Russia planning nuclear-powered manned spaceship
Reactor cruiser aimed at Moon, Mars missions
Russian space chiefs are considering plans for a manned spacecraft with a nuclear powerplant aboard, according to reports. Indications are that the nuclear kit would provide electrical power rather than being used directly for propulsion.
RIA Novosti reports that Anatoly Perminov, chief of the Russian space agency Roscosmos, revealed the scheme at a meeting yesterday. Reportedly Perminov specifically mentioned Megawatt-class nuclear space power systems (MCNSPS), which would normally refer to "an appropriate nuclear reactor heat source" generating electrical power aboard a spacecraft by one of several conversion methods (massive old NASA pdf here).
The report says that the Roscosmos boss mentioned MCNSPS specifically in the context of "implementing large-scale space exploration programs". His fellow Russian space bigwig Anatoly Koroteyev had earlier stated that the key issue with manned missions to the Moon and Mars was "development of new propulsion systems and energy supplies with a high degree of energy-mass efficiency".
Spacecraft today are typically propelled by chemically-fuelled rockets and powered by solar panels (or sometimes fuel cells for short-duration missions). Chemical rockets in particular tend to require so much fuel to accomplish anything that very little actual payload can be carried, especially in the case of return trips beyond Earth orbit.
Any chemically-powered manned mission to Mars would have to coast almost all the way there and back, taking six months each way. Aboard a typical lightweight spacecraft - the only sort that feeble chemical rockets can propel - this would be quite likely to mean astronauts dying of cosmic radiation sickness. Magnetic shielding is a possibility, but this would probably be a serious power drain.