Credit: Alexander Pawlusik, LERCIP Internship Program NASA Glenn Research Center


A nuclear-powered ‘tunnelbot’ – that’s an icy, innovative approach to search for life on Jupiter’s icy moon Europa.

Researchers at the University of Illinois at Chicago performed a concept study for a nuclear-powered “tunnelbot” that can penetrate the ice shell and reach the top of Europa’s ocean while carrying devices and instruments that can be used to search for signs of life or extinct life.

The automaton would also evaluate the habitability of the ice shelf itself.

Europan environments that may harbor life or preserve biosignature. A variety of geologic
and geophysical processes, including ocean currents governed by tides, rotation, and heat exchange, are
required to drive water from the subsurface to the surface and govern how any exchange operates.
SOURCE: Kevin Hand, Jet Propulsion Laboratory, “On the Habitability of Ocean Worlds,” presentation
to the Workshop on Searching for Life across Space and Time, December 5, 2016.

Ice thickness

“Estimates of the thickness of the ice shell range between 2 and 30 kilometers (1.2 and 18.6 miles), and is a major barrier any lander will have to overcome in order to access areas we think have a chance of holding biosignatures representative of life on Europa,” said Andrew Dombard, associate professor of earth and environmental sciences at the University of Illinois at Chicago (UIC).

In a university press statement, Dombard and his spouse, D’Arcy Meyer-Dombard, associate professor of earth and environmental sciences at UIC, are part of a group of scientists on the NASA Glenn Research COMPASS team, a multidisciplinary group of scientists and engineers tasked with designing technology and solutions for space exploration and science missions.

Jupiter’s icy moon Europa displays many signs of activity, including its fractured crust and a dearth of impact craters. Scientists continue to hunt for confirmation of plume activity.
Image Credit: NASA/JPL-Caltech/SETI Institute

Collaborative modeling

COMPASS stands for Collaborative Modeling for Parametric Assessment of Space Systems (COMPASS).

The bot would sample ice throughout the shell, as well as water at the ice-water interface, and would look at the underside of the ice to search for microbial biofilms.

The bot would also have the capability of searching liquid water “lakes” within the ice shell.

Collage of Galileo images of Jupiter’s icy Europa.
Credit: JPL/Univ. of Texas at Austin’s Institute for Geophysics

Device designs

The researchers considered two designs for their robotic tunnel device:

one powered by a small nuclear reactor, and the other powered by General Purpose Heat Source bricks — radioactive heat source modules designed for space missions. Heat from both these sources could be used to melt the ice shell. Communications would be provided by a string of “repeaters” connected to the bot by fiber optic cables.

Below surface

Europa has become a hotbed for the search for life.

Between 1995 and 2003, NASA’s Galileo spacecraft made several flybys of Jupiter’s moon, Europa. Several findings from observations of the moon pointed to evidence of a liquid ocean beneath Europa’s icy surface. The ocean, researchers believe, could harbor microbial life, or evidence of now-extinct microbial life.

The tunnelbot idea was recently floated at the American Geophysical Union meeting in Washington, D.C.

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