was developed for an infi-nite array of subarrays. Overall the 1×1 m array was found to

be successful in meeting the objectivesof the GLISTIN demonstration antenna,especially with respect to the 0.042°,1/10th of the beamwidth of each stick,relative beam alignment between sticks.This work was done by Sembiam Rengara-

jan, Mark S. Zawadzki, and Richard E.Hodges of Caltech for NASA’s Jet PropulsionLaboratory. For more information, [email protected]. NPO-47416

Large Ka-Band Slot Array for Digital Beam-Forming ApplicationsNASA’s Jet Propulsion Laboratory, Pasadena, California

HEMT-based receiver arrays with ex-cellent noise and scalability are alreadystarting to be manufactured at 100 GHz,but the advances in technology shouldmake it possible to develop receivermodules with even greater operation fre-quency up to 200 GHz. A prototype het-erodyne amplifier module has been de-veloped for operation from 140 to 170GHz using monolithic millimeter-waveintegrated circuit (MMIC) low-noise InPhigh electron mobility transistor(HEMT) amplifiers. The compact, scalable module is cen-

tered on the 150-GHz atmospheric win-

dow using components known to operatewell at these frequencies. Arrays equippedwith hundreds of these modules can beoptimized for many different astrophysi-cal measurement techniques, includingspectroscopy and interferometry. This module is a heterodyne receiver

module that is extremely compact, andmakes use of 35-nm InP HEMT technol-ogy, and which has been shown to haveexcellent noise temperatures whencooled cryogenically to 30 K. This reduc-tion in system noise over prior art hasbeen demonstrated in commercial mix-ers (uncooled) at frequencies of

160–180 GHz. The module is expectedto achieve a system noise temperature of60 K when cooled. An MMIC amplifier module has been

designed to demonstrate the feasibilityof expanding heterodyne amplifier tech-nology to the 140 to 170-GHz frequencyrange for astronomical observations.The miniaturization of many standardcomponents and the refinement of RFinterconnect technology have clearedthe way to mass-production of hetero-dyne amplifier receivers, making it a fea-sible technology for many large-popula-tion arrays.

Development of a 150-GHz MMIC Module Prototype for Large-Scale CMB Radiation NASA’s Jet Propulsion Laboratory, Pasadena, California


This work furthers the recent re-search efforts in compact coherent re-ceiver modules, including the develop-ment of the Q/U ImagingExperimenT (QUIET) modules cen-tered at 40 and 90 GHz, and the pro-

duction of heterodyne module proto-types at 90 GHz. This work was done by Pekka P. Kan-

gaslahti, Lorene A. Samoska, Todd C. Gaier,and Mary M. Soria of Caltech; Patricia E.Voll, Sarah E. Church, Judy M. Lau, and

Matthew M. Sieth of Stanford University;and Daniel Van Winkle and Sami Tantawi ofSLAC National Accelerator Laboratory forNASA’s Jet Propulsion Laboratory. Further in-formation is contained in a TSP (see page 1).NPO-47664

Coupling Between Waveguide-Fed Slot Arrays NASA’s Jet Propulsion Laboratory, Pasadena, California

Coupling between two waveguide-fedplanar slot arrays has been investigatedusing full-wave analysis. The analysis em-ploys the method-of-moments solutionto the pertinent coupled integral equa-tions for the aperture electric field of allslots. In order to compute coupling be-tween two arrays, the input port of thefirst array is excited with a TE10 modewave while the second one is match-ter-minated. After solving the momentmethod matrix equations, the aperturefields of all slots are obtained and

thereby the TE10 mode wave received atthe input port of the second array is de-termined. Coupling between two arraysis the ratio of the wave amplitude arriv-ing in the second array port to the inci-dent wave amplitude at the first arrayport. The coupling mechanism has beenstudied as a function of spacing betweenarrays in different directions, e.g. theelectric field plane, the magnetic fieldplane, and the diagonal plane. Com-puted coupling values are presented fordifferent array geometries.

This work is novel since it provides agood understanding of coupling be-tween waveguide-fed slot arrays as afunction of spacing and orientation fordifferent aperture distributions andarray architectures. This serves as a use-ful tool for antenna design engineersand system engineers. This work was done by Sembiam Rengara-

jan of Caltech for NASA’s Jet Propulsion Lab-oratory. For more information, contact [email protected]

A method has been designed for usingmultiple independent stations to dis-criminate fast transient radio sourcesfrom local anomalies, such as antennanoise or radio frequency interference(RFI). This can improve the sensitivity of

incoherent detection for geographicallyseparated stations such as the very longbaseline array (VLBA), the future squarekilometer array (SKA), or any other co-incident observations by multiple sepa-rated receivers.

The transients are short, broadbandpulses of radio energy, often just a fewmilliseconds long, emitted by a varietyof exotic astronomical phenomena.They generally represent rare, high-energy events making them of great

Multiple-Beam Detection of Fast Transient Radio SourcesNASA’s Jet Propulsion Laboratory, Pasadena, California

Break-out boxes (BOBs) are necessaryfor all electrical integration/cablecheckouts and troubleshooting. Becausethe price of a BOB is high, and no workcan be done without one, often the pro-cedure stops, simply waiting for a BOB.A less expensive BOB would take lesstime in the integration, testing, andtroubleshooting process.The PCB-based BOB works and looks

the same as a standard JPL BOB, called“Gold Boxes.” The only differences be-tween the old BOB and the new PCB-based BOB is that the new one has 80 per-cent of its circuitry in a printed circuit

board. This process reduces the time forfabrication, thus making the BOBs less ex-pensive. Moreover, because of its uniquedesign, the new BOBs can be easily assem-bled and fixed. About 80 percent of thenew PCB-based BOB is in a $22 (at thetime of this reporting) custom-designed,yet commercially available PCB.This device has been used successfully

to verify that BOB cables were properlymade. Also, upon completion, the BOBwas beeped out via a multimeter to en-sure that all sockets on the connectorswere properly connected to the respec-tive banana jack.

When compared to the Gold BoxBOBs, the new BOB has many advan-tages. It is much more cost efficient, itdelivers equal usability at substantiallylower cost of the BOB, and the Gold Boxis much heavier when compared to thenew BOB. The new BOB is also a bitlonger and much more versatile in thatconnectors are easily changeable and if abanana jack is broken, it can be replacedinstead of throwing away an entire BOB.This work was done by Jason H. Lee of

Caltech for NASA’s Jet Propulsion Labo-ratory. For more information, [email protected]. NPO-46799

PCB-Based Break-Out BoxNASA’s Jet Propulsion Laboratory, Pasadena, California


scientific value. For RFI-robust adap-tive detection of transients, using mul-tiple stations, a family of algorithmshas been developed. The techniqueexploits the fact that the separated sta-tions constitute statistically independ-ent samples of the target. This can beused to adaptively ignore RFI eventsfor superior sensitivity. If the antennasignals are independent and identi-cally distributed (IID), then RFIevents are simply outlier data pointsthat can be removed through robustestimation such as a trimmed or Win-sorized estimator.

The alternative “trimmed” estimatoris considered, which excises thestrongest n signals from the list of short-beamed intensities. Because local RFI isindependent at each antenna, this inter-ference is unlikely to occur at many an-tennas on the same step. Trimming thestrongest signals provides robustness toRFI that can theoretically outperformeven the detection performance of thesame number of antennas at a singlesite. This algorithm requires sorting thesignals at each time step and dispersionmeasure, an operation that is computa-tionally tractable for existing array sizes.

An alternative uses the various stationsto form an ensemble estimate of theconditional density function (CDF) eval-uated at each time step. Both methodsoutperform standard detection strate-gies on a test sequence of VLBA data,and both are efficient enough for de-ployment in real-time, online transientdetection applications.This work was done by David R. Thomp-

son, Kiri L. Wagstaff, and Walid A. Majid ofCaltech for NASA’s Jet Propulsion Laboratory.Further information is contained in a TSP (seepage 1). NPO-47678

This innovation can be run as a stand-alone network application on any com-puter in a networked environment. Thisdesign can be configured to control oneor more routers (one instance perrouter), and can also be configured tolisten to a policy server over the networkto receive new policies based on the pol-icy-based network management technol-ogy. The Router Agent Technologytransforms the received policies intosuitable Access Control List syntax forthe routers it is configured to control. Itcommits the newly generated access con-trol lists to the routers and providesfeedback regarding any errors that were

faced. The innovation also automaticallygenerates a time-stamped log file regard-ing all updates to the router it is config-ured to control.This technology, once installed on a

local network computer and started, isautonomous because it has the capabilityto keep listening to new policies from thepolicy server, transforming those policiesto router-compliant access lists, and com-mitting those access lists to a specified in-terface on the specified router on thenetwork with any error feedback regard-ing commitment process.The stand-alone application is named

RouterAgent and is currently realized as

a fully functional (version 1) implemen-tation for the Windows operating systemand for CISCO routers.This work was done by Edward T. Chow,

Gurusham Sudhir, Hsin-Ping Chang, MarkJames, and Yih-Chiao J. Liu of Caltech andWinston Chiang of the University of SouthernCalifornia for NASA’s Jet Propulsion Labora-tory. Further information is contained in aTSP (see page 1).The software used in this innovation is

available for commercial licensing. Please con-tact Daniel Broderick of the California Insti-tute of Technology at [email protected] to NPO-47228.

Router Agent Technology for Policy-Based Network ManagementNASA’s Jet Propulsion Laboratory, Pasadena, California


Software

Remote Asynchronous Mes-sage Service Gateway

The Remote Asynchronous MessageService (RAMS) gateway is a special-pur-pose AMS application node that enablesexchange of AMS messages betweennodes residing in different AMS “con-tinua,” notionally in different geograph-ical locations. JPL’s implementation ofRAMS gateway functionality is inte-grated with the ION (InterplanetaryOverlay Network) implementation ofthe DTN (Delay-Tolerant Networking)bundle protocol, and with JPL’s imple-mentation of AMS itself. RAMS protocoldata units are encapsulated in ION bun-dles and are forwarded to the neighbor-ing RAMS gateways identified in thesource gateway’s AMS management in-formation base. Each RAMS gateway has interfaces in

two communication environments: theAMS message space it serves, and theRAMS network — the grid or tree of mu-tually aware RAMS gateways — that en-ables AMS messages produced in onemessage space to be forwarded to othermessage spaces of the same venture.Each gateway opens persistent, privateRAMS network communication chan-nels to the RAMS gateways of other mes-sage spaces for the same venture, inother continua. The interconnectedRAMS gateways use these communica-tion channels to forward message peti-tion assertions and cancellations amongthemselves. Each RAMS gateway sub-scribes locally to all subjects that are ofinterest in any of the linked messagespaces. On receiving its copy of a mes-sage on any of these subjects, the RAMSgateway node uses the RAMS network toforward the message to every otherRAMS gateway whose message spacecontains at least one node that has sub-scribed to messages on that subject. Onreceiving a message via the RAMS net-work from some other RAMS gateway,the RAMS gateway node forwards themessage to all subscribers in its own mes-sage space. In this way, the RAMS protocol enables

the free flow of published applicationmessages across arbitrarily long, deepspace links while protecting efficient useof those links: only a single copy of anymessage is ever transmitted on anyRAMS network communication channel,

no matter how many subscribers will re-ceive copies when the message reachesits destination message space. Note that the nature of the RAMS

network communication channels de-pends on the implementation of theRAMS network. In order to communi-cate over the RAMS network for a givenventure, each RAMS gateway must knowthe RAMS network location — an end-point in the protocol used to implementthe RAMS network (e.g., the DTN bun-dle protocol) — at which every otherRAMS gateway for that venture receivesRAMS network traffic. Again, this exten-sion of the publish/subscribe model tointerplanetary communications is invisi-ble to application nodes. Applicationfunctionality is unaffected by these de-tails of network configuration, and theonly effects on behavior are those thatare intrinsic to variability in messagepropagation latency. This work was done by Shin-Ywan Wang

of Caltech and Scott C. Burleigh of SBAR forNASA’s Jet Propulsion Laboratory. Further in-formation is contained in a TSP (see page 1).This software is available for commercial li-

censing. Please contact Daniel Broderick ofthe California Institute of Technology [email protected]. Refer to NPO-44048.

Automatic Tie Pointer forIn-Situ Pointing Correction

The MARSAUTOTIE program gener-ates tie points for use with the Marspointing correction software “In-SituPointing Correction and Rover Microlo-calization,” (NPO-46696) Soft ware TechBriefs, Vol. 34, No. 9 (September 2010),page 18, in a completely automatedmanner, with no operator intervention.It takes the place of MARSTIE, althoughMARSTIE can be used to interactivelyedit the tie points afterwards. These tiepoints are used to create a mosaic whoseseams (boundaries of input images)have been geometrically corrected to re-duce or eliminate errors and mis-regis-trations. The methods used to find ap-propriate tie points for use in creating amosaic are unique, having been de-signed to work in concert with the“MARSNAV” program to be most effec-tive in reducing or eliminating geomet-ric seams in a mosaic. The program takes the input images

and finds overlaps according to the

nominal pointing. It then finds the mostinteresting areas using a scene activitymetric. Points with higher scene activityare more likely to correlate successfullyin the next step. It then uses correlationtechniques to find matching points inthe overlapped image. Finally, it per-forms a series of steps to reduce thenumber of tie points to a manageablelevel. These steps incorporate a numberof heuristics that have been devisedusing experience gathered by tie point-ing mosaics manually during MER oper-ations. The software makes use of thePIG library as described in “PlanetaryImage Geometry Library” (NPO-46658),NASA Tech Briefs, Vol. 34, No. 12 (Decem-ber 2010), page 30, so it is multi-mission,applicable without change to any in-situmission supported by PIG. The MARSAUTOTIE algorithm is au-

tomated, so it requires no user inter-vention. Although at the time of this re-porting it has not been done, thisprogram should be suitable for integra-tion into a fully automated mosaic pro-duction pipeline. This work was done by Robert G. Deen of

Caltech for NASA’s Jet Propulsion Labora-tory. For more information, [email protected] software is available for commercial

licensing. Please contact Daniel Broderick ofthe California Institute of Technology [email protected]. Refer to NPO-47083.

Jitter Correction Jitter_Correct.m is a MATLAB func-

tion that automatically measures andcorrects inter-frame jitter in an image se-quence to a user-specified precision. Inaddition, the algorithm dynamically ad-justs the image sample size to increasethe accuracy of the measurement. The Jitter_Correct.m function takes

an image sequence with unknownframe-to-frame jitter and computes thetranslations of each frame (column androw, in pixels) relative to a chosen refer-ence frame with sub-pixel accuracy. Thetranslations are measured using a CrossCorrelation Fourier transformationmethod in which the relative phase ofthe two transformed images is fit to aplane. The measured translations arethen used to correct the inter-frame jit-ter of the image sequence. The functionalso dynamically expands the image sam-


ple size over which the cross-correlationis measured to increase the accuracy ofthe measurement. This increases the ro-bustness of the measurement to variablemagnitudes of inter-frame jitter. This work was done by Mordecai J. Waegell

and David M. Palacios of Caltech for NASA’sJet Propulsion Laboratory. For more informa-tion, contact [email protected] software is available for commercial li-


MSLICE SequencingMSLICE Sequencing is a graphical

tool for writing sequences and integrat-ing them into RML files, as well as forproducing SCMF files for uplink. Whenoperated in a testbed environment, italso supports uplinking these SCMF filesto the testbed via Chill.This software features a freeform tex-

tural sequence editor featuring syntaxcoloring, automatic content assistance(including command and argumentcompletion proposals), complete withtypes, value ranges, unites, and descrip-tions from the command dictionary thatappear as they are typed. The sequenceeditor also has a “field mode” that allowstabbing between arguments and displaystype/range/units/description for eachargument as it is edited. Color-codederror and warning annotations on prob-lematic tokens are included, as well asindications of problems that are not visi-ble in the current scroll range. “QuickFix” suggestions are made for resolvingproblems, and all the features affordedby modern source editors are also in-cluded such as copy/cut/paste,undo/redo, and a sophisticated find-and-replace system optionally using reg-ular expressions.The software offers a full XML editor

for RML files, which features syntax col-oring, content assistance and problemannotations as above. There is a form-based, “detail view” that allows structuredediting of command arguments and se-quence parameters when preferred. The“project view” shows the user’s “work-space” as a tree of “resources” (projects,folders, and files) that can subsequentlybe opened in editors by double-clicking.

Files can be added, deleted, dragged-dropped/copied-pasted between foldersor projects, and these operations are un-doable and redoable.A “problems view” contains a tabular

list of all problems in the current work-space. Double-clicking on any row in thetable opens an editor for the appropriatesequence, scrolling to the specific linewith the problem, and highlighting theproblematic characters. From there, onecan invoke “quick fix” as described aboveto resolve the issue. Once resolved, sav-ing the file causes the problem to be re-moved from the problem view.This work was done by Thomas M. Crockett,

Joseph C. Joswig, Khawaja S. Shams, Jeffrey S.Norris, and John R. Morris of Caltech forNASA’s Jet Propulsion Laboratory. For more in-formation, contact [email protected] software is available for commer-

cial licensing. Please contact DanielBroderick of the California Institute ofTechnology at [email protected] to NPO-47292.

EOS MLS Level 2 Data Processing SoftwareVersion 3

This software accepts the EOS MLS cal-ibrated measurements of microwave radi-ances products and operational meteoro-logical data, and produces a set ofestimates of atmospheric temperatureand composition. This version has beendesigned to be as flexible as possible. Thesoftware is controlled by a Level 2 Config-uration File that controls all aspects ofthe software: defining the contents ofstate and measurement vectors, definingthe configurations of the various forwardmodels available, reading appropriate apriori spectroscopic and calibration data,performing retrievals, post-processing re-sults, computing diagnostics, and out-putting results in appropriate files.In production mode, the software op-

erates in a parallel form, with one in-stance of the program acting as a master,coordinating the work of multiple slaveinstances on a cluster of computers,each computing the results for individ-ual chunks of data. In addition, to doconventional retrieval calculations andproducing geophysical products, theLevel 2 Configuration File can instruct

the software to produce files of simu-lated radiances based on a state vectorformed from a set of geophysical prod-uct files taken as input. Combining boththe retrieval and simulation tasks in asingle piece of software makes it far eas-ier to ensure that identical forwardmodel algorithms and parameters areused in both tasks. This also dramaticallyreduces the complexity of the codemaintenance effort.This work was done by Nathaniel J. Livesey,

W. Van Snyder, William G. Read, Michael J.Schwartz, Alyn Lambert, Michelle L. Santee,Honghanh T. Nguyen, Lucien Froidevaux,Shuhui Wang, Gloria L. Manney, Dong L.Wu, and Paul A. Wagner of Caltech;Christina Vuu of Raytheon; and Hugh C.Pumphrey of the University of Edinburgh forNASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected] software is available for commercial li-


DspaceOgre 3D GraphicsVisualization Tool

This general-purpose 3D graphics vi-sualization C++ tool is designed for visu-alization of simulation and analysis datafor articulated mechanisms. Examples ofsuch systems are vehicles, robotic arms,biomechanics models, and biomolecularstructures. DspaceOgre builds upon theopen-source Ogre3D graphics visualiza-tion library. It provides additional classesto support the management of complexscenes involving multiple viewpoints anddifferent scene groups, and can be usedas a remote graphics server.This software provides improved sup-

port for adding programs at the graph-ics processing unit (GPU) level for im-proved performance. It also improvesupon the messaging interface it exposesfor use as a visualization server.This work was done by Abhinandan Jain,

Steven Myint, and Marc I. Pomerantz ofCaltech for NASA’s Jet Propulsion Labora-tory. For more information, contact [email protected] software is available for commercial li-



Manufacturing & Prototyping

Thermoelectric materials provide ameans for converting heat into electricalpower using a fully solid-state device.Power-generating devices (which in-clude individual couples as well as multi-couple modules) require the use of n-type and p-type thermoelectricmaterials, typically comprising highlydoped narrow band-gap semiconductorswhich are connected to a heat collectorand electrodes.To achieve greater device efficiency

and greater specific power will requireusing new thermoelectric materials, inmore complex combinations. One suchmaterial is the p-type compound semi-conductor Yb14MnSb11 (YMS), whichhas been demonstrated to have one ofthe highest ZT values at 1,000 °C, thedesired operational temperature ofmany space-based radioisotope thermo-electric generators (RTGs).Despite the favorable attributes of the

bulk YMS material, it must ultimately beincorporated into a power-generatingdevice using a suitable joining technol-ogy. Typically, processes such as diffu-sion bonding and/or brazing are usedto join thermoelectric materials to theheat collector and electrodes, with thegoal of providing a stable, ohmic contactwith high thermal conductivity at the re-quired operating temperature.Since YMS is an inorganic compound

featuring chemical bonds with a mixtureof covalent and ionic character, simplemetallurgical diffusion bonding is diffi-cult to implement. Furthermore, the Sbwithin YMS readily reacts with most met-als to form antimonide compounds witha wide range of stoichiometries. Al-though choosing metals that react toform high-melting-point antimonidescould be employed to form a stable reac-tion bond, it is difficult to limit the reac-tivity of Sb in YMS such that the elec-trode is not completely consumed at anoperating temperature of 1,000 °C. Pre-vious attempts to form suitable metal-lization layers resulted in poor bonding,complete consumption of the metalliza-tion layer or fracture within the YMSthermoelement (or leg).

An approach to forming a stable met-allization layer to consolidated YMSparts or legs has been developed, how-ever, using thin molybdenum foils. Thefoil is diffusion bonded to the YMS partat temperatures above 900 ºC, under theapplication of adequate pressure for sev-eral hours. Use of a thin foil eliminatesthe fracture typically observed withinYMS parts when thicker foils are used(induced by thermo-mechanicalstresses) as seen in the figure. The metalcan be bonded prior to dicing of the legsfrom a hot-pressed/consolidated YMSform, or it can be bonded to a pre-cutleg of the correct geometry. The contactis thermally stable with respect to YMS,exhibiting no de-bonding or increase incontact resistance after a 1,000 °C vac-uum heat treatment for 1,500 hours.This metallization layer may then bebonded or brazed to other components,such as heat collectors or current-carry-ing electrodes. To enable successfulbonding of the molybdenum metalliza-tion requires the preparation of YMSlegs of sufficient strength, which is facil-itated by the hot pressing of YMS pow-ders above 900 °C (using proper cooling

rates to minimize residual stress forma-tion and avoid fracture of the parts). This metallization layer may then be

bonded or brazed to other components,such as heat collectors or current-carry-ing electrodes. Furthermore, it can beimplemented at both the hot and coldsides of the leg. It can also be applied asa metallization layer to other similarcompositions of thermoelectric materi-als. The specific nature of the interac-tion between Mo and YMS is still underinvestigation; however, it is clear themolybdenum reacts sufficiently to forman adequate bond, without the extensivereaction observed with similar metalssuch as nickel, niobium, or titanium.The process may be similar to that in-volved in the formation of othermetal/ceramic bonds, wherein themetal has limited solubility in the ce-ramic material (for example, in diffu-sion bonded metal/alumina joints).This work was done by Samad Firdosy, Billy

Chun-Yip Li, Vilupanur Ravi, JeffreySakamoto, Thierry Caillat, Richard C. Ewell,and Erik J. Brandon of Caltech for NASA’s JetPropulsion Laboratory. Further information iscontained in a TSP (see page 1). NPO-46670

Metallization for Yb14MnSb11-Based Thermoelectric Materials Process enables device fabrication using advanced, high-temperature thermoelectric material. NASA’s Jet Propulsion Laboratory, Pasadena, California

Mo Foil

Yb14MnSb11

~3 mm

Metallized Yb14MnSb11 Leg, terminated on both ends with Mo layers.


A solvent/non-solvent sintering tech-nique has been devised for joining poly-meric microspheres to make porousmatrices for use as drug-delivery devicesor scaffolds that could be seeded withcells for growing tissues. Unlike tradi-tional sintering at elevated temperatureand pressure, this technique is prac-ticed at room temperature and pres-sure and, therefore, does not causethermal degradation of any drug, pro-tein, or other biochemical with whichthe microspheres might be loaded to

impart properties desired in a specificapplication. Also, properties of scaf-folds made by this technique are morereproducible than are properties ofcomparable scaffolds made by tradi-tional sintering. The technique involves the use of two

miscible organic liquids: one that is andone that is not a solvent for the affectedpolymer. The polymeric microspheresare placed in a mold having the size andshape of the desired scaffold, then thesolvent/non-solvent mixture is poured

into the mold to fill the void volume be-tween the microspheres, then the liquidmixture is allowed to evaporate. Some ofthe properties of the resulting scaffoldcan be tailored through choice of theproportions of the liquids and the diam-eter of the microspheres.This work was done by Cato T. Laurencin,

Justin L. Brown, and Lakshmi Nair of theUniversity of Virginia for Johnson Space Cen-ter. For further information, contact the John-son Technology Transfer Office at (281) 483-3809. MSC-24227-1

Solvent/Non-Solvent Sintering To Make Microsphere ScaffoldsLyndon B. Johnson Space Center, Houston, Texas


Green Design

An enhanced algorithm is developedthat builds on a previous innovation offuel-optimal powered-descent guidance(PDG) for planetary pinpoint landing.The PDG problem is to compute con-strained, fuel-optimal trajectories toland a craft at a prescribed target on aplanetary surface, starting from a “para-chute cut-off” point and using a throt-tleable descent engine. The previous in-novation showed the minimal-fuel PDGproblem can be posed as a convex opti-mization problem, in particular, as a Sec-ond-Order Cone Program, which can besolved to global optimality with deter-ministic convergence properties, andhence is a candidate for onboard imple-mentation. To increase the speed androbustness of this convex PDG algo-rithm for possible onboard implementa-tion, the following enhancements are in-corporated:• Fast detection of infeasibility (i.e., con-trol authority is not sufficient for soft-landing) for subsequent fault re sponse.

• The use of a piecewise-linear controlparameterization, providing smoothsolution trajectories and increasingcomputational efficiency. • An enhanced line-search algorithm foroptimal time-of-flight, providingquicker convergence and boundingthe number of path-planning itera-tions needed. • An additional constraint that analyti-cally guarantees inter-sample satisfac-tion of glide-slope and non-sub-surfaceflight constraints, allowing larger dis-cretizations and, hence, faster opti-mization. • Explicit incorporation of Mars rota-tion rate into the trajectory computa-tion for improved targeting accuracy.These enhancements allow faster con-

vergence to the fuel-optimal solutionand, more importantly, remove the needfor a “human-in-the-loop,” as constraintswill be satisfied over the entire path-planning interval independent of step-size (as opposed to just at the discrete

time points) and infeasible initial condi-tions are immediately detected. Finally,while the PDG stage is typically only afew minutes, ignoring the rotation rateof Mars can introduce 10s of meters oferror. By incorporating it, the enhancedPDG algorithm becomes capable of pin-point targeting.This work was done by Behcet Acikmese, James

C. Blackmore, and Daniel P. Scharf of Caltechfor NASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected]. In accordance with Public Law 96-517,

the contractor has elected to retain title to thisinvention. Inquiries concerning rights for itscommercial use should be addressed to:Innovative Technology Assets ManagementJPLMail Stop 202-2334800 Oak Grove DrivePasadena, CA 91109-8099E-mail: [email protected] to NPO-46648, volume and number


Enhanced Fuel-Optimal Trajectory-Generation Algorithm for Planetary Pinpoint LandingEnhancements are incorporated to allow faster convergence to the fuel optimal solution.NASA’s Jet Propulsion Laboratory, Pasadena, California


Materials

A process using a modified dielec-trophoresis device separates single-walledcarbon nanotubes (SWNTs) according totheir polarizability in electric fields. Thisdepends on the size and dielectric con-stant of individual nanotubes and easilyseparates metallic from semiconductingnanotubes. Separation by length has alsobeen demonstrated. Partial separation(enrichment) according to bandgap(which is linked to polarizability) has alsobeen shown and can be improved to fullseparation of individual types of semicon-ducting SWNTs with better control overoperational parameters and the length ofSWNT starting material. This process anddevice can be scaled affordably to gener-ate useful amounts of semiconductingSWNTs for electronic device develop-ment and production.

In this study, a flow injection dielec-trophoresis technique was used with amodified dielectrophoresis device. Thelength, width, and height of the modi-fied chamber were 28, 2.5, and 0.025cm, respectively. On the bottom of thechamber, there are two arrays of 50-µm-wide, 2-µm-thick gold electrodes, whichare connected to an AC voltage genera-tor and are alternately arranged so thatevery electrode is adjacent to two elec-trodes of the opposite polar. There is anadditional plate electrode on the top ofthe chamber that is negatively biased. During the experiment, a syringe

pump constantly pumps in the mobilephase, 1-percent sodium dodecylbenzenesulfonate (SDBS) solution, into thechamber. The frequency and voltage areset to 1 MHz and 10 V peak-to-peak, re-

spectively. About 150 µL of SWNTs in 1-percent SDBS decanted solution are in-jected to the mobile phase through a sep-tum near the entrance of the chamber.The flow rate of the mobile phase is set to0.02 cm3/min. The injected SWNTs sam-ple flows through the chamber before itis lead into a fluorescence flow-throughcell and collected for further analysis.The flow-through cell has three windows,thus allowing the fluorometer to collectfluorescence spectrum and visible ab-sorption spectrums simultaneously.Dielectrophoresis field-flow fraction-

ation (DEP-FFF) generally depends oninteraction of a sedimentation forceand DEP force for particle separation,and SWNTs are neutrally buoyant inwater. In this innovation, the thirdelectrode was added to create a sedi-

Separation of Single-Walled Carbon Nanotubes with DEP-FFFSimultaneous type and diameter separation of SWNTs is achieved by using flow injection dielectrophoresis.Lyndon B. Johnson Space Center, Houston, Texas

This technology exploits the organicdecomposition capability and hydro -philic properties of the photocatalyticmaterial titanium dioxide (TiO2), a non-toxic and non-hazardous substance, toaddress contamination and biofoulingissues in field-deployed optical sensorsystems. Specifically, this technology in-corporates TiO2 coatings and materialsapplied to, or integrated as a part of, theoptical surfaces of sensors and calibra-tion sources, including lenses, windows,and mirrors that are used in remote, un-attended, ground-based (land or mar-itime) optical sensor systems. Current methods used to address con-

tamination or biofouling of these opticalsurfaces in deployed systems are costly,toxic, labor intensive, and non-preventa-tive. By implementing this novel tech-nology, many of these negative aspectscan be reduced. The functionality of this

innovative self-cleaning solution to ad-dress the problem of contamination orbiofouling depends on the availability ofa sufficient light source with the appro-priate spectral properties, which can beattained naturally via sunlight or supple-mented using artificial illumination suchas UV LEDs (light emitting diodes). In land-based or above-water systems,

the TiO2 optical surface is exposed tosunlight, which catalyzes the photocat-alytic reaction, facilitating both the de-composition of inorganic and organiccompounds, and the activation of super-hydrophilic properties. Since underwateroptical surfaces are submerged and havelimited sunlight exposure, supplemen-tary UV light sources would be requiredto activate the TiO2 on these optical sur-faces. Nighttime operation of land-basedor above-water systems would require thisaddition as well. For most superhy-

drophilic self-cleaning purposes, a rain-water wash will suffice; however, for someapplications an attached rainwater collec-tor/dispenser or other fresh water dis-pensing system may be required to washthe optical surface and initiate the re-moval of contaminates. Deploy ment ofthis non-toxic,non-hazardoustechnologywill take advantage of environmental ele-ments (i.e. rain and sunlight), increasethe longevity of unattended optical sys-tems, increase the amount of time be-tween required maintenance, and im-prove the long-term accuracy of sensormeasurements.This work was done by Robert Ryan, Lauren

Underwood, and Kara Holekamp of ScienceSystems and Applications, Inc., George May ofInstitute of Technology Development, and BruceSpiering and Bruce Davis of Stennis SpaceCenter. For more information contact RobertRyan at (228) 688-2276. Refer to SSC-00303.

Self-Cleaning Coatings and Materials for DecontaminatingField-Deployable Land and Water-Based Optical SystemsStennis Space Center, Mississippi


mentation force based on DC elec-trophoresis. This makes this particulardevice applicable to separations on anyneutrally buoyant particles in solutionand a more general process for abroad range of nanomaterials sortingand separations.This work was done by Howard K. Schmidt,

Haiqing Peng, Noe Alvarez, Manuel Mendes,

and Matteo Pasquali of Rice University forJohnson Space Center. For further informa-tion, contact the JSC Innovation PartnershipsOffice at (281) 483-3809. In accordance with Public Law 96-517,

the contractor has elected to retain title tothis invention. Inquiries concerning rightsfor its commercial use should be addressedto:

Rice University Office of Technology Transfer —MS 705P.O. Box 1892Houston, TX 77005Phone No.: (713) 348-6188E-mail: [email protected] to MSC-24368-1/70-1, volume and

number of this NASA Tech Briefs issue, andthe page number.

A novel, low-cost approach to stabiliza-tion of Li metal anodes for high-per-formance rechargeable batteries was de-veloped. Electrolyte additives areselected and used in Li cell electrolytesystems, promoting formation of a pro-tective coating on Li metal anodes forimproved cycle and safety performance.

Li batteries developed from the newsystem will show significantly improvedbattery performance characteristics, in-cluding energy/power density, cycle/calendar life, cost, and safety. This work was done by Tuqiang Chen of

TH Chem for Glenn Research Center. Furtherinformation is contained in a TSP (see page 1).

Inquiries concerning rights for the commer-cial use of this invention should be addressedto NASA Glenn Research Center, InnovativePartnerships Office, Attn: Steven Fedor, MailStop 4–8, 21000 Brookpark Road, Cleve-land, Ohio 44135. Refer to LEW-18715-1.

Li Anode Technology for Improved PerformanceJohn H. Glenn Research Center, Cleveland, Ohio


Bio-Medical

tThis innovation is derived from a pro-prietary amplification scheme that isbased upon random fragmentation of thegenome into a series of short, overlappingtemplates. The resulting shorter DNAstrands (<400 bp) constitute a library ofDNA fragments with defined 3’ and 5’ ter-mini. Specific primers to these termini arethen used to isothermally amplify this li-brary into potentially unlimited quantitiesthat can be used immediately for multipledownstream applications including geleletrophoresis, quantitative polymerasechain reaction (QPCR), comparative ge-nomic hybridization microarray, SNPanalysis, and sequencing. The standard reaction can be per-

formed with minimal hands-on time,and can produce amplified DNA in aslittle as three hours. Post-fragmentationwhole genome amplification-based tech-nology provides a robust and accuratemethod of amplifying femtogram levelsof starting material into microgramyields with no detectable allele bias. Theamplified DNA also facilitates thepreservation of samples (spacecraft sam-ples) by amplifying scarce amounts oftemplate DNA into microgram concen-

trations in just a few hours. Based on fur-ther optimization of this technology, thiscould be a feasible technology to use insample preservation for potential futuresample return missions. The research and technology develop-

ment described here can be pivotal indealing with backward/forward biologi-cal contamination from planetary mis-sions. Such efforts rely heavily on an in-creasing understanding of the burdenand diversity of microorganisms presenton spacecraft surfaces throughout as-sembly and testing. The development and implementa-

tion of these technologies could signifi-cantly improve the comprehensivenessand resolving power of spacecraft-associ-ated microbial population censuses, andare important to the continued evolu-tion and advancement of planetary pro-tection capabilities. Current molecularprocedures for assaying spacecraft-asso-ciated microbial burden and diversityhave inherent sample loss issues at prac-tically every step, particularly nucleicacid extraction. In engineering a molec-ular means of amplifying nucleic acidsdirectly from single cells in their native

state within the sample matrix, this inno-vation has circumvented entirely theneed for DNA extraction regimes in thesample processing scheme. As typically 90 percent of the biomate-

rial held within a sample is lost at the ex-traction step, the absence of DNA ex-traction in processing a sample of lowbiomass is quite appealing and seem-ingly superior, at least in theory. If cur-rent understanding of spacecraft-associ-ated microbial burden/diversity is basedon a mere 10% of the actual sample col-lected, then a much broader diversityand elevated bioburden should be ableto be resolved upon mitigating this ≈90% loss of sample biomatter. This inno-vative process should lend considerablecredence to such assays, and ultimatelyresult in a much more comprehensiveknowledge base of the abundance andphylogenetic diversity of microbes onand around spacecraft surfaces. This work was done by James (Nick) Benar-

dini and Myron T. La Duc of Caltech andJohn Langmore of Rubicon Genomics forNASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected]

Post-Fragmentation Whole Genome Amplification-Based Method This method has application in hospital cleanliness validation assays, pharmaceuticaldevelopment, and medical device manufacturing and packaging. NASA’s Jet Propulsion Laboratory, Pasadena, California

A novel approach for the immediatesealing of traumatic wounds is under de-velopment. A portable microwave genera-tor and handheld antenna are used to sealwounds, binding the edges of the woundtogether using a biodegradable proteinsealant or “solder.” This method could beused for repairing wounds in emergencysettings by restoring the wound surface toits original strength within minutes. Thistechnique could also be utilized for surgi-cal purposes involving solid visceral organs

(i.e., liver, spleen, and kidney) that cur-rently do not respond well to ordinary sur-gical procedures.A miniaturized microwave generator

and a handheld antenna are used to de-liver microwave energy to the proteinsolder, which is applied to the wound.The antenna can be of several alterna-tive designs optimized for placement ei-ther in contact with or in proximity tothe protein solder covering the wound.In either case, optimization of the de-

sign includes the matching of imped-ances to maximize the energy deliveredto the protein solder and wound at achosen frequency. For certain applica-tions, an antenna could be designed thatwould emit power only when it is in di-rect contact with the wound.The optimum frequency or frequen-

cies for a specific application would de-pend on the required depth of penetra-tion of the microwave energy. In fact, acomputational simulation for each spe-

Microwave Tissue Soldering for Immediate Wound ClosureWounds can be closed rapidly, without staples, sutures, or tapes.Lyndon B. Johnson Space Center, Houston, Texas


cific application could be performed,which would then match the characteris-tics of the antenna with the protein sol-der and tissue to best effect wound clo-sure. An additional area of interest withpotential benefit that remains to be vali-dated is whether microwave energy caneffectively kill bacteria in and aroundthe wound. Thus, this may be an effi-cient method for simultaneously steriliz-ing and closing wounds.Using microwave energy to seal

wounds has a number of advantagesover lasers, which are currently in exper-imental use in some hospitals. Laser tis-sue welding is unsuitable for emergencyuse because its large, bulky equipmentcannot be easily moved between operat-

ing rooms, let alone relocated to fieldsites where emergencies often occur. Inaddition, this approach is highly de-pendent on the uniformity and thick-ness of the protein solder as well as thesurgeon’s skills. In contrast, the use ofmicrowave energy is highly tolerant ofthe thickness of the protein solder, levelof fluids in and around the wound, andother parameters that can adversely af-fect the outcome of laser welding. How-ever, controlling the depth of penetra-tion of the microwave energy into thewound is critical for achieving effectivewound sealing without damaging the ad-jacent tissue. In addition, microspheresthat encapsulate metallic cores couldalso be incorporated into the protein

solder to further control the depth ofpenetration of the microwave energy.This work was performed by G. Dickey

Arndt, Phong H. Ngo, Chau T. Phan, andDiane Byerly of Johnson Space Center; JohnDusl of Jacobs Sverdrup; Marguerite A. Sog-nier of Universities Space Research Associa-tion; and Jim Carl of Advanced Electromag-netics. For further information, contact theJSC Innovation Partnerships Office at (281)483-3809.This invention is owned by NASA, and a

patent application has been filed. Inquiriesconcerning nonexclusive or exclusive licensefor its commercial development should be ad-dressed to the Patent Counsel, Johnson SpaceCenter, (281) 483-1003. Refer to MSC-24238-1.

Principles, Techniques, and Applications of Tissue Microfluidics This technique can be used in the diagnosis of diseases such as cancer. NASA’s Jet Propulsion Laboratory, Pasadena, California

The principle of tissue microfluidicsand its resultant techniques has beenapplied to cell analysis. Building mi-crofluidics to suit a particular tissuesample would allow the rapid, reliable,inexpensive, highly parallelized, selec-tive extraction of chosen regions of tis-sue for purposes of further biochemicalanalysis. Furthermore, the applicabilityof the techniques ranges beyond the de-scribed pathology application. For ex-ample, they would also allow the posingand successful answering of new sets ofquestions in many areas of fundamentalresearch. The proposed integration of mi-

crofluidic techniques and tissue slicesamples is called “tissue microfluidics”because it molds the microfluidic ar-chitectures in accordance with eachparticular structure of each specific tis-sue sample. Thus, microfluidics can bebuilt around the tissues, following thetissue structure, or alternatively, themicrofluidics can be adapted to thespecific geometry of particular tissues.By contrast, the traditional approach isthat microfluidic devices are struc-tured in accordance with engineeringconsiderations, while the biologicalcomponents in applied devices areforced to comply with these engineer-ing presets. The proposed principles represent a

paradigm shift in microfluidic technol-

ogy in three important ways: • Microfluidic devices are to be directlyintegrated with, onto, or around tissuesamples, in contrast to the conven-tional method of off-chip sample ex-traction followed by sample insertionin microfluidic devices. • Architectural and operational princi-ples of microfluidic devices are to besubordinated to suit specific tissuestructure and needs, in contrast to theconventional method of building de-vices according to fluidic functionalone and without regard to tissuestructure. • Sample acquisition from tissue is to beperformed on-chip and is to be inte-grated with the diagnostic measure-ment within the same device, in con-trast to the conventional method ofoff-chip sample prep and subsequentinsertion into a diagnostic device. Amore advanced form of tissue integra-tion with microfluidics is tissue encap-sulation, wherein the sample is com-pletely encapsulated within amicrofluidic device, to allow for fullsurface access. The immediate applications of these

approaches lie with diagnostics of tissueslices and biopsy samples — e.g. for can-cer — but the approaches would also bevery useful in comparative genomics andother areas of fundamental research in-volving heterogeneous tissue samples.

The approach advocates and utilizesthe bottom-up customization of mi-crofluidic architectures to biosamples,in contrast to the traditional top-downapproach of building the architecturesfirst and then putting the biosamples in-side. Further, as particular embodimentsof the above principle, novel techniquesof sub-sample selection and isolation arepresented. These techniques would havewide applicability in fundamental re-search and biomedical diagnostics. In particular, an in situ microfluidic

technique of single-cell isolation, ormultiple single-cell isolations, is de-scribed, and is performed upon tissuesections attached to pathology glassslides. The technique combines the ad-vantages of preserving the architec-tural integrity of the tissue sectionwhile allowing flexibility and precisionof cell selection, rapid prototyping,and enhanced sample purity, whilebenefiting from the experience of thepathologist in the selection process.The result is a system that would allowthe rapid and reliable biochemicalanalysis and diagnosis of pathologicprocesses with sensitivity extendeddown to the level of even a single cell,with high levels of confidence in the di-agnostic determination. These techniques would allow the ex-

traction of cells and cell nuclei chosenfor their potentially pathologic origin,


A process has been developed that canconfer novel properties, such as metal re-sistance, to a host bacterium. This sameprocess can also be used to produceRNAs and peptides that have novel prop-erties, such as the ability to bind particu-lar compounds. It is inherent in themethod that the peptide or RNA will be-have as expected in the target organism.Plasmid-born mini-gene libraries codingfor either a population of combinatorialpeptides or stable, artificial RNAs carry-ing random inserts are produced. These

libraries, which have no bias towards anybiological function, are used to trans-form the organism of interest and toserve as an initial source of genetic varia-tion for stress-driven evolution. The transformed bacteria are propa-

gated under selective pressure in orderto obtain variants with the desired prop-erties. The process is highly distinctfrom in vitro methods because the vari-ants are selected in the context of thecell while it is experiencing stress.Hence, the selected peptide or RNA will,

by definition, work as expected in thetarget cell as the cell adapts to its pres-ence during the selection process. Oncethe novel gene, which produces thesought phenotype, is obtained, it can betransferred to the main genome to in-crease the genetic stability in the organ-ism. Alternatively, the cell line can beused to produce novel RNAs or peptideswith selectable properties in large quan-tity for separate purposes. The system al-lows for easy, large-scale purification ofthe RNAs or peptide products.

Stress-Driven Selection of Novel PhenotypesA methodology allows the experimental design of novel peptides and RNAs that have desired properties.Lyndon B. Johnson Space Center, Houston, Texas

The aim of tissue engineering (TE) isto restore tissue and organ functionswith minimal host rejection. TE is seenas a future solution to solve the crisis ofdonor organs for transplant, which facesa shortage expected only to increase inthe future. In this innovation, a flexibleand configurable scaffold has been con-ceived that mechanically stresses cellsthat are seeded on it, stimulating themto increased growth. The influence of mechanical stress/

loading on cell growth has been ob-served on all forms of cells. For exam-ple, for cartilages, studies in animals, tis-sue explants, and engineered tissuescaffolds have all shown that cartilagecells (chondrocytes) modify their extra-cellular matrix in response to loading.The chondrocyte EMC production re-

sponse to dynamics of the physical envi-ronment (in vivo cartilage develop-ment) illustrates a clear benefit (bettergrowth) when stressed. It has beenshown that static and dynamic compres-sion regulates PRG4 biosynthesis by car-tilage explants. Mechanical tissue stimulation is bene-

ficial and (flexible) scaffolds with mov-able components, which are able to in-duce mechanical stimulation, offeradvantages over the fixed, rigid scaffolddesign. In addition to improved cellgrowth from physical/mechanical stimu-lation, additional benefits include theability to increase in size while preserv-ing shape, or changing shape.By making scaffolds flexible, allowing

relative movement between their com-ponents, adding sensing (e.g., for de-

tecting response of cells to drug releaseand to mechanical actions), buildingcontrols for drug release and move-ment, and building even simple algo-rithms for mapping sensing to action,these structures can actually be madeinto biocompatible and biodegradablerobots. Treating them as robots is a per-spective shift that may offer advantagesin the design and exploitation of thesestructures of the future.This work was done by Adrian Stoica of Cal-

tech for NASA’s Jet Propulsion Laboratory. Formore information, contact [email protected] invention is owned by NASA, and a

patent application has been filed. Inquiries con-cerning nonexclusive or exclusive license for itscommercial development should be addressed tothe Patent Counsel, NASA Management Of-fice–JPL. Refer to NPO-47142.

Robotic Scaffolds for Tissue Engineering and Organ Growth Biocompatible and biodegradable smart scaffolds could reconfigure their shape and size toaccommodate organ development. NASA’s Jet Propulsion Laboratory, Pasadena, California

e.g. cancer. The chief advantages of theproposed methods are their speed, ease,reliability, and capacity to select individ-ual cells from a tissue slice populationwith a higher degree of purity and speci-ficity. The result is the extracted DNAcan be biochemically analyzed with ahigher degree of diagnostic accuracy, asthe isolated sub-sample would not be di-luted by unwanted material from theambient tissue. In comparison to other

techniques, the proposed methodswould combine high specificity withhigh speed. This work was done by Lawrence A. Wade

of Caltech and Emil P. Kartalov, Darryl Shi-bata, and Clive Taylor of the University ofSouthern California for NASA’s Jet PropulsionLaboratory. Further information is containedin a TSP (see page 1).In accordance with Public Law 96-517,

the contractor has elected to retain title to this

invention. Inquiries concerning rights for itscommercial use should be addressed to:Innovative Technology Assets ManagementJPLMail Stop 202-2334800 Oak Grove DrivePasadena, CA 91109-8099E-mail: [email protected] to NPO-47561, volume and number



The process has been reduced to prac-tice by imposing sub-inhibitory concen-trations of NiCl2 on cells of the bac-terium Escherichia coli that weretransformed separately with the peptidelibrary and RNA library. The evolved re-sistant clones were isolated, and se-quences of the selected mini-gene vari-ants were established. Clones resistant toNiCl2 were found to carry identical plas-mid variants with a functional mini-genethat specifically conferred significantnickel tolerance on the host cells. Se-quencing of the selected mini-gene re-vealed a propensity of the encoded pep-tide to bind transient metal ions.Expression of the mini-gene markedlyimproved growth parameters of the

evolved clones at sub-inhibitory concen-trations of NiCl2 while being slightlydetrimental in the absence of stress. Sim-ilar results have been obtained with theRNA libraries. Overall, the results demonstrate a very

natural outcome of the selection experi-ments in which the mini-genes were ex-pected to be either successfully inte-grated into bacterial genetic networks,or rejected depending upon their effecton host fitness. This described approachcan be useful as a laboratory model tostudy the dynamics of bacterial adaptiveevolution on the molecular level. It canalso provide a strategy for screening ex-pressed DNA libraries in search of novelgenes with desirable properties.

This work was done by George E. Fox, Vic-tor G. Stepanov, and Yamei Liu of the Uni-versity of Houston/College of Natural Sci-ences & Mathematics for Johnson SpaceCenter.In accordance with Public Law 96-517,

the contractor has elected to retain title to thisinvention. Inquiries concerning rights for itscommercial use should be addressed to:Office of Intellectual Property ManagementUniversity of Houston316 E. CullenHouston, TX 77204-2015Phone No.: (713) 743-9155www.research.uh.eduRefer to MSC-24230-1, volume and num-

ber of this NASA Tech Briefs issue, and thepage number.


Physical Sciences

A novel method has been developedfor performing very fine calibration ofa spectrometer. This process is particu-larly useful for modern miniaturecharge-coupled device (CCD) spec-trometers where a typical factory wave-length calibration has been performedand a finer, more accurate calibrationis desired. Typically, the factory cali-bration is done with a spectral linesource that generates light at knownwavelengths, allowing specific pixels inthe CCD array to be assigned wave-

length values. This method is good toabout 1 nm across the spectrometer’swavelength range. This new methodappears to be accurate to about 0.1nm, a factor of ten improvement.White light is passed through an un-

balanced Michelson interferometer,producing an optical signal with signifi-cant spectral variation. A simple theorycan be developed to describe this spec-tral pattern, so by comparing the actualspectrometer output against this pre-dicted pattern, errors in the wavelength

assignment made by the spectrometercan be determined.The primary unique feature of this in-

novation is its ability to calibrate everypixel across a given wavelength range asopposed to only calibrating a few pixelsand interpolating the other values as iscurrently done.This work was done by Stephen Simmons

and Robert Youngquist of Kennedy SpaceCenter. Further information is contained in aTSP (see page 1). KSC-13331

Method for Accurately Calibrating a Spectrometer UsingBroadband LightJohn F. Kennedy Space Center, Florida

Devices that generate both high en-ergy and high temperature are requiredto ignite reliably the propellant mixturesin combustion chambers like those pres-ent in rockets and other combustion sys-tems. This catalytic microtube rocket ig-niter generates these conditions with asmall, catalysis-based torch. While tradi-tional spark plug systems can requireanywhere from 50 W to multiple kW ofpower in different applications, this sys-tem has demonstrated ignition at lessthan 25 W. Reactants are fed to the ig-niter from the same tanks that feed thereactants to the rest of the rocket orcombustion system. While this specificigniter was originally designed for liquidmethane and liquid oxygen rockets, itcan be easily operated with gaseous pro-pellants or modified for hydrogen use incommercial combustion devices. For the present cryogenic propellant

rocket case, the main propellant tanks— liquid oxygen and liquid methane, re-spectively — are regulated and split intodifferent systems for the individualstages of the rocket and igniter. As thecatalyst requires a gas phase for reaction,either the stored boil-off of the tanks canbe used directly or one stream each of

fuel and oxidizer can go through a heatexchanger/vaporizer that turns the liq-uid propellants into a gaseous form. Forcommercial applications, where the re-actants are stored as gases, the system issimplified. The resulting gas-phasestreams of fuel and oxidizer are then fur-ther divided for the individual compo-nents of the igniter. One stream each of the fuel and oxi-

dizer is introduced to a mixingbottle/apparatus where they are mixedto a fuel-rich composition with an O/Fmass-based mixture ratio of under 1.0.This premixed flow then feeds into thecatalytic microtube device. The totalflow is on the order of 0.01 g/s. The mi-crotube device is composed of a pair ofsub-millimeter diameter platinum tubesconnected only at the outlet so that thetwo outlet flows are parallel to eachother. The tubes are each approximately10 cm long and are heated via directelectric resistive heating. This heatingbrings the gasses to their minimum re-quired ignition temperature, which islower than the auto-thermal ignitiontemperature, and causes the onset ofboth surface and gas phase ignition pro-ducing hot temperatures and a highly

reacting flame. The combustion products from the

catalytic tubes, which are below the melt-ing point of platinum, are injected intothe center of another combustion stage,called the primary augmenter. The reac-tants for this combustion stage comefrom the same source but the flows ofnon-premixed methane and oxygen gasare split off to a secondary mixing appa-ratus and can be mixed in a near-stoi-chiometric to highly lean mixture ratio.The primary augmenter is a componentthat has channels venting this mixed gasto impinge on each other in the centerof the augmenter, perpendicular to theflow from the catalyst. The total cross-sectional area of these channels is on asimilar order as that of the catalyst. Theaugmenter has internal channels thatact as a manifold to distribute equallythe gas to the inward-venting channels.This stage creates a stable flame kernelas its flows, which are on the order of0.01 g/s, are ignited by the combustionproducts of the catalyst. This stage is de-signed to produce combustion productsin the flame kernel that exceed the au-tothermal ignition temperature of oxy-gen and methane.

Catalytic Microtube Rocket Igniter This device can also be used on commercial combustion devices such as furnaces, powergenerators, and gas-fueled cooking appliances like grills, ranges, and ovens. John H. Glenn Research Center, Cleveland, Ohio

While these combined componentswill mix and produce a near stoichio-metric flame with a temperature highenough to ignite the reactants in mostcombustion devices, the overall massflow rate and energy is still relativelylow. For the extreme conditions of ignit-ing a cryogenic propellant chemicalrocket, this total may not be enough tomaintain a flame in the adverse environ-ment. To enable this operation, anothergas phase stage called the secondaryaugmenter is added in series with thefirst two components. As more heat re-lease is required, the mass flow rate is in-creased by an order of magnitude tomore than 0.1 g/s for this stage. Theflows are kept separate, however, untilinjected where they impinge and mixwithin this secondary augmenter. Again,

the flows are distributed via a manifoldsystem then injected through ports thatare sized more than an order of magni-tude larger than the total port area ofthe first two components. The mixtureis kept fuel rich so that the temperatureis regulated below the melting point ofthe components. With the ignition ofthis stage, a large stable torch is pro-duced to ignite the cryogens. The hardware is designed so that the

total size of the device was similar tothat of a traditional spark plug. Like-wise, the outlet of the igniter mimicsthat of a spark plug in order to have itact as a direct replacement in combus-tion devices. In tests it functioned assuch, lighting chambers with propel-lant flows an order of magnitude larger.Operation was demonstrated with back

pressures as low as 0.01 atmospheres upto approximately 10 atmospheres andin theory, these bounds could be wider.Ignition was demonstrated with reac-tant temperatures near chilled-in cryo-genic conditions. This igniter serves asa low-energy alternative to spark igni-tion and can operate as an ignitionsource for a variety of commercial com-bustion devices. This work was done by Steven J. Schneider

and Matthew C. Deans of Glenn ResearchCenter. Further information is contained in aTSP (see page 1).Inquiries concerning rights for the commer-

cial use of this invention should be addressedto NASA Glenn Research Center, InnovativePartnerships Office, Attn: Steven Fedor, MailStop 4–8, 21000 Brookpark Road, Cleve-land, Ohio 44135. Refer to LEW-18565-1.

Panoramic images with a wide field ofview intend to provide a better under-standing of an environment by placingobjects of the environment on one seam-less image. However, understanding thesizes and relative positions of the objectsin a panorama is not intuitive and proneto errors because the field of view is un-natural to human perception. Scientistsare often faced with the difficult task ofinterpreting the sizes and relative posi-tions of objects in an environment whenviewing an image of the environment oncomputer monitors or prints. Apanorama can display an object that ap-pears to be to the right of the viewerwhen it is, in fact, behind the viewer.This misinterpretation can be verycostly, especially when the environmentis remote and/or only accessible by un-manned vehicles. A 270° cylindrical display has been de-

veloped that surrounds the viewer withcarefully calibrated panoramic imagerythat correctly engages their natural kines-thetic senses and provides a more accu-rate awareness of the environment. Thecylindrical immersive display offers amore natural window to the environmentthan a standard cubic CAVE (Cave Auto-matic Virtual Environment), and thegeometry allows multiple collocated usersto simultaneously view data and share im-portant decision-making tasks.

A CAVE is an immersive virtual realityenvironment that allows one or moreusers to absorb themselves in a virtualenvironment. A common CAVE setup isa room-sized cube where the cube sidesact as projection planes. By nature, allcubic CAVEs face a problem with edgematching at edges and corners of thedisplay. Modern immersive displays havefound ways to minimize seams by creat-ing very tight edges, and rely on the userto ignore the seam. One significant defi-ciency of flat-walled CAVEs is that thesense of orientation and perspectivewithin the scene is broken across adja-cent walls. On any single wall, parallellines properly converge at their vanish-ing point as they should, and the senseof perspective within the scene con-tained on only one wall has integrity. Un-fortunately, parallel lines that lie on ad-jacent walls do not necessarily remainparallel. This results in inaccuracies inthe scene that can distract the viewerand subtract from the immersive experi-ence of the CAVE. The cylindrical display overcomes the

problem of distorted edges. Its smoothsurface is perfectly equidistant from theviewer when he or she is positioned nearthe center. This eliminates the artifactsof a flat-walled CAVE where the viewingsurface varies in distance from theviewer wherever he or she may stand

within it. The display is a curved rear-projected screen comprising three-quar-ters of a 12-ft-diameter (≈3.7-m-diame-ter) cylinder. The projection surface is ahigh-contrast, unity gain, flexible screenmaterial. The screen is about 6.5 ft (≈2m) tall, and the height of the actualimage displayed on the screen is approx-imately 5 ft (≈1.5 m). A single consumervideo card outputs to three short-throwprojectors that are mounted behind thescreen. Each projector illuminates 90° ofthe screen and overlaps slightly with anadjacent projector. The resolution of theentire cylindrical display is about3,500×1,024 pixels. The projectors areedge-blended and calibrated into aseamless display using Scalable DisplayTechnologies’ camera-based calibration. This system, known as Stage, is designed

to address two critical visualization prob-lems. First, people viewing imagery fromsurface spacecraft often incorrectly esti-mate the size of objects in the environ-ment because imagery on a standard com-puter screen does not occupy the correctportion of their visual field. Second, peo-ple viewing panoramic images frequentlyfail to understand the relative positions ofobjects in the environment because thepanoramic image is rolled out flat and pre-sented in front of them instead of wrap-ping around them. These fundamental er-rors have well-documented and dramatic

Stage Cylindrical Immersive Display This collaborative design environment enables design engineers to be immersed in a car orairplane, for example, to evaluate the designs of components. NASA’s Jet Propulsion Laboratory, Pasadena, California


This innovation enables a means for ac-tively measuring atomic oxygen fluence(accumulated atoms of atomic oxygen perarea) that has impinged upon spacecraftsurfaces. Telemetered data from the deviceprovides spacecraft designers, researchers,and mission managers with real-time meas-urement of atomic oxygen fluence, whichis useful for prediction of the durability ofspacecraft materials and components.

The innovation is a compact fluencemeasuring device that allows in-spacemeasurement and transmittance ofmeasured atomic oxygen fluence as afunction of time based on atomic oxy-gen erosion yields (the erosion yield of amaterial is the volume of material that isoxidized per incident oxygen atom) ofmaterials that have been measured inlow Earth orbit. It has a linear electrical

response to atomic oxygen fluence, andis capable of measuring high atomic oxy-gen fluences (up to >1022 atoms/cm2),which are representative of multi-yearlow-Earth orbital missions (such as theInternational Space Station).The durability or remaining structural

lifetime of solar arrays that consist of poly-mer blankets on which the solar cells areattached can be predicted if one knows

Atomic Oxygen Fluence MonitorApplications include the semiconductor industry where atomic oxygen is used to clean and/orremove photoresist from semiconductor surfaces.John H. Glenn Research Center, Cleveland, Ohio

Acquiring cheap, moving video was im-possible in a vacuum environment, due tocamera overheating. This overheating isbrought on by the lack of cooling media invacuum. A water-jacketed camera coolerenclosure machined and assembled fromcopper plate and tube has been developed. The camera cooler (see figure) is cup-

shaped and cooled by circulating wateror nitrogen gas through copper tubing.

The camera, a store-bought “spy type,” isnot designed to work in a vacuum. Withsome modifications the unit can be ther-mally connected when mounted in thecup portion of the camera cooler. Thethermal conductivity is provided by cop-per tape between parts of the cameraand the cooled enclosure. During initial testing of the demon-

stration unit, the camera cooler kept the

CPU (central processing unit) of thisvideo camera at operating temperature.This development allowed video record-ing of an in-progress test, within a vac-uum environment. This work was performed by Geoffrey A.

Laugen of Caltech for NASA’s Jet PropulsionLaboratory. For more information, [email protected]. NPO-47417

Vacuum Camera Cooler Cooler maintains proper operating temperature.NASA’s Jet Propulsion Laboratory, Pasadena, California

(a)

consequences. Viewers frequently believean object is beside a robot when it is actu-ally behind it, or think that a small rock isactually a large, hazardous obstacle thatmust be avoided. Stage addresses both of

these problems by immersing viewers inan accurate representation of the operat-ing environment. This work was done by Lucy Abramyan, Jef-

frey S. Norris, Mark W. Powell, David S.

Mittman, and Khawaja S. Shams of Caltechfor NASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected]

(b)

Photos of Vacuum Camera Cooler: (a) Camera cooler with camera installed and (b) camera cooler with camera partially removed to expose copper tapeand thermocouple, which are attached to overheating camera CPU.



the atomic oxygen fluence that the solararray blanket has been exposed to. In ad-dition, numerous organizations thatlaunch space experiments into low-Earthorbit want to know the accumulatedatomic oxygen fluence that their materi-als or components have been exposed to.The device is based on the erosion

yield of pyrolytic graphite. It uses two12° inclined wedges of graphite that areover a grit-blasted fused silica windowcovering a photodiode. As the wedgeserode, a greater area of solar illumina-tion reaches the photodiode. A refer-

ence photodiode is also used that re-ceives unobstructed solar illuminationand is oriented in the same direction asthe pyrolytic graphite covered photodi-ode. The short-circuit current from thephotodiodes is measured and either sentto an onboard data logger, or transmit-ted to a receiving station on Earth. Bycomparison of the short-circuit currentsfrom the fluence-measuring photodiodeand the reference photodiode, one cancompute the accumulated atomic oxy-gen fluence arriving in the directionthat the fluence monitor is pointing.

The device produces a signal that islinear with atomic oxygen fluence usinga material whose atomic oxygen erosionyield has been measured over a periodof several years in low-Earth orbit. This work was done by Bruce A. Banks of the

Glenn Research Center. Further information iscontained in a TSP (see page 1).Inquiries concerning rights for the commer-

cial use of this invention should be addressed toNASA Glenn Research Center, Innovative Part-nerships Office, Attn: Steven Fedor, Mail Stop4–8, 21000 Brookpark Road, Cleveland, Ohio44135. Refer to LEW-18639-1.


Information Sciences

Energy-related subsystems in modernaircraft are more tightly coupled withless design margin. These subsystems in-clude thermal management subsystems,vehicle electric power generation anddistribution, aircraft engines, and flightcontrol. Tighter coupling, lower designmargins, and higher system complexityall make preliminary trade studies diffi-cult. A suite of thermal managementanalysis tools has been developed to fa-cilitate trade studies during preliminarydesign of air-vehicle propulsion systems.Simulink blocksets (from MathWorks)

for developing quasi-steady-state andtransient system models of aircraft ther-mal management systems and related

energy systems have been developed.These blocksets extend the Simulinkmodeling environment in the thermalsciences and aircraft systems disciplines.The blocksets include blocks for model-ing aircraft system heat loads, heat ex-changers, pumps, reservoirs, fuel tanks,and other components at varying levelsof model fidelity.The blocksets have been applied in a

first-principles, physics-based modelingand simulation architecture for rapidprototyping of aircraft thermal manage-ment and related systems. They havebeen applied in representative modernaircraft thermal management systemstudies. The modeling and simulation ar-

chitecture has also been used to conducttrade studies in a vehicle level model thatincorporates coupling effects among theaircraft mission, engine cycle, fuel, andmulti-phase heat-transfer materials.This work was done by Kevin McCarthy of

PC Krause & Associates and Ernie Hodge ofModelogics for Glenn Research Center. Forfurther information contact Dr. Jeffrey Dal-ton, Avetec Chief Technology Officer, [email protected] concerning rights for the commer-

cial use of this invention should be addressedto NASA Glenn Research Center, InnovativePartnerships Office, Attn: Steve Fedor, MailStop 4–8, 21000 Brookpark Road, Cleveland,Ohio 44135. Refer to LEW-18463-1/4-1.

Thermal Management Tools for Propulsion System TradeStudies and AnalysisApplications include modeling and simulation in building and data center cooling analysis, andin ground-based vehicle studies.John H. Glenn Research Center, Cleveland, Ohio

Fast iterative algorithms are oftenused for solving Method of Moments(MoM) systems, having a large numberof unknowns, to determine current dis-tribution and other parameters. Themost commonly used fast methods in-

clude the fast multipole method (FMM),the precorrected fast Fourier transform(PFFT), and low-rank QR compressionmethods. These methods reduce theO(N) memory and time requirements toO(N log N) by compressing the dense

MoM system so as to exploit the physicsof Green’s Function interactions. FFT-based techniques for solving

such problems are efficient for space-filling and uniform structures, buttheir performance substantially de-

Technique for Solving Electrically Small to Large Structures forBroadband ApplicationsMethods are combined.Lyndon B. Johnson Space Center, Houston, Texas

A slight deviation from Newtonian dy-namics can lead to new effects associatedwith the concept of physical intelli-gence. Non-Newtonian effects such asdeviation from classical thermodynamicas well as quantum-like properties havebeen analyzed.A self-supervised (“intelligent”) parti-

cle that can escape from Brownian mo-

tion autonomously is introduced. Such acapability is due to a coupling of the par-ticle governing equation with its own Li-ouville equation via an appropriate feed-back. As a result, the governing equationis self-stabilized, and random oscillationsare suppressed, while the Liouville equa-tion takes the form of the Fokker-Planckequation with negative diffusion. Non-

Newtonian properties of such a dynami-cal system as well as thermodynamicalimplications have been evaluated.This work was done by Michail Zak of Caltech

for NASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected]

Introduction to Physical IntelligenceNASA’s Jet Propulsion Laboratory, Pasadena, California


The Modified Gerchberg-Saxton(MGS) algorithm is an image-basedwavefront-sensing method that can turnany science instrument focal plane intoa wavefront sensor. MGS characterizesoptical systems by estimating the wave-front errors in the exit pupil using onlyintensity images of a star or other pointsource of light. This innovative imple-mentation of MGS significantly acceler-ates the MGS phase retrieval algorithmby using stream-processing hardware onconventional graphics cards. Stream processing is a relatively new,

yet powerful, paradigm to allow paral-lel processing of certain applicationsthat apply single instructions to multi-ple data (SIMD). These stream proces-sors are designed specifically to sup-port large-scale parallel computing ona single graphics chip. Computation-

ally intensive algorithms, such as theFast Fourier Transform (FFT), are par-ticularly well suited for this computingenvironment. This high-speed versionof MGS exploits commercially availablehardware to accomplish the same ob-jective in a fraction of the originaltime. The exploit involves performingmatrix calculations in nVidia graphiccards. The graphical processor unit(GPU) is hardware that is specializedfor computationally intensive, highlyparallel computation. From the software perspective, a paral-

lel programming model is used, calledCUDA, to transparently scale multicoreparallelism in hardware. This technologygives computationally intensive applica-tions access to the processing power ofthe nVidia GPUs through a C/C++ pro-gramming interface. The AAMGS (Accel-

erated Adaptive MGS) software takes ad-vantage of these advanced technologies,to accelerate the optical phase error char-acterization. With a single PC that con-tains four nVidia GTX-280 graphic cards,the new implementation can process fourimages simultaneously to produce aJWST (James Webb Space Telescope)wavefront measurement 60 times fasterthan the previous code.This work was done by Raymond K. Lam,

Catherine M. Ohara, Joseph J. Green, Sid-darayappa A. Bikkannavar, Scott A. Basinger,David C. Redding, and Fang Shi of Caltech forNASA’s Jet Propulsion Laboratory. For more in-formation, contact [email protected]. The software used in this innovation is

available for commercial licensing. Please con-tact Daniel Broderick of the California Insti-tute of Technology at [email protected] to NPO-47101.

Accelerated Adaptive MGS Phase RetrievalNASA’s Jet Propulsion Laboratory, Pasadena, California

A new modeling approach is basedon the concept of large eddy simula-tion (LES) within which the largescales are computed and the smallscales are modeled. The new approachis expected to retain the fidelity of the

physics while also being computation-ally efficient. Typically, only models forthe small-scale fluxes of momentum,species, and enthalpy are used to rein-troduce in the simulation the physicslost because the computation only re-

solves the large scales. These modelsare called subgrid (SGS) models be-cause they operate at a scale smallerthan the LES grid.In a previous study of thermodynami-

cally supercritical fluid disintegration and

Large Eddy Simulation Study for Fluid Disintegration and Mixing This work is directly applicable to simulations of gas turbine engines and rocket engines.NASA’s Jet Propulsion Laboratory, Pasadena, California

grades for non-uniformly distributedstructures due to the inherent need toemploy a uniform global grid. FMM orQR techniques are better suited thanFFT techniques; however, neither theFMM nor the QR technique can beused at all frequencies. This method has been developed to

efficiently solve for a desired parameterof a system or device that can includeboth electrically large FMM elements,and electrically small QR elements. Thesystem or device is set up as an oct-treestructure that can include regions ofboth the FMM type and the QR type.The system is enclosed with a cube at a 0-th level, splitting the cube at the 0-thlevel into eight child cubes. This formscubes at a 1-st level, recursively repeatingthe splitting process for cubes at succes-sive levels until a desired number of lev-

els is created. For each cube that is thusformed, neighbor lists and interactionlists are maintained. An iterative solver is then used to de-

termine a first matrix vector product forany electrically large elements as well asa second matrix vector product for anyelectrically small elements that are in-cluded in the structure. These matrixvector products for the electrically largeand small elements are combined, and anet delta for a combination of the ma-trix vector products is determined. Theiteration continues until a net delta isobtained that is within the predefinedlimits. The matrix vector products thatwere last obtained are used to solve forthe desired parameter. The solution forthe desired parameter is then presentedto a user in a tangible form; for example,on a display.

This work was done by Vikram Jandhyalaand Indranil Chowdhury of the University ofWashington for Johnson Space Center. Forfurther information, contact the JohnsonTechnology Transfer Office at (281) 483-3809. In accordance with Public Law 96-517,

the contractor has elected to retain title to thisinvention. Inquiries concerning rights for itscommercial use should be addressed to:Janice C. WalshFederal Reporting Compliance Licensing Spe-

cialistUW Tech TransferUniversity of Washington 4322-11th Avenue, N.E., Suite 500Seattle, WA 98105-4608E-mail: [email protected] to MSC-24439-1, volume and number

of this NASA Tech Briefs issue, and the pagenumber.


mixing, additional small-scale terms, onein the momentum and one in the energyconservation equations, were identifiedas requiring modeling. These additionalterms were due to the tight coupling be-tween dynamics and real-gas thermody-namics. It was inferred that if these termswould not be modeled, the high density-gradient magnitude regions, experimen-tally identified as a characteristic featureof these flows, would not be accuratelypredicted without the additional term inthe momentum equation; these highdensity-gradient magnitude regions wereexperimentally shown to redistribute tur-bulence in the flow. And it was also in-ferred that without the additional term inthe energy equation, the heat flux magni-tude could not be accurately predicted;the heat flux to the wall of combustiondevices is a crucial quantity that deter-mined necessary wall material properties.

The present work involves situationswhere only the term in the momentumequation is important. Without this ad-ditional term in the momentum equa-tion, neither the SGS-flux constant-coef-ficient Smagorinsky model nor theSGS-flux constant-coefficient Gradientmodel could reproduce in LES the pres-sure field or the high density-gradientmagnitude regions; the SGS-flux con-stant-coefficient Scale-Similarity modelwas the most successful in this endeavoralthough not totally satisfactory. With amodel for the additional term in the mo-mentum equation, the predictions ofthe constant-coefficient Smagorinskyand constant-coefficient Scale-Similaritymodels were improved to a certain ex-tent; however, most of the improvementwas obtained for the Gradient model.The previously derived model and anewly developed model for the addi-

tional term in the momentum equationwere both tested, with the new modelproving even more successful than theprevious model at reproducing the highdensity-gradient magnitude regions. Sev-eral dynamic SGS-flux models, in whichthe SGS-flux model coefficient is com-puted as part of the simulation, weretested in conjunction with the newmodel for this additional term in themomentum equation. The most success-ful dynamic model was a “mixed” modelcombining the Smagorinsky and Gradi-ent models. This work is directly applicable to sim-

ulations of gas turbine engines (aeronau-tics) and rocket engines (astronautics). This work was done by Josette Bellan and

Ezgi Taşkinoğlu of Caltech for NASA’s JetPropulsion Laboratory. For more informa-tion, contact [email protected]. NPO-47040

Tropospheric Correction for InSAR Using Interpolated ECMWFData and GPS Zenith Total Delay This technique could be used in environmental remote sensing applications. NASA’s Jet Propulsion Laboratory, Pasadena, California

To mitigate atmospheric errors causedby the troposphere, which is a limitingerror source for spaceborne interfero-metric synthetic aperture radar (InSAR)imaging, a tropospheric correctionmethod has been developed using datafrom the European Centre for Medium-Range Weather Forecasts (ECMWF) andthe Global Positioning System (GPS). The ECMWF data was interpolated

using a Stretched Boundary LayerModel (SBLM), and ground-based GPSestimates of the tropospheric delayfrom the Southern California Inte-grated GPS Network were interpolatedusing modified Gaussian and inversedistance weighted interpolations. Theresulting Zenith Total Delay (ZTD) cor-rection maps have been evaluated, bothseparately and using a combination ofthe two data sets, for three short-inter-val InSAR pairs from Envisat during2006 on an area stretching from north-east from the Los Angeles basin towardsDeath Valley. Results show that the rootmean square (rms) in the InSAR im-ages was greatly reduced, meaning a sig-nificant reduction in the atmosphericnoise of up to 32 percent. However, forsome of the images, the rms increasedand large errors remained after apply-

ing the tropospheric correction. Theresiduals showed a constant gradientover the area, suggesting that a remain-ing orbit error from Envisat was pres-ent. The orbit reprocessing in ROI_pacand the plane fitting both require thatthe only remaining error in the InSARimage be the orbit error. If this is notfulfilled, the correction can be made

anyway, but it will be done using all re-maining errors assuming them to beorbit errors. By correcting for tropos-pheric noise, the biggest error source isremoved, and the orbit error becomesapparent and can be corrected for. After reprocessing the InSAR images

using re-estimated satellite orbits, theoverall rms reduction (using both tro-

The Original InSAR Image (left), the GPS ZTD Difference Correction Map (center), and the correctedInSAR Image (right). The black dots in the middle image correspond to the locations of the GPS sta-tions.

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pospheric and orbit correction) span -ned from 15 to 68 percent. With this tro-pospheric correction, low-frequency er-rors can be removed from InSARimages. Additionally, results show thatfor days with high-quality ECMWF data,the SBLM ZTD correction performs aswell as the GPS ZTD correction. Finally,the tropospheric correction enabled

orbit correction, and by correcting forboth errors, the quality of the InSAR im-ages increased significantly. By correcting for the troposphere,

other errors become visible. The maincontributor to the remaining errors is un-certainties with determining the satelliteorbit. Because the orbit error is now sepa-rated from the tropospheric error, the

orbit can be corrected for more accurately. This work was done by Frank H. Webb,

Evan F. Fishbein, Angelyn W. Moore, SusanE. Owen, Eric J. Fielding, and Stephanie L.Granger of Caltech and Fredrik Björndahland Johan Löfgren of Chalmers University ofTechnology for NASA’s Jet Propulsion Labora-tory. Further information is contained in aTSP (see page 1). NPO-46918

A solution has been developed to thechallenges of computation of derivativeswith respect to geometry, which is notstraightforward because these are nottypically direct inputs to the computa-tional fluid dynamics (CFD) solver. Toovercome these issues, a procedure hasbeen devised that can be used withouthaving access to the mesh generator,while still being applicable to all types ofmeshes. The basic approach is inspiredby the mesh motion algorithms used todeform the interior mesh nodes in asmooth manner when the surface nodes,for example, are in a fluid structure in-teraction problem. The general idea is tomodel the mesh edges and nodes as con-stituting a spring-mass system. Changesto boundary node locations are propa-

gated to interior nodes by allowing themto assume their new equilibrium posi-tions, for instance, one where the forceson each node are in balance. The main advantage of the technique

is that it is independent of the volumet-ric mesh generator, and can be appliedto structured, unstructured, single- andmulti-block meshes. It essentially re-duces the problem down to defining thesurface mesh node derivatives with re-spect to the geometry parameters of in-terest. For analytical geometries, this isquite straightforward. In the more gen-eral case, one would need to be able tointerrogate the underlying parametricCAD (computer aided design) modeland to evaluate the derivatives either an-alytically, or by a finite difference tech-

nique. Because the technique is basedon a partial differential equation (PDE),it is applicable not only to forward modeproblems (where derivatives of all theoutput quantities are computed with re-spect to a single input), but it could alsobe extended to the adjoint problem, ei-ther by using an analytical adjoint of thePDE or a discrete analog.This work was done by Sanjay Mathur of

Jabiru Software and Services, LLC, for GlennResearch Center. Further information is con-tained in a TSP (see page 1)Inquiries concerning rights for the commer-

cial use of this invention should be addressedto NASA Glenn Research Center, InnovativePartnerships Office, Attn: Steve Fedor, MailStop 4–8, 21000 Brookpark Road, Cleve-land, Ohio 44135. Refer to LEW-18499-1.

Technique for Calculating Solution Derivatives With Respect toGeometry Parameters in a CFD CodeJohn H. Glenn Research Center, Cleveland, Ohio

Acute Radiation Risk and BRYNTRN Organ Dose ProjectionGraphical User InterfaceThis program estimates the whole-body effective dose, organ doses, and acute radiation sickness symptoms.Lyndon B. Johnson Space Center, Houston, Texas

The integration of human space ap-plications risk projection models oforgan dose and acute radiation risk hasbeen a key problem. NASA has devel-oped an organ dose projection modelusing the BRYNTRN with SUM DOSEcomputer codes, and a probabilisticmodel of Acute Radiation Risk (ARR).The codes BRYNTRN and SUM DOSEare a Baryon transport code and an out-put data processing code, respectively.The risk projection models of organdoses and ARR take the output fromBRYNTRN as an input to their calcula-tions. With a graphical user interface

(GUI) to handle input and output forBRYNTRN, the response models can beconnected easily and correctly to BRYN-TRN. A GUI for the ARR and BRYN-TRN Organ Dose (ARRBOD) projec-tion code provides seamless integrationof input and output manipulations,which are required for operations of theARRBOD modules.The ARRBOD GUI is intended for

mission planners, radiation shield de-signers, space operations in the missionoperations directorate (MOD), andspace biophysics researchers. BRYN-TRN code operation requires extensive

input preparation. Only a graphicaluser interface (GUI) can handle inputand output for BRYNTRN to the re-sponse models easily and correctly. Thepurpose of the GUI development forARRBOD is to provide seamless integra-tion of input and output manipulationsfor the operations of projection mod-ules (BRYNTRN, SLMDOSE, and theARR probabilistic response model) inassessing the acute risk and the organdoses of significant Solar ParticleEvents (SPEs).The assessment of astronauts’ radia-

tion risk from SPE is in support of mis-


Probabilistic Path Planning of Montgolfier Balloons in Strong,Uncertain Wind Fields This algorithm can be used for underwater unmanned vehicles for automated scientific datacollection and for military uses. NASA’s Jet Propulsion Laboratory, Pasadena, California

Lighter-than-air vehicles such as hot-air balloons have been proposed for ex-ploring Saturn’s moon Titan, as well asother bodies with significant atmos-pheres. For these vehicles to navigate ef-fectively, it is critical to incorporate theeffects of surrounding wind fields, espe-cially as these winds will likely be strongrelative to the control authority of thevehicle. Predictive models of these windfields are available, and previous re-search has considered problems of plan-ning paths subject to these predictedforces. However, such previous work hasconsidered the wind fields as known apriori, whereas in practical applications,the actual wind vector field is not knownexactly and may deviate significantlyfrom the wind velocities estimated bythe model.A probabilistic 3D path-planning algo-

rithm was developed for balloons to useuncertain wind models to generate time-efficient paths. The nominal goal of thealgorithm is to determine what altitudeand what horizontal actuation, if any isavailable on the vehicle, to use to reach a

particular goal location in the least ex-pected time, utilizing advantageouswinds. The solution also enables one toquickly evaluate the expected time-to-goal from any other location and to avoidregions of large uncertainty. This methodis designed for balloons in wind fields butmay be generalized for any buoyant vehi-cle operating in a vector field.To prepare the planning problem, the

uncertainty in the wind field is modeled.Then, the problem of reaching a particu-lar goal location is formulated as aMarkov decision process (MDP) using adiscretized space approach. Solving theMDP provides a policy of what actuationoption (how much buoyancy changeand, if applicable, horizontal actuation)should be selected at any given locationto minimize the expected time-to-goal.The results provide expected time-to-goal values from any given location onthe globe in addition to the action policy.This stochastic approach can also pro-

vide insights not accessible by determin-istic methods; for example, one can eval-uate variability and risk associated with

different scenarios, rather than onlyviewing the expected outcome.The resulting path-planning tool is a

general-purpose guidance algorithmthat can be applied to exploration bal-loons on any moon/planet with atmos-phere, including Titan, Mars, Venus,and gas giants, provided the wind fieldmodels are available. The algorithm isparticularly useful for mission planningand trade studies because it not only de-livers the optimal expected path, butalso provides insights into the variabilityand risk associated with different mis-sion scenarios (e.g., under differentwind variability or vehicle capabilities).Finally, these techniques may be usefulfor other variably buoyant vehicles oper-ating in strong vector fields, such as un-derwater vehicles in ocean currents,which may have additional scientific ormilitary significance.This work was done by Michael Wolf, James

C. Blackmore, and Yoshiaki Kuwata of Caltechfor NASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected]

sion design and operational planning tomanage radiation risks in future spacemissions. The ARRBOD GUI can iden-tify the proper shielding solutions usingthe gender-specific organ dose assess-ments in order to avoid ARR symptoms,and to stay within the current NASAshort-term dose limits. The quantifiedevaluation of ARR severities based onany given shielding configuration and a

specified EVA or other mission scenariocan be made to guide alternative solu-tions for attaining determined objectivesset by mission planners.The ARRBOD GUI estimates the

whole-body effective dose, organ doses,and acute radiation sickness symptomsfor astronauts, by which operationalstrategies and capabilities can be madefor the protection of astronauts from

SPEs in the planning of future lunar sur-face scenarios, exploration of near-Earthobjects, and missions to Mars.This work was done by Francis A. Cu-

cinotta of Johnson Space Center, andShaowen Hu, Hateni N. Nounu, andMyung-Hee Y. Kim of the Universities SpaceResearch Association. Further information iscontained in a TSP (see page 1). MSC-24789-1


Books & Reports

Flight Simulation of ARESin the Mars Environment

A report discusses using the Aerial Re-gional-scale Environmental Survey(ARES) light airplane as an observationplatform on Mars in order to gatherdata. It would have to survive insertioninto the atmosphere, fly long enough tomeet science objectives, and provide astable platform.The feasibility of such a platform was

tested using the Langley Standard Real-Time Simulation in C++. The uniquefeatures of LaSRS++ are: full, six-de-grees-of-freedom flight simulation thatcan be used to evaluate the performanceof the aircraft in the Martian environ-ment; capability of flight analysis fromstart to finish; support of Monte Carloanalysis of aircraft performance; and ac-cepting initial conditions from POST re-sults for the entry and deployment ofthe entry body.Starting with a general aviation model,

the design was tweaked to maintain a sta-ble aircraft under expected Martian con-ditions. Outer mold lines were adjustedbased on experience with the Martian at-mosphere. Flight control was modifiedfrom a vertical acceleration control lawto an angle-of-attack control law. Naviga-tion was modified from a vertical acceler-ation control system to an alpha controlsystem. In general, a pattern of startingwith simple models with well-understoodbehaviors was selected and modified dur-ing testing. This work was done by P. Sean Kenney and

Mark A. Croom of Langley Research Center.Further information is contained in a TSP(see page 1). LAR-17458

Low-Outgassing Photogram-metry Targets for Use inOuter Space

A short document discusses an investi-gation of materials for photogrammetrytargets for highly sensitive optical scien-tific instruments to be operated in outerspace and in an outer-space-environ-ment-simulating thermal vacuum cham-ber on Earth. A key consideration in theselection of photogrammetry-target ma-terials for vacuum environments is theneed to prevent contamination thatcould degrade the optical responses ofthe instruments. Therefore, in addition

to the high levels and uniformity of re-flectivity required of photogrammetry-target materials suitable for use in air,the materials sought must exhibit mini-mal outgassing.Commercially available photogram-

metry targets were found to outgas ex-cessively under the thermal and vac-uum conditions of interest; this findingprompted the investigators to consideroptically equivalent or superior, lower-outgassing alternative target materials.The document lists several materialsfound to satisfy the requirements, butdoes not state explicitly whether thematerials can be used individually ormust be combined in the proper se-quence into layered target structures.The materials in question are an alu-minized polyimide tape, an acrylic pres-sure-sensitive adhesive, a 500-Å-thicklayer of vapor-deposited aluminum,and spherical barium titanate glassbeads having various diameters from 20to 63 µm.This work was done by Jason N. Gross, Henry

Sampler, and Benjamin B. Reed of GoddardSpace Flight Center. Further information is con-tained in a TSP (see page 1). GSC-15373-1

Planning the FUSE MissionUsing the SOVA Algorithm

Three documents discuss the Sustain-able Objective Valuation and Attainabil-ity (SOVA) algorithm and software asused to plan tasks (principally, scientificobservations and associated maneuvers)for the Far Ultraviolet Spectroscopic Ex-plorer (FUSE) satellite. SOVA is a meansof managing risk in a complex system,based on a concept of computing the ex-pected return value of a candidate or-dered set of tasks as a product of pre-as-signed task values and assessments ofattainability made against qualitativelydefined strategic objectives. For the FUSE mission, SOVA auton -

omously assembles a week-long scheduleof target observations and associatedmaneuvers so as to maximize the ex-pected scientific return value whilekeeping the satellite stable, managingthe angular momentum of spacecraft at-titude-control reaction wheels, and striv-ing for other strategic objectives. A six-degree-of-freedom model of thespacecraft is used in simulating the tasks,and the attainability of a task is calcu-

lated at each step by use of strategic ob-jectives as defined by use of fuzzy infer-ence systems. SOVA utilizes a variant of agraph-search algorithm known as the A*search algorithm to assemble the tasksinto a week-long target schedule, usingthe expected scientific return value toguide the search.This work was done by Jim Lanzi, Scott

Heatwole, and Philip R. Ward of GoddardSpace Flight Center and Thomas Civeit, Hum-berto Calvani, Jeffrey W. Kruk, and AnatolySuchkov of Johns Hopkins University. Furtherinformation is contained in a TSP (see page1). GSC-15436-1

Monitoring SpacecraftTelemetry Via Optical or RF Link

A patent disclosure document dis-cusses a photonic method for connect-ing a spacecraft with a launch vehicleupper-stage telemetry system as a meansfor monitoring a spacecraft’s health andstatus during and right after separationand deployment. This method also pro-vides an efficient opto-coupled capabil-ity for prelaunch built-in-test (BIT) onthe ground to enable more efficient andtimely integration, preflight checkout,and a means to obviate any local EMI(electromagnetic interference) duringintegration and test. Additional utilitycan be envisioned for BIT on other plat-forms, such as the International SpaceStation (ISS). The photonic telemetry system imple-

ments an optical free-space link with adivergent laser transmitter beamspoiled over a significant cone angle toaccommodate changes in spacecraft po-sition without having to angle track itduring deployment. Since the space-craft may lose attitude control and tum-ble during deployment, the transmitted laser beam interrogates any one of severallow-profile meso-scale retro-reflective spa-tial light modulators (SLMs) deployedover the surface of the spacecraft. The re-turn signal beam, modulated by theSLMs, contains health, status, and atti-tude information received back at thelaunch vehicle. Very compact low-poweropto-coupler technology already existsfor the received signal (requiring rela-tively low bandwidths, e.g., ≤200 kbps) toenable transfer to a forward pass RF relayfrom the launch vehicle to TDRSS


(Tracking and Data Relay Satellite Sys-tem) or another recipient. The linkwould be active during separation andpost-separation to monitor spacecrafthealth, status, attitude, or other data in-ventories until attitude recovery andground control can be re-established. Anoptical link would not interfere with theexisting upper stage telemetry and bea-con systems, thus meeting launch vehicleEMI environmental constraints.This work was done by K.B. Fielhauer and

B.G. Boone for Goddard Space Flight Center.Further information is contained in a TSP(see page 1). GSC-14832-1

Robust Thermal Control of Propulsion Lines forSpace Missions

A document discusses an approach toinsulating propulsion lines for space-craft. In spacecraft that have propul-sion lines that are located externally

with open bus architecture, the linesare typically insulated by Multi Layer In-sulation (MLI) blankets. MLI onpropulsion lines tends to have largeand somewhat random variances in itsheat loss properties (effective emit-tance) from one location to the next,which makes it an un-robust approachto control propulsion line tempera-tures. The approach described hereconsists of a “clamshell” design inwhich the inner surface of the shell iscoated with low-emissivity aluminizedKapton tape, and the outer surface iscovered with black tape. This clamshellcompletely encloses the propulsionline. The line itself is covered with itsheater, which in turn, is covered com-pletely with black tape. This approach would be low in heater

power needs because even though theouter surface of the prop line (and itsheater) is covered with black tape as wellas the outer surface of the clamshell, the

inner surface of the clamshell is coveredwith low-emissivity aluminized Kaptontape. Hence, the heat loss from the linewill be small and comparable to the MLIbased one. In terms of contamination changing

the radiative properties of surfaces, sincethe clamshell’s inner surface is alwaysprotected during handling and is only in-stalled after all the work on the prop linehas been completed, the controlling sur-face, which is the clamshell’s inner sur-face, is always in pristine condition. This proposed design allows for a

much more deterministic and pre-dictable design using a very simple andimplementable approach for thermalcontrol. It also uses low heater powerand is robust to handling and contami-nation during and after implementation. This work was done by Pradeep Bhandari

of Caltech for NASA’s Jet Propulsion Labora-tory. Further information is contained in aTSP (see page 1). NPO-47441

National Aeronautics andSpace Administration

technology focus electronics/computers

Documents