A nuclear-powered 'tunnelbot' to search for life on Jupiter's icy moon Europa

December 16, 2018 by Sharon Parmet, University of Illinois at Chicago
Artist’s rendering of the Europa “tunnelbot.”  Credit: Alexander Pawlusik, LERCIP Internship Program NASA Glenn Research Center

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.

While researchers generally agree on where to look – underneath the thick, planet-wide ice shell where water is in contact with a rocky core and where biochemical ingredients for may exist – how to get there to collect samples remains a major tactical problem.

"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.

Dombard and his colleagues presented a possible solution to this problem at the American Geophysical Union meeting in Washington, D.C., this week: a nuclear-powered tunneling probe.

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.

The group 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 bot would also evaluate the habitability of the ice shelf itself.

"We didn't worry about how our tunnelbot would make it to Europa or get deployed into the ice," Dombard said. "We just assumed it could get there and we focused on how it would work during descent to the ocean."

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.

The researchers considered two designs for their bot: 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 . Communications would be provided by a string of "repeaters" connected to the bot by fiber optic cables.

NASA routinely sponsors concept studies to test where the technology is that is needed to answer important questions in the solar system. Perhaps no question is more significant than, "Is there life elsewhere?" and Europa is one of the best places to look. Whether a tunneling mission is scheduled, and if so, whether one of these designs is selected, remains to be seen.

Kathleen Craft from the Applied Physics Laboratory at Johns Hopkins University and COMPASS team leads Steven Oleson and J. Michael Newman of the NASA Glenn Research Center also worked on the concept study.

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1 / 5 (5) Dec 16, 2018
While we worry about Biological contamination of other planets and moons, somehow the scientists are overlooking the probability that any such 'radioactive' source may be hazardous to any life forms that 'may' be there to begin with, or that they 'may' become an accidental mutagen by changing/damaging whatever their equivalent of DNA is.

Unexpected, unintended consequences come of this sort of thing so perhaps we should be extremely careful in the use of radioactive materials in the first place.

It might not be the best way for us to say 'Hi' to any possible critters there either, but who knows, mebbe some alien's drive exhaust was what produced the 'Manna from Heaven' for the wandering tribes in the desert...just saying, and no, I dont take that seriously at all, but it IS a relative illustration of what 'may' occur if we used a heat source to melt down to the sea below.

I had thought of this before and realized problems with it. Mechanical, tho harder, would be safer.

1 / 5 (5) Dec 16, 2018
And yes, any mechanical energy is going to need a source of power, and while using radioactives to do the melting itself may be a bad idea, using a reactor on the surface, along with large mats of 'roll out' solar panels could be extended for large surface area, comparatively, to take in what available energy from solar or the reflection of same from local large planet.

But using a drilling type bot that uses locally heated water, via electricity from the surface, would avoid the radiation problem and the exact amount of melt could be well controlled.

This still leads to the problem of a power cord, but an engineered form of the old Co-axial cable, with sub-channels built in, may be viable for both power supply And data transmission in the same line. The cold temperatures there would actually be a help as far as improving conduction, and something like nano-textured surface Teflon for a coating would allow it to slide thru the ice. But still need 2-20 mi. of cable.
5 / 5 (2) Dec 16, 2018
too much chance of contamination and unnecessary if we can just sample plumes of water at the surface
1.3 / 5 (12) Dec 16, 2018
Prediction: No subsurface oceans to be found. The water is likely being produced at the surface by cathode jets, just like on comets.
3.7 / 5 (3) Dec 16, 2018
mor. I agree with you. Testing the plumes for bio-chemical residues would be a much simpler & economically rational means to achieve our stated mission goals. A conservative means of using technology we already have.

In addition to the commitment of funding & human resources to build & launch the driller-probe?

As steel pointed out. There will be an unpredictable level of potentially expensive dangers of success at discovering life within Europa's ice shield.

I do not mean dangerous to Earth-life! Rather, in our usual destructive monkey fashion? There is an excellent chance of us contaminating that moon & exterminating the very non-Earth life we spent all that money & man-hours to reach.

So what's our ROI with that fiasco?

Now, in my (unproven) opinion... Europa trapped ocean will prove tp be sterile. I suspect that will also be the result of exploring the Ocean Worlds in other star systems.

Organic chemistry is not always a byproduct pf bio-chemistry.
3 / 5 (6) Dec 16, 2018
& what a pity...
Not a ;lightening bolt in sight!
Just the repetitious echo
of woo thunder.
Once faded away?
Nothing left behind but well-deserved jeers & mockery.
3.4 / 5 (5) Dec 16, 2018
While we worry about Biological contamination of other planets and moons, somehow the scientists are overlooking the probability that any such 'radioactive' source may be hazardous to any life forms that 'may' be there to begin with
Ahaahaaa so perhaps they're as worried about injuring the ice life there as we are about irradiating all the fishies with our evil nuclear submarines, yes?

Plus they're no doubt already comfortable with radiation.

"The cores of the icy worlds studied by Bouquet and co-authors are thought to have chondrite-like compositions.

"Ocean water permeating the porous rock of the core could be exposed to ionizing radiation and undergo radiolysis, producing molecular hydrogen and reactive oxygen compounds.

"Microbial communities sustained by H2 have been found in extreme environments on Earth," Bouquet said."

-Probably much more radionuclides in their water and ice than here.
1 / 5 (6) Dec 16, 2018
at depth you probably can see by the Cherenkov radiation
not rated yet Dec 17, 2018
TheGhostofOtto1923, you are gently trying to convince the foks for whom: nucular -> tabu -> let's find ridiculous reasoning why it shouldn't be done. No hope to light the nuclear reason in their troglodyte cave, yet you tried, and I don't have to.

2.3 / 5 (3) Dec 17, 2018
Yah it sounds like steelwolf thinks they will be waving the General Purpose Heat Source bricks out in front of them like magic wands or something.

Even so, the General Purpose Heat Source bricks are encased in materials that only let the heat out, as with conventional reactors.
1 / 5 (4) Dec 17, 2018
Considering how the article states it (below), they indeed are looking to Directly use the Heat from the GPHeat bricks and Reactor to do the melting directly, rather than using the electricity to power heaters, they are doing it the direct, crude way.

"...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."

Nuclear power CAN be done correctly and safely, but not with simplistic ideas like this which as other have pointed out may well destroy of kill what we were looking for in the first place.

I am For properly used and controlled nuclear power in some situations where it is appropriate. The present For Profit methods are the major failing and monied lobbyists and politicians overturn the scientist's recommendations all too often. Things get legislated, even if the wording allows the worst to continue
1 / 5 (3) Dec 17, 2018
Even our own bodies are radioactive with C14 and Potassium 40, but that is hellishly different than fissioning U238 on the mass scales involved, relatively, since it is a continuing cascade reaction in the bricks and reactor.

Besides, those bricks break down, and we do not know how they would react in contact with extreme environmental changes they may come in contact with, or what local chemistry may be there that can destroy the casing. And they are nicely plutonium powered ("Each GPHS contains four iridium-clad Pu-238 fuel pellets" (from the Wiki)).

So, yes, they are very much talking about waving their heat bricks around at the bottom of the hole to do said melting. And with as little shielding as they have, since they are made for space operation and not on planet use and are not safe to be around for long at all.

Look at the wiki pix:

And tell me if that is enough shielding for Plutonium to have in YOUR house.
2 / 5 (4) Dec 17, 2018
Prediction: No subsurface oceans to be found. The water is likely being produced at the surface by cathode jets, just like on comets.

not rated yet Dec 17, 2018
"Communications would be provided by a string of "repeaters" connected to the bot by fiber optic cables."

How will these survive the refreezing of the well? I'm not familiar with any known material that can withstand being beaten by planet size glaciers over several kilometers. Happy to be wrong though. And one of you math whizzes can do the math on how much energy it would take to keep a cylinder say 1m radius by 10km deep of water from freezing on Europa. I'm thinking a lot.

Why don't we just do what the Ash Lord did to Rhea, and nuke the whole damn moon to smithereens and just comb through the debris for alien corpses? This will also keep those Moon Lords in check, if ya know what I mean ;)
not rated yet Dec 18, 2018
Nuclear power CAN be done correctly and safely, but not with simplistic ideas like this
So mr steelwolf reads a physorg news release which takes him a minute or two... and concludes he knows that something real scientists and engineers have spent considerable man hours conceptualizing and proposing, is 'simplistic' and dirty and dangerous.

And then goes and finds a wiki pic and says 'I know what that does'.

Who the fuck do you think you are?

I know its not real disrespect. Youre apparently too stupid for that. Its the kind of ignorance that makes me a little sick to my stomach.
not rated yet Dec 19, 2018
Gust, first, I was a welder/engineer, Navy Nuclear Trained.

Look at the pictures of the probe they show, then look at the wiki pic (and do some actual, non-wiki reading on the heat bricks, the pic was from Wiki) of the actual heat bricks used for heating the instruments in places where they dont have the electrical power to waste on heat.

Considering this and seeing the pictures of their probe showing placement of the bricks in the pix of the heat sources and it shows, Plainly that YES, they are going to be leading with their nuclear heat sources to do the melt directly and efficiently.

Just because YOU do not understand what is involved does Not give any right to try your attacks on others, personal insults and a total disregard for how idiotic some of these genius scientists can be (Plenty of smarts, no wisdom in some cases.) shows you out.

They were tasked with finding the easiest, fastest and cheapest manner to do this with materials we have now. Fast and Dirty.
5 / 5 (1) Dec 19, 2018
Well, steel, there are reasons (some irrational) for why we have all these different words. Sometimes they overlap. I'm sure you could add in the ones I missed.
Static is not always Signal.
Signal is not always Data.
Data is not always Information.
Information is not always Knowledge.
Knowledge is not always Education.
Education is not always Comprehension.
Comprehension is not always Wisdom.
& Wisdom is learning from one's past mistakes. So that we can go on & invent spanking brand-new mistakes! Oh, yay?
not rated yet Dec 19, 2018
I was a welder/engineer, Navy Nuclear Trained
Who gives a shit? You have absolutely no idea how nukes are designed by REAL engineers nor do you have any respect for them.

"That is the biggest fool thing we have ever done. The [atomic] bomb will never go off, and I speak as an expert in explosives."
Admiral William D. Leahy comment on the U.S. Atomic Bomb Project, to President Harry S. Truman in 1945. Memoirs: Year of Decisions (1955), Vol. 1, 11.
They were tasked with finding the easiest, fastest and cheapest manner to do this with materials we have now. Fast and Dirty
No, probes that are meant to survive the rigors of a trip across the solar system and to operate in hostile, unknown environments are NOT designed Fast and Dirty.

You really are a dumfuk arent you?
not rated yet Dec 19, 2018
When Gust complains and adds no science himself, he only makes himself look like a fool, and EVERYBODY, but him, seems to already know that. I know the science, I know the tech, I know the task given, what we have to work with and how our govt works so very well (lol)

And maybe studying how they did such things as, oh, land on the moon, when they had literally scraped the aluminum shell of the lander so thin the men were scared they would rupture it with a wrong touch.

Plus, I did military rad work, qualifies me for a lot more than anything you have stated, and the engineering data was a required portion of the high end damage control team training, and being able to back-engineer items for re-building and replace required the engineering know how of materials choice, machining techniques, welding and joining etc.

I have Been There, Done That, and CAN tell you, yes, NASA launches stuff so radioactive and such low shielding it cannot be in your house, nearly every time.
4.7 / 5 (6) Dec 19, 2018
navy nukes are glorified technicians and operators, not engineers. You really think 9 months of school makes you a nuclear engineer?
You are welcome to your opinions, but I have met a lot of dumb nukes in my life who I would barely consider a technician.
5 / 5 (3) Dec 20, 2018
"The water is likely being produced at the surface by cathode jets, just like on comets."

Comet tails don't form at the distance of Saturn. If they did, the rings wouldn't exist for long.
5 / 5 (2) Dec 20, 2018
How will these survive the refreezing of the well?

You can try this experiment at home.package a microcontroller board in a plastic bag. Get a bucket of solid ice. Melt a bit with a hairdryer an dump in the bag. Then let it refreeze. It'll work just fine (The battery life will be shortened, but in this case we're talking atomic batteries in any case)

being beaten by planet size glaciers over several kilometers

That's only a problem if the glaciers move (and then only at the interface of two such glaciers moving relative to one another. No reason at all to land the probe specifically there)
1 / 5 (1) Dec 20, 2018
navy nukes are glorified technicians and operators, not engineers. You really think 9 months of school makes you a nuclear engineer?
We had another troll here who claimed to be an engr for NASA, and had similar inane ideas and disrespect for professionals. Pirouette/russkiye/pussycat_eyes/obamasocks et al. She's still posting as surveillance_egg_unit. I suspect she's also this guy.

Stupid on purpose for lulz. Real sicko.
not rated yet Dec 20, 2018
The Navy time was the beginning of the schooling, lifetime of building things, more school and much learning since. I was doing That stuff when I was a kid.

Like I said, I know tons of very smart folks (PhDs even) with no wisdom at all, some incredibly intelligent folks with little to no schooling, and a wide range in between.

Then there are the troll posters here who Think they have smarts, but instead just know how to hammer on a keyboard witlessly and show the non-posting readers just how disingenious, prevaricating, baiting and generally useless bits of reading by certain individuals that quickly get blocked by the other readers.

In order to see what ignorant/baiting comments they post I have to read the muted comments of them etc as I keep them on ignore normally.

I have studied the problems of doing such landings for many years, the types of materials one may find and doing via Just melt wont work. What happens when you come to a mineral strata in the ice?
not rated yet Dec 20, 2018
I do not have any disrespect for the professionals at all, I DO totally disrespect the politically and money driven Managers whom the corporations hire strictly because they will make more money for them.

It is THEY who drive the quick and dirty directives, and the well trained professionals beneath may send in their memos of dismay, warnings of tragedy and cost. The only ones looked at are cost, and real major easy stuff that their lawyers will tell them has already been decided law and they CANNOT do that. Example: Trump-Cohen.

Using the plutonium powered heat bricks is likely part of a Treaty to reduce weapons grade materials. Putting it in space, where it has little chance to bother anyone over the thousands of years in turning to lead.

I have no doubt the engineers tasked with putting this thing together will do their best to make sure heat sources are impervious to breakdown, but are being told top down what to do, against better judgement, as usual in Corps.
1 / 5 (1) Dec 20, 2018
I have studied the problems of doing such landings for many years
Sure pussytard, I read PopSci as well.

Youre a grade school-level crank no matter what nick you use.
not rated yet Dec 20, 2018
This is my only account, I am not into playing the stupid bot game.

I never said I was a nuclear operator either, that is a different regime, they are more focused on the running of them, buildup of contaminants and fission waste products that if not kept in a semi-balance can choke the output of the entire reactor. That is an extremely focused talent and they burn out, in more ways than one, quickly.

Once one is proficient enough, has studied enough, and actually Done enough, one can do things like, working as a welder for a time for someone else due to economy at the time, and one week I sent several sets of prints back to the office as unbuildable, unworkable as drawn, or would not match to existing structures in various ways.

Next week I got set of prints, plant foreman standing back, but watching me, I spent my 15 min going over prints, went to get materials to start. Foreman stops and asks if there was anything wrong with THIS set of prints (Continued)

not rated yet Dec 20, 2018
(Continued) I assured him that, no, this set looked ok, nothing wrong I saw.

He said Good, because the last week he had spent talking to the people placing orders for items, draftsmen, plant owners and operators etc and said that with me refusing to even start on those projects I saved the company about $1.5M in work, materials, shipping, and then Redoing it all. I got a raise there and then, and they had me look over ALL the prints to hit the floor after that until old neck injuries put me completely unable to work.

Very few people will run a stainless weld vertical up, I will do it fine, with wire, on 16 Ga 310 SS. I have run 400V, 280A air arc, with 100 lb air behind a 1/2 in dia. carbon rod that due to the volts and amps running it vaporizes the steel and blows it away, sounds like a jet, but carves thru steel like putting your finger though fresh icing on a cake. I was good, could 'float' a finish surface by feeling the magnetic current and air flow. I KNOW my limits
5 / 5 (3) Jan 31, 2019
More likely the frozen 20mile thick surface is going to be too hard for armour piercing screws to break
if the probe does not breakup on impact in the first place
life does not include biofilms
after 5billion years if all Jupiter has to show are biofilms
Our worries are over

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