The UK Ministry of Defence is going to acquire some high-altitude "eternal planes".
The unmanned, solar-powered aircraft, known as Zephyrs, fly above the jet streams and will stay aloft for months on end.
Designed and built in Britain, the vehicles will carry small payloads that might consist of reconnaissance cameras or communications equipment.
The MoD is likely to buy two Zephyrs in the first instance.
Originally developed by QinetiQ of Farnborough, the plane technology is now owned and marketed by the Airbus Group.
The Zephyrs hold the absolute endurance record for un-refuelled aeroplanes.
In 2010, a Zephyr-7 flew uninterrupted for 14 days in an MoD demonstration in the US.
Very efficient solar cells combined with energy-dense lithium-sulphur batteries kept its propellers continually turning, maintaining an altitude well above any disruptive weather.
The British plane only came back down because the development team had to pack up and return to the UK.
The latest model, Zephyr-8, represents a substantial improvement in the overall design.
It has a 25m wingspan versus the Zephyr-7's 22.5m, yet the structure is considerably lighter.
This allows it to carry more batteries (40% of the Zephyr-8's roughly 60kg mass is dedicated to energy storage) and more payload - up to 5kg.
Five kilograms might not sound like a lot, but it is more than sufficient to operate a powerful camera system.
In test flights above 65,000ft, high-definition video with a ground resolution of 50cm has been downlinked in real-time.