NASA plans human settlements on the moon and Mars. But it needs to find a way to power them.

Hauling years’ worth of fuel into space would be very expensive.

Brendan Byrne, host of the podcast, “Are we there yet?” says, “The toughest part about space exploration is bringing your resources with you.”

Bryne’s podcast is all about man’s future in space. He says NASA thinks a nuclear reactor could solve the problem.

“This reactor that they’re testing will actually be like a nuclear reactor like we use here on earth to create power.”

But wouldn’t that also be too big to carry into space?

Byrne says, “It’s very, very small. It’s only about the size of a paper towel. It uses a slice of uranium 235 core. It decays, causes heat and that heat can be turned into electrical power.”

NASA believes four of its ‘Kilo power’ reactors could power a space settlement for about 10 years.

NASA already uses a uranium core to power its new horizons probe near Pluto, and other spacecraft.

But is it safe? NASA says it’s thoroughly testing the reactor to make sure it’s can withstand the harsh conditions of space.