TR-201

TR-201

Country of origin	United States
Date	1972-1988
Manufacturer	TRW
Application	Upper stage/Spacecraft propulsion predecessor=LMDE
Status	Retired
Liquid-fuel engine
Propellant	N2O4 / Aerozine 50
Cycle	Pressure-fed cycle
Configuration
Chamber	1
Performance
Thrust, vacuum	41.90 kN (9,419 lbf)
Thrust-to-weight ratio	31.4338235294118
Chamber pressure	7.00 bar
Specific impulse, vacuum	301 s (3,050 N•s/kg)
Dimensions
Length	2.27 m (7.44 ft)
Diameter	1.38 m (4.52 ft)
Dry mass	113 kg (249 lb)
Used in
Delta P, second stage

The TR-201 or TR201 is a hypergolic pressure-fed rocket engine. It was used to propel the upper stage of the Delta rocket from 1972 to 1988. The rocket engine uses Aerozine 50 as a propellent, and N2O4 as the oxidizer. It was developed in early 1970s by TRW as a derivative of the Lunar Module Descent Engine (LMDE). This engine used a pintle injector first developed by TRW in late 1950s and received US Patent in 1972. This injector technology and design is also used on SpaceX Merlin engines.

Delta Usage

The TR-201 engine was used as the second stage for 77 Delta launches between 1972 to 1988. The engine had a 100% reliability record during this 15 year operational period.