[Space, Spaceships] Armor needed for Aerobraking/Re-entry

[Humabout]

Originally Posted by Anthony

In practice, any spaceship that isn't huge can achieve however much drag you really want just by going deeper in the atmosphere, but it may not survive the process.

That is the implication of roh varying with altitude.

It is also worth noting that the portion of the ship facing forward during aerobraking should generally be blunt to keep the shockwaveoff of the craft's frame. Otherwise, the craft will be subjected to substantially higher stresses and heat than otherwise.

Laatly as a follow-up on drag coefficients, a reasonable number would probably fall between around 0.4 ish for an Apollo-style capsule down to as little as 0.04 for an extremely thin, perfectly smooth airfoil-shape. The latter is pretty unlikely to be achieved, though, if for no other reason, no craft will be that smooth. I could believe in the 0.1 ti 0.2 range readily enough, though.