Russia, the US and other nations are to discuss cooperation on building a nuclear-powered spacecraft, according to the head of Roscosmos – the Russian space agency.

Anatoly Perminov, Roscosmos chief, tells state-owned newswire RIA Novosti that nuclear spacecraft plans are to be discussed with NASA on April 15. Perminov added that "countries with a high level of reactor manufacturing technology" are to take part in the talks. The report mentions China, France, Germany and Japan: technically the UK can also make reactors but its capability is weak compared to the main nuclear players and its space presence even more so.

Perminov went on to add that Russia intends to complete its design of a "nuclear engine" for use in space by 2012, and that in order to actually build this, funding of 17 billion roubles ($600m) will be required. He envisages this funding coming primarily from Rosatom, the state nuclear agency, rather than Roscosmos. The international discussions suggest that funding or at any rate cooperation will also be sought from overseas.

In previous reports, Perminov has been quoted as saying that the "engine" design now being worked on is of the type known as "megawatt-class nuclear space power systems" (MCNSPS). This refers specifically to use of a nuclear reactor to generate electricity, but other previous remarks regarding a propulsion capability suggest that the Russian engine could also use reactor heat to eject reaction mass, providing thrust as well as electrical power. Reactors normally generate a large surplus of heat energy over and above their electrical output, so the scope is there to do both propulsion and power generation at once: nuclear rockets using reactors to heat reaction mass were tested decades ago. Because they can use reaction mass selected to be good reaction mass – rather than being forced to accept what chemical fuels can produce – they can get much more shove out of a given weight of fuel.

Modern thinking, however, usually favours nuclear-electric propulsion employing ion engines or plasma rockets rather than a nuclear rocket as such. These can't produce anything like as much thrust as thermal nuclear or chemical rockets – they could never lift themselves off the Earth – but they are far more reaction-mass efficient even than nuclear rockets. They could make interplanetary journeys lasting weeks rather than months, and allow spaceships to carry other things than fuel to a much greater extent.

It's widely acknowledged in the space community that propulsion more powerful than chemical rockets and power generation more capable than solar panels will be necessary if travel beyond Earth orbit is to become a serious activity. From the earliest days of spaceflight and before, in fact, it was assumed that nuclear power would provide both – and that space travel, mining, industry and so forth would soon spread through most of the solar system.

In the real world, humanity's deep-seated fear of nuclear power has meant that very few reactors have ever flown in space. The most powerful were the relatively puny Topaz units employed in Soviet radar-ocean-reconnaissance spysats of yesteryear: so, far from being megawatt-class, these could produce just a few kilowatts. Still feebler radioisotope power units have been used in spy satellites and some scientific projects intended to operate far from the Sun: for instance NASA's next Mars rover is intended to be radioisotope-powered in order to give it the ability to move faster than a very slow crawl. (Despite their tremendous longevity, the present solar-powered Martian rovers have yet to travel as far as the much shorter-lived Soviet moon rovers of the 1970s.)

The Russians are showing every sign of being willing to finally break through the barriers of fear and deploy a powerful nuclear spaceship of the sort which might one day move the space operations of humanity beyond Earth orbit: what the Russians are not showing much sign of is having the money to do so.

The necessary $600m isn't a lot of money to NASA: but in fact NASA has plenty of nuclear space engine designs of its own on file if it wanted to build one. It's hard to see the discussions later this month bearing much fruit, much though space enthusiasts might hope for such. ®