Airbus Zephyr

The Airbus Zephyr is a series of lightweight solar-powered unmanned aerial vehicles (UAV). The latest model is a high-altitude platform station capable of flying at for months at a time without fueling. It has a wingspan of and weighs .

Development

The Zephyr was originally designed and built in 2003 by the British defence contractor QinetiQ.

In a 2008 demonstration for the US military, Zephyr 6 (a smaller-scale version) broke the official world record for the longest-duration unmanned flight, however its 82-hour flight at an altitude of did not set an official record because FAI officials were not involved in the flight.

The Zephyr 7 holds the official endurance record for an unrefuelled, unmanned aerial vehicle with its flight from 9 to 23 July 2010, lasting 336 hours, 22 minutes and 8 seconds (14 days, 22 min, 8 s). It could remain airborne for months thanks to its solar cells and rechargeable batteries. Record claims have been verified by the Fédération Aéronautique Internationale (FAI) for both duration and altitude, at 21,562 metres. It more than doubled the previous endurance record for unmanned flight.

The Zephyr system was sold to EADS Astrium (now Airbus Defence and Space) in March 2013, where it was successfully re-flown as part of the High Altitude Pseudo-Satellite (HAPS) programme.

In 2014 it flew for 11 days in winter, and later near civilian airspace.Bellamy, Woodrow III.
Airbus Zephyr Proves Value For Civil Operations in Middle East
, ''Aviation Today'', 1 October 2014. Accessed: 2 October 2014.

In November 2015, in the House of Commons, British prime minister David Cameron laid out plans during the Strategic Defence and Security Review 2015, to enhance Great Britain's intelligence, surveillance and reconnaissance (ISTAR) capacity. He stated that the UK was to field a "British-designed unmanned aircraft that will fly at the edge of the Earth's atmosphere and allow us to monitor our adversaries for weeks on end, providing critical intelligence for our armed forces." A purchase of two Zephyr 8 planes was reported in February 2016. In August 2016 Ministry of Defence confirmed the purchase of a third Zephyr 8 platform.

In summer 2018 for its maiden flight from Arizona, the Zephyr S remained aloft for 25 days 23 hours 57 minutes, nearly twice as long as the previous record flight of 14 days set by its predecessor. It used Amprius lithium-ion batteries with silicon nanowire anodes for a 435 Wh/kg specific energy up from 300–320 Wh/kg. High-efficiency, lightweight, and flexible inverted metamorphic (IMM) multi-junction epitaxial lift-off (ELO) GaAs solar cell sheets manufactured b
MicroLink Devices
provided the solar power with specific powers exceeding 1,500 W/kg and areal powers greater than 350 W/m².

In addition to Zephyr 8, otherwise known as Zephyr S, full-scale flight testing was scheduled for a twin-tailed Zephyr T variant in 2018 aimed at providing a maritime surveillance and communications capability.

In July 2022, Zephyr S spent 26 days airborne, breaking its previous record from 2018. The flight began on 15 June in Arizona, and by 22 July the plane was still flying after being aloft for 36 days. It marked the Zephyr's first venture into international airspace and over water, and its longest continuous flight using satellite communication controls. By 5 August, it had reached 50 days of continuous flight. On 19 August 2022, the plane was lost over a desert in Arizona with no personal injury reported after a flight time of 64 days.The Airbus Zephyr Comes Crashing Down In Arizona
''Simple Flying''. Retrieved 22 August 2022. It flew over the southern United States, the Gulf of Mexico, and South America, covering a distance of 30,000 nmi (35,000 mi, 56,000 km) during the course of the flight.

Design

The Zephyr 6 is of carbon-fibre construction and uses sunlight to charge a lithium–sulphur battery during the day, which powers the aircraft at night. The aircraft has been designed for use in observation and communications relay.

The vehicle can circle over a particular area for extended periods, with particular emphasis on its potential civil and military applications as an Earth-observation and communications platform. During the day, Zephyr uses its solar cells spread across its wings to recharge high-power lithium–sulphur batteries and drive two propellers. At night, the energy stored in the batteries is sufficient to maintain Zephyr in the sky. The lithium–sulphur batteries are supplied by Sion, and the first version had a battery capacity of 3 kW·h.

Zephyr 7 was larger, at 53 kg, and capable of a maximum altitude between 65,000 and 70,000 feet, it required five ground crew to launch, as opposed to three previously for the Zephyr 6.

The Zephyr 8 has roughly 24 kg of batteries and a 5 kg payload, and is 30% lighter and carry 50% more batteries than the Zephyr 7. It has a 25-metre wingspan. By October 2021, it had flown 2,435 hours.

Zephyr is under consideration for use as an airborne communication station, offering the possibility of replacing 250 cell sites. It can be used to perform intelligence, surveillance and reconnaissance (ISR) with a wide visual payload coverage of 20×30 km (12.4×18.6 mi) and can be equipped with radar, LIDAR and infrared technologies.

Specifications

Accidents and incidents

, three hull losses have been reported:
* March 2019, Wyndham, Western Australia
* 28 September 2019, Wyndham, Western Australia, during the first flight after the first incident in March 2019
* 19 August 2022, Arizona, just before breaking the record for the longest flight of any aircraft (a total of 64 days)

See also

* NASA Pathfinder
* SoLong
* Solar Impulse project
* Vulture (UAV)
* Air Strato

Notes and references

External links

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2000s British experimental aircraft
Zephyr
Solar-powered aircraft
Unmanned military aircraft of the United Kingdom
High-altitude and long endurance aircraft
Airbus Defence and Space aircraft