The SWIM robots - short for Sensing With Independent Microswimmers - demonstrated impressive maneuverability during recent pool tests at the California Institute of Technology (Caltech). Propelled by propellers, the miniature wedge-shaped robots steered themselves to stay on course, executed a back-and-forth "lawnmower" pattern and even spelled out "J-P-L," according to NASA.
Designed to one day search for evidence of life in the salty ocean beneath the icy mantle of Jupiter's moon Europa, these robots could play a key role in detecting chemical and temperature signals that could be evidence of extraterrestrial life, according to scientists at NASA's Jet Propulsion Laboratory (JPL), who designed and tested the robots.
"People might ask: why is NASA developing an underwater robot for space exploration?" says Ethan Schaller, the project's principal investigator at JPL.
"Because there are places in the solar system we want to go to look for life, and we think life needs water. We need robots that can explore these environments - autonomously, hundreds of millions of miles from home," he added.
The latest prototypes are 3D-printed plastics that are assembled using cheap, commercially produced motors and electronics. These robotic swimmers will also eventually be equipped with wireless underwater communication systems to transmit data and triangulate their positions as they explore the oceans on distant icy moons.
The robot used for the tests in the pool is about 42 cm long. The team hopes to eventually cut it down to about 12 cm, which is no more than the length of a mobile phone. To ensure that the robot could be rescued if needed during each of the 20 rounds of testing in the 23-metre pool, it was attached to a fishing line and an engineer walked alongside it carrying the line.
"Underwater robots in general are very tricky, and this is just the first in a series of projects we'll have to work out to prepare for travel in the ocean world. But this is proof that we can build these robots with the capabilities we need and begin to understand what challenges they would face on an underwater mission," Schaller said.
Meanwhile, engineers are testing the SWIM robots in computer simulations that replicate the pressure and gravity the robots would encounter on the moon. By repeatedly sending such palm-sized robots searching for signs of life in these virtual environments, scientists say they are optimizing the robots' designs and refining their abilities to collect scientific data in unfamiliar terrain.
One of the key innovations created for the robotic swarm is a miniaturized multisensor chip developed by engineers at the Georgia Institute of Technology in Atlanta that can measure temperature, pressure, acidity, conductivity and chemical composition - all critical factors in the search for life.
It will be years before the robots can slip through Europa's hidden ocean, which scientists suspect hides twice as much liquid water as all of Earth's oceans combined. Thanks to this vast subsurface ocean, Europa is considered one of the most promising places in our solar system to search for extraterrestrial life. In the 1990s, the moon was studied in detail by NASA's Galileo mission, which provided compelling evidence of the moon's hidden ocean. The next robotic mission to study Europa, Europa Clipper, is on track for a four-year study of the moon's potential to support some form of extraterrestrial life. | BGNES
