The UK Ministry of Defence is close to signing a contract with Airbus Defence & Space for the manufacture and testing of two Zephyr 8 high-altitude pseudo satellites (HAPS).

A £10.6 million ($15.5 million) deal is expected to be firmed in the coming weeks which will see the unmanned air vehicle assessed through an operational concept demonstrator (OCD) programme to determine if the capability will benefit UK forces.

Speaking at the ADS trade association's annual dinner on 2 February, Michael Fallon, UK secretary of state for defence, said a contract would be signed shortly for two Zephyrs "as part of our commitment to invest in battlefield communications technology".

November's Strategic Defence and Security Review revealed the UK was planning to invest in high-altitude surveillance aircraft.

Zephyr, which uses solar energy harvested during the daytime to power its systems at night, can stay aloft for up to 45 days.

The aircraft weighs 30kg (66lb), has a 25m (82ft) wingspan, and operates above the jetstream, at 70,000ft. It has been in development for years, originally by Qinetiq and more recently by Airbus.

The MoD’s interest in the British-built system has been known for some time and airworthiness testing in 2014 led to the Zephyr 7 variant being the first registered HAPS in the UK, designated PS001.

OCD tests will be conducted in 2017, the MoD says, and a maiden flight test of the Zephyr 8 is expected to take place in 2016. The aircraft can carry a 5kg payload, and it is envisioned it will be used to complement ground operations for surveillance and communications relay.

Zephyr 8 stress test - Airbus Defence & Space

Zephyr 8 stress testing

Airbus Defence & Space

In December, British company Roke Manor was contracted under the UK’s Defence Growth Partnership to develop a communications payload for high-altitude UAVs such as Zephyr.

While not designed exclusively for the Airbus platform, the company says the sensor system takes into consideration its size, weight and power constraints.

The data link payload communicates with ground-based cellular infrastructure at a distance of 50km, transmitting high-bandwidth, real-time images and video, using commercial off-the-shelf 3G systems, alongside beam-forming technology to transmit to a defined point.