This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: From 2021 to 2024, NASA's Ingenuity helicopter became the first vehicle of its kind to explore the Martian atmosphere and surface. With that proof of concept complete, NASA is preparing to send a trio of helicopters to search for the most precious resource for future astronaut missions: water.
Known as the SkyFall trio, these helicopters will detect frozen water within the top few meters of Martian regolith. To find possible water sources, each helicopter will use ground-penetrating radar with a flexible, fabric-based antenna extended beneath the spacecraft. The antennas are specially designed for this mission so they will not interfere with landings or break upon contact with the surface.
They also recently cleared a round of testing at NASA's Jet Propulsion Laboratory. When deployed, these three helicopters (one larger and two smaller) will fly over the Martian landscape and project ground-penetrating radar signals in an ultra-wide frequency range—500 to 2,500 megahertz (MHz)—at depths of several meters beneath the surface. While the longer wavelengths in this range can penetrate several yards below the surface, the shorter wavelengths provide finer detail about the uppermost surface layers.
Even though satellites can map large ice deposits a few dozen meters (tens of yards) beneath the surface, they are effectively blind to shallow deposits (5 m; 16 feet). These deposits are crucial to future crewed missions, as astronauts will need easily accessible water sources. "The only way to detect shallow subsurface ice remotely is to fly close to the ground," said Adrian Tang, SkyFall's ground-penetrating radar lead instrument scientist at JPL, in a NASA press release.
"By flying low and slow, a SkyFall helicopter could capture radar images that resolve the fine layering where dry soil gives way to ice, detecting its presence and mapping its extent." Each SkyFall helicopter will be equipped with four instruments, similar to those on NASA's Ingenuity Mars Helicopter. During its three years in operation, the helicopter showed that controlled flight in Mars' rarefied atmosphere is possible and demonstrated that an aerial perspective can provide valuable data for surface missions (such as possible travel routes and research site selection). However, radio communications remain a challenge for SkyFall's mission profile.
Traditional antennas would need to be about 48 cm (19 inches) and have a clear view of the ground to operate in this part of the electromagnetic spectrum. However, this isn't practical, since the minimum clearance between the helicopter and the Martian surface will be only about 15 cm (6 inches). After considering multiple potential designs, the SkyFall team selected the Vivaldi antenna: a flat, curvilinear design that can cover a large, continuous range of radio frequencies and resembles curved blades placed back to back.
Extract — continue reading at the source.
