NASA funds spherical 'Aerobots' that could explore the caves of Saturn's moon Titan

Spherical "Aerobots" may one day swarm the caves of Titan — a moon of Saturn that NASA says is one of the most Earthlike in our solar system.

Titan is covered in rivers, lakes and seas of hydrocarbons, like methane and ethane, as well as a strange "karst" terrain including underground sinkholes and caves .

No rover could easily traverse this surface, but flying vehicles may have more success.

So a new grant, under the early-stage NASA Innovative Advanced Concepts (NIAC) program, aims to create small, flying vehicles that could explore those caves.

It's unclear if the aerobots — called SPARK , or Solid-state Propulsion for Autonomous Reconnaissance of Karst — would be ready in time for NASA's Dragonfly mission to Titan, project lead Daniel Drew, an assistant professor at the University of Hawaii at Mānoa, told Space.com.

That's because SPARK is beginning a nine-month Phase 1 grant and would need to at least get through the up-to-two-year Phase 2 before things look "more realistic" for a liftoff, he noted.

Dragonfly, meanwhile, is targeted for a 2028 launch but if the mission is delayed, that provides more possibilities for late-mission additions.

"Where does that line up with the current Titan mission timeline, assuming we've missed the window for Dragonfly? I don't know," Drew said of SPARK.

But whenever the mission lifts off, Drew said SPARK has a good chance of doing well on Titan with its novel ion (electric) thrusters.

Drew said his design could "provide persistence, maneuverability, robustness to the challenging near-cryogenic [icy] conditions, and minimize downwash disturbance of scientifically-important hydrocarbon layering." He hopes that SPARK, he added, could be a cave-exploration forerunner at Titan similar to the Ingenuity helicopter on Mars that made 72 flights — more than tenfold what the Red Planet demo mission was supposed to do.

Drew has been working on a particular type of ion thrusters, called electrohydrodynamic (EHD) propulsion, since he did graduate school at the University of California, Berkeley.

Thanks in part to a National Science Foundation (NSF) fellowship, Drew explored several designs for flying and became interested in creating robots that flap their wings in a way similar to real-life creatures.

While exploring, he stumbled on the hobbyist "lifter" community "pretty much by chance," he said.

"These [prototypes] are triangular balsa wood, magnet wire, and aluminum foil prototypes.