(AP) -- The four astronauts who will close out NASA's space shuttle program are at their Florida launch site, eager for a Friday takeoff.

Commander Christopher Ferguson and his crew flew into from Houston on Monday, the Fourth of July. NASA staff handed them small U.S. flags, as their launch director greeted them out on the runway.

The four will take Atlantis on the last flight of NASA's 30-year shuttle program. Atlantis will make a supply run to the , before joining Discovery and Endeavour in retirement.

Ferguson says it will be a busy 12-day flight. But when it's over, he says the astronauts will be "very proud to put the right-hand bookend on the ."