Matches in DBpedia 2014 for { ?s ?p The J-2X is a liquid-fuel cryogenic rocket engine planned for use on NASA's Space Launch System. Built in the United States of America by Aerojet Rocketdyne (formerly, Pratt & Whitney Rocketdyne), the J-2X will burn cryogenic liquid hydrogen & liquid oxygen propellants, with each engine producing 1,307 kN (294,000 lbf) of thrust in vacuum at a specific impulse (Isp) of 448 seconds (4.39 km/s). The engine will have a mass of approximately 5,450 pounds (2,470 kg), significantly heavier than its predecessors.The J-2X was originally intended to be based on the J-2 used on the S-II and S-IVB stages of the Saturn rockets used during the Apollo program, but as required thrust for the Ares I increased due to weight problems it became a clean sheet design. It entered development in 2007 as part of the now-cancelled Constellation program. Originally planned for use on the upper stages of the Ares I and Ares V rockets, the J-2X is now intended for use in the 2030s and beyond on the Earth Departure Stage of the Block II Space Launch System, the successor to the Constellation program. The engine is intended to be more efficient and simpler to build than its J-2 ancestor, and cost less than the RS-25 Space Shuttle Main Engine. Differences in the new engine include the removal of beryllium, a centrifugal turbo pump versus the axial turbo pump of the J-2, different chamber and nozzle expansion ratios, a channel-walled combustion chamber versus the tube-welded chamber of the J-2, a redesign of all the electronics, a gas generator and supersonic main injector based on the RS-68, and the use of 21st-century joining techniques.. }
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- J-2X abstract "The J-2X is a liquid-fuel cryogenic rocket engine planned for use on NASA's Space Launch System. Built in the United States of America by Aerojet Rocketdyne (formerly, Pratt & Whitney Rocketdyne), the J-2X will burn cryogenic liquid hydrogen & liquid oxygen propellants, with each engine producing 1,307 kN (294,000 lbf) of thrust in vacuum at a specific impulse (Isp) of 448 seconds (4.39 km/s). The engine will have a mass of approximately 5,450 pounds (2,470 kg), significantly heavier than its predecessors.The J-2X was originally intended to be based on the J-2 used on the S-II and S-IVB stages of the Saturn rockets used during the Apollo program, but as required thrust for the Ares I increased due to weight problems it became a clean sheet design. It entered development in 2007 as part of the now-cancelled Constellation program. Originally planned for use on the upper stages of the Ares I and Ares V rockets, the J-2X is now intended for use in the 2030s and beyond on the Earth Departure Stage of the Block II Space Launch System, the successor to the Constellation program. The engine is intended to be more efficient and simpler to build than its J-2 ancestor, and cost less than the RS-25 Space Shuttle Main Engine. Differences in the new engine include the removal of beryllium, a centrifugal turbo pump versus the axial turbo pump of the J-2, different chamber and nozzle expansion ratios, a channel-walled combustion chamber versus the tube-welded chamber of the J-2, a redesign of all the electronics, a gas generator and supersonic main injector based on the RS-68, and the use of 21st-century joining techniques.".