Space: Science & Technology / 2021 / Article / Tab 1

Review Article

Application Prospect of Fission-Powered Spacecraft in Solar System Exploration Missions

Table 1

Titan Saturn system mission comparison of Radioisotope Power System (RPS) and Fission Power System (FPS).

SubsystemRPS 2008 ASRGFPS 1 kWe Stirling reactorFPS 1 kWe thermoelectric reactor

Science108 kg, 182 We, ~5 Tb data return108 kg, 182 We, ~9 Tb data return108 kg, 182 We, ~9 Tb data return
Mission~13 yr~15 yr (1 yr Earth spiral out)~16 yr (2 yr Earth spiral out
LauncherAtlas 551, short fairing; of 0.6 km2/s2 (6250 kg stage mass)Atlas 551, long fairing; of ~14.8 km2/s2 (8300 kg stage mass)Atlas 551, long fairing; of ~22 km2/s2 (9600 kg stage mass)
SEP stage~15 kWe, 500 kg Xe, 2+1 NEXT~19 kWe, 1400 kg Xe, 2+1 NEXT~19 kWe, 1800 kg Xe, 3+1 NEXT
Orbiter power system operation time~500 kg, ~7 yr operation (reactor activated ~7 yr after launch at the final Earth flyby)~700 kg, ~7 yr operation (reactor activated ~7 yr after launch at the final Earth flyby)
Aerobraking4-meter antenna for drag area, ballistic coefficient 77 kg/m2 (2 months of aerobraking campaign)4.5-meter drag flap plus a 2.25-meter antenna with the same 77 ballistic coefficients (2 months of aerobraking campaign)4.5-meter drag flap plus a 2.25-meter antenna 88 ballistic coefficient (~2.1 months of aerobraking campaign)
Communication4 m antenna, X/Ka, 25 We/35 We RF, 140 kbps2.25 m antenna, X/Ka, 70 We/250 We RF, 250 kbps2.25 m antenna, X/Ka, 70 We/250 We RF, 250 kbps
Attitude control system (Titan Ops)Four 25 Nms reaction wheels, LVLH around TitanFour 150 Nms reaction wheels, Gravity Gradient around TitanFour 150 Nms reaction wheels, Gravity Gradient around Titan
Total S/C dry mass (with margins)~3200 kg~4200 kg~5000 kg