In a message dated 11/18/97 2:47:04 PM, you wrote: >have you considered some kind of superconductivity derivative? surely >Jupiter's (or the Sun's) magnetosphere is intense enough even for a >gradual acceleration up to 1/5 C. I'm not clear what kind of system your talking about, but given the small size and weak intensity of planetary magnetospheres, this doesn't seem possible. Kelly