NASA is developing a flexible Vivaldi antenna made of polyester and Vectran to equip three SkyFall Mars helicopters for late 2028. The innovative 5-ounce radar system will fold during landings and spring back into position to detect shallow subsurface ice beneath the Martian regolith.
Mars exploration is about to get a lot lower to the ground. NASA plans to send three specialized rotorcraft to the Red Planet aboard the Space Reactor-1 Freedom mission in late 2028, utilizing what the agency describes as a daring mid-air deployment
to launch the fleet, according to reporting from Popular Science.
Unlike Ingenuity, the autonomous helicopter that relied on the Perseverance rover as a communications relay, the new SkyFall aircraft will operate with greater independence. Each helicopter will carry advanced instruments capable of visible light imagery, temperature monitoring, near-infrared surface mapping, and subsurface radar data collection.
Searching for Shallow Ice With Low-Flying Mars Helicopters
Orbiting spacecraft can detect thick ice deposits buried deep beneath the Martian surface. However, those high-altitude instruments miss the top few yards of regolith—the loose mixture of dust and broken rock covering the planet. That shallow layer holds the most practical value for future exploration missions, as it contains accessible frozen water that could potentially serve as drinking water, breathable oxygen, or rocket fuel.
Reaching that hidden ice requires an entirely different approach from high-altitude orbital observation.
By operating low and slow above the terrain, the helicopters can capture radar imagery. This technique reveals the fine geological layering where dry soil gives way to ice, allowing scientists to map the precise extent of the shallow deposits.
Engineering a Flexible Vivaldi Antenna for a Six-Inch Clearance
Designing the radar equipment presented a major spatial challenge for engineers at the Jet Propulsion Laboratory. SkyFall’s radar operates across a broad frequency range spanning from 500 to 2,500 megahertz, using wavelengths between 5 and 24 inches to scan down to about 16 feet into dry Martian dirt. A conventional rigid antenna built for that frequency range would need to measure roughly 19 inches long.
The problem is that the fuselage of the Mars helicopters clears the Martian surface by only about 6 inches at its lowest point. A rigid antenna would inevitably smash against rocks or snap off during touchdown.
To solve this, engineers adopted a flat-profile design known as a Vivaldi antenna, which can send and receive signals across a wide band of frequencies. Originally invented by Peter Gibson—who named the shape after composer Antonio Vivaldi because its curved lines resembled a violin—the antenna was small enough to work because Martian dirt blocks radio waves far less than soil on Earth does.
Even with those advantages, the antenna still measured about 1.5 times longer than the helicopter’s landing legs.
Gebara added that the Vivaldi antenna must routinely bend out of the way during a landing, flexing even further if it touches down directly on a rock, before springing back into its original shape as the aircraft lifts off for data collection.
Surviving Simulated Mars Landings at the Jet Propulsion Laboratory
Because SkyFall is scheduled to perform dozens of individual flights, its antenna had to endure severe mechanical stress without losing structural integrity or radio performance. Engineers wrapped the structure in polyester and layers of Vectran—the high-performance manufactured fiber previously used to construct landing airbags for the Spirit and Opportunity rovers.
Combined with flexible fiberglass strips and a lightweight magnesium frame, the complete antenna assembly weighs roughly 5 ounces, equivalent to the weight of slightly more than two violin bows.
To prove the concept, the team subjected the hardware to rigorous tests inside the Jet Propulsion Laboratory’s Environmental Test Laboratory. Technicians bent the antenna into extreme post-landing positions, subjected it to temperature swings reaching up to 170 degrees Fahrenheit to replicate Martian day-and-night cycles, and flipped it upside down to exceed the physical stress of Mars’ one-third gravity.
After enduring the mechanical and thermal equivalent of 200 Mars landings—more than double the requirement of an actual mission—the equipment cleared its testing hurdles. Tang confirmed that the evaluation successfully answered the team’s primary engineering questions ahead of the 2028 launch window.
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