Ares I-X upper stage simulator segment 3 is lowered onto segment 2.

Inside the Vehicle Assembly Building's high bay 4 at NASA's Kennedy Space Center in Florida, Ares I-X upper stage simulator segment 3 is lowered onto segment 2. The upper stage simulator comprises 11 segments, each approximately 18 feet in diameter, that will be used in the test flight identified as Ares I-X in 2009. The test flight will provide NASA an early opportunity to test and prove hardware, facilities and ground operations associated with the Ares I crew launch vehicle. The data will ensure the entire vehicle system is safe and fully operational before astronauts begin traveling to orbit. The simulator segments will simulate the mass and the outer mold line and will be more than 100 feet of the total vehicle height of 327 feet. Photo credit: NASA/Jack Pfaller