On Mon, 4 Nov 2002, Bruce Moomaw wrote:
> As for mechanical drilling through ice rather than melting; it can be done, > but all the studies conducted over the past few years have concluded that, > on balance, it requires much more energy expenditure than hot-water jet > melting. There might also be steering problems with it. On the other hand, > rotary grinders may be a necessary addition to the Europa Cryobot's nose to > chew through the salt (or sulfur) buildup in front of it. I was careful to use the ice-cube analogy rather than the grinder analogy. The energy requirements for melting or grinding are due to the requirement for breaking interatomic bonds (in ice - hydrogen bonds). The hot-water melting approach may be used because that is what the Russian's have extensively studied drilling holes with. Grinding is a common idea because that is largely how we drill oil wells (so there is a lot of off the shelf technology there). *But* if you have a strategy that breaks as few interatomic bonds as possible (thus the nicrome wire ice cube idea) you could cut the energy requirements significantly. (What I had actually imagined was a bunch of nanobots cutting the ice into micron-sized chunks and carrying them from the front of the probe to the back of the probe and dumping them in a dusty trash heap. But I didn't want to get raked over the coals for bringing up nanotech again... :-)) Someone should visit a junk yard (in places where they still have these) or a refrigerator repair shop and see if they can lay their hands on an old icemaker and take it apart and see how it works. The nice thing about the nicrome wire idea is that its really easy to test. You could imagine a mechanical head where the goes in circles (or a square pattern) melts out the ice cubes (say 1/4-1/10 the area of the probe head). Then a vertical conveyor system that grabs onto the cube, hauls it up the length of the probe and deposits them in an ever lengthening trash heap. Interestingly enough the force of gravity pulling on the ever lengthening trash pile might be enough to drive the probe downward. Of course the probe would have to be designed to withstand this pressure. If its properly promoted, its the type of thing you could get the groups that spend their time on things like Robo-wars to be interested in. Robert == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
