Space shuttle Discovery set for launch on March 11

Posted by Wolfgang Gruener

Cape Canaveral (CA) – Following a series of delays, NASA today said that Discovery can now be prepared for mission STS-119. An investigation focusing on the shuttle’s flow control valves did not reveal any damage and convinced engineers and managers that Discovery is ready for flight. Lift off is scheduled for March 11.
 
STS-119 was originally scheduled to launch on February 12, but was delayed several times as NASA said it required time to understand what caused the damage to a flow control valve on Discovery’s sister ship, Endeavour, during its November 2008 flight. In late February, NASA said that it would take more than 4000 images of each of the three valves to analyze the devices in detail, reviewing them for possible evidence of cracks. Engineers were also looking into the effects of a possible damage to those valves and what may happen when a valve breaks, or if pieces break off and potentially damage other parts of the shuttle - such as the pressurization lines between the shuttle and the external fuel tank.

In a presentation given earlier today, which included a formal presentation of the shuttle's flow control valve work, engineers cleared the three valves installed in Discovery of crack indications.  

The three flow control valves, one for each space shuttle main engine, channel gaseous hydrogen from the engines through the main propulsion system and back to the external fuel tank. This flow regulation maintains the tank's structural integrity and delivers liquid hydrogen to the engines at the correct pressure. NASA did not provide any information what impact a cracked valve may have on the entire shuttle.

Scheduled for a 9:20 pm EDT launch, the 14-day mission STS-119 will deliver the S6 truss segment to the ISS and install the final set of power-generating solar arrays: The payload will include two solar array wings, each of which has two 115-foot-long arrays, for a total wing span of 240 feet, including the equipment that connects the two halves and allows them to twist as they track the sun. Altogether, the four sets of arrays can generate 84 to 120 kilowatts of electricity, which is enough to provide power for more than 40 average homes. The new devices will be able to provide double the amount of power available for scientific research, according to NASA.  

The mission will be led by Commander Lee Archambault, who will be joined by six crew mates, pilot Tony Antonelli and mission specialists Joseph Acaba, Steve Swanson, Richard Arnold, John Phillips and Japan Aerospace Exploration Agency astronaut Koichi Wakata. Wakata will replace space station crew member Sandra Magnus, who has been aboard the station for more than four months now. He will return to Earth during the next station shuttle mission, STS-127, planned to launch in June 2009.

The seven STS-199 astronauts are expected to arrive at Kennedy Space Center on Sunday, March 8.

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