Hey, welcome back, steel shark. I was wondering how things were going there. Yeah it is a great game, isn't it! So similar to Frontier/First Encounters and so different!
As for emergency oxygen, you can upgrade your life support system to give you plenty of time to get help if the situation is dire.
Two life lines in Open play:
Fuel Rats: If you're out of fuel, oxygen is running low and you don't want to die in space
https://fuelrats.com/
It's for real though so don't use it if you don't need it. Same goes for
The Hull Seals
https://hullseals.space/
if your ship is so damaged you can't get back to safety
Threadfin: Hah! Awesome! Have a blast!