
US-A (RORSAT) with Buk-reactor
Voyager 2 with RTG power sources[NASA]
Nuclear power sources were and are used on spacecraft, when solar arrays are insufficient in providing enough power, especially on deep space missions to the outer solar system and on high-power application like radar satellites.
Currently, three types of nuclear energy sources have been used in space applications:
The missions, which required nuclear power sources, fell in following categories:
Nuclear propulsion has not yet be implemented, although ground tests of nuclear engines like the Nerva have been conducted. More likely is the future implementation of nuclear powered electric engines, as proposed for NASA's project Prometheus, which might propel a Jupiter Tour (JIMO - Jupiter Icy Moons Orbiter) spacecraft to orbit several moons of Jupiter.
The main risk of nuclear powered missions is, that radioactivity could be released in the event of an accident or reentry. Several accidents happened, some causing severe radioactive pollution.
Complete Mission List:
Failure List:
| Mission | Failure | Failure Description | Radioactivity released |
|---|---|---|---|
Launch failure |
RTG burned up |
Yes | |
Launch failure |
RTG recovered intact |
No | |
Reentered |
RTG undamaged, but lost. No radioactivity measured |
No | |
Launch failure |
Reactor burned up, radioactivity measured |
Yes | |
Reentered |
Reactor burned up over Canada, radioactive pollution on the ground |
Yes | |
Reentered |
Reactor core burned up over South Atlantic |
Yes | |
Launch failure |
Unknown |
Unknown |