Guess what?The Hubble Space Telescope was named after Edwin Hubble, an astronomer whose contributions to astronomy include a classification system for galaxies and the Hubble Constant. The Hubble Constant defines the relationship between a galaxy's distance from the Earth and the speed with which the galaxy is moving away from the Earth.
Long before man ventured into space, astronomers longed for the ability to put a telescope in space far above Earth's obscuring atmosphere. In 1962, a National Academy of Sciences committee recommended the development of just such a telescope. In 1968 and 1972, satellites for observing the stars were launched. These satellites provided the basis on which a larger, more powerful space-based telescope could be built. With the development of the Space Shuttle came the capability for the delivery and servicing of a space telescope. In 1973, NASA selected a team of scientists to determine the basic design of the telescope while Congress authorized the funding for the telescope in 1977. Construction and assembly of the telescope was completed in 1985. The Hubble Space Telescope was originally due to be launched in 1986, but the explosion of the Space Shuttle Challenger delayed the launch until April 24, 1990. Once in orbit, a defect in the optical mirrors of the telescope prevented the clarity that scientists had hoped for when viewing images provided by the telescope. On December 2, 1993, a crew from the Space Shuttle Endeavor installed corrective devices which brought the images into clear focus.
|The Hubble has a variety of scientific instruments on-board. Among the instrumentation are two cameras, two spectrographs, and guidance sensors. Hubble is controlled by scientists here on Earth who use gyroscopes to measure the rate at which Hubble is moving. When Hubble is being re-aimed from one object to another, it moves very, very slowly. Other gyroscopes help keep the telescope pointed steadily at its target. Scientists communicate with Hubble by radio signals. Hubble, in turn, sends images and data it has gathered to Earth by radio signals. Data from Hubble are relayed to the Tracking and Data Relay Satellite (TDRS) that is in a geosynchronous orbit above Earth. This satellite relays the data to a terminal in White Sands, New Mexico. This terminal then sends the information up to another satellite which then sends it down to NASA at Goddard Space Flight Center in Greenbelt, Maryland. Any communication to Hubble has to travel back along the same path.|
|Hubble has two solar panels which are each 2.3 meters by 11.9 meters in size. These panels convert sunlight directly into electricity which Hubble then uses to power its instrumentation. It takes 96 minutes for Hubble to complete one orbit of Earth. The Hubble was designed to work in orbit for fifteen years. The Space Shuttle and its astronauts are to perform servicing missions throughout Hubble's lifetime. In addition to keeping Hubble running smoothly, astronauts will attach new instrumentation to further increase Hubble's capabilities. Just such a mission occurred in February of 1997 when the astronauts not only installed new instruments, but made repairs to the insulation which protects Hubble from the extreme temperatures in space.|
A QuestionThe Hubble Space Telescope is dependent on whom for any repairs it may need?
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