----- Original Message ----- From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Saturday, November 02, 2002 6:11 PM Subject: Re: Guidance System for Icepick I, and Cryobot thoughts
In a message dated 11/1/2002 8:04:34 AM Alaskan Standard Time, [EMAIL PROTECTED] writes: Would information regarding MIT's Robopike (a robot that imitates the behavior of a fish) be of use to Icepick? Relevant URL: http://web.mit.edu/towtank/www/pike/ Larry Yes, I think so, particularly considering that so far, we haven't come up with a good means of steering this beast. I have considerable concerns that if/when a terrestial Icepick is developed (let along a Europa/Mars version), it could be completely blocked by a rock the size of a fist. If we could figure out some way to wiggle past such obstacles, we would have done a huge leap forward for this project. _____________________ Well, if the article is correct, simple differential melting at the nose of a rigid-body Cryobot does a surprisingly effective job of allowing it to quickly veer at relatively sharp angles -- so any sonar or radar obstacle detection system capable of seeing obstacles more than a few dozen meters ahead of the Cryobot will probably be adequate to let it dodge around any boulders it's likely to encounter. _______________________ Bruce Moomaw's article, suggesting, as Robt. Bradbury pointed out, that we need AT LEAST a kW of power also concerns me, and suggests that we are going to have to come up with some heating source from chemical interaction (thermite/thermate/magnesium, etc), instead of merely relying on electricity from a battery. It's also interesting that the probe developed in the 1960s did have considerable trouble with meltwater, so much that they went to the trouble of pumping it back out of the hole. Read Moomaw's first extract on that test. ________________________ I think we had better face facts: it will be impossible to give a Cryobot a self-contained power source adequate for its purposes using onboard batteries. All Cryobots, including the ones NASA itself uses, will have to be heated either by onboard Pu-238 (which we ain't got, thank God), or -- for Earth-based Cryobots, or relatively shallow planetary ones penetrating only a short distance -- by a substantial amount of electricity supplied through a cable from the surface lander. The last I heard, the team designing the possible 2007 "CryoScout" Mars Scout mission to penetrate a hundred meters or so through Mars' north polar icecap were still undecided about whether its Cryobot would use a very small supply of onboard Pu-238, or electricity supplied from the surface lander. It's time I talked to them again, to see what they're willing to tell me (although that may not be much, since the competition to pick the four finalists from the 20 Mars Scout proposals offered isn't scheduled to be settled until December 4 and the teams are all very close-mouthed until then). Side note: CryoScout is one of at least four Mars Scout proposals that would use the 2001 Mars Surveyor Lander, which was almost completely built before the mission was cancelled. There's a real chance that thing will end up flying to Mars after all. == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
