[hopespringseternal]

I understnd the structural and thermal superioriy of Ti over Al, but I thought the temperatures required to compromise the structural integrity of Al would cook anyone inside the vehicle anyway, rendering the subject moot.

It is a lot smaller problem to keep certain parts (passenger cabin, etc.) cool than to keep the entire structure cool. Remember that you only have a few minutes of high temps.

The whole thing gets a lot simpler if you minimize reentry heating along with maximizing the heat tolerance of the structure. Shuttle is exactly the opposite case: maximum reentry heating and minimal tolerance for structural heating. This mandated both fragile refractory heat shielding and an intolerance for breaks in that heat protection. This is a big part of the reason the shuttle is so expensive. The heat shielding must be rigorously inspected and there is a lot of it.

[RadioAstronomer]

It is a lot smaller problem to keep certain parts (passenger cabin, etc.) cool than to keep the entire structure cool.

You do need to be careful you do not exceed the thermal integrity of your more exposed areas however.

[tjg]

I see. Thanks again.