AAE450 Senior Spacecraft Design Project Aquarius Kowalkowski - 1 2\22\2007 Mike Kowalkowski Week 6: February 22 nd 2007 Project Aquarius Power Engineering Group MRCF, LP, NPS Vehicle Focal HAB, MLV, MR Power Contact

AAE450 Senior Spacecraft Design Project Aquarius Kowalkowski - 2 2\22\2007 EP / NPS Brayton Reactor Sizing Conceptual Design –Common 2 MWe, 10 year reactor for NPS & EP –Surface reactor buried Boron-aluminum bay & LiH / W cap provide “safe” radiation dose at 6 m 4 –Closed Brayton Cycle (24%) conversion efficiency P / M / V – EP System –Power: 2 MWe capacity –Mass: 27.6 mt a –Radiation Area: 2270 m^2 b –Volume: m^3 (Rogge) a includes a 20% budget 1 b includes a 10% budget 1 Comp. Turb.. Shield Mars Ground Reactor T.A. Power Conditioner Main Rad.

AAE450 Senior Spacecraft Design Project Aquarius Kowalkowski - 3 2\22\2007 MRCF / LP Sizing MRCF (Mars Rocket Construction Facility): –Oversized mobile tent –Mass: 0.38 mt –Stowed Volume: 21.5 m^3 –Power: 0.0 kWe Aluminum poles & nylon mass included Mobile system so rocket can be constructed on the launch pad. LP (Launch Pad): –Launch gantry only MLV Mass Lifted: 500 mt Power: 85 kWe –5 minute lift time Highly dependent on finalized mass of MLV –1.0 km from HAB requires significant cabling mass at higher (1.0 MWe) power 6 On the order of 1 mt Ryan Scott developing code MRCF Over LP 25 m 50 m

AAE450 Senior Spacecraft Design Project Aquarius Kowalkowski - 4 2\22\2007 Backup Slides Week 4 Readiness Level

AAE450 Senior Spacecraft Design Project Aquarius Kowalkowski - 5 2\22\2007 EP / NPS Reactor Sizing Logic (1) Reactor mass –Scaled from nuclear power fuel number with 3x shield provision 65 MWd/kg –Courtesy: Courtney Rogge 8 24% CBC cycle efficiency 9 Additional masses baselined against documentation 1,2,3,9 –Surface reactors have higher power conditioning requirements, accounting for higher overall masses, but the fundamental reactor is the same Thermal radiator concept –Radiators are also aluminum skin of the EP system and are deployable on the surface. Surface power conditioning and distribution –Masses and volumes not entered into the reactor bed. Shield analysis –With a safety zone of 6 meters, the HAB will be placed 100 meters to 400 meters from the nuclear power source without significant risk

AAE450 Senior Spacecraft Design Project Aquarius Kowalkowski - 6 2\22\2007 EP / NPS Reactor Sizing Logic (2) Reactor Mass –21.8% Total System Shield Mass –20.5% Total System Turbo alternators –16.6% Total System Thermal Radiators –15.6% Total System Power Conditioning (Surface) –13.5% Total System Heat Exchanger / Controller –11.97% Total System

AAE450 Senior Spacecraft Design Project Aquarius Kowalkowski - 7 2\22\2007 EP / NPS Reactor Sizing Logic (2) As has been previously recognized, shielding mass and reactor mass have been difficult to size, primarily because of security classifications of referenced codes. After ~10 hours / day for four days of autonomous research and consultation with the nuclear engineering department, these numbers are shown to be embraced and accepted by current research. A purer, mathematically based code is being developed from the Sandia National Laboratory RSMASS-D reactor and shield sizing study 5, Auburn University’s Lunar electricity wiring study 6, and NASA’s Lunar power management and distribution guidelines 7. Although these mathematical models will add further integrity to the final mass and volume numbers, the overall system masses should not reduce or increase significantly from the numbers presented today. This mathematical model will serve as a check to the NPS literature sizing model presented today and should be complete by next week.

AAE450 Senior Spacecraft Design Project Aquarius Kowalkowski - 8 2\22\2007 System Mass Trends

AAE450 Senior Spacecraft Design Project Aquarius Kowalkowski - 9 2\22\2007 Specific System Power

AAE450 Senior Spacecraft Design Project Aquarius Kowalkowski \22\2007 Calculations Sheet EP/NPS Reference full spreadsheet online under references. 1,2,3,8 Kowalkowski.xls … 8 pages

AAE450 Senior Spacecraft Design Project Aquarius Kowalkowski \22\2007 Calculations Sheet MRCF/LP Reference full spreadsheet online under references. Kowalkowski.xls … 8 pages

AAE450 Senior Spacecraft Design Project Aquarius Kowalkowski \22\2007 Power Systems Trade Study Thermoelectric vs. Sterling vs. Brayton 10 –Assume high temperature (2000K) Brayton Cycle 1 Most efficient power cycle above 100kWe, blade and coating technology available –Current power requirements on the surface 1MWe ISPP / LP 150 kWe HAB With a 90% conditioning and distribution coefficient, 1.25 MWe –This could allow for a reduction of size in reactor, but I have been told that ISPP fuel requirements may increase, increasing the total amount of fuel needed to near 1.5 MWe levels (Kassab) –This is dependent on MLV mass

AAE450 Senior Spacecraft Design Project Aquarius Kowalkowski \22\2007 Cited References 1 Mason, Lee. A Comparison of Fission Power Systems Options for Lunar & Mars Surface Applications. AIP - Space Technology and Applications International Forum, Available online. 2 Juhasz, Albert, et. al. Lunar Surface Gas Turbine Power Systems with Fission Reactor Heat Source. 3 rd International Energy Conversion Engineering Conference, Available online. 3 Juhasz, Albert, et. al. Multimegawatt Gas Turbine Power Systems for Lunar Colonies. 4 th International Energy Conversion Engineering Conference, Available online. 4 Wright, Steven A and David Poston. Low Mass Radiation Shielding for Martian Surface Power Reactors. AIP - Space Technology and Applications International Forum, Available online. 5 Marshall, Albert C. RSMASS-D: An Improved Method for Estimating Reactor Mass and Shield Mass for Space Reactor Applications. Sandia National Laboratories, Available Online. 6 Gordon, Lloyd B. Electrical Transmission on Lunar Surface: Part 1 – DC Transmission. Auburn University, Auburn, Alabama. March Available Online. 7 Metclaff, Kenneth J. Lunar PMAD Technology Assessment. NASA Lewis Research Center. Feb Available Online. 8 Courtney Rogge. Conversations with a Nuclear Engineer. 19 February Basic Reactor Fuel Mass and Volume Sizing. 9 Baggenstoss, W.G. and T.L. Ashe. “Mission Design Drivers for Closed Brayton Cycle Space Power Conversion Configuration.” Journal of Engineering for Gas Turbines and Power. October 1992, Vol. 114, pgs Mason, Lee. A Comparison of Brayton and Sterling Space Nuclear Power Systems for Power Levels from 1 Kilowatt to 10 Megawatts. AIP - Space Technology and Applications International Forum, Available online.