94 October 2018 //^ http://www.combataircraft.net
TAKING A LOOK BEHIND THE HEADLINES
BYBY ROBERT BECKHUSEN ROBERT BECKHUSEN
XXXXXXXXX...
94 October 2018 //^ http://www.combataircraft.net
DISPATCHES FROM THE FRONT LINE
OF AEROSPACE TECHNOLOGY
BY DAVID AXE
ZEPHYR
DRONE FLIES
FOR NEARLY
A MONTH
STRAIGHT
A
IRBUS’S ZEPHYR SOLAR-
POWERED drone lew for 25 days
straight during a test light over
Yuma, Arizona beginning on July
11 this year. The light represented
a record for aircraft endurance,
breaking the previous 14-day record also set by
a Zephyr back in 2015.
The long light has big implications for military
surveillance. Unmanned aerial vehicles like
the Zephyr could loiter over a low-intensity
battleield far longer than current drones can do.
The latest high-endurance MQ-9 Reaper drone
maxes out at 40 hours in the air.
The propeller-driven Zephyr belongs to a class
of aircraft known as ‘high-altitude pseudo-
satellites’, or HAPs. Flying as high as 70,000ft for
weeks or even months at a time, HAPs perform
many of the same missions that low-orbiting
satellites do.
‘The main HAP applications are in
telecommunications and remote sensing,
both civilian and military’, Flavio Araripe
d’Oliveira, Francisco Cristovão Lourenço de
Melo and Tessaleno Campos Devezas wrote in a
2016 paper.
Compared to comms satellites, HAPs have
the advantages of lower latency and the ability
to land for maintenance or reconiguration,
d’Oliveira, de Melo and Devezas explained. Forsurveillance missions, HAPs — unlike satellites
— can linger over a particular area and could
produce images with better resolution, since
they ly lower than satellites do.
HAPs could be more vulnerable to enemy
defenses, though. While satellites orbit many
hundreds of miles over earth, beyond the reach
of most conventional weaponry, the Zephyr —
so far, the only HAP undergoing realistic testing
— attained a maximum altitude of 70,000ft,
well under the ceiling for modern air defense
missile systems such as the Russian S-300.
Also, the drone is slow, with a cruising speed of
just 20mph.
The Zephyr and similar pseudo-satellite
drones could be best-suited for operations
over lightly defended territory. In 2016, the UK
Ministry of Defence bought three Zephyrs for
around $6 million apiece in order to evaluate
them for potential use by the military and other
government agencies.
‘Zephyr is a cutting-edge, record-breaking
piece of kit that will be capable of gathering
constant, reliable information over vast
geographical areas at a much greater level of
detail than ever before’, the then UK Defence
Secretary Michael Fallon said in a statement.
Airbus is still reining the Zephyr, in particular
its power consumption. During daytime, the
lightly built, solar-powered drone — which
features an 82ft wingspan and yet weighs just
165lb — can ly as high as 70,000ft while also
charging its batteries.
After the sun goes down, Zephyr runs on
batteries and slowly loses altitude. During the
record-setting Yuma light, the drone dipped as
low as 50,000ft at night.
The challenge for Airbus is to balance weight
and power consumption to produce the optimal
light proile for a particular task. ‘You have toind the right equation between lying altitude
plus battery life, maintaining this or that power’,
said Alain Dupiech, an Airbus spokesperson.
It’s unclear just how long the Zephyr could
stay aloft under the right conditions. The drone’s
lithium-ion battery eventually dies, forcing it to
land for maintenance. But battery technology is
advancing rapidly, driven in part by consumer
demand for electric cars, d’Oliveira, de Melo and
Devezas wrote.
In the short term, a maximum endurance of
several months is not inconceivable. But longer
lights might not be particularly useful for
surveillance and comms missions, Dupiech said.
‘At this stage, most of those missions are not
calling for a year-and-a-half up there.’
Airbus has scheduled the Zephyr’s next test
light for October in western Australia.While satellites
orbit many
hundreds of miles over
earth, beyond the reach
of most conventional
weaponry, the Zephyr
attained a maximum
altitude of 70,000ft,
well under the ceiling
for modern air defense
missile systems
The Zephyr solar-powered drone takes
flight. Airbus Defence and Space