technology focus electronics/computers - ntrs.nasa.gov · technology focus electronics/computers...

Technology Focus

Electronics/Computers

Software

Materials

Mechanics/Machinery

Manufacturing

Bio-Medical

Physical Sciences

Information Sciences

Books and Reports

11-13 November 2013

https://ntrs.nasa.gov/search.jsp?R=20140001107 2019-08-15T05:20:22+00:00Z

NASA Tech Briefs, November 2013 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 CenterDavid Morse(650) [email protected]

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

Glenn Research CenterKimberly A. Dalgleish-Miller(216) [email protected]

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

Jet Propulsion LaboratoryDan Broderick(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 CenterTerry L. Taylor(256) [email protected]

Stennis Space CenterRamona Travis(228) [email protected]

NASA Headquarters

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

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

NASA Field Centers and Program Offices

5 Technology Focus: Data Acquisition5 Cryogenic Liquid Sample Acquisition System for

Remote Space Applications

5 Spatial Statistical Data Fusion (SSDF)

6 GPS Estimates of Integrated Precipitable Water Aid Weather Forecasters

6 Integrating a Microwave Radiometer into Radar Hardware forSimultaneous Data Collection Between the Instruments

7 Rapid Detection of Herpes Viruses for Clinical Applications

7 High-Speed Data Recorder for Space, Geodesy, and OtherHigh-Speed Recording Applications

8 Datacasting V3.0

9 Electronics/Computers9 An All-Solid-State, Room-Temperature, Heterodyne Receiver

for Atmospheric Spectroscopy at 1.2 THz

10 Stacked Transformer for Driver Gain and Receive SignalSplitting

10 Wireless Integrated Microelectronic Vacuum Sensor System

13 Manufacturing & Prototyping13 Fabrication Method for LOBSTER-Eye Optics in <110> Silicon

13 Compact Focal Plane Assembly for Planetary Science

14 Fabrication Methods for Adaptive Deformable Mirrors

15 Software15 Visiting Vehicle Ground Trajectory Tool

15 Workflow-Based Software Development Environment

15 Mobile Thread Task Manager

17 Mechanics/Machinery17 A Kinematic Calibration Process for Flight Robotic Arms

17 Magnetostrictive Alternator

19 Materials & Coatings19 Bulk Metallic Glasses and Composites for Optical and

Compliant Mechanisms

21 Bio-Medical21 Detection of Only Viable Bacterial Spores Using a Live/Dead

Indicator in Mixed Populations

21 Intravenous Fluid Generation System


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.

11-13 November 2013


Technology Focus: Data Acquisition

There is a need to acquire auto n -omously cryogenic hydrocarbon liquidsample from remote planetary locationssuch as the lakes of Titan for instru-ments such as mass spectrometers.There are several problems that had tobe solved relative to collecting the rightamount of cryogenic liquid sample intoa warmer spacecraft, such as not allow-ing the sample to boil off or fractionatetoo early; controlling the intermediateand final pressures within carefully de-signed volumes; designing for variousparticulates and viscosities; designing tothermal, mass, and power-limited space-craft interfaces; and reducing risk. Priorart inlets for similar instruments inspaceflight were designed primarily for

atmospheric gas sampling and are notuseful for this front-end application. These cryogenic liquid sample acqui-

sition system designs for remote spaceapplications allow for remote, au-tonomous, controlled sample collec-tions of a range of challenging cryogenicsample types. The design can controlthe size of the sample, prevent fractiona-tion, control pressures at various stages,and allow for various liquid sample lev-els. It is capable of collecting repeatedsamples autonomously in difficult low-temperature conditions often found inplanetary missions. It is capable of col-lecting samples for use by instrumentsfrom difficult sample types such as cryo-genic hydrocarbon (methane, ethane,

and propane) mixtures with solid partic-ulates such as found on Titan. The de-sign with a warm actuated valve is com-patible with various spacecraft thermaland structural interfaces. The design uses controlled volumes,

heaters, inlet and vent tubes, a cryogenicvalve seat, inlet screens, temperatureand cryogenic liquid sensors, seals, andvents to accomplish its task. This work was done by Paul Mahaffy,

Melissa Trainer, Don Wegel, Douglas Hawk,Tony Melek, Christopher Johnson, MichaelAmato, and John Galloway of Goddard SpaceFlight Center. Further information is con-tained in a TSP (see page 1). GSC-16510-1

Cryogenic Liquid Sample Acquisition System for Remote Space Applications Goddard Space Flight Center, Greenbelt, Maryland

As remote sensing for scientific pur-poses has transitioned from an experi-mental technology to an operationalone, the selection of instruments hasbecome more coordinated, so that thescientific community can exploit com-plementary measurements. However,tech nological and scientific hetero-geneity across devices means that thestatistical characteristics of the datathey collect are different. The chal-lenge addressed here is how to com-bine heterogeneous remote sensingdata sets in a way that yields optimal sta-tistical estimates of the underlying geo-physical field, and provides rigorousuncertainty measures for those esti-mates. Different remote sensing datasets may have different spatial resolu-tions, different measurement error bi-ases and variances, and other disparatecharacteristics.A state-of-the-art spatial statistical

model was used to relate the true, but

not directly observed, geophysical fieldto noisy, spatial aggregates observed byremote sensing instruments. The spa-tial covariances of the true field and thecovariances of the true field with theobservations were modeled. The obser-vations are spatial averages of the truefield values, over pixels, with differentmeasurement noise superimposed. Akriging framework is used to infer opti-mal (minimum mean squared errorand unbiased) estimates of the truefield at point locations from pixel-level,noisy observations.A key feature of the spatial statistical

model is the spatial mixed effects modelthat underlies it. The approach modelsthe spatial covariance function of theunderlying field using linear combina-tions of basis functions of fixed size. Ap-proaches based on kriging require theinversion of very large spatial covariancematrices, and this is usually done bymaking simplifying assumptions about

spatial covariance structure that simplydo not hold for geophysical variables. Incontrast, this method does not requirethese assumptions, and is also computa-tionally much faster. This method is fun-damentally different than other ap-proaches to data fusion for remotesensing data because it is inferentialrather than merely descriptive. All ap-proaches combine data in a way thatminimizes some specified loss function.Most of these are more or less ad hoc cri-teria based on what looks good to theeye, or some criteria that relate only tothe data at hand.This work was done by Amy J. Braverman

and Hai M. Nguyen of Caltech, and NoelCressie of the Ohio State University forNASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected] software is available for commercial li-

censing. Please contact Dan Broderick [email protected]. Refer toNPO-48131.

Spatial Statistical Data Fusion (SSDF)The approach models the spatial covariance function of the underlying geophysical field usinglinear combinations of multi-resolution spatial basis functions of low dimensionality.NASA’s Jet Propulsion Laboratory, Pasadena, California

6 NASA Tech Briefs, November 2013

The conventional method for inte-grating a radiometer into radar hard-ware is to share the RF front end be-tween the instruments, and to haveseparate IF receivers that take data atseparate times. Alternatively, the radarand radiometer could share the an-tenna through the use of a diplexer,but have completely independent re-ceivers. This novel method shares theradar’s RF electronics and digital re-ceiver with the radiometer, while allow-

ing for simultaneous operation of theradar and radiometer.Radars and radiometers, while often

having near-identical RF receivers, gen-erally have substantially different IF andbaseband receivers. Operation of thetwo instruments simultaneously is diffi-cult, since airborne radars will pulse at arate of hundreds of microseconds. Ra-diometer integration time is typically 10sor 100s of milliseconds. The bandwidthof radar may be 1 to 25 MHz, while a ra-

diometer will have an RF bandwidth ofup to a GHz. As such, the conventionalmethod of integrating radar and ra-diometer hardware is to share the high-frequency RF receiver, but to have sepa-rate IF subsystems and digitizers. Toavoid corruption of the radiometer data,the radar is turned off during the ra-diometer dwell time.This method utilizes a modern radar

digital receiver to allow simultaneousoperation of a radiometer and radar

Integrating a Microwave Radiometer into Radar Hardware forSimultaneous Data Collection Between the InstrumentsElectronics are shared between the instruments.Goddard Space Flight Center, Greenbelt, Maryland

Global Positioning System (GPS) mete-orology provides enhanced density, low-la-tency (30-min resolution), integrated pre-cipitable water (IPW) estimates to NOAANWS (National Oceanic and AtmosphericAdminis tration Nat ional Weather Service)Weather Forecast Offices (WFOs) to pro-vide improved model and satellite dataverification capability and more accurateforecasts of extreme weather such as flood-ing. An early activity of this project was toincrease the number of stations contribut-ing to the NOAA Earth System ResearchLaboratory (ESRL) GPS meteorology ob-serving network in Southern California byabout 27 stations. Following this, the LosAngeles/Oxnard and San Diego WFOsbegan using the enhanced GPS-based IPWmeasurements provided by ESRL in the2012 and 2013 monsoon seasons. Fore-casters found GPS IPW to be an effectivetool in evaluating model performance,and in monitoring monsoon developmentbetween weather model runs for im-proved flood forecasting.GPS stations are multi-purpose, and

routine processing for position solutionsalso yields estimates of troposphericzenith delays, which can be convertedinto mm-accuracy PWV (precipitablewater vapor) using in situ pressure andtemperature measurements, the basis forGPS meteorology. NOAA ESRL has im-

plemented this concept with a nation-wide distribution of more than 300 “GPS-Met” stations providing IPW estimates atsub-hourly resolution currently used inoperational weather models in the U.S.This work was done by Angelyn W. Moore of

Caltech; Seth I. Gutman and Kirk Holub of

NOAA Earth System Research Laboratory;Yehuda Bock of UC San Diego’s Scripps Insti-tution of Oceanography; and David Daniel-son, Jayme Laber, and Ivory Small of NOAANational Weather Service. Further informationis contained in a TSP (see page 1). NPO-48881

GPS Estimates of Integrated Precipitable Water Aid Weather ForecastersThis technique improves weather-forecasting operations.NASA’s Jet Propulsion Laboratory, Pasadena, California

ABPI09-23-13 BT

5 10 15 20 25 30 35 40 45 50 55 60 65 70

Updated: Friday, July 19, 2013 12:24:46 PM

IPW Legendless than (mm)

Durmid Hills, CA

Durmid Hills, CA

IFW PRES TEMP Info

6543210

IPW

(cm

)

07/16 07/17 07/18 07/19 07/20

Date (m/d UTC)

IPW

(in

ches

)2.2

1.5

1

0.5

0

Integrated precipitable Water

A screenshot from http://gpsmet.noaa.gov of ground GPS-based Integrated Water Vapor Informationutilized by NOAA NWS San Diego Weather Forecasting Office during the 2013 monsoon season. Theupward IWV trend supported satellite data and contributed to the issuance of a flood watch.


High-Speed Data Recorder for Space, Geodesy, and OtherHigh-Speed Recording ApplicationsGoddard Space Flight Center, Greenbelt, Maryland

A high-speed data recorder and replayequipment has been developed for reli-able high-data-rate recording to diskmedia. It solves problems with slow orfaulty disks, multiple disk insertions,high-altitude operation, reliable per-formance using COTS hardware, andlong-term maintenance and upgradepath challenges.The current generation data recor -

ders used within the VLBI communityare aging, special-purpose machines thatare both slow (do not meet today’s re-

quirements) and are very expensive tomaintain and operate. Furthermore,they are not easily upgraded to take ad-vantage of commercial technology de-velopment, and are not scalable to mul-tiple 10s of Gbit/s data rates required bynew applications.The innovation provides a software-

defined, high-speed data recorder that isscalable with technology advances in thecommercial space. It maximally utilizescurrent technologies without beinglocked to a particular hardware plat-

form. The innovation also provides acost-effective way of streaming largeamounts of data from sensors to disk, en-abling many applications to store rawsensor data and perform post and signalprocessing offline.This recording system will be applica-

ble to many applications needing real-world, high-speed data collection, in-cluding electronic warfare, software-defined radar, signal history storage ofmultispectral sensors, development ofautonomous vehicles, and more.

with a shared RF front end and digitalreceiver. The radiometer signal is cou-pled out after the first down-conversionstage. From there, the radar transmit fre-quencies are heavily filtered, and thebands outside the transmit filter are am-plified and passed to a detector diode.This diode produces a DC output pro-portional to the input power. For a con-ventional radiometer, this level would bedigitized. By taking this DC output andmixing it with a system oscillator at 10MHz, the signal can instead be digitizedby a second channel on the radar digitalreceiver (which typically do not acceptDC inputs), and can be down-convertedto a DC level again digitally. This unintu-itive step allows the digital receiver to

sample both the radiometer and radardata at a rapid, synchronized data rate(greater than 1 MHz bandwidth).Once both signals are sampled by the

same digital receiver, high-speed qualitycontrol can be performed on the ra-diometer data to allow it to take data si-multaneously with the radar. The ra-diometer data can be blanked duringradar transmit, or when the radar returnis of a power level high enough to cor-rupt the radiometer data. Additionally,the receiver protection switches in theRF front end can double as radiometercalibration sources, the short (four-mi-crosecond level) switching periods inte-grated over many seconds to estimatethe radiometer offset.

The major benefit of this innovationis that there is minimal impact on theradar performance due to the integra-tion of the radiometer, and the ra-diometer performance is similarly min-imally affected by the radar. As theradar and radiometer are able to oper-ate simultaneously, there is no ex-tended period of integration time lossfor the radiometer (maximizing sensi-tivity), and the radar is able to maintainits full number of pulses (increasingsensitivity and decreasing measurementuncertainty).This work was done by Matthew McLinden

and Jeffrey Piepmeier of Goddard Space FlightCenter. Further information is contained in aTSP (see page 1). GSC-16490-1

Rapid Detection of Herpes Viruses for Clinical ApplicationsLyndon B. Johnson Space Center, Houston, Texas

There are eight herpes viruses that in-fect humans, causing a wide range of dis-eases resulting in considerable morbid-ity and associated costs. Varicella zostervirus (VZV) is a human herpes virus thatcauses chickenpox in children and shin-gles in adults. Approximately 1,000,000new cases of shingles occur each year;post-herpetic neuralgia (PHN) followsshingles in 100,000 to 200,000 peopleannually. PHN is characterized by debil-itating, nearly unbearable pain forweeks, months, and even years. Theonset of shingles is characterized bypain, followed by the zoster rash, leading

to blisters and severe pain. The problemis that in the early stages, shingles can bedifficult to diagnose; chickenpox inadults can be equally difficult to diag-nose. As a result, both diseases can bemisdiagnosed (false positive/negative). A molecular assay has been adapted

for use in diagnosing VZV diseases. Thepolymerase chain reaction (PCR) assayis a non-invasive, rapid, sensitive, andhighly specific method for VZV DNA de-tection. It provides unequivocal resultsand can effectively end misdiagnoses.This is an approximately two-hour assaythat allows unequivocal diagnosis and

rapid antiviral drug intervention. It hasbeen demonstrated that rapid interven-tion can prevent full development of thedisease, resulting in reduced likelihoodof PHN. The technology was extendedto shingles patients and demonstratedthat VZV is shed in saliva and blood ofall shingles patients. The amount of VZVin saliva parallels the medical outcome.This work was done by Duane Pierson of

Johnson Space Center, and Satish Mehta ofEnterprise Advisory Services, Inc. For furtherinformation, contact the JSC InnovationPartnerships Office at (281) 483-3809.MSC-25009-1


Datacasting V3.0 provides an RSS-based feed mechanism for publishingthe availability of Earth science datarecords in real time. It also provides autility for subscribing to these feeds andsifting through all the items in an auto-matic manner to identify and downloadthe data records that are required for aspecific application. Datacasting is a method by which mul-

tiple data providers can publish theavailability of new Earth science dataand users download those files that meeta predefined need; for example, to onlydownload data files related to a specificearthquake or region on the globe. Datacasting is a server-client archi-

tecture. The server-side software isused by data providers to create andpublish the metadata about recently

available data according to the Data-casting RSS (Really Simple Syndica-tion) specification. The client softwaresubscribes to the Datacasting RSS andother RSS-based feeds. By configuringfilters associated with feeds, data con-sumers can use the client to identifyand automatically download files thatmeet a specific need. On the client side, a Datacasting feed

reader monitors the server for new feeds.The feed reader will be tuned by theuser, via a graphical user interface(GUI), to examine the content of thefeeds and initiate a data pull after somecriteria are satisfied. The criteria mightbe, for example, to download sea surfacetemperature data for a particular regionthat has cloud cover less than 50% andduring daylight hours. After the granule

is downloaded to the client, the user willhave the ability to visualize the data inthe GUI. Based on the popular concept of pod-

casting, which gives listeners the capa-bility to download only those MP3 filesthat match their preference, Earth sci-ence Datacasting will give users amethod to download only the Earth sci-ence data files that are required for aparticular application. This work was done by Andrew W. Bing-

ham, Sean W. McCleese, Robert G. Deen, NgaT. Chung, and Timothy M. Stough of Caltechfor NASA’s Jet Propulsion Laboratory. Furtherinformation is contained in a TSP (see page 1).This software is available for commercial li-


Datacasting V3.0 NASA’s Jet Propulsion Laboratory, Pasadena, California


Electronics/Computers

An All-Solid-State, Room-Temperature, Heterodyne Receiverfor Atmospheric Spectroscopy at 1.2 THzThis receiver enables terahertz heterodyne spectroscopy of outer planet atmospheres withoutcryogenic cooling.NASA’s Jet Propulsion Laboratory, Pasadena, California

Heterodyne receivers at submillimeterwavelengths have played a major role inastrophysics as well as Earth and plane-tary remote sensing. All-solid-state het-erodyne receivers using both MMIC(monolithic microwave integrated cir-cuit) Schottky-diode-based LO (local os-cillator) sources and mixers are uniquelysuited for long-term planetary missionsor Earth climate monitoring missions asthey can operate for decades without theneed for any active cryogenic cooling.However, the main concern in usingSchottky-diode-based mixers at frequen-cies beyond 1 THz has been the lack ofenough LO power to drive the devicesbecause 1 to 3 mW are required to prop-erly pump Schottky diode mixers. Recentprogress in HEMT- (high-electron-mobil-ity-transistor) based power amplifiertechnology, with output power levels inexcess of 1 W recently demonstrated atW-band, as well as advances in MMICSchottky diode circuit technology, haveled to measured output powers up to 1.4mW at 0.9 THz.Here the first room-temperature tun-

able, all-planar, Schottky-diode-based re-ceiver is reported that is operating at 1.2THz over a wide (≈20%) bandwidth.The receiver front-end (see figure) con-sists of a Schottky-diode-based 540 to640 GHz multiplied LO chain (featur-ing a cascade of W-band power ampli-fiers providing around 120 to 180 mWat W-band), a 200-GHz MMIC frequencydoubler, and a 600-GHz MMIC fre-quency tripler, plus a biasable 1.2-THzMMIC sub-harmonic Schottky-diodemixer. The LO chain has been de-signed, fabricated, and tested at JPL andprovides around 1 to 1.5 mW at 540 to640 GHz. The sub-harmonic mixer con-sists of two Schottky diodes on a thinGaAs membrane in an anti-parallel con-figuration. An integrated metal insula-tor metal (MIM) capacitor has been in-cluded on-chip to allow dc bias for theSchottky diodes. A bias voltage ofaround 0.5 V/diode is necessary to re-

duce the LO power required down tothe 1 to 1.5 mW available from the LOchain. The epilayer thickness and dop-ing profiles have been specifically opti-mized to maximize the mixer perform-ance beyond 1 THz.

The measured DSB noise tempera-tures and conversion losses of the re-ceiver are 2,000 to 3,500 K and 12 to 14dB, respectively, at 120 K, and 4,000 to6,000 K and 13 to 15 dB, respectively, at300 K. These results establish the state-

Photo and Performance of the Schottky-diode based 1.2-THz heterodyne receiver.

RF Frequency (GHz)

DSB

Mix

er N

ois

e Te

mp

erat

ure

(K

)

DSB

Mix

er C

on

vers

ion

Lo

ss (

dB

)8,000

6,000

4,000

2,000

0 1,060 1,100 1,140 1,180 1,220 1,260 1,300

16.00

12.00

8.00

4.00

0.00

NPO-48896 ABPI

05-30-13 le


Wireless Integrated Microelectronic Vacuum Sensor System This system is applicable to facility monitoring applications, as well as cryogenic fluidmanufacture and transport.Stennis Space Center, Mississippi

NASA Stennis Space Center’s (SSC’s)large rocket engine test facility requiresthe use of liquid propellants, includingthe use of cryogenic fluids like liquid hy-drogen as fuel, and liquid oxygen as anoxidizer (gases which have been lique-fied at very low temperatures). Thesefluids require special handling, storage,and transfer technology. The biggestproblem associated with transferringcryogenic liquids is product loss due toheat transfer. Vacuum jacketed piping isspecifically designed to maintain highthermal efficiency so that cryogenic liq-uids can be transferred with minimalheat transfer. A vacuum jacketed pipe is essentially

two pipes in one. There is an inner car-

rier pipe, in which the cryogenic liquidis actually transferred, and an outerjacket pipe that supports and seals thevacuum insulation, forming the “vac-uum jacket.” The integrity of the vac-uum jacketed transmission lines thattransfer the cryogenic fluid from deliv-ery barges to the test stand must bemaintained prior to and during enginetesting. To monitor the vacuum in thesevacuum jacketed transmission lines, vac-uum gauge readings are used. At SSC,vacuum gauge measurements are doneon a manual rotation basis with two tech-nicians, each using a handheld instru-ment. Manual collection of vacuum datais labor intensive and uses valuable per-sonnel time. Additionally, there are

times when personnel cannot collect thedata in a timely fashion (i.e., when a leakis detected, measurements must betaken more often). Additionally, distri-bution of this data to all interested par-ties can be cumbersome.To simplify the vacuum-gauge data

collection process, automate the datacollection, and decrease the labor costsassociated with acquiring these measure-ments, an automated system that moni-tors the existing gauges was developedby Invocon, Inc. For this project, Invo-con developed a Wireless Integrated Mi-croelectronic Vacuum Sensor System(WIMVSS) that provides the ability togather vacuum-gauge measurements au-tomatically and wirelessly, in near-real

of-the-art for all-solid-state, all-planarheterodyne receivers at 1.2 THz operat-ing at either room temperature or usingpassive cooling only. Since no cryogeniccooling is needed, the receiver is emi-nently suited to atmospheric heterodyne

spectroscopy of the outer planets andtheir moons.This work was done by Jose V. Siles, Imran

Mehdi, Erich T. Schlecht, Samuel Gulkis,Goutam Chattopadhyay, Robert H. Lin,Choonsup Lee, and John J. Gill of Caltech;

Bertrand Thomas of Radiometer Physic; andAlain E. Maestrini of Observatoire de Parisfor NASA’s Jet Propulsion Laboratory. Fur-ther information is contained in a TSP (seepage 1). NPO-48896

In a high-speed signal transmission sys-tem that uses transformer coupling,there is a need to provide increasedtransmitted signal strength withoutadding active components. This inven-tion uses additional transformers toachieve the needed gain. The prior artuses stronger drivers (which require anIC redesign and a higher power supplyvoltage), or the addition of another ac-tive component (which can decrease reli-ability, increase power consumption, re-duce the beneficial effect of serializer/deserializer preemphasis or deemphasis,and/or interfere with fault containmentmechanisms), or uses a different trans-former winding ratio (which requires re-design of the transformer and may notbe feasible with high-speed signals thatrequire a 1:1 winding ratio).This invention achieves the required

gain by connecting the secondaries of

multiple transformers in series. Theprimaries of these transformers arecurrently either connected in parallelor are connected to multiple drivers.There is also a need to split a receivesignal to multiple destinations withminimal signal loss. Additional trans-formers can achieve the split. Theprior art uses impedance-matching se-ries resistors that cause a loss of signal.Instead of causing a loss, most instanti-ations of this invention would actuallyprovide gain. Multiple transformers areused instead of multiple windings on asingle transformer because multiplewindings on the same transformerwould require a redesign of the trans-former, and may not be feasible withhigh-speed transformers that usuallyrequire a bifilar winding with a 1:1ratio. This invention creates the split byconnecting the primaries of multiple

transformers in series. The secondaryof each transformer is connected toone of the intended destinations with-out the use of impedance-matching se-ries resistors.This work was done by Kevin R. Driscoll of

Honeywell for Johnson Space Center. For fur-ther information, contact the JSC InnovationPartnerships Office at (281) 483-3809. Title to this invention has been waived

under the provisions of the National Aero-nautics and Space Act {42 U.S.C. 2457(f)},to Honeywell. Inquiries concerning licensesfor its commercial development should be ad-dressed to:HoneywellP.O. Box 52199Phoenix, AZ 85072-2199Refer to MSC-24854-1/6-1, volume and

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

Stacked Transformer for Driver Gain and Receive Signal SplittingLyndon B. Johnson Space Center, Houston, Texas


time — using a low-maintenance, low-power sensor mesh network. TheWIMVSS operates by using a self-config-uring mesh network of wireless sensorunits. Mesh networking is a type of net-working where each sensor or node cancapture and disseminate its own data,but also serve as a relay to receive andtransmit data from other sensors. Eachsensor node can synchronize with adja-cent sensors, and propagate data fromone sensor to the next, until the destina-tion is reached. In this case, the destina-tion is a Network Interface Unit (NIU).The WIMVSS sensors are mounted onthe existing vacuum gauges. Informa-tion gathered by the sensors is sent tothe NIU. Because of the mesh network-ing, if a sensor cannot directly send the

data to the NIU, it can be propagatedthrough the network of sensors. TheNIU requires antenna access to the sen-sor units, AC power, and an Ethernetconnection. The NIU bridges the sensornetwork to a WIMVSS server via an Eth-ernet connection. The server is config-ured with a database, a Web server, andproprietary interface software thatmakes it possible for the vacuum meas-urements from vacuum jacketed fluidlines to be saved, retrieved, and then dis-played from any Web-enabled PC thathas access to the Internet. Authorizedusers can then simply access the datafrom any PC with Internet connection.Commands can also be sent directlyfrom the Web interface for control andmaintenance of the sensor network.

The technology enabled by theWIMVSS decreases labor required forgathering vacuum measurements, in-creases access to vacuum data by mak-ing it available on any computer withaccess to the Internet, increases the fre-quency with which data points can beacquired for evaluating the system, anddecreases the recurring cost of the sen-sors by using off-the-shelf componentsand integrating these with heritage vac-uum gauges.This work was done by Eric Krug, Brian

Philpot, Aaron Trott, and Shaun Lawrenceof Invocon, Inc., for Stennis Space Center.For more information, please contact Invo-con, Inc. at (281) 292-9903. Refer to SSC-00342.


Manufacturing & Prototyping

Fabrication Method for LOBSTER-Eye Optics in <110> SiliconThe major advantages are the potential for higher x-ray throughout and lower cost over theslumped micropore glass plates.Goddard Space Flight Center, Greenbelt, Maryland

Soft x-ray optics can use narrow slotsto direct x-rays into a desirable patternon a focal plane. While square-pack,square-pore, slumped optics exist forthis purpose, they are costly. Silicon (Si)is being examined as a possible low-costreplacement. A fabrication method wasdeveloped for narrow slots in <110> Sidemonstrating the feasibility of stackedslot optics to replace micropores. Current micropore optics exist that

have 20-micron-square pores on 26-mi-cron pitch in glass with a depth of 1 mmand an extent of several square centime-ters. Among several proposals to emu-late the square pore optics are stackedslot chips with etched vertical slots.When the slots in the stack are posi-tioned orthogonally to each other, thecomponent will approach the soft x-rayfocusing observed in the micropore op-tics. A specific improvement Si providesis that it can have narrower sidewalls be-tween slots to permit greater throughputof x-rays through the optics. In general,

Si can have more variation in slot geom-etry (width, length). Further, the side-walls can be coated with high-Z materialsto enhance reflection and potentially re-duce the surface roughness of the re-flecting surface.Narrow, close-packed deep slots in

<110> Si have been produced usingpotassium hydroxide (KOH) etchingand a patterned silicon nitride (SiN)mask. The achieved slot geometries havesufficient wall smoothness, as observedthrough scanning electron microscope(SEM) imaging, to enable evaluation ofthese slot plates as an optical elementfor soft x-rays. Etches of different anglesto the crystal plane of Si were evaluatedto identify a specific range of etch anglesthat will enable low undercut slots in theSi <110> material. These slots with thenarrow sidewalls are demonstrated toseveral hundred microns in depth, and atechnical path to 500-micron deep slotsin a precision geometry of narrow, close-packed slots is feasible. Although intrin-

sic stress in ultrathin wall Si is observed,slots with walls approaching 1.5 micronscan be achieved (a significant improve-ment over the 6-micron walls in micro -pore optics). The major advantages of this tech-

nique are the potential for higher x-raythroughout (due to narrow slot walls)and lower cost over the existing slumpedmicropore glass plates. KOH etching ofsmooth sidewalls has been demonstratedfor many applications, suggesting its fea-sibility for implementation in x-ray op-tics. Si cannot be slumped like the mi-cropore optics, so the focusing will beachieved with millimeter-scale slot platesthat populate a spherical dome. Thepossibility for large-scale production ex-ists for Si parts that is more difficult toachieve in micropore parts.This work was done by James Chervenak

and Michael Collier of Goddard Space FlightCenter, and Jennette Mateo of SB Microsys-tems. Further information is contained in aTSP (see page 1). GSC-16717-1

Compact Focal Plane Assembly for Planetary ScienceNew fabrication methods were incorporated to produce an ultra-lightweight and compact radiometer.Goddard Space Flight Center, Greenbelt, Maryland

A compact radiometric focal plane as-sembly (FPA) has been designed inwhich the filters are individually co-reg-istered over compact thermopile pixels.This allows for construction of an ultra-lightweight and compact radiometric in-strument. The FPA also incorporates mi-cromachined baffles in order tomitigate crosstalk and low-pass filterwindows in order to eliminate high-fre-quency radiation.Compact metal mesh bandpass filters

were fabricated for the far infrared(FIR) spectral range (17 to 100 mi-crons), a game-changing technologyfor future planetary FIR instruments.This fabrication approach allows the di-

mensions of individual metal mesh fil-ters to be tailored with better than 10-micron precision. In contrast, conven-tional compact filters employed inrecent missions and in near-term instru-ments consist of large filter sheets man-ually cut into much smaller pieces,which is a much less precise and muchmore labor-intensive, expensive, anddifficult process.Filter performance was validated by

integrating them with thermopile ar-rays. Demonstration of the FPA will re-quire the integration of two technolo-gies. The first technology is compact,lightweight, robust against cryogenicthermal cycling, and radiation-hard mi-

cromachined bandpass filters. Theyconsist of a copper mesh supported ona deep reactive ion-etched siliconframe. This design architecture is ad-vantageous when constructing a light-weight and compact instrument be-cause (1) the frame acts like a jig andfacilitates filter integration with theFPA, (2) the frame can be designed soas to maximize the FPA field of view, (3)the frame can be simultaneously used asa baffle for mitigating crosstalk, and (4)micron-scale alignment features can bepatterned so as to permit high-precisionfilter stacking and, consequently, in-crease the filter bandwidth and sharpenthe out-of-band rolloff.


The second technology consists ofleveraging, from another project, com-pact and lightweight Bi0.87Sb0.13/Sb ar-rayed thermopiles. These detectors con-sist of 30-layer thermopiles deposited inseries upon a silicon nitride membrane.At 300 K, the thermopile arrays are

highly linear over many orders of magni-tude of incident IR power, and have a re-ported specific detectivity that exceedsthe requirements imposed on futuremission concepts.The bandpass filter array board is inte-

grated with a thermopile array board by

mounting both boards on a machinedaluminum jig.This work was done by Ari Brown, Shahid

Aslam, Wei-Chung Huang, and RosalindSteptoe-Jackson of Goddard Space Flight Cen-ter. Further information is contained in aTSP (see page 1). GSC-16704-1

Fabrication Methods for Adaptive Deformable MirrorsTwo methods are presented.NASA’s Jet Propulsion Laboratory, Pasadena, California

Previously, it was difficult to fabricatedeformable mirrors made by piezoelec-tric actuators. This is because numerousactuators need to be precisely assembledto control the surface shape of the mir-ror. Two approaches have been devel-oped. Both approaches begin by de-positing a stack of piezoelectric filmsand electrodes over a silicon wafer sub-strate. In the first approach, the siliconwafer is removed initially by plasma-based reactive ion etching (RIE), andnon-plasma dry etching with xenon di-fluoride (XeF2). In the second ap-proach, the actuator film stack is im-mersed in a liquid such as deionizedwater. The adhesion between the actua-tor film stack and the substrate is rela-tively weak. Simply by seeping liquid be-tween the film and the substrate, theactuator film stack is gently releasedfrom the substrate.The deformable mirror contains mul-

tiple piezoelectric membrane layers aswell as multiple electrode layers (someare patterned and some are unpat-terned). At the piezolectric layer,polyvinylidene fluoride (PVDF), or itsco-polymer, poly(vinylidene fluoride tri-fluoroethylene P(VDF-TrFE) is used.The surface of the mirror is coated witha reflective coating. The actuator filmstack is fabricated on silicon, or siliconon insulator (SOI) substrate, by repeat-edly spin-coating the PVDF or P(VDF-TrFE) solution and patterned metal(electrode) deposition.In the first approach, the actuator film

stack is prepared on SOI substrate.Then, the thick silicon (typically 500-mi-cron thick and called handle silicon) ofthe SOI wafer is etched by a deep reac-tive ion etching process tool (SF6-basedplasma etching). This deep RIE stops atthe middle SiO2 layer. The middle SiO2layer is etched by either HF-based wetetching or dry plasma etch. The thin sil-icon layer (generally called a device

layer) of SOI is removed by XeF2 dryetch. This XeF2 etch is very gentle andextremely selective, so the released mir-ror membrane is not damaged. It is pos-sible to replace SOI with silicon sub-strate, but this will require tighter DRIEprocess control as well as generallylonger and less efficient XeF2 etch.In the second approach, the actuator

film stack is first constructed on a siliconwafer. It helps to use a polyimide inter-mediate layer such as Kapton becausethe adhesion between the polyimide andsilicon is generally weak. A mirror mountring is attached by using adhesive. Then,the assembly is partially submerged inliquid water. The water tends to seep be-tween the actuator film stack and siliconsubstrate. As a result, the actuator mem-brane can be gently released from the sil-icon substrate. The actuator membraneis very flat because it is fixed to the mir-ror mount prior to the release.Deformable mirrors require ex-

tremely good surface optical quality. Inthe technology described here, the de-formable mirror is fabricated on pris-

tine substrates such as prime-grade sili-con wafers. The deformable mirror isreleased by selectively removing the sub-strate. Therefore, the released de-formable mirror surface replicates theoptical quality of the underlying pris-tine substrate.This work was done by Risaku Toda, Victor

E. White, Harish Manohara, Keith D. Patter-son, Namiko Yamamoto, Eleftherios Gdoutos,John B. Steeves, Chiara Daraio, and SergioPellegrino of Caltech 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 thisinvention. Inquiries concerning rights for itscommercial use should be addressed to:Innovative Technology Assets ManagementJPLMail Stop 321-1234800 Oak Grove DrivePasadena, CA 91109-8099E-mail: [email protected] to NPO-48665, volume and number

of this NASA Tech Briefs issue, and thepage number.

NPO48665ABPI

07-26-12 BT

PiezoelectricMembrane Layers

Electrodes

Reflective Coating

Stiffener Rim

The Deformable Mirror concept includes electrodes, a reflective coating, stiffener rim, and piezoelec-tric membrane layers.


Software

Visiting Vehicle Ground Trajectory Tool

The International Space Station (ISS)Visiting Vehicle Group needed a target-ing tool for vehicles that rendezvouswith the ISS. The Visiting VehicleGround Trajectory targeting tool pro-vides the ability to perform both real-time and planning operations for theVisiting Vehicle Group. This tool pro-vides a highly reconfigurable base,which allows the Visiting Vehicle Groupto perform their work. The applicationis composed of a telemetry processingfunction, a relative motion function, atargeting function, a vector view, and2D/3D world map type graphics.The software tool provides the ability

to plan a rendezvous trajectory for vehi-cles that visit the ISS. It models these rel-ative trajectories using planned and real-time data from the vehicle. The toolmonitors ongoing rendezvous trajectoryrelative motion, and ensures visiting ve-hicles stay within agreed corridors.The software provides the ability to up-

date or re-plan a rendezvous to supportcontingency operations. Adding new pa-rameters and incorporating them intothe system was previously not availableon-the-fly. If an unanticipated capabilitywasn’t discovered until the vehicle was fly-ing, there was no way to update things.This work was done by Dustin Hamm of

Johnson Space Center. Further information iscontained in a TSP (see page 1). MSC-24763-1

Workflow-Based SoftwareDevelopment Environment

The Software Developer’s Assistant(SDA) helps software teams more effi-ciently and accurately conduct or executesoftware processes associated with NASAmission-critical software. SDA is a processenactment platform that guides softwareteams through project-specific standards,processes, and procedures. Software proj-ects are decomposed into all of their re-quired process steps or tasks, and eachtask is assigned to project personnel. SDAorchestrates the performance of work re-quired to complete all process tasks in the

correct sequence. The software then noti-fies team members when they may beginwork on their assigned tasks and providesthe tools, instructions, reference materi-als, and supportive artifacts that allowusers to compliantly perform the work.A combination of technology compo-

nents captures and enacts any softwareprocess use to support the software lifecy-cle. It creates an adaptive workflow envi-ronment that can be modified as needed.SDA achieves software process automa-tion through a Business Process Manage-ment (BPM) approach to managing thesoftware lifecycle for mission-critical proj-ects. It contains five main parts: TieFlow(workflow engine), Business Rules (rulesto alter process flow), Common Reposi-tory (storage for project artifacts, ver-sions, history, schedules, etc.), SOA (in-terface to allow internal, GFE, or COTStools integration), and the Web Portal In-terface (collaborative web environment).The advantages of automating the

software process using SDA are:• Software systems are delivered faster,less expensively, with fewer defects,and requiring fewer highly skilled per-sonnel.• Portal-based collaboration allows largegeographically dispersed teams towork in concert via a simple and con-sistent Web interface.• A portal allows individuals to cus-tomize their views of the software proj-ect/process based on their projectrole.• Electronic task handoffs improve over-all team efficiency.• Tedious and clerical work are auto-mated.• Highly skilled personnel spend moretime on their areas of expertise insteadof in processing paperwork.• Greater project management visibilitythrough real-time status, dashboardviews, alerts, and reports gives usersmore time to avert problems or reactto new events.• Complete audit trail for all events in -volving the project, process, and associ-ated people.• Process is treated as an IT asset, mak-ing it possible to modify and optimizethe process.

• Faster ROI than manual implementa-tion.This work was done by Michel E. Izygon of

Tietronix Software, Inc. for Johnson SpaceCenter. Further information is contained in aTSP (see page 1). MSC-24424-1

Mobile Thread Task Manager

The Mobile Thread Task Manager(MTTM) is being applied to parallelizingexisting flight software to understand thebenefits and to develop new techniquesand architectural concepts for adaptingsoftware to multicore architectures. It allo-cates and load-balances tasks for a groupof threads that migrate across processorsto improve cache performance.In order to balance-load across

threads, the MTTM augments a basicmap-reduce strategy to draw jobs from aglobal queue. In a multicore processor,memory may be “homed” to the cacheof a specific processor and must be ac-cessed from that processor. The MTTBarchitecture wraps access to data withthread management to move threads tothe home processor for that data so thatthe computation follows the data in anattempt to avoid L2 cache misses.Cache homing is also handled by amemory manager that translates identi-fiers to processor IDs where the datawill be homed (according to rules de-fined by the user). The user can alsospecify the number of threads andprocessors separately, which is impor-tant for tuning performance for differ-ent patterns of computation and mem-ory access.MTTM efficiently processes tasks in

parallel on a multiprocessor computer.It also provides an interface to make iteasier to adapt existing software to amultiprocessor environment.This work was done by Bradley J. Clement,

Tara A. Estlin, and Benjamin J. Bornstein ofCaltech for NASA’s Jet Propulsion Laboratory.Further information is contained in a TSP(see page 1).This software is available for commercial li-



Mechanics/Machinery

The Mars Science Laboratory (MSL)robotic arm is ten times more massivethan any Mars robotic arm before it, yetwith similar accuracy and repeatabilitypositioning requirements. In order to as-sess and validate these requirements, ahigher-fidelity model and calibrationprocesses were needed. Kinematic calibration of robotic arms

is a common and necessary process toensure good positioning performance.Most methodologies assume a rigid arm,high-accuracy data collection, and somekind of optimization of kinematic param-eters. A new detailed kinematic and de-flection model of the MSL robotic armwas formulated in the design phase and

used to update the initial positioningand orientation accuracy and repeatabil-ity requirements. This model included ahigher-fidelity link stiffness matrix repre-sentation, as well as a link level thermalexpansion model. In addition, it in-cluded an actuator backlash model. Analytical results highlighted the sen-

sitivity of the arm accuracy to its jointinitialization methodology. Because ofthis, a new technique for initializing thearm joint encoders through hardstopcalibration was developed. This in-volved selecting arm configurations touse in Earth-based hardstop calibrationthat had corresponding configurationson Mars with the same joint torque to

ensure repeatability in the differentgravity environment. The process used to collect calibra-

tion data for the arm included the useof multiple weight stand-in turrets withenough metrology targets to recon-struct the full six-degree-of-freedom lo-cation of the rover and tool frames. Thefollow-on data processing of the metrol-ogy data utilized a standard differentialformulation and linear parameter opti-mization technique. This work was done by Curtis L. Collins

and Matthew L. Robinson of Caltech forNASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected]

A Kinematic Calibration Process for Flight Robotic Arms NASA’s Jet Propulsion Laboratory, Pasadena, California

This innovation replaces the linearalternator presently used in Stirlingengines with a continuous-gradient,impedance-matched, oscillating mag-netostrictive transducer that elimi-nates all moving parts via compression,maintains high efficiency, costs less tomanufacture, reduces mass, and elimi-nates the need for a bearing system.The key components of this new tech-

nology are the use of stacked magne-tostrictive materials, such as Terfenol-D,under a biased magnetic and stress-in-duced compression, continuous-gradi-ent impedance-matching material, coils,force-focusing metallic structure, andsupports. The acoustic energy from the

engine travels through an impedance-matching layer that is physically con-nected to the magnetostrictive mass.Compression bolts keep the structureunder compressive strain, allowing forthe micron-scale compression of themagnetostrictive material and eliminat-ing the need for bearings.The relatively large millimeter dis-

placement of the pressure side of theimpedance-matching material is re-duced to micron motion, and under-goes stress amplification at the magne-tostrictive interface. The alternatingcompression and expansion of the mag-netostrictive material creates an alter-nating magnetic field that then induces

an electric current in a coil that iswound around the stack. This produceselectrical power from the acoustic pres-sure wave and, if the resonant frequencyis tuned to match the engine, can re-place the linear alternator that is com-monly used. This work was done by Rodger Dyson and

Geoffrey Bruder of Glenn Research Center.Further information 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-18939-1.

Magnetostrictive Alternator John H. Glenn Research Center, Cleveland, Ohio


Bulk Metallic Glasses and Composites for Optical andCompliant MechanismsThis innovation has uses in the aerospace, optics, bio-implants, spacecraft, and sportingequipment industries.NASA’s Jet Propulsion Laboratory, Pasadena, California

Mechanisms are used widely in engineering applica-tions due to their ability to translate force and move-ment. They are found in kinematic pairs, gears, cams,linkages, and in flexure mechanisms (also known ascompliant mechanisms). Mechanisms and flexures areused widely in spacecraft design, especially in the areaof optics, where precise positioning of telescope mirrorsrequires elastic flexing of elements. A compliant mech-anism is generally defined as a flexible mechanism thatuses an elastic body deformation to cause a displace-ment (such as positing a mirror). The mechanisms areusually constructed as a single monolithic piece of ma-terial, and contain thin struts to allow for large elasticbending with low input force. This creates the largestproblem with developing precise mechanisms; theymust be fabricated from a single piece of metal, but arerequired to have strict accuracy on their dimensions.They are generally required to have high strength, elas-ticity, and low coefficient of thermal expansion.The two biggest problems with conventional mecha-

nisms are fabrication and materials selection. Plasticprototypes can be readily produced at low cost using3D printing or molding, and utilize the large elasticityof polymers, but the mechanisms are unsuitable forstructural applications due to their low strength anddegradation, especially in spacecraft (polymers de-grade in space due to the high UV exposure). A com-pliant mechanism used in a real engineering applica-tion must typically be made of metal, and must befabricated either by machining or by an additive manu-facturing process for metals. They are generally madefrom aluminum (low density and high machinability)or titanium (high strength and large elasticity). How-ever, since the struts of the mechanism must be verythin (typically less than one mm thick), traditional ma-chining is difficult to use because the struts bend dur-ing machining.The use of amorphous metals (AMs) and their com-

posites is ideal for both the mechanical properties andprocessing of compliant mechanisms and flexures.AMs have high strength, the elasticity of polymers,and the processability of plastics. They can be easilyfabricated into monolithic mechanisms at signifi-cantly lower cost than machining, and exhibit per-formance better than tany crystalline material in thesame application. Since they can be fabricated usingreusable steel or brass molds, many parts can be fabri-cated using only the initial material cost and the ini-tial mold cost. This allows for many mechanisms to bemade cheaply.

Some Examples of Processing and Products: (a) Compliant mechanisms can be fabri-cated easily from plastics by pressing them into heated molds. (b) Examples of cross-blade flexures often used in optics to support mirrors. (c) Design of multi-piece, water-cooled brass molds for casting amorphous metals and (d) an ingot of amorphous metalbefore heating and forging. (e) Once forged, the amorphous metal or composite fillsthe small features of the mold. (f) A steel ejector that snugly fits into the brass mold isused to push out the amorphous metal mechanism from the mold. (g) The amorphousmetal flexure is pressed out of the mold with a press. (h) In another geometry, a cart-wheel flexure can be fabricated from amorphous metal, seen here after trimming, andthe undamaged mold from which it was cast. (i) Side-by-side amorphous metal flexures;cartwheel (left) and cross-blade (right).

Materials & Coatings


AMCs (amorphous metal composites)are composite alloys that exhibit similarproperties and processing ability tomonolithic AMs, but also have the abilityto be much tougher (to avoid brittle fail-ure), have much higher fracture tough-ness and fatigue life, and also can betuned to have low coefficient of thermalexpansion (CTE) by utilizing low CTE in-clusions. These combinations of proper-ties (mechanical performance and pro-cessing ability) have not been utilized forcompliant mechanisms until now.AMs (which are also known as bulk

metallic glasses or BMGs) and their com-posites can be fabricated into optome-chanical, compliant, or flexure mecha-nisms easily and at low cost. Toaccomplish this, a selected compositionof AM or AMC is fabricated into a feed-stock material that is heated (using radiofrequency heating or resistance heating)

and forged into a final part with eithernet or near-net shape. Because AM alloyshave low melting temperatures, they canbe melted and forced into a very com-plex mold, just like a plastic, but form aglass under the high cooling rate ob-tained by cooling lines in the mold. Thequenched part does not react with themold and is mechanically robust enoughto survive the ejection process. The finalpart has the same tolerances as the mold(since there is very little shrinkage whenforming a glassy metal) and yet can be re-moved without damaging the mold. Thisoffers the potential to develop mecha-nisms that outperform currently avail-able metals (aluminum, titanium, andsteel) but that also can be fabricated in alow-cost, repeatable process. The result-ing mechanisms, demonstrated here forTi-Zr-Be alloys, have 2% elastic limit, upto 2 GPa yield strength, hardness >50 Rc,

fracture toughness >100 MPa m1/2, andexcellent fatigue limit. Prototypes havebeen developed into two common mech-anisms, a crossblade, and a cartwheelflexure (see figure).This work was done by Douglas C. Hof-

mann and Gregory S. Agnes of Caltech forNASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected] 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 321-1234800 Oak Grove DrivePasadena, CA 91109-8099E-mail: [email protected] to NPO-48768, volume and number

of this NASA Tech Briefs issue, and thepage number.


Bio-Medical

Detection of Only Viable Bacterial Spores Using a Live/DeadIndicator in Mixed PopulationsThis technology can be used by the food and phar maceutical industries to validate sterility and quality.NASA’s Jet Propulsion Laboratory, Pasadena, California

This method uses a photoaffinity labelthat recognizes DNA and can be used todistinguish populations of bacterial cellsfrom bacterial spores without the use ofheat shocking during conventional cul-ture, and live from dead bacterial sporesusing molecular-based methods.Biological validation of commercial

sterility using traditional and alterna-tive technologies remains challenging.Recovery of viable spores is cumber-some, as the process requires substan-tial incubation time, and the extendedtime to results limits the ability toquickly evaluate the efficacy of existingtechnologies. Nucleic acid amplifica-tion approaches such as PCR (poly-merase chain reaction) have shownpromise for improving time to detec-tion for a wide range of applications.Recent real-time PCR methods are par-ticularly promising, as these methodscan be made at least semi-quantitativeby correspondence to a standard curve.

Nonetheless, PCR-based methods arerarely used for process validation,largely because the DNA from deadbacterial cells is highly stable andhence, DNA-based amplification meth-ods fail to discriminate between liveand inactivated microorganisms.Currently, no published method has

been shown to effectively distinguish be-tween live and dead bacterial spores.This technology uses a DNA bindingphotoaffinity label that can be used todistinguish between live and dead bacte-rial spores with detection limits rangingfrom 109 to 102 spores/mL.An environmental sample suspected

of containing a mixture of live and deadvegetative cells and bacterial en-dospores is treated with a photoaffinitylabel. This step will eliminate any vege-tative cells (live or dead) and dead en-dospores present in the sample. To fur-ther determine the bacterial sporeviability, DNA is extracted from the

spores and total population is quanti-fied by real-time PCR.The current NASA standard assay

takes 72 hours for results. Part of thisprocedure requires a heat shock step at80 °C for 15 minutes before the samplecan be plated. Using a photoaffinitylabel would remove this step from thecurrent assay as the label readily pene-trates both live and dead bacterial cells.Secondly, the photoaffinity label canonly penetrate dead bacterial spores,leaving behind the viable spore popula-tion. This would allow for rapid bacterialspore detection in a matter of hourscompared to the several days that it takesfor the NASA standard assay.This work was done by Alberto E. Behar of

Caltech; Christina N. Stam of Oak Ridge As-sociated Universities; and Ronald Smiley ofthe U.S. Food and Drug Administration forNASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected]

The ability to stabilize and treat pa-tients on exploration missions will de-pend on access to needed consumables.Intravenous (IV) fluids have been iden-tified as required consumables. A reviewof the Space Medicine ExplorationMedical Condition List (SMEMCL) listsover 400 medical conditions that couldpresent and require treatment duringISS missions.The Intravenous Fluid Generation

System (IVGEN) technology providesthe scalable capability to generate IVfluids from indigenous water supplies.It meets USP (U.S. Pharmacopeia)standards. This capability was per-formed using potable water from the

ISS; water from more extreme environ-ments would need preconditioning.The key advantage is the ability to fil-ter mass and volume, providing theequivalent amount of IV fluid: this iscritical for remote operations or re-source-poor environments. TheIVGEN technology purifies drinkingwater, mixes it with salt, and transfersit to a suitable bag to deliver a sterilenormal saline solution.Operational constraints such as mass

limitations and lack of refrigerationmay limit the type and volume of suchfluids that can be carried onboard thespacecraft. In addition, most medicalfluids have a shelf life that is shorter

than some mission durations. Conse-quently, the objective of the IVGEN ex-periment was to develop, design, andvalidate the necessary methodology topurify spacecraft potable water into anormal saline solution, thus reducingthe amount of IV fluids that are in-cluded in the launch manifest.As currently conceived, an IVGEN sys-

tem for a space exploration missionwould consist of an accumulator, a puri-fier, a mixing assembly, a salt bag, and asterile bag. The accumulator is used totransfer a measured amount of drinkingwater from the spacecraft to the purifier.The purifier uses filters to separate anyair bubbles that may have gotten

Intravenous Fluid Generation System This system can be used in remote medical facilities where limitations such as lack ofrefrigeration may limit the type and volume of medical fluids being stored or transported. John H. Glenn Research Center, Cleveland, Ohio


trapped during the drinking water trans-fer from flowing through a high-qualitydeionizing cartridge that removes theimpurities in the water before enteringthe salt bag and mixing with the salt tocreate a normal saline solution.

This work was done by John McQuillen andTerri McKay of Glenn Research Center, andDaniel Brown and John Zoldak of ZIN Tech-nologies. Inc. Further information is con-tained in a TSP (see page 1).Inquiries con-cerning rights for the commercial use of this

invention should be addressed to NASA GlennResearch Center, Innovative Partnerships Of-fice, Attn: Steven Fedor, Mail Stop 4–8, 21000Brookpark Road, Cleveland, Ohio 44135.Refer to LEW-19044-1.

National Aeronautics andSpace Administration

technology focus electronics/computers - ntrs.nasa.gov · technology focus electronics/computers...

Documents