The Hubble Telescope is an orbiting telescope that provides clear images from space. It is a reflecting telescope and gathers light with a mirror 94 inches in diameter. It is named after an American Astronomer, Edwin Hubble who made important astronomic discoveries in the 1920’s.
Pictures taken by the Hubble Telescope include: stars surrounded by disks, galaxies, colliding galaxies, and evidence that most galaxies have black holes in their centre.
The Hubble Telescope is in orbit about 380 miles above the Earth. It views the galaxy without having to look through the Earth’s atmosphere which bends light because of diffraction; also because the atmosphere is moving. This is why stars appear to twinkle and blurs the image seen from telescopes on Earth. Because the Hubble Telescope is above the Atmosphere, it produces much finer images.
The Hubble Telescope can also observe ultraviolet and infared light that is blocked by the atmosphere.
NASA operates the telescope and it is controlled by radio commands. Astronomers tell the telescope where to point and data is sent back to them by radio.
The Hubble Telescope has two different kinds of uses; it takes images and spectrographs, which analyse light that is converted into electronic signals.
Although the Hubble Telescope has been a huge success, there are disadvantages: it uses fuel, so it has a limited lifetime but also, it costs millions of dollars to repair and launch.
History
The Space Shuttle Discovery launched the telescope into orbit in 1990. Soon after, they discovered a flaw with its light gathering mirror which made the images less clear than they would have been. So engineers designed an optical device that would make up the error. It was installed in 1993, and it worked as planned.
During this, astronauts also mounted new apparatus on the telescope. They were installed in 1997, 1999 and 2002.
In 2004, NASA cancelled a servicing mission, scheduled for 2006 because of a concern