On a calm clear High Desert October evening, Interorbital Systems’ NEPTUNE rocket series’ main engine roared to life in its first hot-firing test in Mojave, Calif.
The engine, the IOS GPRE 7.5KNTA (General Purpose Rocket Engine; 7,500 pound thrust; Nitric Acid; Turpentine; Ablative cooling), blasted a 22-foot plume of fire across Interorbital’s Mojave Spaceport test area, scorching the sand an additional 50 feet beyond the plume end.
The all-composite chambered 7,500-pound (33,362-newton) thrust engine is the largest rocket engine in the world utilizing high-density, storable nitric acid and turpentine. These hypergolic propellants provide almost instantaneous chemical ignition.
This static firing marks a major milestone in the evolution of the company’s NEPTUNE Modular Orbital Launch Vehicle series.
Refining the engine operation paves the way for the first flight test of the CPM – Common Propulsion Module – the stand-alone rocket that is the primary construction element of various bundled configurations that yield launch vehicles specially designed to meet specific mission requirements.
IOS’ first orbital launcher is a seven-module rocket designated the NEPTUNE 7 (N7) – powered by seven of the GPRE 7.5KNTA engines – and purposed to lift a mixed-manifest of some 24 TubeSats and CubeSats on each launch.
Interorbital recently completed a NASA Phase I SBIR contract, awarded to further the development of the NEPTUNE Modular Rocket series.