Complete the crappy first draft. The v1.0.

Then revise and edit till your eyes fall out.

For what to do next:

Heighten the tension.

If your characters in Homeworld seem too bored and comfortable on Mars-

Blow up Planet Earth.

Or make them think that’s what happened.

Maybe back on earth Hollywood fully conquers the Whitehouse and everything in the media is government controlled CGI spin.
So when funding for the Mars mission gets cut, they can’t just tell the Mars colony theres no more supply ships on the way. The spinmeisters create a war of the worlds scenario - a fake media presentation in which earth gets destroyed or wiped out by plague or really anything short of cracking the globe in half.
Nothing the colonists can observe via telescope but everything that can be transmitted to the colony com uplink- before the transmitter ‘goes dark forever’ and Earth switches to all fiber optic because EM radiation has been proven hazardous to health in the state of California and outlawed or whatever.

So then you have Survivor:Mars.

Will the colony fracture into smaller hostile tribes or get held together by a charasmatic/ messianic leader? Will Clem the guy who seems useless make some kicka$$ Martian homebrew beer so they can all forget their troubles in a drunken stupor? Will Veronica Mars steal Spaceman Skips ( mechanical Jarvik7G) heart?

So many options.

Write out six short real world scenarios- 3 good that happened to you and 3 bad that could happen. Number 1 thru 6.

Get a standard die ( Like dice, but only 1) .Roll it.
Then grab the scenario with that number and hammer it into the script.

Roll again.

For an epic event scale, roll 1D20.

Hope any of this helps.

I hate writers block too.

I like PDAs though, and have really enjoyed your work on Writingonyourpalm over the years.

Cheers.