In the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida, the upper stage simulator segments are being prepared for the test flight identified as Ares 1-X in July 2009. The upper stage simulator comprises 11 segments, each approximately 18 feet in diameter. The segments will simulate the mass and the outer mold line. The upper stage accounts for nearly one-quarter of the total height of the Ares 1. It will take the Ares 1 on the second phase of its journey from Earth, providing the guidance, navigation and control needed for the second phase of the Ares 1 ascent flight.