Flame trenches/deflectors are essential for avoiding reflections of acoustic waves from damaging the rocket system while taking off. This is discussed in this YouTube video - Why doesn't the sound of a rocket launch kill you?

But taking the artistic representation of Martian take off and landing, say from the movie Martian or Elon Musk's tweet, there is an absence of flame trench.

So this kindles the question - whether a flame trench is required in Martian condition. How will the launch site in Mars look like?

  • $\begingroup$ Flame trenches are not essential; they simply allow for slightly less robust rocket construction. $\endgroup$ Oct 1, 2018 at 1:50

1 Answer 1


One aspect of this is the amount of energy used. When a falcon rocket lands, the landing pad is just pavement. One reason that is enough is because there is so much less energy being used to land a mostly empty rocket. Obviously when landing on a raw unprepared site on another planet there can be no flame trench or landing pad. Rockets will obviously have to take off of those sites. However the gravity is so much less on Mars or the moon, a lot less energy is needed, even for a fully loaded take off. So in a sense, that problem has not been solved as much as avoided. A much bigger problem at unprepared sites would be flying debris kicked up by the rocket exhaust. It poses a danger to other facilities in the area. That has been discussed on this site.

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    $\begingroup$ ...plus there are options that cost in efficiency but allow to bypass the requirement. Simply start up at lower energy, with something that doesn't risk damaging the rocket until it's high enough. Russian ICBMs launched from mobile launchers are ejected from the launch tube using compressed air, and only ignite the engines afterwards, with a good vertical velocity. $\endgroup$
    – SF.
    Oct 1, 2018 at 8:19
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    $\begingroup$ Not sure about the energy thing - gravity on Mars is still 40% of earth so you'll be still need to be firing the three SL Raptors at a decent load to get off the surface. Not quite the 30+ of Super Heavy, but I don't think it's anywhere near avoided yet. $\endgroup$
    – throx
    Feb 14, 2021 at 23:43

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