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.

Is NASA going to put a nuclear reactor on the moon? Here's what Sean Duffy said about U.S. race against China in space and going to Mars.

This is the first major agency effort by the interim NASA administrator, who is also the Transportation secretary and a former Fox News host.