Meeting Agenda February XX, 2004

1
Radio Isotope Heated Aircraft Propulsion for
Flight Applications on Titan
Presented By
Jonathan A Webb Center for Space Nuclear
Research Idaho National Laboratory
Space Technology and Applications International
Forum February 13, 2008
2
Agenda

• Why Titan
• Titan Exploration Challenges
• Proposed Aircraft
• Aircraft Propulsion Methods
• Conclusions

3
Why Titan??

• High density atmosphere (98 N2, 2 CH4)
• Rivers and lakes of Methane
• Cryo-volcanism
• Immense amounts of organic materials
• EARTH-LIKE EVOLUTIONARY PROCESS

4
Why Titan ??

• Titans orbit dips deep inside Saturns
  magnetosphere
• Charged particle interactions create complex
  organic molecules
• Molecules precipitate and interact with other
  chemicals

5
Proposed Architecture

• Drifts at 32,000 ft altitude
• Drifts at 10 knots
• 278 kg flight mass
• Little ability to steer
• Can not loiter in one area

6
Fixed Wing Alternative

• Fly a fixed wing craft
• Ramjet
• Turbojet
• Turboprop
• Turbofan
• No Oxygen for Combustion
• Replace combustion chamber with radioisotopes
• Ultra-long flight durations

Proposed Mars aircraft
7
Isotopes

• 238Pu
• - a emitter
• - 87 yr half life
• - limited inventory
• - 413 W/kg as PuO2
• 90Sr
• - ß- emitter
• - 29 yr half life
• - available at Hanaford
• - 396 W/kg in an SrO form
• - 239Pu fission products yields a higher ratio
  of 90Sr to 88Sr
• - 239Pu fission products yield SrO at 546 W/kg

8
Ramjet Engine

• No moving parts
• Simplicity
• Most power intensive at low velocity
• Least power intensive at supersonic velocities

9
Turbojet Engine

• Least power intensive at high subsonic
  velocities
• Requires moving parts
• Thrust producing device

10
Turboprop Engine

• Power producing device
• Similar to a turboprop

11
Ramjet
12
Turbine Propulsion
13
Turbine Propulsion
14
Turbine Propulsion
15
2 inch Turboprop Fuel Mass
16
Mass Budget
SrO 69/31
SrO 50/50
PuO2
17
Conclusions

• Required temperatures, power and compression
  ratios are within current levels of experience
• A turboprop flying at 64,000 ft seems to be the
  optimum flight configuration
• More work is required in turbo-machinery design,
  shielding design and heat transfer
• Radioisotope powered long duration aircraft
  appears feasible for deep space exploration
  missions

18
Acknowledgements

• Center for Space Nuclear Research
• Steven Howe
• CSNR Summer Fellows
• M. Dhanasar, B. Gross, J Katalenich, M. Keller,
  C. Miller, D. Osterberg, J. Perkins, P. Ramu, T.
  Reiss, J. Sasser, B. Schrieb, H. Szumilla, R.
  Obrien, J. Joyce, L. Sailer, C. Robinson

19
Questions ??