RS-27A

RS-27A

RS-27A Engine on Delta II
Country of origin	USA
Date	1989
Designer	Rocketdyne
Manufacturer	Rocketdyne, Pratt & Whitney Rocketdyne
Application	Booster
Predecessor	RS-27
Status	In use
Liquid-fuel engine
Propellant	LOX / RP-1
Cycle	Gas Generator
Configuration
Chamber	1
Performance
Thrust (vac.)	1,054.2 kN
Thrust (SL)	890.1 kN (200,102 lbf)
Thrust-to-weight ratio	102.47
Chamber pressure	4.8MPa (700 psia)
Isp (vac.)	302 seconds (2.96 km/s)
Isp (SL)	255 seconds (2.50 km/s)
Burn time	265 Sec
Dimensions
Length	3.78 m (12.40 ft)
Diameter	1.07 m (3.51 ft)
Dry weight	1,147 kg (2,528 lb)
Used in
Delta 7000, first stage

The RS-27A is a liquid-fuel rocket engine developed by Rocketdyne for use on the first stage of the Delta II and Delta III launch vehicles. It provides 1.05 meganewtons (240,000 lbf) of thrust burning RP-1 and LOX in a gas-generator cycle. The engine is a modified version of its predecessor, the RS-27; its thrust nozzle has been extended to increase its area ratio from 8:1 to 12:1, which provides greater efficiency at altitude. The earlier RS-27 was derived from surplus Rocketdyne H-1 engines used in the Saturn 1B launcher.

The RS-27A main engine is neither restartable nor throttleable. In addition to its main engine, the RS-27A includes two vernier engines to provide vehicle roll control during flight. The RS-27A has a run duration of 265 seconds.

External links

• Aerojet Rocketdyne RS-27A Product Page
• Pratt and Whitney RS-27A Brochure