Rocketdyne LOx/LH2 rocket engine. Study 1965. Proposed for later versions of Saturn V. Toroidal aerospike plug nozzle version of J-2.
Status: Study 1965. Thrust: 889.30 kN (199,923 lbf). Specific impulse: 435 s. Specific impulse sea level: 300 s. Burn time: 429 s. Height: 1.25 m (4.10 ft). Diameter: 2.49 m (8.16 ft).