The first test flight of NASA’s crew launch vehicle Ares 1 will use a four-segment solid-rocket booster for its first stage, not the five-segment design specified in the baseline requirement. Ares 1’s current design uses a Space Shuttle-derived five-segment SRB first stage and a new liquid-oxygen/liquid-hydrogen Rocketdyne J-2X-powered upper stage. The launcher will place the agency’s Crew Exploration Vehicle (CEV) into a suborbital trajectory, from which the CEV’s engine would boost it into low-Earth orbit.

The first Ares 1 test is due in April 2009. Steve Cook, NASA’s exploration launch vehicle director, based at Marshall Spaceflight Center, says the first ascent development flight test will “validate our models for max q [dynamic pressure] and stage separation” rather than test the entire ascent flight profile.

Source: Flight International