Top NASAofficials will decide today whether to proceed with the planned launch of thespace shuttle Discovery next week or to stand down and replace several heatshield panels lining the orbiter's wings.
Missionmanagers and engineers are meeting at NASA's Kennedy Space Center (KSC) in CapeCanaveral, Florida in a Flight Readiness Review (FRR) for Discovery's plannedOct. 23 launch toward the International Space Station (ISS).
Among the chieftopics under discussion is whether to haul Discovery off its launch pad andreplace three of the 44 heat-resistant panels along the orbiter's wing leadingedges. NASA's independent Engineering and Safety Center recommended the panelsbe replaced, which would prompt a lengthy delay for Discovery's plannedSTS-120 mission, due to slight defects to their exterior coating, the spaceagency said.
"Thedecision has obviously not been made," NASA spokesperson Kyle Herring, ofthe agency's Johnson Space Center, told SPACE.com Monday. "The FRRtomorrow will determine whether we fly as is and pick Oct. 23."
The leadingedges of Discovery's wings are each covered with 22 panels of reinforcedcarbon-carbon (RCC) designed to withstand searing temperatures of up to 3,000degrees Fahrenheit (1,650 degrees Celsius) as the shuttle reenter's the Earth'satmosphere during landing.
The shuttlehas flown at least twice with some of its wing-mounted heat shield panelsbearing slight defects in their exterior coating. While post-flight inspectionsfound no change in the defects after each flight, engineers remain baffled atthe root cause of the coating loss.
"Atthis point, the space shuttle program has determined that Discovery'sastronauts can safely carry out their mission without having to replace the panels,"NASA said in a statement.
Herringsaid engineers have performed some additional data analysis on the coatingloss, the results of which will be presented during today's preflight meeting. NASAmanagers will also discuss, among other topics, modifications to Discovery'sexternal fuel tank to reduce the amount of foam insulation and debris sheddingduring liftoff.
NASA haskept a close watch on the health of its space shuttles' heat shields and fuel tankfoam insulation since the 2003loss of the Columbia orbiter and its astronaut crew due heat shield damagefrom foam debris.
Discovery'sSTS-120 astronaut crew, commanded by veteran shuttle flyer Pamela Melroy, isslated to launch toward the space station to delivera vital new node to the orbital laboratory. The node, named Harmony in astudent contest, will serve as a connection point for future internationallaboratories.
The shuttleastronauts also expect to perform five spacewalks and relocate an older solar arraysegment outside the space station during their planned 14-day mission.
NASAwill hold a press briefing no earlier than 3:00 p.m. EDT (1900 GMT) on NASA TVto discuss today's Flight Readiness Review meeting for Discovery's STS-120shuttle mission.
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