CRUISING ON STORMY SKIES

Inflatable manta rays could scull through the acid clouds of Venus

In 2020, a group led by Cardiff University announced the potential discovery of phosphine on Venus. Here on Earth, the gas is given off by acid-loving bacteria, so could similar microorganisms be living in the sulphuric clouds of Venus? Unfortunately, a flurry of follow-up observations have cast doubt as to whether phosphine is actually present, but it’s undeniably put Venus back at the top of people’s planetary wishlists.

Venus’s clouds sit at an altitude of around 50 to 70km. Though Venus’s surface pressure is 92 times that of Earth, at an altitude of ›0km it’s around one atmosphere – the same pressure as sea level on Earth – meaning a helium-filled balloon could easily carry a payload of scientific instruments through the air. In fact, in 198›, the Soviet Union did just that when they dropped Vega 1 and 2 onto the planet’s nightside. For two days, they were thrown around the turbulent skies, before the 250km/h wind pushed them round to the dayside and they burst in the heat of the Sun.

Since then, engineers have been searching for ways to better navigate the stormy skies of Venus. A rotorcraft would be ripped apart, but a new concept from the Crashworthiness for Aerospace Structures and Hybrids (CRASH) Lab at the University at Buffalo, New York, could offer a solution. In 2022, the lab was given funding by NIAC to develop the Bioinspired Ray for Extreme Environments and Zonal Exploration (BREEZE), an inflatable spacecraft inspired by a manta ray.

“BREEZE’s articulated wings are based on the ray musculoskeletal system, using an intertwined, redundant actuation network that helps reduce the chance of total system failure,” says Dr Javid Bayandor, who worked on the project. This would gently twist the wings of the craft allowing it to manoeuvre along the air currents like a ray rides ocean currents.

“The bioinspired propulsion provides the light BREEZE flier with unique controllability. [This is] unlike balloon concepts, the flight paths of which are determined purely by wind direction, or conventional propulsion with large fuel consumption rates,” says Bayandor. “BREEZE is one of the first concepts offered to circumnavigate Venus from within its atmosphere and survive, making measurements on the dark side of the planet.”

Circling the planet once every four to six days, it would be able to track weather patterns, map out the surface using radar and perhaps even sniff out biomarkers (including the elusive phosphine). As it’s inflatable, it’s highly compact, so two or three could launch from the same entry vehicle at once, meaning a squadron of BREEZEs could one day float along the winds of Venus.

“As it’s inflatable, it’s highly compact, so two or three could launch from the same entry vehicle at once”