The reactor would launch to the moon by 2030, according to a directive by acting NASA Administrator Sean Duffy that was sent to NASA officials in July and obtained by NPR. It's an ambitious target that has some in the scientific community concerned about high costs and a potentially unrealistic schedule.

Placing an atomic energy source on the lunar surface is “not science fiction,” experts say, but does pose technical challenges.

Acting NASA Administrator Sean Duffy has directed the agency to fast-track plans to put a nuclear reactor on the moon.