Satgen 418  Mobile Phone Sats  by GM4IHJ   (BID SGEN418)    29 Mar 97

The commercial mobile phone saga has recently taken on a few more
twists and turns. The Teledesic proposal (McCraw - backed by Bill
Gates), has just received American FCC permission to go ahead with the
developement of a fleet of 924 satellites using 28 Ghz in 700 Km
altitude low earth orbits. It is noteworthy that this proposal has
added more than 100 satellites to the number proposed in Nov 93. But
much more interesting is the suggestion that the satellites will
provide high speed wide band input to the Internet from anywhere in
the world. This is very different from the 1993 proposal which talked
about providing telephone links to remote communities. Clearly the
market for Internet links is a very big one , and this reappraisal
makes good sense. Operational date is 2002.
The news of Motorolas much smaller system's first launch is less
happy. The original launch was all set to go on 13th Jan 97, but was
called off because of a small insulation panel fault on the Delta
rocket launcher. A new launch date was planned after a delay of about
a week. Unfortunately before that could happen , a totally different
Delta launch of a GPS satellite , blew up just above the launch pad. 
Reports now suggest that all Delta launches have been cancelled, until
the enquiry into this Delta GPS launch accident has reported its
findings and any consequent changes to the Delta rockets have been
implemented. No Delta launches are expected until May 97 at the
earliest. So Motorolas first in orbit tests of its Iridium system is
probably grounded until then.
Meanwhile newspapers in Europe have been full of horror stories
consequent on the above developements. With participants at one
scientific meeting questioning how these hundreds of satellites will
coexist without colliding with one another or with debris already up
in low earth orbit. A question which appears to overlook existing
evidence which suggests that only one satellite is ever known to have
been hit by debris, and that one was reoriented by its controllers and
back in operation in a very short time, showing no signs of loss of
function.
None the less, some of the participants at one meeting went so far as
to suggest it would soon be necessary to make it obligatory to ensure
that any satellite going to low earth orbit was fitted with command
and control of a deorbit system, to bring it out of orbit at the end
of its useful life. A fitting which could add considerably to the cost
of any future Amsats we might want to put up into low earth orbit.
Even more alarmist , participants at the same meeting were told that
it was possible that the November 98 and 99 Leonods meteor showers
will be so strong that hundreds of satellites could be knocked out.
This being the first repeat of this famous 33 year cycle shower since
artificial satellites became numerous. However it has to be said that
Donald Yeomans of JPL produced an excellent paper some time ago
pointing out that not every 33 year repeat is a big one. Sometimes the
Earth does not go through the densest part of the meteor stream , and
in 1998 and 1999 this is just what is predicted to happen. So the
shower may not be all that heavy - unlike the famous Leonids of 1866
which caused panic in some places and prompted that excellent ballad ,
Stars fell on Alabama. The classic rendering of which is the duet by
Ella Fitzgerald and Louis Armstrong. A truly delightful comment on
meteor astronomy .