LA Times: Critic says Space shuttle is "Inherently Unsafe"

Lynndel Humphreys wrote:



Graphite epoxy with a little quartz fiber

and hypothetical diamond titanium alloy

thrown in would be much much
better.


http://www.whitebottom.com/philipball/m03_12.asp

Diamond would be great, but someone is going to have to break down and
tell De Beers that diamonds are just a bunch of carbon, and in the future
it will be as common as dirt.

The RCC panels are manufactured much the same as charcoal. A graphite
impregnated rayon cloth layup. Bake everything out except the carbon. Then
add more carbon (alcohol) and baking everyting out of it again.
Finally add a layer of silicon carbonate.

I would think a better RCC panel might be made out of SiC foam with a layer
of graphite cloth on both sides, all held together with SiC. It would be
stronger and more impact resistant. Instead of somewhat random carbon
(charcoal) with a little bit of graphite in it, it would be single fiber
graphite cloth composite with a foam core. Much stronger, thicker, stiffer
and impact resistant.

Maybe even make the SiC foam on graphite instead of a vitrious carbon

http://www.ultramet.com/

Light weight SiC foam is good at abosrbing impact energy, which would help
stop the leading edge from being fully penitrated.

Kind of looks like NASA isn't going to change it's impact requirements for
the heat shield and is going to continue to fly through a blizzard of
debris. Bussiness as usual. There's a big difference in designing a leading
edge to meet a "no impact" requirement than an "impact resistant"
requirement. The current "no impact" leading edge requirement has a
"bleeding edge" safety factor of only 1.4.

I wonder is NASA's going to change the leading edge safety factor to 4.0
like the TPS?

Craig Fink