NASA Underwater Robots to Search for Life on Moons With Oceans Like Europa | NextBigFuture.com

NASA’s Jet Propulsion Laboratory tested the feasibility of a mission concept called SWIM, short for Sensing With Independent Micro-swimmers. The project envisions a swarm of dozens of self-propelled, cellphone-size robots looking for signs of life on ocean worlds. SWIM is funded by NASA’s Innovative Advanced Concepts program under the agency’s Space Technology Mission Directorate.

NASA and Caltech teams are already developing the next generation of robotic concepts that could potentially plunge into the watery depths of Europa and other ocean worlds, taking the science even further.

This is where an ocean-exploration mission concept called SWIM comes in. Short for Sensing With Independent Micro-swimmers, the project envisions a swarm of dozens of self-propelled, cellphone-size swimming robots that, once delivered to a subsurface ocean by an ice-melting cryobot, would zoom off, looking for chemical and temperature signals that could indicate life.

The prototype used in most of the pool tests was about 16.5 inches (42 centimeters) long, weighing 5 pounds (2.3 kilograms). As conceived for spaceflight, the robots would have dimensions about three times smaller — tiny compared to existing remotely operated and autonomous underwater scientific vehicles.

Led by NASA’s Jet Propulsion Laboratory in Southern California, the SWIM project was supported by NASA’s Innovative Advanced Concepts program under the agency’s Space Technology Mission Directorate. Work on the project took place from spring 2021 to fall 2024.

The SWIM team’s latest iteration is a 3D-printed plastic prototype that relies on low-cost, commercially made motors and electronics. Pushed along by two propellers, with four flaps for steering, the prototype demonstrated controlled maneuvering, the ability to stay on and correct its course, and a back-and-forth “lawnmower” exploration pattern. It managed all of this autonomously, without the team’s direct intervention. The robot even spelled out “J-P-L.”

Digital versions of these little robots got their own test, not in a pool but in a computer simulation. In an environment with the same pressure and gravity they would likely encounter on Europa, a virtual swarm of 5-inch-long (12-centimeter-long) robots repeatedly went looking for potential signs of life. The computer simulations helped determine the limits of the robots’ abilities to collect science data in an unknown environment, and they led to the development of algorithms that would enable the swarm to explore more efficiently.

The simulations also helped the team better understand how to maximize science return while accounting for tradeoffs between battery life (up to two hours), the volume of water the swimmers could explore (about 3 million cubic feet, or 86,000 cubic meters), and the number of robots in a single swarm (a dozen, sent in four to five waves).

In addition, a team of collaborators at Georgia Tech in Atlanta fabricated and tested an ocean composition sensor that would enable each robot to simultaneously measure temperature, pressure, acidity or alkalinity, conductivity, and chemical makeup. Just a few millimeters square, the chip is the first to combine all those sensors in one tiny package.

Of course, such an advanced concept would require several more years of work, among other things, to be ready for a possible future flight mission to an icy moon.

Schaler imagines SWIM robots potentially being further developed to do science work right here at home: supporting oceanographic research or taking critical measurements underneath polar ice.