Overview

The Hubble Space Telescope (HST) is an orbiting observatory designed to provide scientists with a more accurate view of the universe. It was launched on April 24, 1990. The telescope provides a pinpoint accurate tracking system which is aided by its high-tech mechanical systems. It was named in honor of Edwin P. Hubble who discovered evidence that the universe is expanding. The objectives of the HST are to:

• investigate the composition, physical characteristics, and dynamics of celestial bodies
• study the history and evolution of the universe
• examine the formation, structure, and evolution of stars and galaxies
• provide a long-term space based research facility for optical astronomy

Specifications

The main feature of the HST is its primary mirror which measures almost 8 feet (2.4 m) in diameter. During the on-obit check when it was first deployed, scientists discovered a flaw in this primary mirror which prevented perfect focus on incoming light. A subsequent shuttle mission and intricate work on the part of the astronauts repaired this problem as well as upgraded other hardware. The HST was originally retrofitted with five different scientific instruments to aid in studies of the universe:

• Wide-Field Planetary Camera
• Faint Object Camera
• Faint Object Spectrograph
• High-Resolution Spectrograph
• High Speed Photometer

The data that the Hubble Space Telescope receives is transmitted to Earth in a much different manner that previous explorer satellites. The images that the telescope receives are first converted into digital code and then sent by radio waves to Earth. This is accomplished by using its high-gain antennas which transmit at a rate of one million bits per second. There scientists receive the signal and decode it, producing photographs and spectrograph reading.

Accomplishments

The Hubble Space Telescope has produced many valuable images, which include a mysterious dark structure in the spiral galaxy M51. In 1994 the first convincing evidence of a black hole was recorded by the HST. This evidence was the acceleration of gases around the center of the M87 galaxy which lead scientists to deduce that the center mass would have to be 2.5 to 3.5 billions times greater than that of our Sun in order to produce the gravity that would cause this to occur. Also in 1994 the HST provided a spectacular view of Jupiter's bombardment by fragments of the Shoemaker-Levy 9 comet. The data collected during these impacts allowed scientists to determine the chemical makeup of Jupiter's atmosphere. The HST can to do precise research to find out the rate at which other galaxies are retreating from our Milky Way galaxy. This data is very important because it will allow scientist to more accurately calculate the age of the universe. Its most recent discoveries were the images it provided of two colliding galaxies, host galaxies of quasars, and the first planet outside of our solar system ever to be directly photographed.