I dont have art for this yet but I'm working on it. Hear me out tho
We've all heard of Bloodymary. What about Goodmary (HailOmens? GoodBloodyMary? Are we including Iron Lung?) Where Crowley, post S2, gets a letter from Agnes Nutter, telling him to go research the hell out of astrophage and go bully this one schoolteacher in space.
He researches it for about two months, finds a way to not suffocate in space, then drives for half an hour to the Hail Mary, around when Grace and Rocky have just found Planet Adrian.
He then, after thoroughly confusing Grace, makes friends with Rocky, being able to speak his language, and goes, "Hey, if you're trying to stop upstairs from ending the universe again, I can help and also maybe stop them from committing murder on you" and it serves as a good distraction from getting dumped by Azi.
Maybe sometime before the events of PHM, Crowley and Grace worked together, hated each other at first but then became good friends. Some of Grace's students were Warlock and/or Adam.
Crowley's improvised space suit would be like A gas mask, sunglasses/goggles hybrid thing and basically normal clothes, plus a scarf he stole from Aziraphale. He can discorporate from lack of oxygen but not from extreme temperatures or pressure for some reason just for the costume change.
Crowley digs out one of the uniforms from storage and uses his expertise in arts and crafts to embroider them with the name CROWLEY, the british flag and a space agency he made up called OUR SIDE SPACE AGENCY or something.
He helps w/ maintenance (his miracle account has been emptied) and hangs out with Rocky to build stuff. They bully Grace together, despite Crowley being TERRIBLE at maths.
Crowley thinks that Alpha Centauri being the only unaffected star is some sick joke but its just Azi saying 'I'm doing everything I can'
Ive never actually watched Iron Lung so idk where that would fit but its there somewhere.
We just need another depressed science nerd in space. With vision impairments.