Floating in the Atmosphere: Sailplanes on Mars

Exploring Mars is tough. Robotic emissaries have been crawling over the planet’s surface for years, but they move slowly. Flying may be the next stage in vehicular exploration. But how to do so efficiently? There are a lot of problems to solve, what with limited power and thin atmosphere. One proposal is to use inflatable sailplanes, which use atmospheric energy to soar for hours or even days. We spoke with Dr. Sergey Shkarayev, an aerospace engineering professor at the University of Arizona, to learn more about this exciting technology.

What is the major advantage inflatable sailplanes have over other technologies for Mars exploration?

Mars’s atmosphere is very thin – its density is a hundred times lower than that on Earth. Even though the gravity on Mars is significantly lower (2.6 times), it still takes effort to achieve sustained flight on this planet. There are several aircraft designs proposed for Mars exploration. However, their flight endurance is limited by several minutes due to the weight of their motors and the amount of fuel they require on board. In order to overcome this underperformance, we propose an unpowered sailplane (without motor) for flight in the Martian atmosphere.

Can you provide more details on how a sailplane would actually go about exploring Mars?

In addition to conventional static soaring, the sailplane will employ the dynamic soaring method. This is the same mode of flight that natural fliers use here on Earth. Using this method, for instance, an albatross is capable of sustained flight for many hours over the ocean without ever landing.

Dynamic soaring includes a series of cyclic climbs against a non-uniform wind, high-g turns, and descents. The climbing into the wind converts a wind speed gradient in the atmospheric boundary layer into a sailplane’s mechanical energy. During this maneuver, the average flight altitude can be maintained or gained, providing hours or even days of flight by harvesting energy from the atmosphere.

We have demonstrated theoretically that the long endurance flight is feasible on Mars. The idea of small autonomous dynamic soaring sailplanes holds much promise for future discoveries on Mars.

How did you end up having a profession that designs novel ways to explore other planets?

I have over 35 years of industrial and academic experience. Prior to joining the University of Arizona in 1995, I held a faculty position at the Kharkov Aviation University in Ukraine. In addition to my faculty position, I worked as a Vice Chief Designer for an aircraft design company. My knowledge of and affection for aviation is also based on skydiving experience. During my college years, I performed more than 1,200 jumps with a parachute as a member of the university team.