The BAE Systems Persistent High Altitude Solar Aircraft (PHASA-35) is a

High-Altitude Long Endurance Atmospheric satellite (United States usage, abbreviated atmosat) or pseudo-satellite (British usage) is a marketing term for an aircraft that operates in the atmosphere at high altitudes for extended periods of time, in order to provide servic ...

(HALE)

unmanned aerial vehicle An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without any human pilot, crew, or passengers on board. UAVs are a component of an unmanned aircraft system (UAS), which includes adding a ground-based controller ...

(UAV) developed by

BAE Systems BAE Systems plc (BAE) is a British multinational arms, security, and aerospace company based in London, England. It is the largest defence contractor in Europe, and ranked the seventh-largest in the world based on applicable 2021 revenues. ...

in collaboration with Prismatic. Designed as a cheaper alternative to satellites, the aircraft can be used for

surveillance Surveillance is the monitoring of behavior, many activities, or information for the purpose of information gathering, influencing, managing or directing. This can include observation from a distance by means of electronic equipment, such as c ...

border control Border control refers to measures taken by governments to monitor and regulate the movement of people, animals, and goods across land, air, and maritime borders. While border control is typically associated with international borders, it a ...

communications Communication (from la, communicare, meaning "to share" or "to be in relation with") is usually defined as the transmission of information. The term may also refer to the message communicated through such transmissions or the field of inquir ...

and

disaster relief Emergency management or disaster management is the managerial function charged with creating the framework within which communities reduce vulnerability to hazards and cope with disasters. Emergency management, despite its name, does not actuall ...

with a potential ability to stay airborne for up to 12 months. Developed in less than two years, the aircraft carried out its first flight in February 2020 and further trials are currently ongoing.

Development

PHASA-35 was originally designed and developed by engineers who had previously worked on the

Zephyr In European tradition, a zephyr is a light wind or a west wind, named after Zephyrus, the Greek god or personification of the west wind. Zephyr may also refer to: Arts and media Fiction Fiction media * ''Zephyr'' (film), a 2010 Turkish ...

HAPS drone for Qinetiq. When Qinetiq sold Zephyr to

Airbus Defence and Space Airbus Defence and Space is the division of Airbus SE responsible for the development and manufacturing of the corporation's defence and space products, while also providing related services. The division was formed in January 2014 during the ...

in 2013, these engineers left and formed their own company, named Prismatic, to develop a rival aircraft. Development of PHASA-35 consequently began in 2018, in collaboration with BAE Systems, and a first flight was scheduled for 2019. Prior to this, a quarter-scale model, named the PHASE-8, completed a successful first flight in 2017. In September 2019, BAE Systems acquired Prismatic as a subsidiary. After less than two years in development, the PHASA-35 made its maiden flight on 17 February 2020 at the

Woomera Test Range The RAAF Woomera Range Complex (WRC) is a major Australian military and civil aerospace facility and operation located in South Australia, approximately north-west of Adelaide. The WRC is operated by the Royal Australian Air Force (RAAF), a di ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

with support from the UK's

Defence Science and Technology Laboratory The Defence Science and Technology Laboratory (Dstl) is an executive agency of the Ministry of Defence (United Kingdom), Ministry of Defence of the United Kingdom. Its stated purpose is "to maximise the impact of science and technology for the ...

and Australian

Defence Science and Technology Group The Defence Science and Technology Group (DSTG) is part of the Australian Department of Defence dedicated to providing science and technology support to safeguard Australia and its national interests. The agency's name was changed from Defence ...

. Further trials commenced and, in October 2020, the aircraft carried out an endurance trial whilst carrying a sensor payload. The trials saw the aircraft operating 72 hours whilst in a simulated environment of harsh

stratospheric The stratosphere () is the second layer of the atmosphere of the Earth, located above the troposphere and below the mesosphere. The stratosphere is an atmospheric layer composed of stratified temperature layers, with the warm layers of air hi ...

conditions. In January 2021, BAE Systems announced plans to carry out a flight demonstration in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

after acknowledging “strong growing interest” in the aircraft from across the

U.S. Department of Defense The United States Department of Defense (DoD, USDOD or DOD) is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government directly related to national secur ...

and federal agency customer base.

Design

The aircraft is a solar-electric HALE UAV designed as a cheaper alternative to

satellite A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope ...

s and is able to carry out a range of tasks, including border protection, maritime and military surveillance, disaster relief and communications. It is powered by the sun during the day, before switching to battery power during the night and can potentially stay airborne for 12 months. Featuring long-life battery technology, ultra-lightweight solar cells, a wingspan and a weight of , the aircraft is designed to operate in the

stratosphere The stratosphere () is the second layer of the atmosphere of the Earth, located above the troposphere and below the mesosphere. The stratosphere is an atmospheric layer composed of stratified temperature layers, with the warm layers of air ...

References

{{reflist Solar-powered aircraft Unmanned military aircraft of the United Kingdom High-altitude and long endurance aircraft BAE Systems research and development High-wing aircraft Twin-engined tractor aircraft