1. AAE450 Spring 2009 Slide 1 of 8 Final Presentation Back-up Slides Orbital Transfer Vehicle (OTV) Power and Thermal Control Ian Meginnis Ian Meginnis Power Systems

2. AAE450 Spring 2009 Slide 2 of 8 OTV Power Subsystems Ian Meginnis Power Systems PPU (Electric Propulsion) PCDU Battery (LL) 100V DC-DC Converters Individual OTV Components Acronym Definitions: PCDU - Power Conditioning and Distribution Unit PPU - Power Processing Unit LL - Lunar Lander DC - Direct Current Solar Array <200V Solar Array Note: Not to scale

3. AAE450 Spring 2009 Slide 3 of 8 Ian Meginnis Power Systems GroupPower (Watts) Propulsion1529 CommunicationSee “Lunar Lander” Attitude101.4 Power120 Lunar Lander (during Lunar Transfer) 105 TOTAL1959 100g Payload Case Power Budget GroupPower (Watts) Propulsion2029 CommunicationSee “Lunar Lander” Attitude145.4 Power120 Lunar Lander (during Lunar Transfer) 105 TOTAL2534 10kg Payload Case Power Budget GroupPower (Watts) Propulsion38773 CommunicationSee “Lunar Lander” Attitude305.4 Power1731.5 Lunar Lander (during Lunar Transfer) 105 TOTAL42960 Large Payload Case Power Budget

4. AAE450 Spring 2009 Slide 4 of 8 Ian Meginnis Power Systems Power Distribution: 100g Payload OTVPower Distribution: 10kg Payload OTV Power Distribution: Large Payload OTV

5. AAE450 Spring 2009 Slide 5 of 8 Ian Meginnis Power Systems Payload SizeComponentVariableValue 100g Solar Arrays (2 circular arrays) Mass13.06kg Deployed Area6.54m 2 Cost$1.96 Million Battery Mass12.17kg Cost$22,000 10kg Solar Arrays (2 circular arrays) Mass16.89kg Deployed Area8.45m 2 Cost$2.53 Million Battery Mass15.9kg Cost$28,600 Large Solar Arrays (2 rectangular arrays) Mass286.4kg Deployed Area143.2m 2 Cost$42.96 Million Battery Mass271.7kg Cost$488,400 OTV Power Dimensions

6. AAE450 Spring 2009 Slide 6 of 8 Ian Meginnis Power Systems Note: Not to scale Acronym Definitions: PCDU - Power Conditioning and Distribution Unit PPU - Power Processing Unit Batt - Battery DC - Direct Current PPU PCDU Batt DC/DC Converter Aluminum Heat Pipes with Ammonia Aluminum Mount 2 Radiators Electronics Board Thermal Control Hall Thruster Thermal Control Hall Thruster Radiating Heat Shroud Radiating Heat Shroud (Exhaust) OTV Thermal Control (all payloads)

7. AAE450 Spring 2009 Slide 7 of 8 OTV Electronics Thermal Control Ian Meginnis Power Systems Payload SizeComponentMass (kg) 100g Radiators1.2 AmmoniaNegligible Heat Pipes2.2 TOTALS3.4 10kg Radiators1.6 AmmoniaNegligible Heat Pipes2.5 TOTALS4.1 Large Radiators23.4 AmmoniaNegligible Heat Pipes15.3 TOTALS38.7

8. AAE450 Spring 2009 Slide 8 of 8 Ian Meginnis Power Systems Note: Not to scale At least 1 of the OTV’s set of radiators will not be exposed to sun’s rays at any point during the trajectory Each radiator, alone, can provide thermal control for OTV electronics Earth Sun Moon Single, Simplified Orbit of OTV (Large Payload)