On Friday, Space X unveiled its plans for space exploration, and in something of a surprise move, they’re pushing the nuclear option.

The US government should leave conventional space flight to the private sector and return to developing nuclear-powered rockets pursued during the 1960s, the corporation urged at the Joint Propulsion Conference in Nashville, Tennessee. The best write-up I’ve seen (by Aviation Week) basically says that the company would like to develop beefed-up versions of its Falcon 9 rocket that could be used to lift cargo, spacecraft, and crew for a future mission to Mars.

The rockets would be powerful enough to get the crew into orbit, but once there, Space X wants government-built nuclear powered rockets to take over. “Nuclear-powered rockets? Really?” I can hear you ask. Oh you bet! During the 1960s and 70s, the US Atomic Energy Commission and NASA had an active programme known as Nuclear Engine for Rocket Vehicle Application (NERVA). The goal of NERVA was to use a nuclear reactor as a rocket motor. In very crude terms, the idea was to feed liquid hydrogen through the reactor core, which would heat it up, creating a lot of thrust.

To people my age or younger this seems completely nutty, but keep in mind that this was an era in which scientists were trying to run everything off nuclear power (including aircraft). And in fact, the NERVA programme made good progress over the course of a decade. A series of test reactors were built, and one was even intentionally detonated to understand how an accident at launch might spread radiation. The programme continued right up until 1973, when Richard Nixon killed it over cost concerns.

A few years back, I actually travelled to Jackass Flats, Nevada home to the NERVA programme (I think I got that right, but perhaps some eagle-eyed reader will know if I’ve highlighted the wrong facility on Google maps). My tour guide pointed out the rocket stands where NERVA sat, and said that the project had shown that nuclear rockets were a far more fuel-efficient way to power spacecraft than conventional propellants. However, he told me, it wasn’t foolproof. One big problem was that all that super-heated hydrogen corroded the fuel cladding, causing the thing to leak radioactive uranium.

An issue on earth, but perhaps less so in orbit. Using nuclear-powered rockets to get from Earth to Mars could be an idea just so crazy that it would work. Of course, there’s still the little issue of finding the money. It’s worth pointing out that SpaceX prides itself on being cheaper and just as good when it comes to conventional space flight. The fact that they’re willing to cede nuclear propulsion to the government gives some indication of just how difficult, and costly, it will be.

Credit: NASA