Sirius Rocket Engine Family

Sirius is Gilmour Space Technologies’ proprietary hybrid rocket engine, developed in-house at the company’s Helensvale, Queensland facility. The engine burns a combination of LOX (liquid oxygen) oxidizer and a proprietary solid hydrocarbon fuel grain, representing a hybrid approach that provides simplicity advantages over fully liquid engines while offering higher performance than solid rockets.

The Sirius engine powers the Eris launch vehicle’s second and third stages, which are the critical orbital insertion stages. Gilmour’s Eris uses solid propellant for the first stage (for simplicity and cost), then hybrid propulsion for the upper stages. Sirius development has involved multiple static fire tests at Gilmour’s Gold Coast, Queensland test facility.

Gilmour Space Technologies, founded in 2013 by brothers Adam and James Gilmour, is Australia’s most advanced launch company, targeting the Eris rocket’s first orbital launch from the Bowen Space Launch Facility (Orbital Launch Complex 1) in North Queensland. The company raised over A$61 million (including from HESTA and Blackbird Ventures) and targets a launch window from the Queensland coast for SSO inclinations.