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In the movie version of The Martian, the MAV's crew module seems to be designed for atmospheric entry. It has a shallow, gumdrop shape, reminiscent of the Apollo or Orion capsules, and what looks like a tiled heatshield on its underbelly. However, in the text of the film, there is no indication that this vehicle was ever meant to re-enter the atmosphere of either Earth or Mars. There's a chance it is carried back to Earth by the Hermes, at which point the crew use it to re-enter and land, but this seems unlikely, as it doesn't have any maneuvering capabilities with which to deorbit, and I would expect the crew to return in the same Orion capsule that carried them to orbit in the first place. I haven't read the book, so perhaps it offers some explanation, or maybe there was something I missed in the movie.

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    Didn't the MAV have to aerobrake to reach the surface of Mars?
    – DavidW
    Sep 14, 2022 at 7:33
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    @DavidW Right. The MAV's are prepositioned equipment, sent from Earth before the mission(s). It would somehow have to be landed on Mars, which would entail entering the atmosphere.
    – tbrookside
    Sep 14, 2022 at 10:36
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    @DavidW The whole MAV is softlanded on Mars, so yes, it should have some sort of heatshield protection. But I think the question just refers to the return capsule, at the tip of the MAV. This takes the crew from the Martian surface to orbit, so they can rendezvous with the Hermes. Like the OP, I don't see a good reason for that to have a heatshield. Sep 14, 2022 at 11:18
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    @CaptAlgorithm I like this answer quite a bit, although being stranded many miles downrange of the Hab in the event of a launch abort seems like a death sentence in itself. All things considered, losing the MAV at all is a death sentence, isn’t it? Since NASA seems to not have any rescue plans ready, nor enough supplies to tide over even a singe astronaut until Ares IV.
    – Luka
    Sep 15, 2022 at 0:50
  • Because that's how crew capsule look and otherwise it wouldn't look right. It was 100% for cinematographic reasons.
    – Mark Olson
    Sep 16, 2022 at 13:35

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I can't let this go! The only answer for the capsule being designed to survive re-entry is cinematographic: That's how we have been trained to think a launch capsule should look. So that's how they showed it.

A failed return to orbit in a MAV capsule would be fatal regardless of whether or not the astronaut survived re-entry. Mark Whatney survived -- just barely -- because when he woke up he had the Mars Hab, provisions for a crew of six, vehicles, a radioisotope generator (and viable potatoes.) The hypothetical crew of six who survived re-entry would have nothing. They would land far, far from anything else and then die. (Probably quickly of suffocation, but if they somehow survived that, it's a toss-up what would get them: accident, starvation, thirst.)

A responsible space agency -- which no matter what its other flaws, NASA certainly is -- would spend the mass wasted here on a re-entry capability on making the actual ascent to orbit more reliable. (See the Lunar Lander and its return vehicle for a case in point on what actual good engineering does in reality.)

The idea that the capsule would be carried back to Earth and used to land there does not work, either. It is expensive to carry mass to Mars (even with the Hermes) and very, very, very expensive to land it on Mars and then take off with it again. It would be much, much cheaper and much, much, much safer to send up a return capsule (such as SpaceX's Crew Dragon) to rendezvous with Hermes once it reached Earth orbit.

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  • Adding to this, theres no reason for the MAV capsule to separate from its service module/booster after MECO - the capsule itself is not large enough to act as its own service module, which means theres basically zero margin of error for docking to Hermes. Note that the act of separation in the "get Mark Watney to orbit" scenario actually induces a random roll in the capsule as well... Theres also zero mention of using the capsules OMS system to stabilise the capsule or attempt to change its position even slightly... Lots of issues in this depiction IMHO.
    – Moo
    Apr 20, 2023 at 1:43

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