Henry Spencer wrote:
On Thu, 19 Dec 2002, Ian Woollard wrote:
Does anyone know any rules of thumb for a reentry shield? (I'm trying
to design a reusable vehicle.)
*What sort* of reusable vehicle?
Ok, fair point. I was going for a (semi)ballistic reentry.
TPS requirements vary enormously with
your approach to the problem; in particular, semiballistic capsules and
winged vehicles are completely different. (Capsules make short sharp
reentries, for which expendable coolants like the Apollo ablative TPS or
Roton's water cooling are perfect.
Yes, capsule like, semiballistic..
This is a complex problem, and gentle introductions to it fill whole books.
Any recommendations?
The only thing I've found so far is a reference that Apollo used a
shield mass of 15 pounds per square foot(!); but I'm unclear how to
scale this. [presumably more area = less loading = less shield per
square foot]
Lower loading changes the trajectory, particularly for a lifting semi-
ballistic reentry, so the scaling is not simple.
I can do trajectory simulation if I need to; that doesn't scare me; I'm already
doing that on the way up.
Henry Spencer
[EMAIL PROTECTED]
