As scientists continue to wrestle with the vexing problem of how to get humans to Mars and bring them safely home, robotic exploration of the Red Planet has already yielded many amazing discoveries. However, our missions to the planet’s surface have studied only a tiny fraction of the land area, and rovers aren’t likely to get much faster in the future. NASA has just completed preliminary testing on a novel wing designthat could one day allow a Mars probe to soar through the planet’s thin atmosphere and cover great distances.
There are two projects operating in tandem, both based on the same high-lift boomerang-shaped wing design. There’s the Preliminary Research Aerodynamic Design to Lower Drag (Prandtl-d) and the forward-looking Preliminary Research Aerodynamic Design to Land on Mars (Prandtl-m). NASA scientists have been testing the Prandtl-d design for some time now, but it has only recently been subjected to a full battery of wind tunnel tests. This is essential to understand how the wing will perform in a variety of conditions, including those on Mars if the design is carried over to a space mission.
The wind tunnel scale model testing of Prandtl-d was carried out jointly by NASA’s Armstrong Flight Center and Langley Research Center. According to the data, the boomerang wing is remarkably stable, even when it’s completely stalled. That could save a Mars exploration plane from a catastrophic failure when it’s a few million miles away from the nearest repair crew. The airflow patterns over the boomerang wing proved to be totally new to the team, which could account for its ability to generate high lift and remain stable.
The next step for Prandtl-m is a high altitude test of the wing design that will take place later this year. A small prototype of the plane will be released at an altitude of 100,000 feet. The atmosphere up that high is a close approximation of Mars, so it’s important to know if Prandtl-m could generate enough lift to stay aloft in such conditions. If the test goes well, that could be huge for future Mars missions.
NASA doesn’t expect it will have to design an entire mission around Prandtl-m. The beauty of this design is that it could ride to Mars in a 3U CubeSat (about one foot square) connected to the aeroshell of a Mars rover. This module could be ejected when the rover begins its descent, allowing the plane to deploy and fly a tremendous distance before gliding to the surface. It could be used for geological surveys, imaging, and scouting future landing sites up close. The additional weight of the Prandtl-m craft wouldn’t add much of anything to the launch cost either.
NASA believes Prandtl-d could morph into Prandtl-m in time for inclusion on the 2020-era Mars rover. That mission could reach the Red Planet as soon as 2022-2024.