Country of origin | United States |
---|---|
Designer | MSFC/Rocketdyne |
Manufacturer | Rocketdyne |
Application | Upper stage engine |
Associated LV | Saturn MLV Saturn IB-B Saturn V/4-260 Saturn INT-17 |
Predecessor | J-2 |
Successor | RS-25 |
Status | Canceled |
Liquid-fuel engine | |
Propellant | Liquid oxygen / Liquid hydrogen |
Performance | |
Thrust, vacuum | 1,400.7 kN (314,900 lbf) |
Thrust, sea-level | 869.6 kN (195,500 lbf) |
Specific impulse, vacuum | 451 seconds (4.42 km/s) |
Specific impulse, sea-level | 280 seconds (2.7 km/s) |
References | |
References | [1][2] |
The HG-3 was a liquid-fuel cryogenic rocket engine which was designed for use on the upper stages of Saturn rockets in the post-Apollo era.[1] Designed in the United States by Rocketdyne, the HG-3 was to have burned cryogenic liquid hydrogen and liquid oxygen propellants, with each engine producing 1,400.7 kN (315,000 lbf) of thrust during flight.[1] The engine was designed to produce a specific impulse (Isp) of 451 seconds (4.42 km/s) in a vacuum, or 280 seconds (2.7 km/s) at sea level.[1]
Developed from Rocketdyne's J-2 engine used on the S-II and S-IVB stages, the engine was intended to replace the J-2 on the upgraded MS-II-2 and MS-IVB-2 stages intended for use on the Saturn MLV, Saturn IB-B and Saturn V/4-260 rockets, with a sea-level optimised version, the HG-3-SL, intended for use on the Saturn INT-17.[1][2] The engine was cancelled, however, during the post-Apollo drawdown when development of the more advanced Saturn rockets ceased, and never flew, although the engine was later used as the basis for the design of the RS-25 engine.[3]