NASA’s Jet Propulsion Laboratory (JPL) is taking strides toward a groundbreaking mission to explore subsurface oceans on icy moons in the solar system with the development of miniature robots. In September 2024, engineers tested prototypes of a small, self-propelled robot designed to swim through the waters of distant ocean worlds. This prototype is part of a mission concept called SWIM — short for Sensing With Independent Micro-swimmers — that envisions a swarm of tiny, cellphone-sized robots exploring the depths of moons like Jupiter’s Europa, looking for signs of life.
JPL engineers recently conducted a series of tests with the 16.5-inch-long prototypes in a competition swimming pool at Caltech in Pasadena. The robots, powered by low-cost motors and electronics, demonstrated remarkable capabilities. They successfully maneuvered in the water, corrected their paths autonomously, and followed a “lawnmower” exploration pattern. Impressively, one of the robots even spelled out “J-P-L” during the test, showcasing its ability to navigate and execute tasks independently.
“The real challenge in space exploration is designing robots that can operate autonomously in harsh, distant environments,” said Ethan Schaler, principal investigator for the SWIM project. “We need robots that can explore subsurface oceans, hundreds of millions of miles from Earth, searching for the signs of life we believe may exist in these watery worlds.”
While NASA’s Europa Clipper mission, set to launch in 2024, will focus on studying Jupiter’s moon Europa with advanced scientific instruments, the SWIM project is aiming to take exploration to the next level. By deploying these tiny robots, NASA hopes to gather direct measurements of ocean environments, searching for chemical, temperature, and other signs that could indicate the presence of life beneath the icy crusts of moons like Europa and Saturn’s Enceladus.
The testing of SWIM robots is just the beginning. In addition to pool tests, the team has conducted computer simulations that mimic the pressures and gravity of Europa’s environment. These simulations help refine the robots’ exploration strategies, optimize battery life, and determine how the robots can work together in swarms to cover large areas of an ocean.
One of the most exciting developments in the SWIM project is the creation of a tiny sensor that can measure ocean composition, including temperature, pressure, acidity, and chemical makeup. This sensor, developed in collaboration with Georgia Tech, will be integrated into each robot to enable real-time analysis of the environment.
Although the SWIM mission is still years away, with further development needed for a potential flight mission, the success of these early tests demonstrates the feasibility of exploring the subsurface oceans of icy moons with small, autonomous robots. NASA envisions these robots not only supporting future space missions but also being used for oceanographic research on Earth, particularly in remote or polar regions.
With the promising results of these tests, the SWIM project is helping pave the way for future discoveries in our solar system, bringing us closer to understanding whether life could exist beyond Earth.
