Snark rocket engine test
Video of Snark static test showing thrust vectoring.
The purpose of this test was to demostrate thrust control and thrust vectoring and gain more "run time" with the engine. The engine is mounted to a test stand via a load cell to measure the thrust.
The gimbal actuators were programmed to move the engine in a circular pattern. This causes the exhaust plume to sweep out an eliptical pattern on the blast plate. There is a bit of judder in the gimbal movement sometimes. This is due to backlash in the drive - we're planning to eliminate this problem by improving the bearings.
The engine starts at a very low thrust for a couple of seconds during ignition then throttles-up to 350N. There is a programmed reduction in thrust at about 11s into the video.
There is an object which can be seen flapping or flickering near the nozzle exit. This is a piece of tape which was used to hold the igniter into the engine.
The sparks in the plume, visible mostly at shutdown, are due to the combustion chamber's ablative liner doing its job. There are also a lot of sparks due to the plume scouring the rust of the blast deflector.
The yellow Peli box holds a data acqusition system which sends pressure and thrust data back to a computer in the control room via Ethernet.
The throttle valves, fuel and oxidant tanks, flight computer, etc, are all above the engine so are out of shot in this video.
The Snark engine runs on nitrous oxide (oxidant) and isopropyl alcohol (fuel).
The video was taken at Airborne Engineering's Westcott facility on 17th July 2012.