> We're talking about a model that can slowly cut through 500' of ice --
> that's all. So, warm water jets, creating an envelope of warm water around
> the model as it works through the ice, should be sufficient without any
> significant danger of hydraulic pressure. So, we're decided: warm water
> jets are the motive force for the model.
I see no point to this. What you have then is a "toy", not a prototype
for something that might tackle Europa. Witness:
> Our probe represents the efforts of a group of space enthusiasts,
> to demonstrate the feasibility of a real 'Icepick'.
So what??? If you look at the original rockets sent up by Goddard in 1927, there are better kit models today than what he had then.
You have to start somewhere. Coming up with 1001 reasons why you can't do something is not starting.
If you are going to demonstrate "feasibility", then you need to be
realistic about the Europan environment and limitations (i.e. no
solar power) and address them.
That's why we're trying to promote this thing without an extension cord. We're trying to make it somewhat self-sufficient, as we know a probe must be.
Now, I do NOT think we need to mess around with 1) carrying a hydrobot, 2) having a video camera, 3) going to Lake Vostok, etc.
This is simply a small aluminum shell, with an internal heat source, that can go 500' through a hunk of ice, and leave a trail of 5 transponders behind it. That's all. It is not rocket science. It IS doable, with off-the-shelf parts.
Re: (responses to my comments):
> First, you're the expert on finding high energy sources for very small things.
Not really. I simply know what nanotechnology will enable. I am by no means
an "expert" on what current technology allows.
I a far from an expert. I could probably do the calculations on the energy
requirements if the size of the probe were specified. *But* it begs an
issue of how long you want the experiment to run. If NASA is content to
take a decade to reach a planet, then they may be content for half-a-decade
for a probe to melt through an icecap (or longer). That type of progress
isn't something that makes the evening news (if publicity is what you seek).
We are not talking 5 year plans, here. We don't have NASA's budget, or incentive to string out a project for 10 years. This has to be done within 1 or 2 years.
It is no longer sufficient to simply sit back in an armchair and be an untested expert. We all know that there's plenty of theory out there already. What this project is about is taking a small, doable task, and then doing it.
One can certainly find higher energy sources than Pu-238, but then one is
faced with two problems -- (a) the cost of purchasing enough of this material;
(the DOE has allocated millions of $ to purchase the Pu-238 to fuel the
remaining RTGs) and (b) the environmental impact problems.
I've devoted some thought to "fueled" alternatives and I just don't see
any way to do it that won't involve people laughing at it as a stunt
rather than a serious scientific feasibility demonstration. You will
have cartoons in the NY Times of somebody sitting on the surface of
the glacier riding a bicycle attached to a generator to produce the
electricity needed to power the cryobot (for 5 years).
> Can you help us figure out how to get sufficient power to provide
> heat for this model, without relying on a 500' extension cord?
Very hot radioisotopes would do it. But I've mentioned the problems with those.
> Alternatively, can you help to make the model so efficient,
> that a limited power source (such as 3-4 batteries or a propane/gasoline
> heated engine) will be sufficient?
Batteries definitely will *not* do it. You could do it with propane/gasoline
but that is going to require (a) a fuel line; (b) an oxygen line; and
(c) a way to feed those fuel lines through the ice (that may be moving and/or
refreezing). That probably means one needs strong, heat conductive fuel
lines (metal braid encasing plastic?) and a means on the surface to keep
the fuel lines above 0 deg. C. This doesn't sound like an off-the-shelf item.
Alright. Fine. I'm such an idiot, that I'm going to come up with an alternative, in 2 minutes. See if you can beat me.
My suggestion? Thermite. Burns underwater, burns without oxygen. It is simply aluminum powder mixed with iron oxide (rust). Thermite cuts through steel. It will bloody well cut through 500' of ice.
Now, you can use thermite or some other chemical combination to provide heat directly to a nose, or to indirectly heat water, that will then melt through the glacier, thereby preventing a pristine glacier from being contaminated with aluminum oxide, perish the thought.
It doesn't matter that we don't have a radioisotope. We know that is what a real probe requires. We are not out to make a Europa qualified probe. It's simply a feasibility study, and a publicity demonstration. So, any self-contained energy source will do. If you have to use a tiny oxygen tank to feed to a gasoline source, so what? If you have to use thermite, or simply manufacture rocket fuel from the local ice, so what? Just so long as the job gets done, and demonstrates that with similar lateral thinking, the other project of a probe on Europa can also get done.
> It only has to travel 500' through terrestial ice -- it doesn't have to be
> a model that would actually work on Europa.
Then I don't really see the point. Lots of people could see that we could
put a heated probe above Lake Vostok with a lot of propane attached to some
very long cables that could melt its way down to the lake. It wouldn't be
easy however. Europa is going to be a *lot* harder.
> What we don't know is, can we model something similiar, simply to demonstrate
> feasibility?
That is the point precisely. There is a big difference between demonstrating
"feasibility" of penetrating an Earthbound glacier and the feasibility of
penetrating a huge ice cover on a remote moon.
Re: Environmental Impact statements
Ok, at least we have a handle on it.
Re: Other efforts
I would generally agree that we need to know everything that others have
done in this area. It is silly to duplicate efforts and silly to
follow paths that others have shown to be unproductive.
The first order of business, IMO, is for everyone to know what
has been done, what works and what doesn't.
Robert
Bruce attached a website for a similar project. I think ours is somewhat different. One serious cost cutting factor is we are not planning to go to Antarctica. There's plenty of local ice.
