At the moment, commercial usage of space seems to be the next big 'thing' in space exploration. Much of this (tourism, commercial launch companies, etc) will likely use solar power or fuel cell technology. However, some of the more advanced work, including asteroid mining or possibly private scientific exploration, might benefit from using RTGs or other nuclear-based power solutions.

What are the legal issues surrounding this? Does the regulatory framework even exist today to allow the purchase of an RTG from the US or Russia? Would there be regulatory hurdles to overcome as regards the Department of Energy or the EPA?

  • $\begingroup$ The question asks about a "US-based" company, so I think that's enough to answer. $\endgroup$ Jun 20, 2018 at 14:00

2 Answers 2


Focusing on a US-based company as you've asked in your question, there two steps to this issue. The first involves a commercial actor getting a nuclear power system in the first place. That's certainly doable; you might need to get some licenses and go through a bunch of regulatory hoops, but there is no reason you couldn't ultimately get permission to build and operate a RTG or some other system.

Step 2 is the problem. You don't only need permission to build and have the system; you need permission to send it to, and operate in, outer space. That's where we have what some of us call a "regulatory gap" in the United States. There is no USG agency that has the legal authority to say yes to commercial nuclear operations in space. We can do USG activities, because they get permission in different ways, but none of the current agencies that regulate commercial space activities - FCC, FAA, and NOAA - have the legal authority to say yes to nuclear devices, no matter how much they might want to or how well designed the system is. This is actually one example of a broader problem; this regulatory gap also includes many other newly-contemplated space activities, such as commercial habitats.

Finally, the USG can't just look the other way; Article VI of the Outer Space Treaty requires countries to "authorize and supervise" the activities of their companies, which means the United States has to actively regulate what commercial actors do in space, at least to some degree.

So your question raises a very current and pressing issue in U.S. national space law and policy: fixing that regulatory gap. One way to do it would be to pass a law providing some USG agency with broad authority to do "mission authorization." An Obama administration report (pdf warning) suggested something along those lines. Another possibility would have been the Space Renaissance Act proposed by then-Congressperson, now NASA Administrator Bridenstine. Neither of those proposals have moved forward, and the plans of the current administration on this issue aren't yet clear.

For non-US based companies, other domestic legal systems may well have the ability to authorize nuclear activities in outer space, and there is no prohibition on something like that under international law so long as it didn't violate some other international rule, such as by interfering with the operations of other actors.

Finally, there are some NONBINDING guidelines that have been developed internationally that could be used to guide how you might operate a nuclear power source in space.

  • $\begingroup$ For the sending it to and operating in space part, there is the existing Environmental Impact Statement process in the US, which has been used for government nuclear space systems, and which applies just as well to non-governmental entities. In addition, the White House, usually the head of OSTP, has to approve any launch of nuclear material. Even tiny amounts in instruments. (I think OSTP would have to approve launching a household smoke detector.) I'm not sure though whether that approval applies only to government-funded activities, or any US space launch. $\endgroup$
    – Mark Adler
    Jun 20, 2018 at 15:58
  • $\begingroup$ True, but even with that, you still can't get permission to operate commercially in space. $\endgroup$ Jun 20, 2018 at 20:34
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    $\begingroup$ also, if you want to send an RTG, you must actually obtain the appropriate isotope, which is currently very precious. Getting Pu-238 is currently about impossible. Opening production of Am-241 is possible, but don't count on any available stockpile or currently active production facility. $\endgroup$
    – SF.
    Jun 20, 2018 at 22:21
  • $\begingroup$ Is this really another situation where the lack of somebody with authority to say yes, means that the answer has to be no? $\endgroup$
    – ikrase
    Mar 15, 2020 at 15:25
  • $\begingroup$ Yep, that's exactly it, ikrase. $\endgroup$ Mar 25, 2021 at 2:12

As others have said, building the reactor isn't the real challenge, it's the legal hurdle of getting the device into space for use. Now, there are some limited precedents using nuclear technology in space exploration already that could be used to fuel a legal motion, but whether that would make it remains to be seen.

I suspect that any private organization with the resources to legally develop and build a device like this would also have the lobbying and/or legal clout to accomplish this aim.

  • $\begingroup$ Several years ago, one company did try to get a license to launch a nuclear-powered "space tug" from the United States. It was never able to get through the licensing process because of the lack of authority described above. But your point is a good one; I don't think they were super well connected in Washington. $\endgroup$ Mar 25, 2021 at 2:14

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