I remember watching a series a few years back where someone needs to fire a gun in space but the gun needs an atmosphere to work.

So he comes up with an idea: He uses a spare space suit and puts the gun inside so he can fire it. Another character remarks that he better hit his target since he only got one shot.

After he took the shot the glass in the helmet, where the gun was pointing out of, broke and he hit his target.


1 Answer 1


This is the Firefly episode "Our Mrs. Reynolds" as per this entry about Jayne's gun Vera:

In the TV series' episode "Our Mrs. Reynolds", "Vera", Jayne's powerful customized Callahan Full-bore Auto-lock is used to disable a space station which set a trap to catch Serenity. This weapon needs air to operate, so it normally cannot function in the vacuum of space. Unfortunately, the gun must be outside the ship in order to fire without piercing Serenity's own armor. A problem which is remedied by enclosing the weapon in a pressure suit, giving Jayne a few seconds to fire after his first shot before air in the suit runs out.

Because gun cartridges contain both propellant and oxidizer, this probably would not be necessary, something the show's producers admitted afterwards.

  • 16
    The propellant does not need air, but it is possible that the mechanism of the gun won't operate properly in vacuum - lubricants that harden up in vacuum, pressurized components that would burst or bulge.
    – JRE
    Commented Jun 17, 2021 at 17:13
  • 1
    @JRE very likely is also that the metal parts themselves could weld together on contact. See en.wikipedia.org/wiki/Cold_welding, it was a serious problem for mechanical parts in early satellites
    – Hobbamok
    Commented Jun 18, 2021 at 8:20
  • 3
    @Hobbamok Even without the suit, the gun would have been in vacuum less than a minute, so I don't think cold welding, lubricant failure, or anything like that would have been a problem. The more likely explanations are either (a) the gun uses a far-future unobtanium gunpowder that does require ambient air, or (b) Joss Whedon didn't know how guns work. Commented Jun 18, 2021 at 14:57
  • I think there was also a later justification for being able to cycle for the second shot. But yeah, they basically owned up to that they asked some experts, were told there needed to be oxygen/atmosphere, and later learned that they got the wrong advice.
    – FuzzyBoots
    Commented Jun 18, 2021 at 15:15

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