[luckybogey]

I thought the real problem always in the past was the actual weight of a small nuke engine...

[tricky_k_1972]

The problem is not weight, the Russians have actually launched small nuclear reactors for satellites, Cosmos.

The problem with nuclear reactors in space has been, at least with the Russians, design and reliability.

Though the Russians have the most experience with the technology of actual space reactors, we in the US, and to some extent the Japanese and South Africans, have more reliable small reactors.