Musk has stated that the BFS will need a heat shield capable of reentering the atmosphere from interplanetary trajectories. So the ship will come in directly from the transfer trajectory and rely on aerobraking to slow down.

What will the heat shield be made of?

Bonus: What speed would a return from Mars have? How much extra heat, compared to returning from Earth orbit.

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    $\begingroup$ All signs currently point towards an upgraded version of SpaceX's PICA-X material used on the dragon 1 and 2 capsules which, itself, is already an upgrade from the NASA-developed PICA material. spacex.com/news/2013/04/04/pica-heat-shield However SpaceX has not made public exactly what the BFS heat shield will be made of. $\endgroup$
    – Dragongeek
    Feb 12, 2018 at 7:59
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    $\begingroup$ And as designs inevitably change, the PICA-X assumption is dated now. Current possibilities are TUFROC or a TUFROC derived material (TUFROC-X?), or simply a certain alloy of stainless. No confirmed information available yet to answer this. $\endgroup$
    – Saiboogu
    Apr 2, 2019 at 21:30

1 Answer 1


The heat shield will be the same stainless steel used to build the bfs - now named starship. There will be a sandwich of two stainless steel layers where the reentry heat is worst, and in that layer they will pump liquid fuel in the help keep it cool. They even plan to have small perforations in the outer layer to allow the shield to "sweat" so to speak. See test and additional information here: https://www.cnet.com/news/elon-musk-shows-off-fiery-spacex-starship-heatshield-test/

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    $\begingroup$ What about those hexagonal tiles? $\endgroup$ Apr 5, 2019 at 12:52
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    $\begingroup$ Are they stainless steel? $\endgroup$ Apr 7, 2019 at 1:28
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    $\begingroup$ The tiles aren't stainless steel, they are ceramic. teslarati.com/… $\endgroup$ Jul 25, 2019 at 14:13
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    $\begingroup$ @OrganicMarble I wonder if it's worth adding a separate answer, or linking to your vermicelli post? $\endgroup$
    – uhoh
    Oct 22, 2019 at 6:46
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    $\begingroup$ @uhoh the design is too changeable for me to bother, which is why it annoys me when people write "it will be" answers. Especially when they are incomplete and misleading. $\endgroup$ Oct 22, 2019 at 12:04

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