NASA develops small robots to investigate the hidden oceans of icy moons. The prototype called SWIM, which stands for Sensing With Independent Micro-swimmers, was constructed at NASA's Jet Propulsion Laboratory (JPL) in Southern California to demonstrate the feasibility of the mission concept. Tests conducted in the pool of California Institute of Technology in September 2024 showed that robots are capable of impressive maneuverability.

The small wedge-shaped robot prototype was tested with a sensor capsule beneath Alaska's Juneau Icefield in July 2023. NASA's SWIM project envisions a swarm of cellphone-sized underwater robots exploring subsurface oceans on icy moons like Jupiter's Europa and Saturn's Enceladus. A cryobot, a specialized probe that can melt through thick icy crusts, would carry these tiny robots beneath the ice. Once in the ocean the robots will scatter, searching for chemical and temperature cues which could indicate the presence of life.

In July 2023, a tiny 3D-printed robot model, about 5 inches (12 centimeters) long, was tested at Alaska's Juneau Icefield. Designed for NASA's SWIM, the model showcased the envisioned size of future robots aimed at exploring subsurface oceans on icy moons like Jupiter's Europa and Saturn's Enceladus. The Alaska test featured a large waterproof capsule containing the first-generation ocean composition sensor developed by Georgia Tech for the SWIM robots. This sensor measures chemical composition, conductivity, temperature, pressure, and acidity or alkalinity simultaneously.

The field test is part of ORCAA, a JPL project that tests technology and answers scientific questions for future exploration of the surface and subsurface of icy Moons. ORCAA aims to prepare for future missions by testing and simulating alien environments. ORCAA and SWIM, which are supported by NASA’s Planetary Science and Technology from Analog Research program, are important advancements in the search for extraterrestrial intelligence.