The detail that floored me: this 35kN liquid flight engine is the maker's first engine ever. Not a scaled-down demonstrator, not a practice piece in miniature, but a full-size flight engine rated at 8,000 lbf of thrust, built up over three years of work. The engine goes by the name STEWART. For a first attempt to reach that level says a lot about the discipline behind it.
The test itself was a static hot fire at night, dated June 17, 2021, with the engine bolted horizontally to a metal frame. The stand area is ringed with sandbags, barricades and a traffic drum. The system includes main run valves and a nitrogen purge system that pushes high pressure gas through the fluid lines. The footage is slowed six times, and ignition comes around ten seconds in, with the fire extinguishing at roughly the 24 second mark.
What stands out is the plume: a long bright white and orange exhaust with thick smoke, shooting horizontally and kicking up glowing particles and debris. Lingering flame and smoke pockets remain after shutdown, and distant cheering breaks out once the burn ends. The engine is meant for Starsailor, a spaceshot rocket with a target altitude of 135km, a big step up from the maker's past rocket on a 30k COTS solid motor. One open question: clear close-up photos of the engine hardware itself are hard to come by, and I would love to see the actual engine, not just its exhaust.
Project by Space Concordia. Watch it on their YouTube channel: