QUESTION:
Does NASA plan to take the Hubble Telescope back down to Earth when it no longer
is able to function?

ANSWER from Bill Crabb on April 11, 1996:
When the Hubble Space Telescope (HST) program was originally designed, =
the plan was to service the satellite in space every 2.5 years and return =
it to the earth every 5 years for servicing. This implied that we would =
relaunch it every 5 years. We came to realize that for a number of =
reasons this would not be a good idea. Probably the most important reason =
is the cost involved. Every return to earth would mean two shuttle =
flights, one to bring it back and one to put it back up. Shuttle flights =
are expensive. Another reason is that returning to earth and relaunching =
is stressful on the telescope so the fewer times we have to do this the =
better off we are. Can you think of any other reasons why we wouldn't =
want to bring it back to the earth if we are going to use it again? =
Remember that HST is a very sensitive instrument and consider the =
differences between earth and space.

NASA designed the HST to be serviced in orbit. We have already serviced =
it once in 1993 and plan to do it again in 1999 and hopefully 2002. The =
first servicing mission was very successful and we expect the second to =
be as well. The HST is designed to last 15 years, but there is no reason =
it shouldn't be able to go longer if it is still producing good science =
and there is enough money to pay to keep it going.

Whenever NASA and the scientists around the world feel that HST is no =
longer worth the cost of operating it, NASA currently plans to bring it =
back to earth (and probably put it in the Smithsonian museum). One reason =
for doing this is that the telescope is big. Satellites in low orbits =
(about 368 miles) like HST have a tendency to lose altitude over the =
years. This is primarily caused by the little bit of atmosphere up there =
causing friction and therefore dragging the telescope down. This effect =
is worse when the sun is very active (lots of sunspots). This causes the =
atmoshere to heat up and swell a little. This means there is more =
atmosphere to drag the telescope down. Although most of the satellite =
would burn up, there may be pieces big enough to survive and hit the =
earth. We don't want that to happen so periodically we intend to use the =
Space Shuttle to boost it up to a higher altitude. When we eventually =
decide to shut down the HST we would no longer be reboosting so we'd have =
to bring it back to prevent it from reentering the atmosphere.

 I got to see the Hubble Space Telescope before it was launched and I =
consider myself lucky. Someday, when the HST is returned to earth, others =
like yourself will be able to enjoy not only the exciting results the HST =
has produced, but the sight of the vehicle itself!