NASA is charting new territory in space exploration with the development of tiny underwater robots designed to explore alien oceans. These innovative machines, part of the Sensing With Independent Micro-swimmers (SWIM) project, have already been tested in a swimming pool at Caltech and could one day dive into the icy ocean of Jupiter's moon Europa.
The SWIM robots are a bold concept in NASA's long-term strategy to uncover extraterrestrial life. Europa Clipper, NASA's upcoming mission to Europa set for 2030, will conduct flybys to examine whether the moon's subsurface ocean could harbour life. The SWIM project takes this effort a step further, with a swarm of cell phone-sized robots capable of exploring beneath Europa's thick ice crust.
Once delivered to Europa's ocean by an ice-penetrating cryobot, the SWIM robots would fan out, searching autonomously for signs of life by detecting chemical signals and temperature changes. Recent tests at Caltech demonstrated their potential.
“People might ask, why is NASA developing an underwater robot for space exploration? It's because there are places we want to go in the solar system to look for life, and we think life needs water," said Ethan Schaler, principal investigator for SWIM at NASA's Jet Propulsion Laboratory (JPL).
"So we need robots that can explore those environments — autonomously, hundreds of millions of miles from home,” he added.
The prototypes, about 16.5 inches long, used in testing successfully navigated a swimming pool, performing search patterns autonomously and even spelling out "J-P-L." Future iterations designed for Europa would be smaller - about 5 inches long - and equipped with advanced sensors to measure conditions such as temperature, pressure, and chemical composition.
NASA also conducted computer simulations to mimic Europa's conditions, helping to refine the robots' designs and operational algorithms. These simulations guided engineers in balancing exploration efficiency with battery life, which would last up to two hours, and the number of robots deployed in a single swarm.
"It's awesome to build a robot from scratch and see it successfully operate in a relevant environment," Mr Schaler said. "Underwater robots in general are very hard, and this is just the first in a series of designs we'd have to work through to prepare for a trip to an ocean world."
Engineers at Georgia Tech also developed an ocean composition sensor for the robots. This tiny chip, just a few millimetres square, combines multiple sensors to measure environmental factors.
While SWIM robots are designed for icy moons, their potential applications extend to Earth. They could support oceanographic research or provide crucial data from under-polar ice. The SWIM project is supported by NASA's Innovative Advanced Concepts (NIAC) programme, which funds early-stage technologies that could revolutionise space exploration.
