J-2X: Progress on the Ares Upper Stage Engine
NASA's Vision for Exploration requires a safe, reliable, affordable upper stage engine to power the Ares I Crew Launch Vehicle (CLV) and the Ares V Cargo Launch Vehicle (CaLV). The J-2X engine epitomizes NASA's philosophy of employing legacy knowledge, heritage hardware, and commonality to carry the next generation of explorers into low-Earth orbit and out into the solar system. As envisioned by the Exploration Systems Architecture Study (ESAS), the reference lunar mission would begin by launching the Ares V into orbit with the Earth Departure Stage (EDS) transporting the Lunar Surface Access Module (LSAM), followed by the Ares I, carrying the Orion Crew Exploration Vehicle, which would rendezvous with the EDS/LSAM before beginning its journey to the Moon.