@othus12: I don't understand the relevance of the Kings having a better chance of surviving in space, it won't help them much unless they started in space, and though they probably can launch him into space, I really don't think they'd resort to something like that.
He's at least around Buranchi's full speed (otherwise the time spent on the moon would contradict the plot) and even if he was below Buranchi, he would still be able to easily outpace Zebra prior to the skip (I won't comment on Current Zebra because he hasn't many feats yet).
@ohgodwhy: No definite time frame was given, yeah he's most probably faster, but my point was that even if you low ball the feat, Saitama is still a minimum as fast as Buranchi.
btw if boros sent him to outer space instead of the moon he would have died. his strenght matters for shit there.
To be fair, the only reason the Kings could make it back in a situation like that is because they fire projectiles to propel themselves, otherwise they'd be in the same boat under those circumstances.
1. Seven Seas Alliance Generals
2. Don't know these two