I think RTG stands for "Radioactive Thermal Generation" or something like that. It is a hunk of plutonium that, on its own, glows at a high temperature. Since the temperature of space is near absolute zero, there is a large temperature difference. A relatively simple, dependable thermocouple generates electrical power from this temperature difference, making a really long-lasting, dependable battery -- but not of the sort you want in your kid's toys :-) -----Original Message----- From: cctalk-admin(a)classiccmp.org [mailto:cctalk-admin@classiccmp.org]On Behalf Of chris Sent: Monday, May 12, 2003 10:25 AM To: Classic Computer Subject: Re: OT: Voyager watts For the few of us on the list that are idiots (ok, fine, just for me then), what is RTG sourced power? -chris <http://www.mythtech.net>