Eight active spacecraft, including three used by NASA, orbit Mars and collect images of the planet’s surface at about 1 foot per pixel. The three rovers cut across the ground, making a map of the planet’s smaller regions more accurately. But what lies hundreds of miles between rovers and orbiters — including climate systems and geological features such as volcanoes and ravines — often fascinates planetary scientists.
“You have this very important, critical fragment on this planetary boundary layer, as in the first few kilometers above the earth,” said Alexandre Kling, a research scientist at NASA’s Climate Modeling Center. “This is where the whole transition between space and space takes place. This is where the dust is picked up and sent into space, where the trace gases are mixed, where the high winds flow through the mountain valley flow. And we don’t have much detail about it.”
Kling has partnered with a team of University of Arizona engineers who aims to fill this data gap by designing a single-engine airplane that can fly over the Martian for several days at a time, using only wind power. Equipped with light sensors, temperature, gas, and cameras, the sail aircraft will weigh only 50 pounds [11 kg]. The team explains its proposal in a paper published in the journal Aerospace.
Flying albatross
Flying to Mars is challenging due to the small planetary atmosphere, and this is not the first team trying to tackle it. Most notably, NASA Intelligence is a 4-pound helicopter that landed on Mars’ Jezero Crater in 2021. With minimal airplane technology and a 4-foot rotor system span, it is the first tool to test a powerful, controlled plane on another planet. But this solar-powered car can fly for only three minutes at a time, reaching a maximum length of 40 feet [12 m], or about 39 feet.
“These other technologies are minimal in terms of power,” said the paper’s first author, Adrien Bouskela, a student of Arizona Aeronautical Engineering professor Sergey Shkarayev’s Micro Air Vehicles Laboratory. “We are proposing to use in situ just the same, and it is like jumping ahead in those ways to increase activity. Because the vital question is: How can you fly for free?
Lightweight, inexpensive, air-conditioned sails may be the answer. Aircraft with wingspans of up to 11 feet wide will use several different flight modes, including vertical takeoffs where there are enough winds to land. But they can also use dynamic soaring, similar to the albatross on long journeys. It takes advantage of the fact that horizontal wind speeds are usually higher — something ubiquitous on Mars.
