RS-68
Type: Lower Stage Engine
Country of Origin: United States
Manufacturer: Rocketdyne
First Flight:
Status: Retired
Propellant (O/F): Liquid Oxygen/Liquid Hydrogen
Mixture Ratio (O/F by mass):
Cycle: Gas generator
Chambers: 1
Thrust (vac.):
Thrust (s.l.): 2950 kN; 3137 kN (RS-68A)
Throttle: 58% to 102%
ISP (vac.): 410 s; 412 s (RS-68A)
ISP (s.l.): 365 s
Chamber Pressure: 1488 psi
Nozzle Ratio: 21.5:1
Burn time:
Ignitions: 1
Mass: 6600 kg; 6740 kg (RS-68A)
Length: 5.2 m
Diameter: 2.43 m
Used in: Delta IV
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