"This unlocks the next major performance milestone for the Mk-II vehicle, namely supersonic flight," said Stefan Powell, CEO of New Zealand's Dawn Aerospace. "To the best of our knowledge, this would be the first privately funded UAV to break the sound barrier."

The Mk-II actually made its first test flights back in 2021, when the Civil Aviation Authority granted Dawn permission to operate out of conventional airports to assess the airframe and avionics. But the tech demonstrator didn't rocket into the air, it was equipped with surrogate jet engines.

It would be a couple of years before the uncrewed spaceplane nailed its maiden flight powered by a hydrogen peroxide/kerosene rocket engine. At that time it managed speeds of around 196 mph (170 kt or 315 km/h) at altitudes of 6,000 ft (1,829 m).

Dawn has undertaken more than 50 flight tests using jet and rocket engines since 2021, and the latest certification removes the training wheels, so to speak, to unlock unlimited speed at altitudes up to 80,000 ft (~24,385 m). That will take the Mk-II beyond the visual line of site "without the need for restricted airspace" and to supersonic speeds.

"At full performance, the Mk-II will fly faster and 2.5 times higher than any prior aircraft that takes off from a runway, including the current record holder, the SR-71 Blackbird," added Powell.

The latest round of up to 12 test flights are due to start from this month and run until September, with the primary objective reported to be achieving Mach 1.1 at an altitude of 70,000 ft. Plans also call for a demonstration of reusability by undertaking two flights in a day.

The company's eventual aim is to push the Mk-II to over Mach 3 while carrying cargo, on the way to developing an unmanned aircraft capable of rocketing to an altitude of 100 km (62 miles) and have it do so a number of times each year.

While we wait for Dawn to share footage of these supersonic test flights, have a look at a recent static hotfire test for a taste of things to come. Of course, we'll also be keeping an eye on the Quaterhorse from Hermeus, which is being designed to fly beyond Mach 5.