On Sat 2003-12-27T21:05:17 +0100, Poul-Henning Kamp hath writ:
> 53 years is an exceedingly improbable lifetime for any deployed
> system.
On the other hand, the Y2K alarmists made lots of lists of when
various systems are likely to fail. The lists all contain a rather
obscure entry that reads
2072 (exact date TBD) Overflow of Milstar Operating System
2072 is right in the middle of the range of expected years when the
8-bit, signed, GPS Delta-T_LS quantity will hit 128 seconds. So it
may be that several other currently deployed military systems are
using the same signed 8-bit counter for the difference between
unsegmented system time and UTC.
The lifetime of individual satellites in these constellations is only
expected to be 10 years. But I suspect that there is pressure to
avoid having to redesign the downlink protocol, redesign the ground
systems, retest the entire ensemble, work out how to handle the
potentially awkward period of transition, and redeploy new versions of
everything within such a short span of years.
--
Steve Allen UCO/Lick Observatory Santa Cruz, CA 95064
sla_at_ucolick.org Voice: +1 831 459 3046 http://www.ucolick.org/~sla
PGP: 1024/E46978C5 F6 78 D1 10 62 94 8F 2E 49 89 0E FE 26 B4 14 93
Received on Sun Dec 28 2003 - 23:53:14 PST