Lookup how to mine bitcoin in space and how gossiping would work

TLDR is we technically need a new chain, but we can source the start of that new chain with Bitcoin, then gossip that network back to earth to show were on the same block height.

Again the limit here is transmitting data at speed of light

Forgive me in my lack of clarification this is way above my experience level, but do know many have discussed and worked the maths out for this. Just gotta test