Christchurch company Kea Aerospace says it has finalised the design of New Zealand’s first stratospheric aircraft and construction is underway.

The aircraft – which has been named “Kea Atmos Mk 1” or Kea Atmos – is solar-powered, with a wingspan of 12.5 metres and weighing under 40 kilograms.

Chief executive Mark Rocket said Kea Atmos was the first stratospheric aircraft to be built in NZ and construction on it had started in July.

“We’re planning for the first stratospheric flight to take off in early 2023,” he said.

It’s been designed to be able to fly up to 20 kilometres or 65,000 feet into the atmosphere and will be used for high-altitude testing, with the ability to fly test flights of up to 16 hours.

Rocket said at that height, the aircraft would be flying in “extreme” conditions with less than 10% of the air density that is normally available at sea level and temperatures around minus 65C.

“The aircraft needs to be extremely light, but also be incredibly robust to operate successfully in those conditions,” he said.

Last year, Kea Aerospace became the first company to start test flights on the Kaitōrete Spit as part of the government’s new Project Tāwhaki aerospace initiative.

The aircraft flew its first test there last September, with a small prototype aircraft to test autonomous flight capability, solar power, and communications.