[ianburrell]

Nuclear rockets are useless for launching things into orbit. They don't have the thrust-to-weight ratio to get off the ground. Nuclear rockets are useful because they have high specific impulse which means using less fuel for thrust.

[zare_st]

Exactly opposite of what the person above you is talking about.

[sonicanatidae]

shhh...cage match.

[therein]

One of the core teachings of Kerbal Space Program.

[Kim_Bruning]

However, in KSPI [1]: Consider the combination of a nuclear lightbulb with compressed air as the reaction mass: Surprisingly good midpoint qua TWR and ISP! If you install a compressor you can get some pretty interesting SSTOs out of it. Whether these would work IRL is a different question, of course. [2]

Nuclear lightbulb is of course highly theoretical, but scientifically/engineeringly plausible at the least. [3]

[1] https://forum.kerbalspaceprogram.com/topic/173818-181-1122-k...

[2] https://xkcd.com/1244/

[3] https://en.wikipedia.org/wiki/Nuclear_lightbulb

[matheusmoreira]

It's that close flyby of the sun that always gets me.