Yesterday, I asked a question about the square-cube law and propellant tanks.

Do larger rockets tend to have a better mass ratio due to the square cube law?

I have a very similar question about TPS tiles. Does the mass ratio of TPS tiles improve in larger constructions? I mean, is the weight of the TPS divided by the mass of the whole construction better in larger ships, or do larger ships require thicker tiles, resulting in linear growth?

Starship, someday, will transport humans, so it will be much heavier when reentering the atmosphere (life support etc). Therefore, it will need to withstand much more heat. SpaceX doesn't have a different TPS design for these scenarios.

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    $\begingroup$ Do you have any source for a crewed Starship being much heavier? I would assume it would be much lighter since a lot of the cargo volume is occupied by air. Compare, for example, the mass of a fully loaded cargo Falcon 9 with Starlink with a crew launch to the ISS. Obviously, the mass of the first and second stage are the same, so the difference will be the mass of the payload fairings + the payload versus the mass of Crew Dragon plus cargo, consumables, and crew. Crew Dragon with everything inside is less than 7000kg, the Starlink satellites alone are more than 17000kg. $\endgroup$ Oct 12 at 8:23
  • $\begingroup$ To be fair, that's not a 1:1 comparison since Crew Dragon goes to a higher-energy orbit and SpaceX reserves enough propellant for an RTLS landing. $\endgroup$ Oct 12 at 8:24
  • $\begingroup$ @JörgWMittag During reentry, crewed starship will be heavier than the cargo starship due to additional equipment. cargo starship, on the other hand, will be empty during reentry $\endgroup$
    – Krzysiek
    Oct 12 at 10:35


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