U.S. space shuttle Discovery lifts off, delivering solar array wings to ISS

WASHINGTON. March 16. KAZINFORM The U.S. space shuttle Discovery lifted off on Sunday from Cape Canaveral, Florida, on a mission of delivering the International Space Station's (ISS) fourth and final set of solar array wings, completing the station's truss, or backbone.

It is NASA's first space shuttle flight in 2009. The space shuttle set off at 19:43 p.m. EDT (2343 GMT), thundering into a clear sky. Thousands of people came to Kennedy Space Center to see the blastoff. The NASA TV shows that the five engines boosting Discovery and its external tank towards orbit shut down as planned about eight and a half minutes into flight. Shortly after that, the shuttle entered its orbit with a speed of 17,500 miles (28,000 kilometers) per hour. "Everything looks perfect on the orbiter," said Mike Moses, the head of the mission management team, at a live broadcast press conference following the launch. Mike Leinbach, launch director for the mission, also thought the launch was "just gorgeous." "I have seen a lot of launches ...and this was the most visually beautiful," he told reporters at the press conference. "It was just spectacular. When the orbiter and the tank, booster got up in the sun light ...it was just gorgeous." The space shuttle is expected to dock with the ISS on March 17.Its seven crew, commanded by Lee Archambault and include Koichi Wakata, the first Japan Aerospace Exploration Agency's resident station crew member. He will replace NASA astronaut Sandra Magnus as part of the ISS' Expedition 18 crew. Discovery's mission will feature three spacewalks to help install the S6 truss segment to the starboard, or right side of the station and the deployment of its solar arrays. The arrays will provide the electricity to fully power science experiments and support the station's expanded crew of six in May. The truss is a high-tech girder structure made up of 11 segments. It provides the backbone for the station, supporting the U.S. solar arrays, radiators and other equipment. To install the S6 truss segment, the station's robotic arm must extend its reach just about as far as it will go (about 57 feet or 17.4 meters), leaving it with very little room to maneuver. The S6 truss segment weighs a little more than 31,000 pounds or 14,061 kg. After S6 installation, the truss will be 335 feet (102 meters) long. Each solar array wing has two 115-foot-long (35 meters) arrays, for a total wing span of 240 feet (73 meters), including the equipment that connects the two wings and allows them to twist as they track the sun. Altogether, the station's arrays can generate as much as 120 kilowatts of usable electricity -- enough to provide about forty-two 2,800-square-foot (260 square meters) homes with power. The addition of the S6 will nearly double the amount of power for station science -- from 15 kilowatts to 30 kilowatts. The flight will also replace a failed unit for a system that converts urine to potable water. The ISS' Urine Processing Assembly that removes impurities from urine in an early stage of the recycling process is not working. The entire Water Recovery System was delivered and installed during the space shuttle Endeavour's STS-126 mission in November, 2008. Astronauts were able to coax it into use by performing in-flight maintenance, but a distillation unit failed after Endeavour's departure. Discovery entered a launch countdown last Wednesday, before ground crews at NASA's Kennedy Space Center in Cape Canaveral noticed a hydrogen leak in a liquid hydrogen vent line between the shuttle and the external tank. The leak forced NASA to immediately begin unloading fuel from the tank and cancel the Wednesday launch. The shuttle was initially scheduled for launch on Feb. 12, but concerns over suspect fuel control valves in the spacecraft's main engines prompted several delays so engineers could replace them. Like the leaky gas hydrogen line that thwarted Discovery's Wednesday launch, the shuttle's three fuel control valves are also designed to maintain the proper pressure inside the liquid hydrogen fuel reservoir of the orbiter's attached external tank. A similar valve on the shuttle Endeavour cracked during a November 2008 launch and NASA wanted to be sure a similar problem did not pose a risk to Discovery and its crew. Because of the delays, the mission originally slated to last 14days, with four spacewalks, was shortened by one day with one spacewalk eliminated, to make room for an incoming Russian Soyuz spacecraft set to launch March 26. The Soyuz will carry up a fresh crew for the space station. The mission's first spacewalk is expected to take place Thursday to install the new solar wings. The canceled spacewalk chores will be tackled by the space station crew after Discovery leaves. Discovery's delay has also hindered plans to launch a new U.S. military communications satellite from the Cape Canaveral Air Force Station near Discovery's seaside pad at the Kennedy Space Center. The Wideband Global SATCOM-2 satellite was due to launch Saturday atop an Atlas 5 rocket, but will stand down until next week, Kazinform cites Xinhua.