The Ares I-X roll control system module arrives in the Vehicle Assembly Building at NASA's Kennedy Space Center.

The Ares I-X roll control system module arrives in the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The system is designed to perform a 90-degree roll after the rocket clears the launch tower, preventing a roll during flight and maintaining the orientation of the rocket until separation of the upper and first stages. Part of the upper stage simulator, the system module is composed to two modules and four thrusters. The system module will return to earth and splash down; it will not be recovered. 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-X is targeted for launch in July 2009. Photo credit: NASA/Jack Pfaller