The Russian government has assigned funds of 500 million roubles ($16.7m) for the development of a nuclear-powered spacecraft, according to reports. Draft designs are expected to be finalised by 2012.
RIA Novosti reports that 430 million roubles of the space nuke-engine funding has been assigned to the Rosatom state nuclear corporation, and the remaining 70 megaroubles to space agency Roscosmos.
Roscosmos head Anatoly Perminov spoke last year of the need to develop nuclear powered spacecraft, estimating that the full cost of developing such systems would be 17 billion roubles ($580m). This week's announcements have supplied just under three per cent of that sum, explaining why little more than "draft designs" are expected thus far. However other reports have Roscosmos speaking of "tests" in 2015 and "production" beginning in 2018.
Previous reports have quoted Perminov as specifically mentioning "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 (NASA pdf here). However the latest reports speak of nuclear "propulsion", hinting that Russia may seek to explore the use of nuclear heat energy to expel reaction mass directly, rather than to make electricity.
It's also quite possible that Roscosmos will seek to use MCNSPS electric generators to power some kind of plasma or ion rocket, perhaps along the lines of the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) drive under development for NASA by former shuttle astronaut Dr Franklin Chang Díaz.
Anatoly Koroteyev, president of the Russian Academy of Cosmonautics, has already stated that the key technical problem in sending manned missions to the Moon and Mars is the development of new propulsion systems and energy supplies with a high degree of energy-mass efficiency. The chemical rockets used in spacecraft today expel their reaction mass with relatively low energy, making them highly inefficient.
Particularly in the case of round-trip journeys without refuelling at the other end, chemical rocket craft will need to carry so much fuel that they will struggle to deliver any useful payload. They will also be compelled to coast almost the whole way on interplanetary journeys, leading to very long journey times and severe exposure to cosmic radiation for any astronauts or cosmonauts aboard.
Nuclear power has been used aboard spacecraft before, mostly in the form of radioisotope batteries rather than reactors proper. This has usually been for deep space probes travelling far from the sun - hence unable to use solar power - or in secret surveillance satellites needing a lot of energy for their sensors. On those occasions where such use has been made public, there has sometimes been nuclear-technofear-inspired protest. ®