Planetary Exploration With Robot Teams: Implementing Higher Autonomy With Swarm Intelligence

Since the beginning of space exploration, Mars and the moon have been examined via orbiters, landers, and rovers. More than 40 missions have targeted Mars, and over 100 have been sent to the moon. Space agencies continue to focus on developing novel strategies and technologies for probing celestial bodies. Multirobot systems are particularly promising for planetary exploration, as they are more robust to individual failure and have the potential to examine larger areas; however, there are limits to how many robots an operator can control individually. We recently took part in the European Space Agency's (ESA's) interdisciplinary equipment test campaign (PANGAEA-X) at a lunar/Mars analog site in Lanzarote, Spain. We used a heterogeneous fleet of unmanned aerial vehicles (UAVs)-a swarm-to study the interplay of systems operations and human factors. Human operators directed the swarm via ad hoc networks and data-sharing protocols to explore unknown areas under two control modes: in one, the operator instructed each robot separately; in the other, the operator provided general guidance to the swarm, which self-organized via a combination of distributed decision making and consensus building. We assessed cognitive load via pupillometry for each condition and perceived task demand and intuitiveness via selfreport. Our results show that implementing higher autonomy with swarm intelligence can reduce workload, freeing the operator for other tasks such as overseeing strategy and communication. Future work will further leverage advances in swarm intelligence for exploration missions.