On Mon 2007-01-15T08:53:19 -0700, Rob Seaman hath writ:
> Any comments on the practicality of space-rating such timepieces?

GPS uses rubidium cells, and Galileo will.
I've seen ruminations about flying a cesium resonator and an ion trap
on ISS with a goal of redefining the SI second by allowing a long term
calibration of the "continually probe-able on earth" ion against the
"it always falls down on earth" cesium.

> Also - what are the actual use cases requiring a common time scale,
> rather than establishing a separate Martian civil cesium standard and
> simply tracking the deltas?

Robert A. Nelson.
Look up his numerous presentations on a Mars version of GPS in CGSIC,
PTTI, etc., and more recently IAU in Prague
(Which, by the way, includes the calculation that deviation between
Mars coordinate time and Earth coordinate time is about 25 ms
peak to peak.)

Steve Allen                 <[EMAIL PROTECTED]>                WGS-84 (GPS)
UCO/Lick Observatory        Natural Sciences II, Room 165    Lat  +36.99858
University of California    Voice: +1 831 459 3046           Lng -122.06014
Santa Cruz, CA 95064        http://www.ucolick.org/~sla/     Hgt +250 m

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