Originally posted by stumason
It burns easily at room temperature, let alone at 5000c!!
I don't pretend to know about this kind of stuff, but aluminum burns easily at room temperature? What does that mean? Aluminum combusts at 70
degrees? No one said it was
pure aluminum.
Here is what JPL says it is made of, and I think they are probably the experts on this:
What is the aeroshell made of?
Built by the Lockheed Martin Astronautics Co. in Denver, CO., the aeroshell is made out of an aluminum honeycomb structure sandwiched between
graphite-epoxy face sheets. The outside of the aeroshell is covered with a layer of phenolic honeycomb. A phenolic compound is made from benzene and
is typically used in various plastics, disinfectants, and pharmaceuticals. This phenolic honeycomb is filled with an ablative material (also called an
"ablator"), which dissipates heat generated by atmospheric friction.
The ablator itself is a unique blend of cork wood, binder and many tiny silica glass spheres. It was invented for the heat shields flown on the Viking
Mars lander missions 25 years ago. A similar technology was used in the first US manned space missions Mercury, Gemini and Apollo. It is specially
formulated to react chemically with the Martian atmosphere during entry and essentially take heat away, leaving a hot wake of gas behind the vehicle.
(Normal friction without an ablator would cause the heat shield to burn up.) The heat loss to the Martian atmosphere lowers the kinetic energy of the
entry vehicle, thereby it slowing it down .... a lot.....fast! The vehicle will slow from 10,000 mph to about 1000 mph in about a minute, producing
about 10 "Earth gees" of acceleration on the lander and rover.
Both the backshell and heat shield are made of the same materials, but the heat shield has a thicker (1/2 in) layer of the ablator. Also, instead of
being painted, the backshell will be covered with a very thin aluminized mylar blanket to protect it from the cold of deep space. The blanket will
vaporize during Mars atmospheric entry.
This was taken right from
JPL's website
Are you sure you are correct about this? It looks like there is aluminum in the heatshield.
OBTW, you probably shouldn't blast the guy so bad when you are basically wrong.
Edit: One other thing Stunmason, it's ALUMINUM not aluminium

[edit on 7-8-2004 by nyarlathotep]
FIXED LINK
[edit on 8-7-2004 by Kano]