I recently watched, The Martian and was wondering about some of the manoeuvres and propulsion in space.

Specifically the manoeuvre the Ares 3 crew use in the scene where they pick up Mark Watney after he leaves Mars' atmosphere. The crew blow an airlock with an IED in order to slow their relative speed with the MAV and in the same vein, Watney then uses the same principle when he does his 'Iron Man' stunt, using the escaping air to propel himself towards the Ares 3.

My question is, how is this possible? How can escaping an escaping gas (from a pressurised container, a spacecraft or a suit), venting into a vacuum, produce thrust with no particles to act against?

I've seen similar depictions of this in, for example, Battlestar Galactica. The Colonial Vipers vent some kind of gas to aid manoeuvrability.

  • $\begingroup$ It is also basically the same question as space.stackexchange.com/questions/13298/… Same problem with spoilers too... $\endgroup$ Commented Jan 2, 2016 at 20:29
  • $\begingroup$ @RichardC You can mark parts of your question with ">!", to hide spoilers. $\endgroup$ Commented Jan 2, 2016 at 20:31
  • $\begingroup$ @Hohmannfan Yeah sorry about that. First time asking questions on here. Is that hidden? Used <spoiler>Spoiler</spoiler> $\endgroup$
    – 3therk1ll
    Commented Jan 2, 2016 at 20:38
  • $\begingroup$ Think that should be it $\endgroup$
    – 3therk1ll
    Commented Jan 2, 2016 at 20:46
  • 3
    $\begingroup$ Glad it helped - but short answers that are just a reference don't count as answers here. This question is close enough to the other to count as a duplicate of it, if there are a couple more votes that it is a dupe, a link to the that question will be permanently posted under it. That makes it easy to find. $\endgroup$
    – kim holder
    Commented Jan 2, 2016 at 21:02


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