British company Pulsar Fusion demonstrated its latest green hybrid rocket engine in the sleepy mountain town of Gstaad in Switzerland. An impressive visual plume effect of supersonic shock diamonds, typical of a high temperature high mass flow rate rocket exhaust, could be seen through the snowstorm as the team operated the engine in quickly changing conditions.

The exhaust speeds of the engine were recorded at Mach 7. This engine would be capable of launching a small rocket to an altitude of several 10s of km, well above UK airspace, or powering the upper stage of a rocket with a larger booster stage into orbit.

“British companies with space ambitions must be international and fast moving, achieving technological milestones on time and on budget whilst being environmentally conscious. Pulsar’s objective is to build world class technologies that serve as a force for good,” commented CEO, Richard Dinan.

Pulsar’s green (non-toxic) hybrid rocket engine combusts nitrous oxide (N2O) oxidiser and high-density polyethylene (HDPE) fuel and oxygen. The HDPE can be obtained from recycled plastic and the two fuels burn together to produce a non-toxic plume.

The propellants used – nitrous oxide N2O and polyethylene HDPE – are some of the cleanest available to the space industry, producing an exhaust of largely water vapour and having an extremely low production energy requirement, resulting in one of the lowest carbon footprints in the world for an engine of this size.

It is a new model that enables Pulsar to manufacture these compact rocket engines at record lead times, with an enhanced safety factor as due to the design, these engines have relatively benign failure modes in comparison with conventional liquid propulsion engines.

Pulsar Fusion is primarily engaged in the research of high-speed propulsion and clean energy applications from nuclear fusion. Pulsar Fusion received UK government funding in September 2021 to further develop its HET (Hall Effect Thruster) plasma satellite engines, capable of 20 km / second particle exhaust speeds. These Pulsar thrusters have recently been tested at Harwell’s facilities where they withstood 20g’s of vibration, simulating a rocket launch. Pulsar now seeks to IOD (In Orbit Demonstration) test these engines.

The company’s ultimate milestone is to produce a hyper-speed propulsion engine using nuclear fusion technologies of which it has been researching for nine years which could eventually be used for interplanetary travel – and which scientists say could halve the journey time from Earth to Mars. A first prototype is expected in 2025.