In the Vehicle Assembly Building high bay 4 at NASA's Kennedy Space Center in Florida, workers begin adhering a decal of the U.S. flag on one of the Ares I-X upper stage simulator segments. 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. Photo credit: NASA/Jack Pfaller