NASA’s Ambitious Quest: Unleashing Autonomous Robots to Unravel the Mysteries of Jupiter and Saturn’s Icy Moons

Europa follows an elliptical path, and its form is influenced by the gravitational pull of Jupiter, causing it to become distorted when coming closer to the planet.

This alteration in form generates friction within Europa, producing massive amounts of heat through a process termed tidal heating, which melts parts of the ice and creates a vast internal ocean underneath the moon’s thick icy layer.

The internal ocean of Europa is saline and is approximated to be around 100 kilometers deep on average, with a total water volume that is double that of all Earth’s oceans, even though this moon is significantly smaller than our planet.

Comparison of terrestrial oceans and the inner oceans of Europa.

Illustration: NASA/JPL-Caltech

Moreover, internal oceans are also believed to exist on Jupiter’s moons Ganymede and Callisto as well as on Saturn’s moons Titan and Enceladus.

Liquid water is fundamental for life as we comprehend it, which is why these oceanic worlds are leading the search for extraterrestrial beings.

The European Space Agency’s Jupiter Ice Explorer is a spacecraft intended for exploring Jupiter’s ice caps.

Photograph: ESA/M. Pedoussaut

Beneath the Ice Seas

The envisioned autonomous underwater exploration robots created by SWIM are remarkably compact. Their wedge-shaped structures measure roughly 12 centimeters in length. A device called a “cryobot” is set to transport the robots beneath the thick icy shells of these moons, employing nuclear power to melt the surrounding ice. The plan is to house approximately four dozen robots inside the cryobot and enable them to breach the thick ice shell over several years.

A conceptual illustration of SWIM, featuring the cylindrical probe in the upper left segment.

Illustration: Ethan Schaler/NASA/JPL-Caltech

There are advantages to deploying such a large number of exploration robots. One benefit is the capability to survey a broader area. Another advantage is their envisioned teamwork, allowing multiple robots to investigate the same region from different angles, thus minimizing inaccuracies in the observational data.

Each robot will be outfitted with sensors to assess temperature, pressure, acidity, electrical conductivity, and the chemical makeup of the waters it surveys. All these sensors will be integrated onto a chip no larger than a few millimeters square.

“Many might wonder, why is NASA designing an underwater robot for space exploration?” states Ethan Schaller, project manager at NASA’s JPL, interpreting the rationale behind SWIM. “This is because there are locales in the solar system we aim to investigate for signs of life—and we believe life necessitates the presence of liquid water.”

This article initially appeared on WIRED Japan and has been translated from Japanese.