NASA's Innovative Advanced Concepts (NIAC) program is funding the development of spherical 'Aerobots' that could one day explore the caves of Saturn's moon Titan. These Aerobots, or Solid-state Propulsion for Autonomous Reconnaissance of Karst (SPARK), are designed to navigate the moon's unique 'karst' terrain, which includes underground sinkholes and caves. The project lead, Daniel Drew, an assistant professor at the University of Hawaii at Mānoa, is developing ion thrusters that could provide persistence, maneuverability, and robustness in the challenging near-cryogenic conditions of Titan. Drew's work on electrohydrodynamic (EHD) propulsion, a type of ion thruster, has already led to significant milestones, including the first demonstration of microfabricated EHD actuators and a centimeter-scale 'ionocraft' taking off and carrying a payload. The NIAC grant will allow Drew to further explore the benefits of EHD propulsion, such as its scalability, silence, and simplicity. However, Drew acknowledges that EHD propulsion is not very efficient for terrestrial applications and may not compete with more conventional propulsion techniques. The Aerobots could also have applications beyond Titan, such as all-electric aircraft and indoor drones, but their utility will be limited. The project is still in its early stages, with Phase 1 of the grant lasting only nine months. Drew and his team plan to quickly design experiments, perform a trade study, and model thermal effects on the power system. The ultimate goal is to create a comprehensive public report that leverages past research and open-source knowledge in the field.
