Concept of high-altitude pseudo-satellites (HAPS) platform. Credit: ESA.

The European Space Agency (ESA) is set to explore the high-altitude pseudo-satellites (HAPS) platform, which is designed to float or fly at high-altitudes but operates similarly to satellites.

The aerial vehicle platform can remain in the atmospheric position for weeks or months to offer continuous coverage of the territory below without entering outer space.

The optimal working altitude is 20km, above clouds and jet streams, as well as 10km above commercial airliners, where wind speeds are low enough to hold their position for long durations.

“We’ve been looking into the concept for the last 20 years but now, finally, it’s becoming reality.”

Capable of surveying the ground to the horizon 500km away, the platform can offer precise monitoring and surveillance, in addition to high-bandwidth communications or support to existing satellite navigation services.

ESA future-systems specialist Antonio Ciccolella said: “For Earth observation, they could provide prolonged high-resolution coverage for priority regions, while for navigation and telecoms they could shrink blind spots in coverage and combine wide bandwidth with negligible signal delay.

“ESA is looking into how these various domains can be best brought together.”

A number of ESA directorates have already partnered with various parties to investigate the potential of HAPS.

ESA Earth observation specialist Thorsten Fehr said: “We’ve been looking into the concept for the last 20 years but now, finally, it’s becoming reality.

“That’s come about through the maturing of key technologies: miniaturised avionics, high-performance solar cells, lightweight batteries and harness, miniaturisation of Earth observation sensors and high-bandwidth communication links that can deliver competitively priced services.”

ESA is also expected to be benefitted from the product lines designed by various European companies, including Airbus, which has developed a winged, solar-powered Zephyr aircraft that can undertake 14 days of continuous flight without refuelling.