In the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida, the Ares I-X aft booster segment with the aft skirt is lowered onto the mobile launch platform in High Bay 3. This is the start of the buildup of the Ares I-X launch vehicle for the flight test targeted for no earlier than Aug. 30. Part of the Constellation Program, the Ares I-X is the test vehicle for the Ares I, which is the essential core of a space transportation system that eventually will carry crewed missions back to the moon, on to Mars and out into the solar system. Photo credit: NASA/Jack Pfaller