Hubble Space Telescope
by Jeanette CainMore articles in Telescopes
Lyman Spitzer was the astronomer who first proposed the idea of an extraterrestrial observation post. NASA began building the Hubble in 1977, launching in 1990, but soon discovered that Hubble's main mirror was slightly off in shape. Computers came to the rescue by compensating for this fault. A massive black hole in galaxy M87 was discovery by Hubble in 1992, and, in 1993, Hubble's vision problem was corrected by a service mission.
The impact on Jupiter by the Shoemaker-Levy 9's impact was witnessed and recorded by Hubble in 1994. The birth of the Eagle Nebular was photographed in 1995, and provided scientists with a view of galaxies up to 10 billion light-years away. In 1997, Hubble had an infrared camera installed, monitored Mars dust storms, and checked landing areas for the Mars Pathfinder. The most powerful explosion ever witnessed was detected by Hubble in 1999. The detection revealed a galaxy having an energetic gamma-ray burster.
Launched in 1990, after decades of planning by scientists, astronomers, and physicists, the Hubble Space Telescope was launched into orbit above the hazy atmosphere of Earth. The Hubble is run by remote control by astronomers from many countries, but rather than human observations on the eyepiece, Hubble has sensitive light detectors and electronic cameras.
Hubble's heart is a reflecting telescope, but in space, it operates without an outside source of electricity, swivel mounting, and linking cables. Hubble was designed to carry equipment found on satellites, like solar panels for power, reaction wheels for direction, and radio antennas for communication with Earth-bound scientists.
NASA's Goddard Space Flight Center, Maryland, is mission control, which means that all signals, to or from Hubble, go through this center. NASA's engineers keep a continual monitoring of Hubble's equipment, and also act as a go-between the telescope and the Hubble astronomers. These astronomers are located at the Space Telescope Science Institute in Baltimore, Maryland.
Space Shuttle Discovery astronauts, Mark Lee and Steven Smith, serviced Hubble. Since the telescope needs regular servicing, as a car, the shuttle astronauts will replace equipment, including tape recorders, and computers. The Hubble can be updated by installing new cameras and light and infrared radiation detectors. In 1993's first servicing mission, Hubble's vision was corrected by installing contact lenses to correct the problem.
Hubble is an asset for studying the galaxies and stars. Earth-bound telescopes need to look upward through an atmosphere of turbulence, which continually distorts and changes the light coming from these distant places. It is similar to looking at an object through dirty water, and it is the reason that stars seem to twinkle. The Hubble has a clear view of all things in the universe, even quasars billions of light-years away.
1. Couper, Heather and Nigel Henbest. Space Encyclopedia DK Publishing, Inc.: NY 1999
2. Editors. Secrets of the Universe. International Master Publishing: US. 1999