Rutherford (rocket engine)
Sea-level Rutherford engine
|Country of origin||New Zealand|
|Application||First- and second-stage engine|
|Propellant||LOX / RP-1|
|Cycle||Electric pump-fed engine|
|Pumps||2 electric pumps|
|Thrust (vac.)||5,400 lbf (24 kN)|
|Thrust (SL)||5,400 lbf (24 kN)|
First stage: 311 s (3.05 km/s)|
Upper stage: 343 s (3.36 km/s)
Rutherford is a liquid-propellant rocket engine designed by American aerospace company Rocket Lab and manufactured in the United States. It uses LOX and RP-1 as its propellants and is the first flight-ready engine to use the electric-pump feed cycle. It is used on the company's own rocket, Electron. The rocket uses a similar arrangement to the Falcon 9, a two-stage rocket using a cluster of nine identical engines on the first stage and one, optimized for vacuum operation with a longer nozzle, on the second stage. The sea-level version produces 24 kN (5,400 lbf) of thrust and has a specific impulse of 311 s (3.05 km/s), while the vacuum optimized-version produces 24 kN (5,400 lbf) of thrust and has a specific impulse of 343 s (3.36 km/s).
Rutherford, named after renowned New Zealand born British scientist Lord Rutherford, is a small liquid-propellant rocket engine designed to be simple and cheap to produce. It is used as both a first-stage and as a second-stage engine, which simplifies logistics and improves economies of scale. To reduce its cost, it uses the electric-pump feed cycle, being the first flight-ready engine of such type. It is fabricated largely by 3D printing, using a method called electron-beam melting. Its combustion chamber, injectors, pumps, and main propellant valves are all 3D-printed.
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. The use of a pump avoids the need for heavy tanks capable of holding high pressures and the high amount of gas needed to pressurize them and replaces them with a pump.
The pumps (one for the fuel and one for the oxidizer) in electric-pump feed engines are driven by an electric motor. 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%. However, the battery pack increases the weight of the complete engine and presents an energy conversion issue.
Each engine has two small motors that generate 50 hp (37 kW) while spinning at 40 000 rpm. The first-stage battery, which has to power the pumps of nine engines simultaneously, can provide over 1 MW of electric power.
The engine is regeneratively cooled, which means that it first passes the fuel through channels that cool the combustion chamber and nozzle before injecting them for combustion.
- "Electron". Rocket Lab. Retrieved 24 July 2017.
- "Rocket Lab reaches 500 Rutherford engine test fires | Rocket Lab". Rocket Lab. Retrieved 2018-02-01.
- Brügge, Norbert (11 July 2016). "Asian space-rocket liquid-propellant engines". B14643.de. Retrieved 20 September 2016.
- "Propulsion". Rocket Lab. Archived from the original on 19 September 2016. Retrieved 19 September 2016.
- Brügge, Norbert. "Electron NLV". B14643.de. Retrieved 20 September 2016.
- Brügge, Norbert. "Electron Propulsion". B14643.de. Retrieved 20 September 2016.
- "Rocket Lab Reveals First Battery-Powered Rocket for Commercial Launches to Space | Rocket Lab". Rocket Lab. Retrieved 2017-05-25.
- Knapp, Alex (21 May 2017). "Rocket Lab Becomes A Space Unicorn With A $75 Million Funding Round". Forbes. Retrieved 25 May 2017.
- "Rutherford Engine Qualified for Flight". Rocket Lab. March 2016. Archived from the original on 25 April 2016. Retrieved 19 September 2016.
- "New Zealand space launch is first from a private site". BBC News. 2017-05-25. Retrieved 2017-05-25.
- Bradley, Grant (15 April 2015). "Rocket Lab unveils world's first battery rocket engine". The New Zealand Herald. Retrieved 20 September 2016.
- 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.
- "Propulsion". Rocket Lab. Archived from the original on 10 September 2015. Retrieved 19 September 2016.
- 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.
- Morring, Jr., Frank; 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.
- "Rocket Lab Introduction" (PDF). Rocket Lab. Archived from the original (PDF) on 20 September 2016. Retrieved 20 September 2016.