Re: New Material for Mirrors???

Bob Madden (madden@netcom.com)
Wed, 22 Mar 1995 16:07:32 -0800 (PST)

Rich, you have an interesting post here. What is your source to get your IMHO. It sounded to me like the "specific" and "absolute" was somewhat demonstrated (however small that may be). If the material is selected for the Mar's mission, then the factors you discuss may not exist.

I really suspect the material may not be acceptable for mirror use because of surface finish or not being able to polish the surface due to physical properties other than stiffness.

I wonder if the material is an outgrowth of the Shuttle Tiles - thermal management for re-entry?

Back to mirror grinding. I've decided to go back to 400 grit. The hole in the center is too deep! Shucks!

Bob

):-{])) <---- madden@netcom.com madden@svpal.org Remember amateur astronomers: "keep looking for the next Universe"

On Wed, 22 Mar 1995 HOFFMAN@wmich.edu wrote:

> IMHO, it silica aerogel wouldn't work as an optical mirror
> substrate. First, it is not "solid" solid - it is porous,
> so there is not a smooth surface to deposit a reflective
> film on. Second, while it may have a high "specific stiffness"
> (strength divided by weight) due to its very low density,
> it has a low absolute stiffness, so it is very difficult to
> handle without deformation. This would make it impossible to
> figure an optical surface on it.
> Richard Hoffman
>
>