The private space company NSTR Rocket Technologies has completed testing its small liquid rocket engine on July 11. The engine runs on nitrous oxide and white spirit. Specific impulse is 240 s. It features radiative cooling and pyrotechnic ignition.
Tests of the engine were lasted from October 2018 till July 2019. There were four engine modification with 3D printed mixing head as well as traditionally made mixing head of stainless steel. 3D printed mixing heads were made by Center for Additive Technologies from an alloy of cobalt, chromium and molybdenum. The engine (including mixing head) was designed entirely by NSTR Rocket Technologies. One of engine modification is capable to use metal or composite nozzle extension to improve efficiency at higher altitudes.
All tests were performed in the armored chamber for safety reasons. There were more than twenty fire tests and the most part were partly of fully successful.
The engine showed from 35 to 320 kgf thrust depending on test conditions. It is pressure-fed engine. The tank pressure is up to 85 atm. Run time is up to 7 s.
The engine is ready for mass production. We plan to use it as vernier thruster on nanolaunch vehicle. Also, it could be useful for teaching students.
Here is short video of final fire test. This does not mean we stop improving process. Electric spark ignition is on the way.
Soon we tell you about fire tests of more powerful engine designed for our planned sounding rocket.