It’s baaaack: Nuclear propulsion, first floated in the ’60s, is hot again. President Trump’s Mars ambitions might even hinge on it.
Just north of the Tennessee River near Huntsville, Alabama, there’s a six-story rocket test stand in a small clearing of loblolly pines. It’s here, in a secluded corner of NASA’s Marshall Space Flight Center, that the US Army and NASA performed critical tests during the development of the
Redstone rocket. In 1958, this rocket became the first to detonate a nuclear weapon; three years later, it carried the first American into space.
The tangled history of nukes and space is again resurfacing, just up the road from the Redstone test stand. This time NASA engineers want to create something deceptively simple: a rocket engine powered by nuclear fission.
A nuclear rocket engine would be twice as efficient as the chemical engines powering rockets today. But despite their conceptual simplicity, small-scale fission reactors are challenging to build and risky to operate because they produce toxic waste. Space travel is dangerous enough without having to worry about a nuclear meltdown. But for future human missions to the moon and Mars, NASA believes such risks may be necessary.
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Let’s get one thing clear: A nuclear engine won’t hoist a rocket into orbit. That’s too risky; if a rocket with a hot nuclear reactor blew up on the launch pad, you could end up with a Chernobyl-scale disaster. Instead, a regular chemically propelled rocket would hoist a nuclear-powered spacecraft into orbit, which would only then fire up its nuclear reactor. The massive amount of energy produced by these reactors could be used to sustain human outposts on other worlds and cut the travel time to Mars in half.
[…]There were technical hurdles too. While the concept of nuclear rocket engines is simple enough—the reactor brings hydrogen to blistering temperatures and the gas is expelled through a nozzle—designing reactors that could withstand their own heat was not. Earthbound fission reactors operate at around 600 degrees Fahrenheit; the reactors used in rocket engines must be cranked to more than 4,000 degrees F.
Read more at NASA Wants to Send Nuclear Rockets to the Moon and Mars
