How would a fire extinguisher work in space?
(yes…I just watched the movie Space Cowboys in which some real tough dudes save the planet earth, or something like that.)
Anyway, in a scene that’s supposed to be scary*, a fire breaks out in the electronics. And the handsome hero saves the day by reaching out for a standard fire extinguisher, (like the one I have in my kitchen), and dowsing the control panel with foam.
So I started to wonder: what would really happen if you sprayed foam in zero gravity? And what would happen in the space shuttle if electronic parts overheat and start flames? How would the astronauts handle it?
*(right before they ‘accidently’ discover the nuclear missiles, duh),
It works the same as on earth - CO[sub]2[/sub] displaces O[sub]2[/sub] so the fire goes out. In microgravity the CO[sub]2[/sub] won’t sink like on earth, just form an expanding sphere. But the fire burns spherically and slowly anyhow. You probably need less CO[sub]2[/sub] and at a lower nozzle pressure.
But you also need to ensure that the CO[sub]2[/sub] is dissipated so your astronaut doesn’t asphyxiate. Space stations keep air moving to avoid this.
Fun for all - until the CO[sub]2[/sub] alarms start going off, you run out of scrubbers, and you are left with the choice of dying slowly of asphyxiation or sucking vacuum for a quick end…
Not on the Shuttle, but there was an electrical fire on the Mir space station that the crew were able to put out with onboard fire extinguishers. I can only imagine it was a total nightmare while it lasted!
