When this engine runs, it really runs. The maker fired a hybrid rocket motor burning compressed oxygen in a static test, and the burn puts out an average thrust of 3,000N with peaks reaching 5,500N. The exhaust leaves horizontally as a bright flame, and the plume shows clearly defined shock diamonds along its whole length, which is a treat to watch. Total impulse came in at 15,000Ns with a specific impulse of 220s, solid numbers for a project like this.
The setup looks deliberately serious. The cylindrical casing sits horizontally near the ground, held in a metal mounting structure on the right side, and the whole motor is anchored down with heavy chains and cables. An electronic countdown sounds before ignition, and a small puff of light grey smoke appears at the nozzle just beforehand, after which the motor jumps straight to full thrust. A loud combustion roar carries through the burn, and once it ends a cloud of white residual smoke drifts off across the ground.
One detail stands out as an open question: the clip shows the flame cutting out after roughly two to three seconds, while the stated burn time is 5s. Those two figures do not line up, and it is not clear from what is available whether the early cutoff was planned or a hiccup.
As a first look at this engine, the measured thrust and efficiency make it worth following. The GOX pressure and flowrate behind the burn have not been shared, so there is still plenty to learn about how the motor was fed, but the visible plume behavior alone suggests the combustion side is working well.