Outer space
The Hubble telescope holds the distinction of being the only space telescope. It was launched in April 1990 and revolves around the Earth at the rate of five miles per second. It is named after the American astronomer Edwin Hubble, who demonstrated that other galaxies existed in the universe.
Why a Telescope in Space?
Hubble has been able to beam back to Earth images far more clear and detailed than any other telescope on Earth. This is because its position allows it to escape the distortion and blockage that ground-based telescopes experience due to our atmosphere absorbing most of the light. The idea of a space telescope first arose in 1923 when a German scientist proposed it. It took several years of hard work for the idea to take shape.
The Long Process of Building the Telescope
In 1977, the U.S. Congress approved funding for the telescope, and work was started by NASA in collaboration with the European Space Agency. Various universities and contractors were hired, and work was divided on the cameras, spectrographs, fine guidance sensors and the primary 2.4-meter mirror. The launch of the telescope was initially set for October 1986 at a projected cost of $475 million. After experiencing some delays, the telescope was finally ready for launch in 1990 and had cost more than $2 billion to make.
Maintenance of the Hubble
The Hubble space telescope was the first satellite designed to be maintained in space. Soon after its launch, a maintenance trip was made necessary due to the unexpectedly blurry images that were being sent back to Earth. This blurriness was being caused due to a flaw in the primary mirror, and a mission was carried out in 1993 to correct the flaw. After the first successful maintenance mission, three more service repairs have been done, the most recent one in May 2009.
Hubble's Photography
The first images from the Hubble telescope were released in January 1994. Hubble has beamed back more than 900,000 images, which have increased our understanding of the universe by leaps and bounds. The high resolution, pristine imagery has helped establish a more accurate age of the universe to be between 13 billion to 14 billion years. It has helped shed light on the expansion of the universe and the process of dying stars and how new planets are formed.
The Future
Hubble was initially designed to remain in service for 15 years but a recent servicing mission increased its life to May 2013. It will then be replaced by the James Webb Space Telescope, which will be placed at an even further distance from the Earth and is scheduled for launch in 2014.
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