Brian May, the guitarist for Queen has a PhD degree in astrophysics. He might not be able to help fix the issue in the spaceship, but I assume would be able to explain why the issue is happening and I hope could also do the guitar solo to brighton rock to distract from the problem.

Dexter Holland of the Offspring would be pretty high on the list. He has a PhD in molecular biology and is also a licensed pilot.

James Williamson of the Stooges became an electrical engineer, working at AMD and then became VP of technical standards at Sony, most notably helping to codify the Blu-ray standard. If something’s going wrong on a spaceship odds are good that you’ll want an electrical engineer.

Professor Brian Cox of the band Dream

https://en.wikipedia.org/wiki/Brian_Cox_(physicist)

Obviously Brian May from Queen.

David Bowie so he can contact ground control.

Grace Slick and the rest of that band, i.e. starship crew.

Intergalactic Touring Band, you get the idea.

Bruce Dickinson, lead singer in Iron Maiden, can fly planes. He'd be my first choice. And Till Lindemann of Ramstein is a pyrotechnician or something. He could probably figure things out if there were an emergency.

Then there's Buckethead. It's probably his spaceship to begin with.

You don't mention living. Can we have one who passed away. I would say freddy mercury because he would get flash to save every one of us.

Chris Hadfield?

Questlove. Just seems like he'd know what to do.

Henry Rollins, maybe?

Brian May would be a good bet with his PhD in Astrophysics.

One of the guys from that band Limozeen, they turned their tourbus into a space machine.

Doesn't really fit the requirements but actor/singer/guitarist David Peter Capaldi probably still has his old sonic screwdriver tucked in a pocket just in case.

Dexter.

Surely at least one random person is a mechanical engineer or something. I wouldn't be able to make a good guess, though.

Ok Go. For some reason I think they might be able to save us.