NASA is gearing up to test drive a submersible robot underneath Antarctica’s sea ice, with hopes of eventually sending a similar machine to search for aliens in the subsurface oceans of Jupiter’s moon Europa.
The two-wheeled robot, which is called the Buoyant Rover for Under-Ice Exploration (BRUIE), uses buoyancy to anchor itself upside-down on the bottom edge of the ice. This distinguishes it from other free-swimming robot concepts designed to look for extraterrestrial marine life, such as the EurEx (Europa Explorer).
While BRUIE would not be able to probe the depths of alien seas, it could be extremely useful for studying the zone where ice crusts and the ocean environment interact.
"We've found that life often lives at interfaces, both the sea bottom and the ice-water interface at the top,” said Andy Klesh, the lead engineer on BRUIE, in a statement. “Most submersibles have a challenging time investigating this area, as ocean currents might cause them to crash, or they would waste too much power maintaining position.”
“BRUIE, however, uses buoyancy to remain anchored against the ice and is impervious to most currents,” he said.
There is a lot of evidence that Europa, which is slightly smaller than the Moon, has a vast salty ocean under its icy crust that likely contains more water than all of Earth’s oceans combined. In fact, just this week, scientists were able to directly detect plumes of water vapor shooting out of cracks in the ice for the first time.
Liquid water has been an essential ingredient for the development of life on Earth, and its presence on other worlds is considered to be the most significant factor in their potential habitability. As a result, Europa has become one of the most sought after targets for robotic exploration, along with Saturn’s moon Enceladus, which also appears to have a subsurface liquid water ocean.
It would be an immense challenge to land on Europa because Jupiter emits damaging radiation that is expected to scramble spacecraft electronics. Even if a lander pulled off the feat, a Europa submersible would have to find a way to dig or melt its way through six to twelve miles of ice crust to reach the ocean. But if scientists and engineers are able to solve those challenges, BRUIE would be a valuable tool for exploring the eerie waterworlds inside Europa or Enceladus.
The robot has already been tested in Alaska, but in the coming weeks, NASA will team up with the Australian Antarctic Program to drive BRUIE under the sea ice near Casey Station.
“We will trial the endurance of the rover, particularly how long the batteries can last in extreme field conditions and how it handles a variety of terrain,” Klesh said in a statement.
The team hopes that BRUIE will eventually be able to handle being in the icy water for months at a time without running out of power, which will be necessary for its mission to alien worlds. It is unclear if robots will ever find their way to Europa’s seas, but assuming they do, the BRUIE team aims to be ready to make a splash.