Sea Gliders for Other Worlds

An anonymous submitter writes: "NASA has, for the moment, killed funding for research leading to an underwater probe for Europa's suspected saltwater ocean. But it's possible that this is a good thing. SPACE.com proposes that U.S. Navy-funded research into underwater gliders could offer a superior means of probing Europa, exploring Venus, and even diving into the methane/ethane seas of Titan. NASA wanted a big battery and propeller machine under the ice of Europa, but that might break down, stir up water that should left undisturbed, and leak lubricants into a pristine research environment. The navy wants gliders with internal actuators because they have no flaps or propellers, no lubricant, and one already exists that could "fly" under the Pacific from Seattle to Tokyo on a penlight battery! Another model uses no batteries for locomotion at all, but instead taps heat gradients."

Comments

Contamination avoidance

[PD]

Even if the device is hermetically sealed, it seems that contamination can't be avoided. For example, the little pump would have lubricants in it. No matter how the thing is sealed, eventually water will get in and the lubricants will get out. Even a solid glass sphere won't last forever. What the difference between contaminating Europe today, or doing it a million years from now? The point is to avoid contamination, right?

Re:Contamination avoidance

[jweb]

The point is to avoid contamination, right?

Europa exploration basically boils down to two choices: Explore and risk contamination, or don't explore and miss the learning and discovery opportunities present.

Assuming we go with the first option, our stance should be to do as much as possible to avoid contamination. While we will never be able to avoid contamination (even if this thing never breaks, corrodes, or wears out, it'll still be a contamination in the sense that it was artificially placed there), this idea seems to be the best one yet to minimize the impact of any exploration device we create.

Re:Contamination avoidance

[mobydobius]

While I am generally in favour of taking care not to unnecessarily harm the surrounding environment of any place we visit, I am glad that this enlightened attitude has not always been a goal of mankind. I would hate to live in a cave and be fearful of getting eaten by cheetahs. That would seriously distract me from reading slashdot.

Eco-Friendly on Europa?

[Anonymous Coward]

Isn't it odd that they are concerned about damaging the environment on Europa, when producing the ability NOT to will do harm to our environment?

Go Fish.

Problems with a reverse heat gradient

[lkaos]

First of this is incredible technology. Low-impact approachs to exploration are absolutely what we need to avoid screwing up other planets as we have with this planet. Its always bothered me that we trash on Mars... but anyway, one comment in the article struck me as odd:

On Venus or Europa, that process is somewhat reversed. [...]

"A reversed gradient is nothing I would be too concerned about [...]"

So, if there is a reverse gradient, then doesn't that also mean that there is going to be extrordinary convection currents as the heated (and less dense) material rises to the surface. While there logically would also have to be a down current, the mediums would have to be really turbulent.

So, in order to heat up the machine to obtain energy to move actuators, one would have to deal with the turblence (in order to get to the heat source). I wonder if batteries are need in some way...

Now the real question is, how do we get these things off of the planet (or safely disposed of) once they are done being used.

I think this is a question that needs to be addressed more often (low-impact exploration). Who knows what kind of effect our stuff could have on other forms of life. If there were batteries, they would eventually have to leak and then there's battery acid polluting an environment.

The reason this low-impact is important is because it means we can do _more_ exploration without having to worry about the effects.

But how do we get data back?

[Dr. Spork]

It's all well and good to go on long missions under the Europa ice crust, but if this is expected to be of any use to science, there must be a way of getting data back to Earth. I doubt we could equip this thing with a radio powerful enough to send data through potentially miles of water and ice. The original plan for the battery+propeller vehicle was to have it tethered, IIRC. Would this work in the same way? The cooler thing to do would be to let it go free but then returh and report to a base station (or maybe interface with a cable hanging down from the base station into the water.) The base station could then relay the data back to and orbiter and then on to Earth. Anyway, I think this could be the real technological challenge. Even if you can move far on a "penlight battery" you can't send much of a signal with one.

Re:I Want a Plutonium Drive (not kidding)

[Mad Man]

"I know it doesn't sound right to send a bunch of Plutonium to Europa (the Monolith warned us...) but we could shield it reasonably well."

How does contamination by plutonium compare to the intense radiation belts that already exist around Jupiter?