Of course the fuel does not have to be White Phosphorus. Maybe hypergolic
fuels would be better suited. It would be safer to store for such a long
trip. I just thought WP would be a good example because it will burn
anywhere, even in water.
Scott, I think you're planning for an actual probe. That's not what this is about. This is for a terrestial bound model. We do not have the capacity to put up a Europa bound probe, so we have to think locally, and cheap.
Robert Bradbury suggests that there's not enough heat capacity to get through 500 feet of ice. I don't buy it. I came up with thermite, you suggested white phosphorous. We all know that warm water WILL cut through ice. We are not moving the ark through ice, just a 3' metal tube, sprayed with teflon, and enveloped in a pocket of water that is slightly warmer than the surrounding ice. It does not have to be a jet. It simply has to slowly move, without reference to an extension cord out the back.
I still think we can come up with a means of internally heating meltwater, and use that meltwater to provide most of the motive force, or at least most of the drilling. If the powersource is batteries, fine.
1) How much power can 4 motorcycle batteries, linked to an electrical coil surrounding an insulated reservoir produce? Is it enough to heat up enough water to cut a hole in ice? If batteries can heat up a pot of coffee, why can't more and bigger batteries heat up a gallon of warm water?
2) If gasoline / propane requires air to do the same trick, then why not simply put in a scuba tank filled with compressed air, to provide that boost? We don't care if we run out of air... we only have to go 500'. We don't care that this is not a direct correlation with a NASA project, or that such a project will use radioisotopes rather than a gasoline motor and a scuba tank. That project will likely have other bells and whistles that will take up just as much proportionate mass as our make-do heating device will, on the model.
3) If gasoline/propane won't work, then a device that slowly feeds out a chemical mixture of thermite or white phosphorous might -- either to directly heat the ice, or to indirectly heat water for a water drill. We can adjust the effficiency of the burn, to make it cool enough to work with -- that is, instead of an optimum mix of aluminum and iron oxide, the model's mix has a more neutral reactant, to slow the burn time down. Fireworks specialists have all sorts of knowledge on how to make chemicals burn more or less slowly. We can also contain a chemical burner in a ceramic vessel. Excess heat would simply provide additional impetus to the model.
-- John Harlow Byrne
