NASA is funding an ambitious new concept that could send swarms of tiny, silent, spherical “aerobots” floating through the eerie underground caves of Titan, Saturn’s largest moon.

The project is called SPARK or Solid-state Propulsion for Autonomous Reconnaissance of Karst. Led by Daniel Drew, an assistant professor at the University of Hawaii at Mānoa, SPARK uses electrohydrodynamic (EHD) propulsion, commonly known as atmospheric ion thrusters.

As EHD thrusters are solid-state and silent, the tech offers omnidirectional maneuverability without generating heavy downwash that could disturb delicate surface layers.