The Hubble Space telescope has been Orbiting the Earth for over two decades, Hubble has helped to answer some of the most compelling astronomical questions of our time – and uncovered mysteries we never knew existed. Investigating everything from black holes to planets around other stars, Hubble has changed the face of astronomy, ushering in a new chapter of humanity’s exploration of the universe. Although named to honor astronomer Edwin Hubble, the telescope was championed by astronomer Lyman Spitzer. Launched in April of 1990 and poised for many more years of trailblazing science ranging from our own solar system to the edge of the observable universe, NASA’s Hubble Space Telescope is fulfilling the hopes astronomers have long held for a large, optically superb telescope orbiting above the Earth’s distorting atmosphere and providing uniquely clear and deep views of the cosmos. It is NASA’s one of the most well-known and versatile telescopes. It was carried by space shuttle during 1990. It was built with the collaboration of United States Space Agency, European Space agency, and Space Telescope Science Institute.
The HST was set to launch in 1985 but its launch was delayed due to Challenger disaster. It was finally launched on April 25, 1990 on Space shuttle. Another great achievement was the image of Deep Field that revealed at least 1500 galaxies at various stages of development. During its 20 year operation it went under four servicing modules and is still in operation. Since Hubble was launched in 1990, its images have become some of the most iconic in the history of photography. Nasa says the telescope-should keep working until at least 2014, when it will be replaced by a more powerful observatory to be called the James Webb Space Telescope.
2. History of Telescopes
Human’s curiosity to know about the space is not new. During the early ages, humans gazed at the sky and wondered how it looks like outside the earth. This curiosity to know about stars and sky was the first step towards the development of science and astronomy. As humans made advancement in science and technology, during 20th century, many mysteries of space were unfolded. But the findings of space had already been started in early 16th century when first telescope was invented. In fact, telescopes were called spy glass at that time.
First spy glass was invented during 1608 by Holland’s optician Hans Lippershey. The device was called spy glass because it was used to magnify the distant objects on Earth. The device consisted of two lenses. First, primary lens was convex and second lens called eye piece was concave and telescope simply slid inside itself to focus.
During 1609, Galileo Galilei (Ref 1) was in Venice. He heard about the invention of Hans Lippershey’s telescope and started to construct his own improved telescope. His telescope was an arrangement of glasses to magnify objects. His first vision was improved to view only up to eighth power but in next few years he improved it to 20 times further. He mounted it on a stand which made the viewing more stable. At that time he first reported his observations of moon, Jupiter, and Milky Way. Later on he also reported the moons of Jupiter, sunspots, and phrases of Venus. In 1668, Sir Isaac Newton produced first successful telescope. It consisted of a 2 inch concave spherical mirror, a flat secondary mirror and a convex eye piece lens. This design enabled to magnify objects millions of times than a regular lens. It was made of copper and tin. After Galileo, during 18th century, many other scientists and astronomers continued to improve the flaws and qualities of telescopes. In 1850, William Cranch (Ref 2) an American Astronomer, pointed his telescope towards the moon and took the first picture of moon using photographic plate.
A. Early Telescope Technologies
a. Radio Telescope
20th and 21st century was a great revolution in the history of telescopes. As...