“All conventional satellite launch systems use different stages,” says Smart. “There’ll be a first stage rocket that normally gets up to Mach 5 or 6, you’ll have a second scramjet stage that goes two thirds of the way to space and you’ll have a final upper stage that takes the satellite into orbit.”

On the launchpad, Spartan will look and launch like a conventional rocket. Once it reaches hypersonic speeds, however, the first stage will drop away and the scramjet will unfurl its wings to blast the spacecraft into the upper atmosphere. When it runs out of air, the scramjet will separate and a small conventional rocket will carry the satellite into space.

As much of the Spartan system as possible is designed to be reusable. Both the scramjet and first stage rocket will fly themselves back to a runway landing – although the scramjet will undoubtedly look sleeker.

“Once the rocket booster has finished its job we deploy wings and a small propeller and fly back to base,” says Smart, “It’s basically just a big tin can, it’s very light. It’d be like a small ugly aircraft.”

The only part of the launch system that will not survive the flight is the final third stage, which will burn up in the atmosphere after releasing its payload into orbit.

Over the past couple of years, Smart has been carrying out hypersonic tests with a rocket and a two-metre-long scramjet at Woomera – flying the aircraft at hypersonic speeds 400 kilometres across the desert. “It’s the best ever radio controlled plane,” admits Smart, although it’s way too fast to control with a joystick. “We pre-prepare all the flight software, press the button and off it goes.”

Although Smart’s goal is to get Australia back into the satellite launch business, hypersonic aircraft hold the promise of radically reducing flight times on Earth. Most aerospace journalists have written a story on hypersonic travel, promising flights from London to Sydney in two hours, and there have been several proposals to help realise that dream. But could combining conventional rockets and scramjets be the answer instead?