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NASA's Space Shuttle troubles
By Douglas Wu
Comprised heat shield tiles that may ground future missions until NASA finds a solution to the problem of external tank debris striking the space shuttle’s orbiter during takeoff marred the latest mission to the International Space Station.
The space shuttle's mission to the International Space Station ended Tuesday, August 21, 2007, days earlier than planned, with a daytime landing at the Kennedy Space Center in Florida. NASA leaders called the space shuttle home days early ahead of a hurricane in the Caribbean headed for the Gulf of Mexico.
Mission commander Scott J. Kelly, of the US Navy, guided the space shuttle safely down from space despite the problem with the heat shield. Thankfully, the space shuttle's heat resistant tiles, that comprise the heat shield, did their job during re-entry despite gouged tiles on the underside of the orbiter that went all the way to the felt pad between the tile and the orbiter’s aluminum skin. The gouged heat resistant tiles were most likely the result of foam and or ice hitting the underside of the spacecraft during takeoff.
NASA engineers and managers chose not to ask the crew of seven astronauts aboard the space shuttle to execute risky space walks to repair the damaged heat resistant tiles. NASA tests showed the space shuttle's compromised heat shield would be able to stand the rigors of re-entry. Also, the repair procedures could have made the problem worse taking into account the location of the damaged tiles and the materials on board the space shuttle.
Nor did NASA choose to mount a rescue mission using another space shuttle or asking the Russians to launch a rescue rocket. One possible rescue mission could have been launching a Russian spacecraft to take all but Kelly home from the International Space Station. Then, Kelly alone would have flown the space shuttle to Kennedy Space Center. Or, NASA could have chosen to speed preparations for an emergency space shuttle launch to recover the space shuttle's crew waiting at the International Space Station.
Interestingly, NASA decided to have the space shuttle land at Kennedy Space Center and not Edwards Air Force Base in California. Edwards Air Force Base would have afforded the space shuttle the option of using desert as a runway in case of comprised or heat damaged landing gear and brake systems.
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