Project OverviewProject Overviewoject O e eProject Design Structure Mission Profile

R M kFli ht R

Project Design Structure Mission ProfilePrimary Descent Stage Trans-lunarRover Mock-up

l d lFlight Rover

D i(LLO – 2 km)

Trans lunar Injection

Validate critical issues in Design the smallest practical DesignInjection

Low Lunar habitability and crew operations

gpressurized rover to support

E i S tiParking

T fy p

by constructing a full-scale p pp

Constellation sortie-class Test Engine Separation Stage (2 km)

gOrbit Transfer

D ty g

mock-up of the rover cabin andConstellation sortie class

missions with independentTest

ResultsStage (2 km)Descentmock up of the rover cabin and

external interfacesmissions with independent

delivery to moonResults

external interfacesdelivery to moonLanding Stage w/

Burn Delta VLanding Stage w/ Retro Engine BrakingBurn Delta V

Delta IV Heavy to TLIRetro Engine Braking

(2 k )Delta-IV Heavy to TLI (2 km - 1 m)TLI to Low Lunar Parking Orbit 800 m/s Honeycomb inserts

i l hTransfer Descent 135 m/s in legs crush upon l diTransfer Descent 135 m/s

Retro Engine Braking 1725 m/slanding

Retro Engine Braking 1725 m/s

Fi ld RLanding 80 m/s Rover SeparationField Rover Outpost Rover

g Rover Separation Stage (surface)

Start the design and Outpost Rover

Develop a variant of theStage (surface)

gdevelopment process for a

Develop a variant of the basic sortie rover to support TURTLE will

Upon return, two Two crew members will de e op e p ocess o afully functional Earth

basic sortie rover to supportC ll i

TURTLE will autonomously rendezvous

other astronauts will board TURTLE for a fully functional Earth simulation rover for near-

Constellation outpost autonomously rendezvous with crew who will land

board TURTLE for a three day mission with simulation rover for near-

term lunar analogue studiesconstruction and operations with crew who will land

less than 10 km awaysecond three day three EVAs traveling up

term lunar analogue studiesp less than 10 km away missionto 25 km from base

TURTLE Capabilities Gassendi Crater Sample Mission ProfileTURTLE Capabilities pThe sample mission profile shown to the left• Suitports and external platform provide astronaut ingress/egress The sample mission profile shown to the left can be modified for various landing sites to

• Suitports and external platform provide astronaut ingress/egress• Range: 25 km radius around lander over two three day sorties can be modified for various landing sites to

fulfill TURTLE’s science goals• Range: 25 km radius around lander over two three-day sorties

E t l t i f i i t d l fulfill TURTLE’s science goals.• External containers for science equipment and samples S l l l k f b d • Deploy science equipment for longterm data• Supplemental airlock for moving items between rover interior and

t i Deploy science equipment for longterm data collectionexterior collection

• Collect data to help advance the lunar base design• Stability margins: 37° longitudinal, 48° lateral Collect data to help advance the lunar base design• Obtain samples for study on Earth• 3.45 m length x 3.24 m width x 2.93 m height Obtain samples for study on Earth• Perform basic analysis of samples on the moon

g g• Total initial mass: 1750 kg with all consumables but no suits or Perform basic analysis of samples on the moon

• Increase understanding of lunar habitability• Total initial mass: 1750 kg, with all consumables but no suits or

astronauts Increase understanding of lunar habitabilityastronauts

TURTLE DesignTURTLE Designg3 5 MPaPressure Shell 3.5 MPa

G hit E T300/934Pressure Shell

• Graphite Epoxy T300/934f• Safety Factor = 3

• Geometry• Cylinder 2.43 m long, y g,

1.83 m diameter• Semi-elliptical endcaps

d 0 325extend 0.325 m• Double-layered shell built

d h iaround chassis• 8.4 mm inner layer in

li d i i t 10cylinder, rising to 10 mm on endcapsendcaps2 mm o te la e fo• 2 mm outer layer for micrometeoroid protectionmicrometeoroid protectionMax stress: 198 MPa• Max stress: 198 MPaM 240 k• Mass 240 kg

Mobility SystemDriving Window Terramechanics Mobility System• Non pneumatic Al Alloy 2024

Driving Window Terramechanics• 4 wheels, independently • Double-paned

• Non-pneumatic Al Alloy 20241 h l di t f 0 5 , d p d y

steered and poweredDouble paned• Inner: 20 mm fused silica glass

• 1 m wheel diameter for 0.5 m ground clearance p

• Suspension system:• Inner: 20 mm fused silica glass• Outer: 13 mm aluminosilicate

ground clearance8 Suspension system:

MacPherson struts• Outer: 13 mm aluminosilicate

glass• 8 grousers MacPherson struts

• Spring const 35 kN/mglass

• FOV: 45° L/R 20° down 5° up• 0.3 m wheel-width • Spring const. 35 kN/m

• Damp const 1 kN·s/m• FOV: 45° L/R, 20° down, 5° up • Top speed 15 km/hr on level • Damp const. 1 kN·s/m

DC brushless wheel hubTop speed 15 km/hr on level ground • DC brushless wheel hub

motors with 5:1 gear traing

• Stopping distance: 4.34 mChassisAl i All 6061 T6

motors with 5:1 gear trainSt i t l li

Stopping distance: 4.34 m over 2.1 s

Chassis• Aluminum Alloy 6061-T6 • Steering control: linear

t t 18° t iover 2.1 s

• 9 2 m turning radius at top• Safety Factor = 1.4 actuators; 18° steering angle

• 9.2 m turning radius at top speed, on level ground

• Minimum 15% margin of angleM ti b ki f

speed, on level ground• TURTLE accommodates 20°g

safety for each piece • Magnetic braking from t d Ti C bid di

• TURTLE accommodates 20slope with positive drawbary p

• Mass 163 kg motors and Ti-Carbide discsslope with positive drawbar pullMass 163 kg pull

AvionicsAvionicsC i tiN i i & A Console & Control Layout CommunicationsNavigation & Autonomy

Lunar Relayy

F d R

g y• Autonomously rendezvous

Ka-Band S-Bandb b

Deep SpaceSatellite (LRS)Accelerate B kForward ReverseControls:

ywith crew or outpost

Max Data Rate 120 Mbps 20 MbpsDirection Transmit Two Way

p pNetwork (DSN)Accelerate Brake

p• Determines rover’s lunar Direction Transmit Two-Way

53 cm O / b lTurn Turn Turn TurnDetermines rover s lunar position

Antennas53 cm

Parabolic Omni/Parabolic HGA

Ka Trunk to E th

TurnLeft

TurnRight

TurnLeft

TurnRight

position• Maps and navigates around

HGA HGA

G i 40 dBi 0 dBi/20 dBi

Earthg g• Maps and navigates around

obstacles with LIDAR (TRL 4) LIDAR Point CloudImage: Velodyne Acoustics Inc Gain 40 dBi 0 dBi/20 dBi

System Power 50 250S/Ka

3 000 kmAccelerateBrake

obstacles with LIDAR (TRL 4) Image: Velodyne Acoustics, Inc.

Command & Data Handling System Power 50 250RF Power 2 100

3,000 kmNavigator’s InterfaceConsole:

Command & Data HandlingC t t d b A i i F ll D l

RF Power 2 100Optimal Receiver LRS LRS S/Ka

Driver’s Interface 2x DU-1310g

DU-1310Console:• Components connected by an Avionics Full Duplex

Eth t (AFDX) t k (TRL 4)p

Optimal Link 9 4 3 0

S/Ka380,000 kmEthernet (AFDX) network (TRL 4)

Margin 9.4 3.0

U Whil M i N Y• Three next generation RAD 750 computers (TRL 7)

Use While Moving No YesUsable Antennas 2 5• Distributed Computing Units (DCU) powered by Usable Antennas 2 5Transceivers 2 3Al I di tLunar Imagery: NASA

p g ( ) p yField Programmable Gate Arrays (FPGA) Transceivers 2 3Alarm Indicator

And Backup Terminal

Lunar Imagery: NASAg y ( )• DCUs run control loops for life critical systems And Backup TerminalDCUs run control loops for life critical systems

jProject TURTLE:Project TURTLE: Terrapin Undergraduate Rover for Terrestrial Lunar ExplorationTerrapin Undergraduate Rover for Terrestrial Lunar Explorationp g p

University of MarylandUniversity of Maryland

David Berg James Briscoe Kanwarpal Chandhok Joshua Colver Enrique Coello Aaron Cox Stuart Douglas Andrew Ellsberry Sara Fields DavidDavid Berg, James Briscoe, Kanwarpal Chandhok, Joshua Colver, Enrique Coello, Aaron Cox, Stuart Douglas, Andrew Ellsberry, Sara Fields, David Gers, Zohaib Hasnain, Ali Husain, Madeline Kirk, Jason Laing, May Lam, Jason Leggett, Michael Levashov, Ryan Levin, Joseph Lisee, Omar , , , , g, y , gg , , y , p ,

Manning Thomas Mariano Jessica Mayerovitch Brian McCall David McLaren Adam Mirvis Ryan Murphy Aleksandar Nacev Hasan OberoiManning, Thomas Mariano, Jessica Mayerovitch, Brian McCall, David McLaren, Adam Mirvis, Ryan Murphy, Aleksandar Nacev, Hasan Oberoi, Ugonma Onukwubiri Stephanie Petillo Tiffany Russell Matt Schaffer Ali Reza Shishineh Jacob ZwillingerUgonma Onukwubiri, Stephanie Petillo, Tiffany Russell, Matt Schaffer, Ali-Reza Shishineh, Jacob Zwillinger

Advisors: Dr Dave Akin and Dr Mary BowdenAdvisors: Dr. Dave Akin and Dr. Mary Bowden

TURTLE DesignTURTLE DesignTURTLE DesignCrew SystemsCrew Systems

Interior Layout Life Support Systems Nutrition SuitportInterior Layout Life Support SystemsAtmosphere • Water management: Continuous re-

p• Decreased mass andAtmosphere

C bi 55 2 kP / 8 i

gsupply from fuel cells, with microbial • Decreased mass and

volume for EVAs:• Cabin pressure: 55.2 kPa / 8 psi (Identical to LSAM)

pp y ,filter and 0.5 ppm iodine

volume for EVAs: 145 kg, 0.25 m3

(Identical to LSAM)A h i i i 39% O

pp• Diet corresponds to World Health

g,• “Garage door”

• Atmospheric composition: 39% O2, 61% N R F t 1 4 f

pOrganization for 95th percentile male

gmovement sweeps le th n 0 5 m361% N2, R-Factor = 1.4, for zero-

b th EVA (b d EMU

g pwith high physical activity level, less than 0.5 m3

P i e me h ni mprebreathe EVAs (based on EMU parameters)

g p y y ,representative of Skylab astronaut diet • Passive mechanisms

preferred forparameters)Di t ib t i l ti t 2 03 3/ i

Radiationpreferred for connections• Distributors circulating at 2.03 m3/min • Potable water tank overhead for GCRconnections

• Seals: inflatable• LiOH, particulate filters and activated

Potable water tank overhead for GCR shielding

Seals: inflatable isomeric materials, , p

charcoal to maintain cabin atmosphereshielding

• SPEs treated as contingency scenarios:,

standard o-rings, d t mitig tion• O2 and pressure sensors allow

SPEs treated as contingency scenarios: seek shelter beneath rover or employ E l D i i Pl f

dust mitigation2 p

computer control of regulators on O2seek shelter beneath rover or employ natural landforms External Driving Platform

1 Fi t id kit AED

p g 2and N2 tanks

natural landforms g• Ingress/egress, plus

21. First aid kit, AED,

supplemental oxygen

2Overhead

Water Storage

Ingress/egress, plus three powered 9 2 supplemental oxygen

2 Fire extinguishers

Water Storage pconfigurations: launch, internal driving

9

36

7

2. Fire extinguishers

3 Food / food wasteinternal driving, external driving3

57 3. Food / food waste

storageexternal driving

• Adjustable components5

4. Clothing storage• Adjustable components

to accommodate all48

g g

5. Suitportsto accommodate all required astronaut

6

p

6. Computers9

qgeometries

1

p

7. Storage locker9

Internal • Mass is approximately 30 kg including1 7. Storage locker

8. Supplemental Airlock Wastewater Driving

External Driving

30 kg including actuators8. Supplemental Airlock

9 Beds (stowed)Tank

External Driving

Ingress/ Egress

actuators9. Beds (stowed) Ingress/ Egress

TURTLE P TURTLE Th l C t lTURTLE Power TURTLE Thermal Controlh h b f l ll Wi h i l l h i d i l h (813 W)Three Proton Exchange Membrane fuel cells Without active control, solar heating and internal component heat (813 W) g

• Three-fold redundancy: One fuel cell is able tog

raise thermal equilibrium temperature to 330 K (beyond habitable limits)Three fold redundancy: One fuel cell is able to power all rover systems

raise thermal equilibrium temperature to 330 K (beyond habitable limits)P i C t l A ti C t lpower all rover systems

• Power requirements broken into five stages as• Passive Control: • Active Control:

• Power requirements broken into five stages as shown below

Aeroglaze A276 white paint (TRL 9) Helium gas heat exchanger (TRL 4)shown below

Si l h h liAvg Power Req’d Stage Length Energy Req’d

• Single phase helium gas h t hAvg. Power Req d.

(W)Stage Length

(hrs)Energy Req d.

(kWhr)exchange system: chosen f i li it d b t(W) (hrs) (kWhr)

Transfer Stage 290 167 48for simplicity and robustness

Transfer Stage 290 167 48Descent & Landing Stage #1 1330 0 92 1 2

• Heat removed by an internal Descent & Landing Stage #1 1330 0.92 1.2Descent & Landing Stage #2 1070 0 08 0 1

heat exchanger, then Descent & Landing Stage #2 1070 0.08 0.1

Standby Stage 430 220 92expelled through external

Standby Stage 430 220 92Sortie Mission Stage 3240 190 622

radiatorSortie Mission Stage 3240 190 622

T t l 578 764 • The gas is compressed so Total — 578 764 g pthat the efficiency is

Fuel cells supplied with cryogenic liquid oxygen and liquid hydrogen. After y

maximized without reaching unrealistic mass flow ratespp y g q yg q y greaction, potable water is stored for use by astronauts during the mission. (TRL 3)

g• The coefficient of performance for this system is 2.2reaction, potable water is stored for use by astronauts during the mission. (TRL 3)

Fuel Tank Boil-off:The coefficient of performance for this system is 2.2

H t E hFuel Tank Boil-off:• Boil off effects from solar heating converts the liquid propellants into unusable gases

Heat Exchangers• Boil-off effects from solar heating converts the liquid propellants into unusable gases

Excess fuel tank size and perforated MLI insulation layer (TRL 7) requirements wereInternal External

• Excess fuel, tank size, and perforated MLI insulation layer (TRL 7) requirements were d t i d f d i d bl f l

• Piping containing cold gas • Corrugated radiator design with a planar determined for a desired usable fuel massR d d d i i id d h h i b d

p g g gabsorbs energy from the area of 8 m² maximizes radiation area

• Redundancy, mass, and space restrictions were considered when choosing number and gy

cabin air passed over it • Radiator cross section composed of size of tanks

p• Film heat transfer equilateral right triangles with thickness 2

Number of Mass of Diameter Length Layers Percent coefficients of the moving mm and height 3.7 cm (chosen using the Number of

TanksMass of

FuelDiameter Length Layers

of MLIPercent

Extra Fuel

ggas were used to heat flux terms in the overall heat transfer

Tanks Fuel of MLI Extra FuelLOX 2 243 k 46 4 82 1 2 9%

gdetermine the necessary system)

LOX 2 243 kg 46.4 cm 82 cm 1 2.9%y

diameter (1 cm) and LH2 4 32.9 kg 50 cm 82 cm 2 10.8%

( )length (21 m) of the pipesg ( ) p p

ConclusionsConclusionsCost AnalysisC iti l TRLR li bilit Cost AnalysisCritical TRLsReliability

Components Rel LOM Non- TotAssumptions:TRL 1-3Components Rel LOMSuitport Systems 9998

System Non-Recur Recur. Tot.

($M)Assumptions:1) Use existing launch

TRL 1 3• Suitport connectionsSuitport Systems .9998

Wh l 9900

Recur. ($M)R 1600 850 2450

1) Use existing launch vehicle (no DDT&E)

• Suitport connectionsS it t h iWheels .9900 Rover 1600 850 2450vehicle (no DDT&E)

2) Initial flight in 2020• Suitport mechanisms

Motors .9990 Transit 850 990 18402) Initial flight in 20203) 85% construction

• Suit with detachable

Suspension .9900 Lander 280 250 5303) 85% construction

learning curvePLSSSuspension .9900

Avionics Hardware 9983

Lander 280 250 530Science

learning curve4) T i i t t l• Lander leg honeycomb Avionics Hardware .9983

S f 9990

Science Package 25 78 1034) Ten missions totalg y

inserts Software .9990 Package

D lt IV 2500 2500• Lander detachmentFuel Tanks .9990 Delta-IV - 2500 2500Total Cost:• Lander detachment

mechanismsThermal/Radiation .9980 Total 2800 4700 7400$7 4 billion

mechanisms• Cryogenic PEM fuel cellsThermal/Radiation .9980

Batteries 9990$7.4 billionRated at a CRL of 4 based on preliminary

• Cryogenic PEM fuel cellsBatteries .9990Fi l 9723

Rated at a CRL of 4 based on preliminary design eadinessFinal .9723 design readiness

O tpost Ro eOutpost RoverOutpost RoverOutpost CONOPS - Logistics Docking OptionsOutpost CONOPS Logistics Docking Options• There will be two supplies of fuel, one on the rover and one at the Outpost to Rover docking Retractable dockingpp ,

outpost for refuelingOutpost to Rover docking g

R t t bl d ki t t ioutpost for refuelingG d h h i i d h f d

• Docking using the suitport hatch as • Retractable docking structure is d i d d ll d– Gray waste water stored throughout a mission and then transferred to

g g pconnection to a rigid docking structure depressurized and collapsed

h t ithe outpost to regenerate LOX and LH2

g gat the outpost when not in usethe outpost to regenerate LOX and LH2

Water from solid waste possibly used to regenerate fuelp

O t t ld it th h th• Extended and pressurized when – Water from solid waste possibly used to regenerate fuel • One astronaut would exit through the

ti it t id i d ki th

pdocked to TURTLE’s suitport

• Food, clothing and LiOH canisters resupplied by shirt-sleeve transfer connecting suitport, aid in docking the d th t th t t

doc ed to U s su tpo tFood, clothing and LiOH canisters resupplied by shirt sleeve transferAt h i li d t ll

rover, and then enter the outpost h h l k• Atmospheric gases resupplied externally through an airlock or suitport

• Two possible methods for external refueling• Two possible methods for external refueling– Replace tanks: easy with light tanks, p y g

but requires extra tanksbut requires extra tanksUmbilical: more complicated system– Umbilical: more complicated system to develop, but easier to usep,

Rover Mock upRover Mock-uppThe rover mock-up was constructed as a design tool to determine most effective and Interior Testingp gefficient interior layout and to test the feasibility of a suitport for ingress and egress.

Interior Testingefficient interior layout and to test the feasibility of a suitport for ingress and egress.Construction • Left vs center driving positionConstruction • Left vs. center driving position

• Bed vs. hammock,Bed vs. hammock,

• Effectively place storage containers, computers, and small support items in the cabinpp

Suitport TestingSu tpo t est gSuitport testing provided a way to determine if suitports are feasible for ingress/

Final ProductSuitport testing provided a way to determine if suitports are feasible for ingress/

f TURTLE d t t t th “ d ” th d f i th PLSSFinal Product egress for TURTLE and to test the “garage door” method of removing the PLSS

Rover constructionRover construction began in latebegan in late

February and lastedFebruary and lasted til l t A il funtil late April for

the final product

O t hOutreachOutreachOverview General Public K-12th GradeOverview General Public K-12th Grade• 100% Team Participation• 100% Team Participation • UMD Open Houses • Elementary School and Middle School • 18 Events from February to May 2008

p yDrew Elementary School toured the Space Systems18 Events from February to May 2008

Four presentations to prospective students and Drew Elementary School toured the Space Systems Lab with 50 students and teachers on March 7th

• 143 Contact Hours parents with at least three team members at each Lab with 50 students and teachers on March 7 . Team members visited two area middle schools

Technical Communitypopen house. The presentation covered general

Team members visited two area middle schools.Technical Community open house. The presentation covered general

information about the design class and the TURTLE• Preliminary Design Review: December 2007 information about the design class and the TURTLE design

B li D i R i M h 6 2008design.

• Baseline Design Review: March 6, 2008 • Maryland Day: April 26 2008

• Rover Rollout: April 9 2008• Maryland Day: April 26, 2008

• Rover Rollout: April 9, 2008 First official display of the rover mock up Maryland Day is a university-wide day of activities forFirst official display of the rover mock-up Maryland Day is a university wide day of activities for

the local community to view the labs departmentsthe local community to view the labs, departments, and groups in the universityand groups in the university. • High SchoolHigh School

Presentations at four local high schools for sciencePresentations at four local high schools for science and engineering class and clubsand engineering class and clubs

• Critical Design Review: April 22,2008 Intermission included mock-up and suitport demos

AIAA/SGT Smoke Visualization Demop p

Celestia Simulator AIAA/SGT Smoke Visualization Demo

AcknowledgementsAcknowledgementsThe TURTLE Team would like to thank Maryland Space Grant y pConsortium for generously funding our rover mock-up,

CDR visitors watching a mock up and

g y g p,NASA/USRA for RASC-AL travel funds, and the Space Systems CDR visitors watching a mock-up and

suitport demonstration Candy Rover ConstructionClimbing into the Mock-up

/ , p yLaboratory for mockup fabrication and testing support.suitport demonstration Candy Rover ConstructionClimbing into the Mock up y p g pp