Subj: Our FIRST space
station
Date: 9/12/00 10:02:20 PM Pacific Daylight Time
From: cleland@nwlink.com (James Cleland)
To: BARDSQUILL@aol.com
9/12/00
Lest we forget, long ago we had a nice, big space station, Skylab...launched
by a Saturn rocket, and larger than Mir. Cost a bundle of money. Astronauts
visited it, I think, about 3 or 4 times. Then....
"An event that received considerable press coverage involved the fall of
Skylab in 1979. Skylab was a manned space station whose measurements of the
Sun from above the atmosphere generated important new insights into the operation
of the Sun. It had not been intended to allow Skylab to fall, and when it
did, it was not clear just where this massive object would come down. A report
of the National Academy of Sciences describes what happened:
It became a media event with all the ingredients of suspense and potential
for catastrophe to frighten a confused public. When the last astronaut left
Skylab in 1974, it was thought that the spacecraft was in a safe parking-orbit,
where it could await a visit by an early Space Shuttle flight, which would
push it to a higher orbit for safekeeping until it could be refurbished and
reactivated. Unfortunately, the plan was frustrated by a delay in the Space
Shuttle schedule and by the rapid rise of solar activity toward sunspot maximum.
With high sunspot activity came a hotter and denser atmosphere at Skylab
altitude, which increased the drag on Skylab and caused the orbit to decay
much faster than anticipated. Skylab thus fell victim to solar activity.
Our inability to predict where it would fall exemplifies our current lack
of instruments to observe with adequate precision the solar output of extreme
ultraviolet and X-rays, which control the density of the atmosphere at satellite
altitudes.
And so Skylab was destroyed by the activity of the Sun that it had been designed,
in part, to study. Fortunately, after a fiery reentry, its remains fell in
a remote area of Australia and harmed no one. Scientists and politicians,
along with everyone else who had been following the story, breathed a sigh
of relief."