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RS-27
First stage of a Delta II rocket, including an RS-27
Country of originUnited States
Date1974
Designer Rocketdyne
Manufacturer Rocketdyne
Application Booster
Predecessor H-1
Successor RS-27A, RS-56
StatusRetired
Liquid-fuel engine
Propellant LOX / RP-1
Cycle Gas Generator
Configuration
Chamber1
Performance
Thrust, vacuum1,023 kN (230,000 lbf)
Thrust, sea-level971 kN (218,000 lbf)
Chamber pressure4.9 MPa (49 bar)
Specific impulse, vacuum295 seconds (2.89 km/s)
Specific impulse, sea-level264 seconds (2.59 km/s)
Burn time274 Sec
Dimensions
Length3.63 m (11.9 ft)
Diameter1.07 m (3.51 ft)
Dry weight1,027 kg (2,264 lb)
Used in
Delta 2000, 3000, 5000, 6000, first stage [1]

The RS-27 was a liquid-propellant rocket engine developed in 1974 by Rocketdyne to replace the aging MB-3 in the Delta. Incorporating components of the venerable MB-3 and the H-1 designs, the RS-27 was a modernized version of the basic design used for two decades. It was used to power the first stage of the Delta 2000, 3000, 5000, and the first model of the Delta II, the Delta 6000.

The RS-27 was a modified Rocketdyne H-1 built to power the first stage of the Saturn I and Saturn IB and replaced the MB-3 engine that had been used on previous versions of the Delta launcher. NASA had a large supply of surplus H-1 engines in the early 1970s, as the Apollo program was ending. [2] [3] In addition to its main engine, the RS-27 included two vernier engines to provide vehicle roll control during flight. [4] RS-27 was later developed into the RS-27A and RS-56. [5] [6]

RS-27A

RS-27A
RS-27A Engine on Delta II
Country of originUnited States
Date1989
Designer Rocketdyne
Manufacturer Rocketdyne, Pratt & Whitney Rocketdyne
Application Booster
Predecessor RS-27
StatusRetired
Liquid-fuel engine
Propellant LOX / RP-1
Cycle Gas Generator
Configuration
Chamber1
Performance
Thrust, vacuum1,054.2 kN
Thrust, sea-level890.1 kN (200,102 lbf)
Thrust-to-weight ratio102.47
Chamber pressure4.8MPa (700 psia)
Specific impulse, vacuum302 seconds (2.96 km/s)
Specific impulse, sea-level255 seconds (2.50 km/s)
Burn time265 Sec
Dimensions
Length3.78 m (12.40 ft)
Diameter1.70 m (5.58 ft)
Dry weight1,147 kg (2,528 lb)
Used in
Delta 7000, first stage [7]

The RS-27A is a liquid-fuel rocket engine developed in 1980s 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; [8] its thrust nozzle has been extended to increase its area ratio from 8:1 to 12:1, which provides greater efficiency at altitude.

The RS-27A main engine is neither restartable nor throttleable. In addition to its main engine, it includes two vernier engines to provide vehicle roll control during flight. [9] When used as the main booster propulsion system for the Delta II family of launch vehicles, has an operational duration of 265 seconds. The last RS-27A engine was used for the ICESat-2 launch on 15 September, 2018.

External links

References

  1. ^ "Delta". Astronautix. Archived from the original on August 17, 2013. Retrieved March 5, 2015.
  2. ^ "RS-27". Astronautix. Archived from the original on October 11, 2011. Retrieved March 5, 2015.
  3. ^ Kyle, Ed. "Extended Long Tank Delta". SpaceLaunchReport.com. Retrieved March 5, 2015.
  4. ^ J. K. Ganoung; H. Eaton (April 1, 1981). "The Delta Launch V The Delta Launch Vehicle- P ehicle- Past, Pr ast, Present, and F esent, and Future". The Space Congress Proceedings. 18: 6-6. Retrieved March 12, 2023.
  5. ^ "Atlas IIA(S) Data Sheet". Space Launch Report. Retrieved 9 January 2016.
  6. ^ "RS-27A". Astronautix. Archived from the original on 5 August 2014. Retrieved 10 January 2016.
  7. ^ Astronautix: RS-27A Engine
  8. ^ Astronautix: RS-27 Engine
  9. ^ "RS-27A Engine". purdue.edu. Retrieved May 7, 2023.