Most Interesting Rocket Engines

Rocket Engines which are interesting from a technological and historical perspective.

In previous articles I’ve talked about theoretical aspects of rocket engines, what rocket engine and propellant to use etc. But lets talk about concrete rocket engines actually in use today and what makes them interesting.

Rutherford Engine

One fascinating modern engine is the Rutherford Engine from Rocket Lab. This is a fairly small and simple engine.

The Rutherford Engine is the worlds first electric rocket engine.

What makes it interesting is that instead of a turbo pump, the centrifugal pump feeding the combustion chamber is driven by a brushless electric motor. The motor gets electricity from a lithium ion battery. This is quite a novelty which has probably only happened due to the big advances which has been made on battery technology these last years.

Direct current from the battery is turned into alternating current (AC) by the inverter and fed to an electric engine, driving two pumps. One pump for the fuel and one for the liquid oxygen. This causes the fuel and oxygen to enter the combustion chamber at high pressure. The fuel is sent in tubes spiraling around the nozzle to cool it down, otherwise it could get so hot that it would get destroyed. Illustration from Wikipedia by Duk.

Another interesting aspect with this engine is that most of it is 3D printed. It powers the Electron rocket which is only 17 meters long and 1.2 meters in diameter, and which can lift a payload of 150 to 225 kg into orbit. That isn’t a lot, but due to advances in manufacturing…