(AP) -- The four astronauts who will bid goodbye to the space shuttle program are practicing for their July 8 launch.
Commander Christopher Ferguson and his crew met with journalists Wednesday morning at the launch pad. They will board Atlantis on Thursday for a mock countdown.
Astronaut Rex Walheim says he gets goosebumps, thinking that Atlantis will blast off one final time in just a couple more weeks. The mission is the last of NASA's 30-year shuttle program.
Atlantis got a new fuel valve this week. The old one showed a possible leak last week when the external fuel tank was filled to check for cracking. So far, the 50 reinforced brackets on the tank show no signs of cracks. The new valve, meanwhile, will be tested this weekend.
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