CAPE CANAVERAL, Fla. -- The upper stage simulator segments are positioned across the floor of the Vehicle Assembly Building's high bay 4 at NASA's Kennedy Space Center in Florida. Four of the segments are already stacked. The upper stage simulator will be used in the test flight identified as Ares I-X in 2009. Ares I-X is the test vehicle for the Ares I, which is part of the Constellation Program to return men to the moon and beyond. Ares I is the essential core of a safe, reliable, cost-effective space transportation system that eventually will carry crewed missions back to the moon, on to Mars and out into the solar system. Ares I may also use its 25-ton payload capacity to deliver resources and supplies to the International Space Station, or to "park" payloads in orbit for retrieval by other spacecraft bound for the moon or other destinations. The upper stage simulator comprises 11 segments, each approximately 18 feet in diameter. 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 KSC-08pd3931