Rutherford engine
Sea-level Rutherford engine
Country of originUnited States
New Zealand
DesignerRocket Lab
ManufacturerRocket Lab
ApplicationFirst- and second-stage engine
StatusActive
Liquid-fuel engine
PropellantLOX[1] / RP-1[1]
CycleElectric pump-fed engine
Pumps2 electric pumps
Configuration
Chamber1
Performance
Thrust, vacuum
  • Original: 5,500 lbf (24 kN)[2]
  • Updated: 5,800 lbf (26 kN)[3]
Thrust, sea-level
  • Original: 5,500 lbf (24 kN)
  • Updated: 5,600 lbf (25 kN)[3]
Thrust-to-weight ratio72.8
Specific impulse, vacuum343 s (3.36 km/s)[2][1]
Specific impulse, sea-level311 s (3.05 km/s)[2][1]
Dimensions
Diameter25 cm (9.8 in)
Dry weight35 kg (77 lb)[3]
Used in
Electron, HASTE
References
References[4][5][6][7]

Rutherford is a liquid-propellant rocket engine designed by aerospace company Rocket Lab[8] and manufactured in Long Beach, California.[9] The engine is used on the company's own rocket, Electron. It uses LOX (liquid oxygen) and RP-1 (refined kerosene) as its propellants and is the first flight-ready engine to use the electric-pump feed cycle. The rocket uses a similar engine arrangement to the Falcon 9; a two-stage rocket using a cluster of nine identical engines on the first stage, and one vacuum-optimized version with a longer nozzle on the second stage. This arrangement is also known as an octaweb.[10][6][7] The sea-level version produces 24.9 kN (5,600 lbf) of thrust and has a specific impulse of 311 s (3.05 km/s), while the vacuum optimized-version produces 25.8 kN (5,800 lbf) of thrust and has a specific impulse of 343 s (3.36 km/s).[11]

First test-firing took place in 2013.[12] The engine was qualified for flight in March 2016[13] and had its first flight on 25 May 2017.[14] As of August 2023, the engine has powered 40 Electron flights in total, making the count of flown engines 399, including one engine flown twice.[15]

Description

Rutherford is named after renowned New Zealand-born scientist Ernest Rutherford. It is a small liquid-propellant rocket engine designed to be simple and cheap to produce. It is used as both a first-stage and a second-stage engine, which simplifies logistics and improves economies of scale.[6][7] To reduce its cost, it uses the electric-pump feed cycle, being the first flight-ready engine of such type.[5] It is fabricated largely by 3D printing, using a method called laser powder bed fusion, and more specifically Direct Metal Laser Solidification (DMLS®). Its combustion chamber, injectors, pumps, and main propellant valves are all 3D-printed.[16][17][18]

As with all pump-fed engines, the Rutherford uses a rotodynamic pump to increase the pressure from the tanks to that needed by the combustion chamber.[5] The use of a pump avoids the need for heavy tanks capable of holding high pressures and the high amounts of inert gas needed to keep the tanks pressurized during flight.[19]

The pumps (one for the fuel and one for the oxidizer) in electric-pump feed engines are driven by an electric motor.[19] The Rutherford engine uses dual brushless DC electric motors and a lithium polymer battery. It is claimed that this improves efficiency from the 50% of a typical gas-generator cycle to 95%.[20] However, the battery pack increases the weight of the complete engine and presents an energy conversion issue.[19]

Each engine has two small motors that generate 37 kW (50 hp) while spinning at 40 000 rpm.[20] The first-stage battery, which has to power the pumps of nine engines simultaneously, can provide over 1 MW (1,300 hp) of electric power.[21]

The engine is regeneratively cooled, meaning that before injection some of the cold RP-1 is passed through cooling channels embedded in the combustion chamber and nozzle structure, transferring heat away from them, before finally being injected into the combustion chamber.

See also

References

  1. ^ a b c d "Electron". Rocket Lab. Retrieved 24 July 2017.
  2. ^ a b c "rocket lab reach 500 rutherford engine test fires".
  3. ^ a b c "Rocket Lab Increases Electron Payload Capacity, Enabling Interplanetary Missions and Reusability". Rocket Lab. Retrieved 6 August 2020.
  4. ^ Brügge, Norbert (11 July 2016). "Asian space-rocket liquid-propellant engines". B14643.de. Retrieved 20 September 2016.
  5. ^ a b c "Propulsion". Rocket Lab. Archived from the original on 19 September 2016. Retrieved 19 September 2016.
  6. ^ a b c Brügge, Norbert. "Electron NLV". B14643.de. Archived from the original on 27 September 2016. Retrieved 20 September 2016.
  7. ^ a b c Brügge, Norbert. "Electron Propulsion". B14643.de. Archived from the original on 27 September 2016. Retrieved 20 September 2016.
  8. ^ "Rocket Lab Reveals First Battery-Powered Rocket for Commercial Launches to Space | Rocket Lab". Rocket Lab. Retrieved 25 May 2017.
  9. ^ Knapp, Alex (21 May 2017). "Rocket Lab Becomes A Space Unicorn With A $75 Million Funding Round". Forbes. Retrieved 25 May 2017.
  10. ^ "Meet the Octaweb – SpaceX". blogs.nasa.gov. Retrieved 18 September 2020.
  11. ^ "Electron". Rocket Lab. Archived from the original on 7 May 2021. Retrieved 1 February 2018.
  12. ^ "10 things about Rocket Lab". 27 May 2017. Archived from the original on 21 May 2021. Retrieved 25 November 2019.
  13. ^ "Rutherford Engine Qualified for Flight". Rocket Lab. March 2016. Archived from the original on 25 April 2016. Retrieved 19 September 2016.
  14. ^ "New Zealand space launch is first from a private site". BBC News. 25 May 2017. Retrieved 25 May 2017.
  15. ^ @RocketLab (24 August 2023). "260 399 Rutherford engines launched to space" (Tweet) – via Twitter.
  16. ^ Bradley, Grant (15 April 2015). "Rocket Lab unveils world's first battery rocket engine". The New Zealand Herald. Retrieved 20 September 2016.
  17. ^ Grush, Loren (15 April 2015). "A 3D-Printed, Battery-Powered Rocket Engine". Popular Science. Archived from the original on 31 January 2016. Retrieved 20 September 2016.
  18. ^ "Propulsion". Rocket Lab. Archived from the original on 10 September 2015. Retrieved 19 September 2016.
  19. ^ a b c Rachov, Pablo; Tacca, Hernán; Lentini, Diego (2013). "Electric Feed Systems for Liquid-Propellant Rockets" (PDF). Journal of Propulsion and Power. AIAA. 29 (5): 1171–1180. doi:10.2514/1.B34714. Retrieved 16 September 2016.
  20. ^ a b Morring, Frank Jr.; Norris, Guy (14 April 2015). "Rocket Lab Unveils Battery-Powered Turbomachinery". Aviation Week & Space Technology. Archived from the original on 4 March 2016. Retrieved 16 September 2016.
  21. ^ "Rocket Lab Introduction" (PDF). Rocket Lab. Archived from the original (PDF) on 20 September 2016. Retrieved 20 September 2016.

External links

Rocket engines and solid motors for orbital launch vehicles
Rocket Lab
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