The observation of the sky from the earth is, of course, simplified considerably by using various telescopes, but the atmosphere does, however, obscure and prevent the view of the stars and their radiation.
After various probes had made a large contribution to scientific space research, the Hubble_space_telescope was deployed, on April 24th, 1990, in an orbit around the Earth by the spaceship Discovery. It is probably the most ambitious project ever in the field of astronomy.
The Hubble telescope orbits at a height of 611 kilometers above the earth, where it is not affected by variations in the air, night lights or light dispersion.
In the first year itself, almost 500 observation projects were transmitted to the earth. It is expected to take measurements and pictures from space and transmit them to the earth for 15-20 years. Hubble can detect sources of light that are one hundred times weaker than those that can be seen with the most powerful telescope on the earth.
Among the most important tasks of the telescope is the measurement of the distances between the various galaxies. That is where it gets its name from, because Edwin P. Hubble (1889-1953) had made a great deal of progress in astronomy with his classification of galaxies.
Other research results regarding the structure and chemical composition of planets and other stellar bodies are being saved and transmitted to the ground station. The Hubble telescope is 13 meters long and its main mirror has a diameter of 2.4 meters. It can detect visible and ultraviolet_radiation.
The light falling on the main mirror (concave) is reflected via a secondary mirror (convex) before it is bundled by a hole in the primary mirror. The scientific instruments for processing the collected data are located in the rear part of the telescope. High-resolution images as well as wide-angle images from various highly sensitive cameras are sent to the earth.
The pictures of Jupiter were particularly impressive. In 1994, it was hit by fragments of the comet Shoemaker Levy 9, of which detailed images were sent to the earth. Originally, the Hubble-Telescope was supposed to have been deployed in 1988. In January 1986, when the Challenger tragedy took place, in which the spaceship exploded and was destroyed just 73 seconds after lift-off and the seven-person crew was killed, the American space program was put on hold for some time.
A short time after the deployment of the Hubble telescope, the main mirror was found to be damaged; however, the crew of the spaceship "Endeavor" repaired it in 1993. Since then, it has been continuously relaying back impressive new images and data.
