Path: utzoo!utgpu!attcan!uunet!lll-winken!lll-tis!ames!ncar!tank!uxc!uxc.cso.uiuc.edu!m.cs.uiuc.edu!kenny
From: kenny@m.cs.uiuc.edu
Newsgroups: sci.space.shuttle
Subject: Re: Info wanted on Atlantis "secret" mi
Message-ID: <22000012@m.cs.uiuc.edu>
Date: 15 Dec 88 17:56:00 GMT
References: <684@pyuxd.UUCP>
Lines: 28
Nf-ID: #R:pyuxd.UUCP:684:m.cs.uiuc.edu:22000012:000:1315
Nf-From: m.cs.uiuc.edu!kenny    Dec 15 11:56:00 1988


karn@jupiter.UUCP (Phil R. Karn) writes:
PK>each day's passes over Moscow will all find it in darkness;

henry@utzoo.UUCP replies:
HS>what's the equivalent "shadow period" for, say, Sakhalin Island or
HS>Vladivostok?
[...]
HS>	There is therefore quite strong evidence that either (a) the
HS>	satellite does not require daylight over the USSR to function,

You're both assuming that the satellite's primary mission is observing
the USSR.  It's quite possible that the `hot' areas demanding up-to-
the-minute satellite observation are at lower latitudes, say, Central
America or the Middle East.  Either area has higher-probability
scenarios for US military action than the USSR.

Moreover, correct me if I'm wrong, but I make the regression of the
nodal angle about 4.3 degrees per day.  This gives a 69-day cycle with
respect to the Sun, as the spacecraft's passes come 20 minutes or so
earlier each day.  The spacecraft will be usable for a given
high-latitude area during about half the cycle (more in summer, less
in winter) so there will be windows of only several weeks, not several
months, that the spacecraft is nonfunctional for a given target.
Any bets that ONR is depending on the existing KH-11 to last the
winter, and planning on using the new bird come spring, when the
geometry gets much better?

A-T