Manned Interplanetary Space Vehicle Using D-3He Inertial Electrostatic Fusion
R. Burton1, H. Momota2, N.
Richardson1, M. Coventry2, Y. Shaban2 and G. H. Miley1
1University of Illinois at
Urbana-Champaign, Urbana, Illinois 61801
2NPL Associates, Inc,
A preliminary system design is presented for a high performance 100 MWe manned space
vehicle in the 500 metric ton class, based on Inertial Electrostatic Fusion (IEC), with
trip times to the outer planets of several months. An IEC is chosen because it
simplifies structure results in a very high power to weight ratio. The fusion
reactor uses D-3He fuel which generates 14.7-MeV protons as the primary
reaction product. The propulsion system design philosophy is based on direct
conversion of proton energy to electricity, avoiding the thermalization of the working
fluid to maximize efficiency. The principle system components crew compartment,
electronics, fusion reactor, traveling wave direct energy converter, step-down
transformer, rectifier, ion thruster and heat rejection radiators are described.
|Image of 100-MWe IEC Fusion Powered Space Craft with Ion
The design requires that an IEC reactor with a proton energy gain (power in 14.7-MeV
protons/input electric power) of 4 or better is necessary to keep radiator mass and size
at acceptable levels. Extrapolation of present laboratory scale IEC experiments to
reactor relevant conditions is possible theoretically, but faces several open issues
including stability under high-density conditions. Since unburned fusion fuels are
recycled rather than exhausted with the propellant, problems of fuel weight and
preservation of 3He are minimized. The 100-MWe propulsion system is based on
NSTAR-extrapolated krypton ion thrusters operating at a specific impulse of 16,000 seconds
and a total thrust of 1020 N.
Thrust time for a typical outer planet
mission ?V of 50,000 m/s is then ~200 days.