Last month, European aerospace manufacturer Airbus concluded the summer test program for its solar-powered 'Zephyr' aircraft. The plane even managed to set a world record along the way. Let's take a closer look at everything you need to know about this project.

A long-running project

The Zephyr program actually dates back to 2003, when it was not yet an Airbus project. At this point in time, QinetiQ, which is also a rare operator of the Avro RJ70 and RJ100, ran the operation. Following the production of the original Zephyr in 2003, a further three models from this line of solar-powered uncrewed aerial vehicles have been built.

The program passed ownership from QinetiQ to EADS Astrium in 2013. This company became known as Airbus Defence and Space later that year, following a merger with Cassidian and Airbus Military. The latest model from the Zephyr series is known as the Zephyr 8 or Zephyr S. This is the version that Airbus has been testing in Arizona this summer.

Airbus Zephyr Arizona
The Zephyr drone was lost above Arizona. Photo: Airbus

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A busy summer

What makes the Airbus Zephyr S special is that this solar-powered aircraft has outstanding endurance and altitude capabilities. These were plain to see in Airbus's report of a busy summer of testing for the aircraft in the Arizona desert. This saw the plane make a total of six flights, of which four were at low-altitude, and two were stratospheric.

Six flights may not necessarily sound like a lot, but each of the stratospheric journeys lasted a staggering 18 days. These were key in helping the Zephyr S to reach the 2,435 flight hour mark for stratospheric flights alone. In the course of the tests, it also achieved a world altitude record for its class when it reached an impressive 76,100 feet.

Airbus Zephyr
The Zephyr can fly much higher and for much longer than conventional aircraft. Photo: Airbus

Positively received

While the Zephyr S can only carry a 5 kg payload, this is enough to support the 'Optical Advanced Earth Observation system for Zephyr', otherwise known as OPAZ. The purpose of the testing was to prove the capability of Airbus's High Altitude Platform System (HAPS). James Gavin, Future Capability Group Head at Defence Equipment & Support, stated:

"Working with Airbus and the Zephyr team during the 2021 flight campaign, significant progress has been made towards demonstrating HAPS as a capability. This summer’s activities represent an important step towards operationalizing the stratosphere."

The Director of Capability and MDI Change Programme at Strategic Command, Major General Rob Anderton-Brown, was also impressed by the Zephyr. He added:

"Zephyr is an important programme within UK Strategic Command and the recent successful flight has required many innovative technical solutions. This represents a significant milestone for Zephyr which is informing the development of new concepts and ways of enabling military operations, particularly in the context of Multi-Domain Integration."

Airbus Defence and Space Getty
Defence and Space accounts for around a fifth of Airbus's revenue. Photo: Getty Images

How it works and might be used

The reason that the Zephyr can stay in the air for so long is the sustainable nature of its propulsion. Flying in the stratosphere, the plane has direct exposure to sunlight, which it harnesses to power its solar cells. By day, these drive its propellers and recharge its batteries. By night, these batteries have sufficient energy to keep the plane flying in darkness.

Airbus foresees a variety of ways in which prospective operators could use the Zephyr. Its ability to remain in the air for so long opens various doors. The company explains:

"Zephyr will provide the potential to revolutionize disaster management, including monitoring the spread of wildfires or oil spills. It provides persistent surveillance, tracing the world’s changing environmental landscape and will be able to provide communications to the most unconnected parts of the world."

What do you make of the Airbus Zephyr? Would you like to see solar power play more of a role in creating a sustainable aviation industry? Let us know your thoughts in the comments.