QUESTION:
What kind of materials is the Hubble Telescope made of?

ANSWER from Bob Chapman on May 1, 1996:
The Hubble Space Telescope is made of lots of different materials.  The
main structure of the telescope must be very strong, and must not be
sensitive to large temperature changes as it goes in and out of sunlight
while it circles the earth.  It is made of a material called graphite
epoxy.  Filaments of graphite are mixed into epoxy, similar to the epoxy
you might use to repair broken things.  This structure is light weight,
strong and insensitive to temperature changes, just like it must be.  The
structure that holds the science instruments is also made of graphite
expoxy and is covered by a shell of aluminum.

Most of the outer surface of the telescope is covered with blankets of
multilayer insulation known as MLI.  The MLI consists of 15 layers of
Kapton which is coated with a thin covering of aluminum.  The outer layer
of the MLI is something called Teflon Flexible Optical Solar Reflector.
The blankets are held in place with reflective tape.

The primary mirror is made of a special glass known as ultra-low-expansion
 glass, or ULE glass for short, so that it is also not sensitive to
temperature changes.  The mirror is a "sandwich" of two thin solid plates
of the glass with a honeycomb of the glass between them.  This makes the
mirror light weight. If the mirror were solid, it would weigh 8000
pounds.  The honeycomb weighs only 1800 pounds.

So you can see that the Hubble Telescope is built out of many different
materials.  The materials were chosen by the engineers who designed the
spacecraft to make sure it was able to perform well in the harsh
environment of space.