lunar exploration transportation system (lets)
DESCRIPTION
Lunar Exploration Transportation System (LETS). MAE 491 / 492 2008 IPT Design Competition Instructors: Dr. P.J. Benfield and Dr. Matt Turner Team Frankenstein Final Review Presentation 4/29/08. Team Disciplines. The University of Alabama in Huntsville Team Leader: Matt Isbell - PowerPoint PPT PresentationTRANSCRIPT
Lunar Exploration Transportation System (LETS)
MAE 491 / 4922008 IPT Design Competition
Instructors: Dr. P.J. Benfield and Dr. Matt Turner
Team Frankenstein
Final Review Presentation4/29/08
Team Disciplines• The University of Alabama in Huntsville
– Team Leader: Matt Isbell– Structures: Matthew Pinkston and Robert Baltz– Power: Tyler Smith– Systems Engineering: Kevin Dean– GN&C: Joseph Woodall– Thermal: Thomas Talty– Payload / Communications: Chris Brunton– Operations: Audra Ribordy
• Southern University– Mobility: Chase Nelson and Eddie Miller
• ESTACA– Sample Return: Kim Nguyen and Vincent Tolomio
Overview• Mission Statement• The Need• The Solution• Performance• Schedule• Operations• Structures• GN&C
• Communications• Payload• Power• Thermal• Risk Management• Conclusions• Questions
Mission Statement
• To provide NASA with a reliable and multi-faceted lander design that will provide the flexibility to conduct CDD requirements, scientific investigations, and technology validation tasks at different areas on the moon
The Need
• Only 6% of lunar surface explored– Apollo missions
• Only orbital visits since Apollo• Mobile lunar laboratory with return
capabilities is vital to the exploration and understanding of the lunar surface
• The lunar surface is an unexploited record of the history of the solar system
• Sample polar sites and crater floors
The Solution
• Lander/Rover
• Penetrators
• RTG
Cyclops
PerformanceCDD Requirement Requirement Assessment Remark
Landed Mass 932.8 kg Exceeds Actually 810 kg
Survive Lunar Cruise 28 days Meets Capable of surviving lunar cruise exceeding 28 days
Operational Period 1 year Meets TRL 9 materials will remain functional beyond 1 year
Sample Lunar Surface 15 dark Exceeds Mobility allows roving to as many sites as is needed
CommunicationSend and Receive
(real time) Exceeds Capable of sending data at 150 Mbps
Landing Parameters 12º slope within 100 m ExceedsSix wheel rocker bogey system allows landing on slopes
greater than 12 degrees
Survive Launch of 6 G's 6 G's Exceeds Cyclops structure will handle g-loads exceeding 6 g’s
TechnologyRequirements TRL9 Meets Materials used are TRL 9
Power Requirements Store Power in Dark
Conditions Exceeds RTG can provide the power needed during dark conditions
Thermal ConditionsSurvive Temperature
Changes ExceedsMaterials used will withstand temperatures exceeding the
50K to 380K range
Sample Return Vehicle Sample Return (Goal) Meets Exceeds the sample return expectations
MobileRoving/Real-Time
Mobility Exceeds 6 wheel rocker bogey allows roving in real-time
Schedule
Operations
Cyclops
Penetrators 2.5km
1.6km
1. 5km
2. Deploy Penetrators
3-4. Decent
5. Land
6. Release Propulsion System
7. Rove To Edge of Crater
Operations• Launch - September 30, 2012• Arrive at moon - October 6, 2012• Operations start 5km from lunar surface• October 8, 2012
– Decent • Shoot 15 penetrators into Shackleton Crater for dark region sampling
– Landing• Drop off “single site box” to accomplish single site goals
• October 9, 2012– Rove to rim of Shackleton Crater
• October 11 - 18, 2012– Receive all data from penetrators
• October 19, 2012– Relay all data from penetrators to LRO for transmission to Mission
Control• 5 orbits needed
Operations• October 22, 2012 – March 4, 2013
– Rove to, collect and relay data from 29 lighted sites• March 5 – March 7, 2013
– Rove to, collect sample, and launch SRV• March 8 – July 22
– Rove to, collect and relay data from Lighted sites 30 - 59• July 23 – 25
– Rove to rim of Shackleton crater• July 26 – September 27
– Rove to, collect and relay data from Dark Sites (if penetrators fail)
• September 30, 2013– System Shut Down
Structures• System Specifications (Auxiliary Systems)• Penetrator Ring Platform
– Outer Diameter- 3.189 m. – Aluminum Construction (6061 T6)- Mounted penetrators (spring released at a 4 degree
dispersion angle)• Attitude Control
– Main thrusters- MR 80B– Attitude Control Thrusters- MR 106– Hydrazine Tank x 2- 0.549 m. Outer Diameter– Aluminum Frame (6061 T6)
• Single Site Box– Max Box Dimensions – 1.54 x 0.688 x 0.356 m.– Integrated Sample Return Vehicle
Penetrator Ring Platform
Attitude Control System
Cyclops
Structures• System Specifications (Main)
– Main Chassis• Dimensions – 1.54 x 1.54 x 0.356 m.• Aluminum Frame (6061 T6)• Carbon composite exterior• MLI Insulation
– 6 Wheel Passive Rocker Bogie Mobility System• Proven Transportation Platform (MER,
Pathfinder)• 0.33 m. Outer Diameter Wheels• Can navigate up to a 45 degree angle• Max speed of 90 m/hr.• Aluminum construction (6061 T6)• Maxon EC 60 Brushless DC motor (60mm) x
6• Maxon EC 45 Brushless DC motor (45mm) x
8– Camera
• (SSI) Dimensions – 0.305 x 0.203 x 0.152 m.
– Scoop Arm• Max Reach- 1.727 m.
Before Deployment
After Deployment
Structures
• Maxon 60mm EC 60 x 6
• Nominal torque 830 mNm
• Maxon 45mm EC 45 x 8
• Nominal torque 310 mNm
Wheel Motors Steering Motors
GN&C• Decent/Landing
– A LIDAR system will be used to control, navigate, and stabilize while in descent
• Post Landing – An operator at mission control will
manually navigate lander/rover• A Surface Stereo Imager (SSI)
periscopic, panoramic camera will be used to survey the lunar surface, provide range maps in support of sampling operations, and to make lunar dust cloud measurements
GN&C
• Descent Imaging– A Mars Descent Imager (MARDI) will
be used to view both the penetrator dispersion and the landing/descent of the Cyclops
• Processor– A BAE RAD750 will be used for all
controls processing
Communications • Rover
– Parabolic Dish Reflector Antenna (PDRA)
• T-712 Transmitter – Communication Bandwidth : X-band– Data Transmission Rate: 150 Mbps
• Data Storage Capacity: 10 Gb
• Penetrators – Omnidirectional Antenna
• Communication Bandwidth: S-band • Data Transmission Rate: 8 Kbps• Data Storage Capacity: 300 Mb
Communications/Payload• Single Site Box (SSB)
– Determines lighting conditions every 2 hours for one year, micrometeorite flux, and assess electrostatic dust levitation
– Omnidirectional Antenna • Communication Bandwidth: S-band • Data Transmission Rate: 8 Kbps• Data Storage Capacity: 1Gb
– Surface Stereo Imager (SSI) – Mass: 10 Kg– Dimensions: 155x68.5x35.5 cm– Power: Solar Panel
Payload• Gas Chromatograph Mass Spectrometer (GCMS)
– Performs atmospheric and organic analysis of the lunar surface – Mass: 19 Kg– Dimensions: 10x10x8 cm– Power: Rover
• Surface Sampler Assembly (SSA)– Purpose is to acquire, process and distribute samples from the
moon’s surface to the GCMS – Mass: 15.5 Kg– Dimensions: 110X10X10 cm– Power: Rover
Payload• Penetrators (Deep Space 2 )
– Mission’s main source of data acquisition in the permanent dark regions
– Mass (15 Penetrators): 53.58 Kg – Dimensions: 13.6Dx10L cm– Power: 2 Lithium Ion Batteries Each
• Miniature Thermal Emission Spectrometer (Mini-TES) – Objective to provide measurements of
minerals and thermo physical properties on the moon
– Mass: 2.4 Kg– Dimensions: 23.5x16.3x15.5 cm– Power: Rover
Power• RTG
– TRL9– Constant power supply– Thermal output can be utilized for
thermal systems• Lithium-Ion Batteries
– Commercially available– Easily customizable– Rechargeable
• Solar – Used for Single Site Box– Conventional– Increasingly efficient in well light
areas
POWER SUBSYSTEM
Type (solar, battery, RTG) Solar, Lithium-ion, RTG
Total mass 47.63 kg
Total power required 643.525 W
Number of solar arrays 1
Solar array mass/solar array 1.13 kg
Solar array area/solar array 0.12 square meter
Number of batteries 2
Battery mass/battery 3.25 kg
Number of RTGs 1
RTG Mass/RTG 40 kg
PowerPower Analysis
Component Subcomponents Consumption (W)
Mobility 342.625
SRV 25
GN&C 115.5
Payload 34.6
Communications 70.8
Thermal 55
Operations 0
Power Supply 865
RTG 400
Li-ion Battery 455
Solar Cell 10 (Not in Total)
Minimum Totals 643.525
Contingency Supply 33% 212.36325
Total 855
• Total Power Required– 643.525 W
• Peak Power– Mobility
• 342.625 W– Data Collection/Transfer
• 276.2 W– Single Sight Box
• 7.8 W• RTG
– 400 W • Lithium-Ion Batteries
– 455 W for both• Solar Cells
– 10 W (SSB - Not included in Total)• 33% Contingency Power• Total Power Supplied to Lander
– 855 W
Thermal
• Cyclops uses three types– Heat transfer pipes– Paraffin heat switches
• Radiator heat switches• Diaphragm heat
switches
– Multi-Layer Insulation
Thermal• Two standard types of switches are used as a
redundant check to prevent over heating
Thermal
• Heat is well controlled– MLI has low heat
absorbance– Heat switches allow close
tolerance controlMass (kg)
Heat pipes 4.62
Heat Switches 3
MLI 3.78
Total 11.4
Risk Management5 1
4 9 2 3
3 8 5 4
2 6,7 10
1
1 2 3 4 5
LIKELIHOOD
CONSEQUENCES
# Mission Criticality Level Risk1 high Penatrator Failure - Penatrators fail upon impact or do not launch at all2 medium RTG Ovherheat - RTG puts out too much heat for the system to handle3 high Thermal Shutdown - the system gets overheats and shuts down4 medium Mobility - the drive system of the lander fails5 medium Camera Failure - the camera breaks and does not transmit images6 medium Structure Failure - the structure collapes7 medium Navigation - the navigation system fails8 low SRV Failure - the SRV fails to launch9 low Single Site Box - the box fails during the year
10 medium Communications - loss of all communications with the rover
Likelihood1 improbable23 probable45 definite
Consequences1 the mission can still be completed23 mission operates at limited capacity45 total mission failure
Likelihood1 improbable23 probable45 definite
Conclusions
• “There’s no place this thing can’t go”
• If penetrators fail, remaining mission will not be compromised
• Reliable multi-faceted design
Questions