First visualized, as a concept, in 1946 and then launched in 1990, the Hubble telescope monitors the universe from its position orbiting the Earth. It has been bringing us images of of colliding galaxies, the formation of new stars and even pictures of planets orbiting distant suns.
The Hubble is able to see so much further and so much better than observatories on the ground because the light gathered by the space telescope does not have to go through the Earth's atmosphere. And when light that is coming from distant space objects is not being absorbed, distorted or reflected by various atmospheric layers, the images are much clearer and more detailed.
The telescope is named after Edwin Hubble, the man who made the amazing discovery that the universe is expanding through his observations of distant galaxies. Looking through the most powerful optical instruments of his day, the young astronomer Hubble made a remarkable discovery. The galaxies he was viewing, through the giant lenses in the year 1929, were fleeing away from us at ever increasing speeds depending upon how far they were from the Earth. This observation of how the universe was growing larger has become known as Hubble's Law. It is fitting that this instrument which now monitors distant galactic events occurring in our ever growing universe should bear his name.
Creating the telescope was a massive challenge. Not only must it be a high performance telescope capable of viewing distant galaxies clearly, it would have to cope with massive changes in temperature as it orbits the Earth, traveling closer and then further from the Sun. To cope with the constant temperature changes, scientists came up with a multi-layered insulating shroud which keeps the telescope at a more or less constant temperature.
Another big job for the engineers on the project were the mirrors for the telescope. These were ground and then polished from early 1979 to May 1981, a total of two years! They were kept as light as possible using a low expansion glass to which was added a reflective coat of aluminum and a protective layer of magnesium fluoride.
Once the telescope was launched, the technological problems weren't over. In 1993, just a few years after launch, a service mission into space had to be launched to fix a malfunctioning mirror that was causing a loss of picture quality. In 2007, after over a decade and a half of service, its main camera and several gyroscopes that keep the telescope stable stopped working. Space shuttle Atlantis was used to upgrade and replace the failed equipment keeping the space instrument operational.
In all, five space walking service calls have been made to the Hubble, allowing the telescope to continue to take wonderful images until it is replaced by the new James Webb Space Telescope, This latest space scope is expected to be launched and in service in 2015.
The Hubble telescope has given us unprecedented images of comets, planets, stars and galaxies. It has established the existence of black holes which can only be seen through their effect on light and nearby objects. It is a shining example of our technological abilities in our scientific pursuit of the wonders of the universe.