Ascent propulsion system

Ascent propulsion system (APS)
Apollo LM ascent engine
Country of originUnited States
Date1964–72
ManufacturerBell Aircraft / Rocketdyne
ApplicationLunar Ascent Stage/Spacecraft propulsion
PredecessorBell 8247
SuccessorRS-18
StatusRetired
Liquid-fuel engine
PropellantN
2
O
4
/ Aerozine 50
Mixture ratio1.6
CyclePressure-fed
PumpsNone
Configuration
Chamber1
Nozzle ratio46
Performance
Thrust, vacuum3,500 pounds-force (16 kN)
Thrust-to-weight ratio16.7 (weight on Earth)
Chamber pressure120 pounds per square inch (8.3 bar)
Specific impulse, vacuum311 seconds (3.05 km/s)
Burn time200 seconds
RestartsDesigned for 1 restarts
Dimensions
Length510 inches (1,300 cm)
Diameter100 inches (250 cm)
Dry mass209.6 pounds (95.1 kg)
Used in
Lunar module as ascent engine
References
References

The ascent propulsion system (APS) or lunar module ascent engine (LMAE) is a fixed-thrust hypergolic rocket engine developed by Bell Aerosystems for use in the Apollo Lunar Module ascent stage. It used Aerozine 50 fuel, and N
2
O
4
oxidizer. Rocketdyne provided the injector system, at the request of NASA, when Bell could not solve combustion instability problems.