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On Wed, 22 Mar 2000, Lesa wrote:
> What happens to all the satellites and other pieces of technology that are
> left in space? Do they continue to orbit our plant, disintegrate or are
> broken into small pieces, fall to or collide with other planets, or What?
> Is this a problem to be considered in this millennium?
The problem of space debris is a serious one. In the past, old
satellites, pieces of rockets, and astronaut trash were left in Earth
orbit. Things near the earth (within a few hundred miles) re-enter the
atmosphere fairly quickly (within a few years) because there is still a
little air to slow them down at these low orbits.
However, things in higher orbit remain in orbit forever. Anything with
motors on them tend to explode eventually, creating swarms on tiny debris.
Even dust from meteors can hit satellites, knocking off chips of paint.
Even a fleck of paint can do serious damage at 17,000 miles per hour!
These days, satellite manufacturers are becoming more conscious about
de-orbiting satellites when they are finished being used. The best
examples are the Iridium satellites, a series of satellites belonging to a
failed communications company. Rather than stranding the satellites in
space, Iridium and their partners are spending several million dollars to
de-orbit the satellites.
Problems still exist with existing trash, and various schemes have been
developed for finding ways to clean up space. In the meantime, radar is
used to locate larger pieces of space junk (sizes of nuts and bolts or
larger). The space shuttle must routinely make orbital corrections to
avoid such junk. The International Space Station recently announced that
the shielding on the newest Russian module is too thin, and that the
module has a 25% chance of being punctured by space debris during the life
of the space station. So, space trash is still a serious concern!
Thanks for writing!
Sincerely,
Kurtis Williams
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