William Atkins
Wednesday, 04 February 2009 06:35
Science -
Space
Page 1 of 2
NASA announced on Tuesday, February 3, 2009 that its next assembly mission to the International Space Station will be delayed at least one week in order to check out iffy control valves on space shuttle Discovery, the NASA orbiter that will take its STS-119 crew up into space.
The gaseous hydrogen (GH2) flow control valves are part of the orbiter’s main propulsion system.
Late last week, NASA engineers and technicians installed three of these flow control valves onto the space shuttle Discovery after finding out that one of three GH2 valves on the space shuttle Endeavour, during the last NASA mission (STS-126), failed during ascent on November 14, 2008.
The other two valves worked nominally (normally).
For additional information on this swap-out, check out the
Florida Today article “
NASA Gears Up For Shuttle Valve Swap.”
John Shannon, the NASA shuttle program manager, stated,
"With this one exception, we're ready to go.” [News-press.com: “
Valve trouble delays Discovery shuttle launch”]
The mission (15A) to the ISS will install the fourth starboard truss segment (S6) onto the backbone of the Station, along with the fourth (and last) set of solar arrays, radiators, and batteries.
The News-press article stated,
“The delay is necessary to allow engineers time to be sure that pieces of Discovery's new flow control valves, which are used to pressurize the space shuttle's hydrogen propellant tank as it rockets spaceward, won't chip off and damage vital plumbing between the spacecraft's main engines and its 15-story external tank."
The action by NASA was taken due to a problem with one of the values on the last shuttle mission in November 2008. Read page two for more.
