By Jim Bowery
Copyright 2001
An ultracentrifugal engine of our technology, that can attain the same thrust as one of NASA's Space Shuttle Main Engines (SSME) could be fabricated in a high performance automotive machine shop using a standard sized aluminum round.
The ultracentrifugal engine is designed to dramatically collapse the complexity, and mass, of high pressure engines into a few simple parts that can be fabricated in any high performance automotive machine shop; the only exceptions being the cryogenic bearings made from silicon nitride and the rotary seal.
Innovation in rocket engines is being held back by the high cost of entry to experimentation with high performance engines. Simpler high performance engines made from widely available materials fabricated using widely available tools could dramatically enhance the rate of evolution in rocket engines.
Increasing pressure in the tanks costs a lot of mass compared to increasing pressure in the engine, so it is better to create pressure in the engine. The main problems here are all the complications surrounding high pressure engines, including the inducer, gas generator, turbine, cooling channels, injectors and all the plumbing connecting these devices.
A rocket's empty mass consists basically of its payload, its tanks and its engine. It's tanks and its engine need to provide enough pressure to create a high exhaust velocity (see the rocket equation below).
The "rocket equation" Velocity = ExhaustVelocity*ln(FueledRocketMass/EmptyRocketMass) shows a rocket's "burn out" velocity decreases the more massive the rocket is when empty of fuel (including its payload). Making the empty rocket lighter can have a huge impact on how fast a rocket of a given size can go.
Earth has a gravitational "well" that is precariously close to the limit of what rockets can climb out of using chemical energy. Improvement in rockets have a big impact on the economy of climbing out of that well.
Getting to low earth orbit is the primary barrier to the unlimited solar energy, material and space of space, and Earth's biosphere is decreasingly capable of supporting the load placed on it by an expanding technological civilization.