The Hubble Space Telescope (HST abbreviated English name from the initials of the Hubble Space Telescope, or just Hubble) is a telescope placed in the outer layers of Earth’s atmosphere, about 600 kilometers altitude, in orbit around the Earth (each orbit takes about 92 minutes). It was launched on April 24, 1990 with the Space Shuttle Discovery as a joint project of NASA and European Space Agency.
The telescope can reach an angular resolution better than 0.1 arcseconds. The HST is named in honor of Edwin Hubble, American astronomer. It is planned to replace it with the Next Generation Space Telescope (NGST) in 2013.
Observed outside the atmosphere has many advantages, because the atmosphere distorts the images and filters out electromagnetic radiation at certain wavelengths, particularly in ‘ultraviolet.
On January 27, 2007, the telescope came into safemode because of a failure. Tool Advanced Camera for Surveys has stopped working and engineers at NASA have disabled the tool to allow the use of other instruments aboard the telescope.
The telescope weighs about 11 tonnes, is 13.2 meters long, has a maximum diameter of 2.4 meters and cost $ 2 billion. This is a reflector with two mirrors in configuration Ritchey-Chrétien. The primary mirror is a concave parabolic mirror of 2.4 meters in diameter, which refers to the light on a hyperbolic convex mirror of about 50 centimeters in diameter. The distance between the vertices of the two mirrors is of 4.9 meters. As approximating the two spherical mirrors, one can calculate the point of formation of the Cassegrain focus, getting the image is formed about 1.5 meters behind the primary.
Two solar panels generate electricity, which is mostly used to power cameras and the three gyroscopes used to orient and stabilize the telescope. In 15 years of career Hubble has taken more than 700.000 astronomical images!
“There is no room for both.” And so the famous Hubble Space Telescope will give way to his successor named James Webb Space Telescope in honor of the man who led the U.S. space companies in the years of the conquest of the Moon. On July 31, NASA announced the 2010 handover. But the community of astronomers are raised voices of protest to obtain an extension.
How to give up a telescope for 13 years has admirably fulfilled the role of observer of the universe? He works full time and produces data about data. And it is the only tool to “see” dall’infrarosso ultraviolet. NASA, however, must deal with its coffers empty, especially after the Columbia tragedy. “The fear is that by extending the stay of Hubble, slipping the launch of the new telescope, since there are no funds to keep them both”, says Physics Today. Given the choice, NASA prefers to invest in new, partly because its maintenance is cheaper. What will happen to Hubble? The initial plan to take him to Earth for its display in a museum, but now the idea is to do so by attaching a rocket to regulate his return explosive atmosphere. We suggest you visit http://www.spacetelescope.org/images/archive/bestof/ where you can find an extensive collection of the most beautiful images captured by Hubble!