Hubble Space Telescope
The Hubble Space Telescope (HST) is a famous telescope. It is the first optical telescope orbiting the Earth. Being above the atmosphere means it can see the sky more clearly than a telescope on the ground, because the atmosphere blurs starlight before it reaches earth. Even telescopes on mountains where the atmosphere is thinner can not produce images as good as Hubble. Named after the astronomer Edwin Hubble, the Hubble Space Telescope can observe 24 hours a day. The telescope can take pictures of things so far away it would be nearly impossible to see them from anywhere else.
It actually observes less than 20% of the time. It was made by both NASA and the ESA working together. It is 600 km in space and was launched April 24 1990. It completes a full orbit of Earth every 97 minutes. That means it travels at 5 miles per second. If you were going this speed on Earth, you would be able to get from New York to San Francisco in 10 minutes.
The Hubble itself is the size of a large school bus, but still small enough to fit inside the cargo bay of a Space Shuttle. It was repaired in 1993 due to small imperfections in the picture quality.
Launch.
The telescope was launched in 1991 by a space shuttle. When it entered orbit, everything seemed fine. But there was a problem with the telescope that wasn't discovered until it started taking pictures.
Problems.
When the HST took its first pictures, astronomers were so happy to see the images. But they noticed a problem with the telescope's mirror. The mirror was not curved right, but only by.0002 inches. Still, this was enough to cause the images to be blurred. Some said, unkindly, that Hubble was nearsighted.
Repair.
Another space shuttle was sent up shortly after to repair the space telescope. The repair was far from easy. What the astronauts would do is install cameras and other optical equipment to compensate for the wrongly-curved mirror. When astronaut Story Musgrave opened one of the doors on Hubble to install a new camera, the door wouldn't close, so Musgrave and the other astronauts had to think of a creative way to get around the problem. Eventually, Hubble was fixed.
Repairs and servicing missions have been made to the Hubble Space Telescope now and then.
Future.
Hubble will soon be replaced by other better and more complex telescopes, like the NGST and the Terrestrial Planet Finder
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