Learn about the maintenance of the Hubble Space Telescope and the assigned tasks to the crew of this mission.
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The Hubble Space Telescope Maintenance 1/3 Deployed bon April the 25th 1990, the Hubble Space Telescope is a giant observatory aboard a spacecraft. It can make observations of the universe using visible near ultraviolet and near infrared light spectra above the filtering effect of earth’s atmosphere. Because of its ability to capture faint light in fine detail and the precision of its observations, the Hubble Space Telescope rapidly expanded astronomers understanding of the cosmos. But like most intricate pieces of manmade machinery, the Hubble Telescope needs regular maintenance and servicing. This week, we join a seven-man crew on the space shuttle Discovery as they link up with the Space Observatory during the last days of the 20th century. This is mission STS-103. The men on that mission who are charged with the responsibility of restoring the Hubble to its full operational capability, mission commander Curt Brown, a colonel in the United States Air Force making his 6th voyage into space and he served as commander. By contrast on his first flight into space is pilot Scott Kelly, lieutenant commander with the US Navy. Five mission specialists are assigned to the flight. Payload Commander is Steven Smith. He’ll team with John Grunsfeld on his first and third of three scheduled space walks known officially as extravehicular activities or EVAs. European Space Agency astronaut Jean-FranÇois Clervoy is serving as the flight engineer and primary robot arm operator and Claud Nicolai from Switzerland is another representative of the European Space Agency. STS-103 is his fourth mission into space and he’ll take part on the second space walk. He’ll be joined on that expedition by Michael Foale, who’s making his fifth journey into space. We joined the Discovery crew towards the end of their third day in space. As part of their preparations for the first of the EVAs on the following day, staff at the Houston Mission Control Center ordered the pressure in Discovery’s cabin to be lowered to 10.2 pounds per square inch. This is part of the procedure to reduce the amount of nitrogen in the blood of space walking astronauts. Alter, they will breath pure oxygen. Though steps are designed to eliminate the possibility of nitrogen bubbles forming in their blood during space walks and causing an attack of the bands, a condition similar to the one that can affect deep-sea divers brought to the surface too quickly. The following day, Discovery astronauts completed the two highest priority tasks of their Hubble Space Telescope servicing with a space walk that was the second longest in history. Astronaut Steve Smith and John Grunsfeld installed six new gyroscopes and six voltage temperature improvement kits in the telescope during their eight-hour, 15 minutes space walk. Working deliberately, Smith and Grunsfeld replaced three rate sensor units, each containing two gyroscopes. Four of Hubble’s gyroscopes had failed making the telescope unable to point itself precisely enough. At least three operable gyroscopes are needed to point the telescope with the accuracy required to track its astronomical targets. The space walkers also installed voltage temperature improvement kits on wiring from Hubble’s solar arrays to each of its six batteries. The kits are designed to improve control of the charging of the space telescope’s 10-year-old batteries. With Hubble latched up right in the payload bay, Smith and Grunsfeld completed all major task scheduled for the first of three space walks on three consecutive days. A few minor objectives including applying lubricant to the door of one of the telescope’s bays and taking close-up photos of the voltage temperature improvement kits were left undone. Flight and telescope controllers decided to cancel the photography job and schedule a 10-minute lubrication job for the next space walk. The duration of the space walk was second only to the eight-hour, 29-minute space walk from endeavor on STS-49 in May 1992.
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