Rocket Engines
Our rocket engines are built to customer specifications.  Below is a selection of engines that illustrate some of our capabilities.  Click on any engine class to learn more.

• XR-2P1 15 lbf N2O-Ethane
  R&D and educational, variable propellants and third fluid injections
   
• XR-3E17 56 lbf N2O-Ethane
  Stationkeeping - storable
   
• XR-3B4 50 lbf N2O-Isopropyl
  Stationkeeping - storable
  
  
• XR-3M9 50 lbf LOX-Methane
  Stationkeeping - storable
   
• XR-4A3 400 lbf LOX-Alcohol
  Auxilliary or primary propulsion
   
• XR-4K14 1,500 lbf LOX-Kerosene
  Primary propulsion, 'Rocket Racer' engine
   
• XR-4K5 1,800 lbf LOX-Kerosene
  Primary propulsion
   
• XR-5M15 7,500 lbf LOX-Methane
  Primary propulsion, space storable

XR-4A3, 400lbf LOX/Alcohol EZ Rocket Engine

In June of 2000, after we had concluded tests of our proprietary oxygen/alcohol igniter, we set to work on a 160 lb thrust liquid oxygen and isopropanol engine, which we ran in October of the same year. Following successful tests of this engine, known as the XR-3A2, in November, 2000, we started to design and build the regeneratively cooled 400 lb thrust LOX/alcohol engines that we eventually integrated into a Long-EZ airplane to create our EZ-Rocket aircraft.

Twin XR-4A3 engines propelling the EZ-Rocket

The XR-4A3 engines went through multiple acceptance tests before the first flight of the EZ-Rocket on July 21, 2001.  Early flights on engines 101 and 102 quickly lead to design improvements, and serial numbers 103 and 104 powered 20 of the 26 flights of the EZ-Rocket.

The flight test program passed its first milestone by flying with both engines for an engine run time of 96 seconds, and a total flight time of five minutes and twenty seconds. Later flights achieved burn times of up to 2.5 minutes, altitudes to 11,500 feet, and two cross-country flights, capturing a world record.

Specific impulse of this engine is higher than either the engines in the Bell X-1 or the Redstone, which also used LOX/alcohol.

The fact that two 4A3 engines powered an aircraft safely, reliably, and routinely multiple times proved to us the viability of civilian rocket-powered aviation. Routine operations must be the primary criterion for rocket engine development. Our approach is to build safe and reliable rocket engines first, then progress to the higher performance needed for orbital launch vehicles.