Rocketdyne J-2 Tag Archives: Rocketdyne J-2. 11 October 1968, 15:02:45 UTC, T plus 000:00:00.36. The five Rocketdyne J-2 engines of the S-II second stage received the Engine Start Command at T + 161.95 seconds. They produced 1,169,662 pounds of thrust (5,202.92 kilonewtons), and were themselves shut down at T + 549.06 seconds. The second stage was jettisoned and the single J-2 of the S-IVB third stage started at T + 553.2 and shut down at T + 694.7 seconds. Rocketdyne's J-2 was America's largest production liquid hydrogen fueled rocket engine before the Space Shuttle main engines (SSME), and is being revived in support of NASA's return to the Moon. The J-2 was a major component of the Saturn V rocket. Five J-2 engines were used on the S-II, the second stage of the Saturn. J-2S. An experimental program to improve the performance of the J-2 was started in 1964 as the J-2X (not to be confused with a later variant by the same name). Rocketdyne LOx/LH2 rocket engine. Used in the Saturn IVB stage in Saturn IB and Saturn V, and the Saturn II stage in the Saturn V. First flight 1966. Sea level versions with reduced expansion ratio were proposed for Saturn II first stage use. Upgraded toroidal aerospike versions (J-2T-200K and J-2T-250K) were developed for upgrades to Saturn upper stages. The modestly improved J-2S was tested and provided basis for X-33 linear aerospike engine thirty years later. Rocketdyne won approval to develop the J-2 in June 1960 and the first flight, AS-201, occurred on 26 February 1966. The J-2 underwent several minor upgrades over its operational history to improve the engine's performance, with two major upgrade programs, the de Laval nozzle-type J-2S and aerospike-type J-2T, which were cancelled after the conclusion of the Apollo program. Rocketdyne J-2. Connected to: {{::readMoreArticle.title}}. The J-2 was a liquid-fuel cryogenic rocket engine used on NASA's Saturn IB and Saturn V launch vehicles. Built in the U.S. by Rocketdyne, the J-2 burned cryogenic liquid hydrogen (LH2) and liquid oxygen (LOX) propellants, with each engine producing 1,033.1 kN (232,250 lbf) of thrust in vacuum. The engine's preliminary design dates back to recommendations of the 1959 Silverstein Committee. Rocketdyne won approval to develop the J-2 in June 1960 and the first flight, AS-201, occurred on 26 February 1966 J-2X Engine. Tracy Lamm February 26, 2007. Pratt & Whitney Rocketdyne. J-2 Engine Lineage. J-2X: Adding a new member to the family. 1960-1970. Configuration Thrust Isp Mass Length. J-2 230 klb 425 sec 3,492 lb 116 in. Pratt & Whitney Rocketdyne. 1965-1971. J-2S 265 klb 436 sec 3,800 lb 116 in. 1996-2001. X-33 261 klb 419 sec 7,500 lb 79 in. 2006-. J-2X 294 klb 448 sec 5,450 lb 185 in. Requirements. J-2X: Apollo-era Derivative Engine. CEV Upper Stage and CaLV EDS Engine. Upper Stage (1 J-2X). 280 klb LOx/LH2..