Rutherford is a
liquid-propellant rocket engine designed by aerospace company
Rocket Lab and manufactured in
Long Beach,
California. 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.
The sea-level version produces of thrust and has a
specific impulse of , while the vacuum optimized-version produces of thrust and has a specific impulse of .
First test-firing took place in 2013. The engine was qualified for flight in March 2016
and had its first flight on 25 May 2017. As of May 2022, the engine has powered 26 Electron flights in total, making the count of flown engines 260.
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.
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
3D printing or additive manufacturing is the Manufacturing, construction of a three-dimensional object from a computer-aided design, CAD model or a digital 3D modeling, 3D model. It can be done in a variety of processes in which material is ...
, using a method called
electron-beam melting
Electron-beam additive manufacturing, or electron-beam melting (EBM) is a type of additive manufacturing, or 3D printing, for metal parts. The raw material (metal powder or wire) is placed under a vacuum and fused together from heating by an ele ...
. 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 amounts of inert gas needed to keep the tanks pressurized during flight.
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 motor
A brushless DC electric motor (BLDC motor or BL motor), also known as an electronically commutated motor (ECM or EC motor) or synchronous DC motor, is a synchronous motor using a direct current (DC) electric power supply. It uses an electronic ...
s 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 while spinning at 40 000
rpm.
The first-stage battery, which has to power the pumps of nine engines simultaneously, can provide over of electric power.
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
*
Curie (rocket engine)
*
TEPREL
*
Merlin (rocket engine family)
References
External links
Rocket Lab Propulsion Section
{{Rocket Lab
Rutherford
Rocket engines using kerosene propellant
Rocket engines using the electric pump-fed cycle
Space programme of New Zealand
Space program of the United States