The problem is for human inhabitants, the size of an RTG needed to provide power would be enormous and extremely dangerous to put into orbit. A more traditional fission generator could be much safer to put into orbit with the right design constraints, and deliver about a hundred times more power.
One such design would be to fuel the reactor on-orbit, and to launch the fuel in a vehicle with an escape system and isolation cask to ensure the fuel's safety during launch even in the event of failure... even though I honestly don't believe NASA will choose this option because of the weight/multiple launch problem, and the fact that they really want a reactor that's autonomous with respect to fueling and almost all aspects of serviceability. They're already playing around with designs on their own, even before they started soliciting commercial manufacturers and design partners to get in on it, with Kilopower and their 1KW KRUSTY prototype.
The problem is for human inhabitants, the size of an RTG needed to provide power would be enormous and extremely dangerous to put into orbit. A more traditional fission generator could be much safer to put into orbit with the right design constraints, and deliver about a hundred times more power.
One such design would be to fuel the reactor on-orbit, and to launch the fuel in a vehicle with an escape system and isolation cask to ensure the fuel's safety during launch even in the event of failure... even though I honestly don't believe NASA will choose this option because of the weight/multiple launch problem, and the fact that they really want a reactor that's autonomous with respect to fueling and almost all aspects of serviceability. They're already playing around with designs on their own, even before they started soliciting commercial manufacturers and design partners to get in on it, with Kilopower and their 1KW KRUSTY prototype.