In a paddock on a property just outside of Rathdowney in south-east Queensland, Adam Gilmour, a former Citibank executive turned rocket man, looks anxiously at his watch.

The testing of an engine that is designed to propel 1500 kilograms into orbit has hit a hitch. In the ironically named "VIP tent" on the next hill, the founder and chief executive of Gilmour Space Technologies speaks into his walkie-talkie with his engineers and technicians in the bunker on the other side of the gully, next to the hybrid rocket engine.