NASA proposes nuclear ‘tunnelbot’ to search for extraterrestrial life

Jupiter’s moon Europa, photographed by NASA’s spacecraft Galileo. Credit: NASA/JPL-Caltech/SETI Institute

Europe may be the most likely place to host extraterrestrial life. Beneath the surface is a salt-water ocean, warmed by the play of gravity on the moon’s metal core. But how do you do by means of peer sheet of ice?

Melt your way down, with a nuclear-powered robot.

At least that is the proposal submitted to the American Geophysical Union in Washington, DC this week.

NASA Glenn Research center is a multidisciplinary COMPASS team was established to develop technology to meet the challenges of the exploration of space.

Europe is a large.

The ice that covers this moon of Jupiter could be anywhere between 2 and 30 km thick.

But, underneath, could live.

And find the open throwing our understanding of how common life is in our universe, how resilient it is and how it occurs.


Planetary scientists are not even sure Europe is an ocean. But all signs point. The most tempting of these are the plumes of the liquid-water, that periodically erupt from the surface.

The COMPASS team has completed a concept study on the technologies that are capable of piercing the ice with a suite of sensors and sending the data that it collects back to Earth.

The best option is, they argue, is a nuclear-powered ‘tunnelbot’.

Nuclear power packs the most energy in a small space.

And it doesn’t even need to be built into a nuclear reactor — though that was one of the concept designs. In its simplest form, radioactive ‘brick’ would just emit a heat source in front of a tube-shaped probe which then gradually drops as the ice turns to slush.

The power from nuclear fuel cells are amply demonstrated by the likes of Voyager 1 and 2, still to send back signals as they are about to cross into interstellar space about 40 years after they were launched.


The nuclear ‘tunnelbot’ would deploy a lander with a fiber-optic string of data ‘repeaters’ to roll out as it sinks.

Such a Europe tunnelbot’ would be relatively large. And risky to start.

“We didn’t have to worry about how our tunnelbot would make it to Europe or are deployed in the ice,” says the University of Illinois at Chicago associate professor Andrew Dombard. “We thought that it might come out, we have focused on how it would work in the descent to the ocean.”

That is the purpose of their mission. Whether or not such a nuclear-powered ‘tunnelbot’ is built and deployed, the next step. But the decision will be based on an informed study of what it would take to take a look under Europa’s ice.

Sending a probe to Europa is one of NASA’s big ambitions for the coming decades. But getting the mission past an increasingly sceptical US Congress is not easy.


The project’s main advocate was Texas Republican John Culberson, who is the chairman of the subcommittee that funds NASA. The NASA study, that the nuclear-powered ‘tunnelbot’ is a result of his efforts.

But he lost his seat in the recent mid-term elections.

And President Donald Trump’s most recent budget states he has no intention of funding a Europa lander.

Some experts express the fear that such an attempt would be a ‘bridge too far’: we simply do not know enough about the icy moon, but still.

“It is a mission that came out of the Congress, in contrast to a mission that came out of the science,” says The Planetary Society’s Emily Lakdawalla.

Others argue that the long run of time for such ambitious missions means now is the time to get to work in the direction of the project.

And we are set to learn more about the mysterious moon anyway.

The Europa Clipper mission — a space probe designed to orbit the moon — has received initial funding. Her goal is to make the circle as low as 25 km for a maximum of three years, mapping of Europa’s icy surface and gleaning what it could be about chemicals being spewed into the feathers.

It is to be hoped that the Clipper will be ready for launch in 2022. It takes six years for the probe to reach Jupiter and establish itself in an orbit around Europa.

This story was previously published in the

Follow us

Don't be shy, get in touch. We love meeting interesting people and making new friends.

Most popular