Satgen 603  LEO Lament  by GM4IHJ   (BID SGEN603)      2000-10-14

Readers of Satgens long past, will be aware of the flourish with
which the advocates of " Low Earth Orbit Commercial Satellites for
everything ",set out their proposals for the take over of the radio
amateur 2m and 70 cm bands, ( Satgen 376 of 8 June 1996 refers).

Since then , things , have not exactly gone their way. IRIDIUMs 80+
satellites have flown and fallen. Overtaken by the massive build up
of terrestrial mobile telephone networks, it operators found
themselves with very few customers and a lot of complaints. Daisy
chaining of rapidly orbiting independent LEO sats, proved much more
difficult than anticipated. Such that submerged in a welter of
limited opportunities and less than forecast equipment performance,
the whole network is now about to be de orbited.

GLOBALSTAR following later with a simpler system , made some headway.
But is currently trying to raise more cash to stay in limited
operation.

ICO did not get off the ground before financial troubles took it out
of contention. Its effects ( ground station licenses etc) have been
purchased by TELEDESIC, who suggest it will reappear as part of an
"Internet in the Sky". Offering 64Mbps downlinks and 2Mbps uplinks,
from a mix of medium altitude and geostationary orbiters.

Meanwhile Orbcomm, which offered a simple message store and forward
facility, rather than real time voice or data links. Concentrated on
transport users and gave up the mass market. But even here the going
has been too tough, and Orbcomm has been forced to seek legal
protection from its creditors, just this last month.

All of which makes Amsats efforts in this latter field of store and
forward, look pretty good.  Uosats and the Koreasats, with
their 9600 bps up and down, having provided a successful service for
ten years up to this time of writing. With IHJ among many others,
being especial grateful to all those who provide gateways to these
satellites.

Meanwhile, totally contrary to expectations, ("Iridium will kill
geosat phones etc").The geostationary telephone providers have gone
from strength to strength, with Inmarsat and ACes being two excellent
examples. For though their ground station equipment is bulky and
somewhat expensive, it has the merit of working rain or shine. With
excellent service coverage up from 73S to 73N, plus first class data
and speech quality. Perhaps as some Amsat members once suggested. We
should have gone for a geosat rather than the odd P3D orbit we may
get by the end of next year. But this leaves unanswered the geosat
station keeping problem. For one important thing about geostationary
satellites is that they are not naturally geostationary. In that the
Sun , Moon and Earths irregular tugs and pushes all conspire to pull
them off station. So fuel and thrusters are regularly in use to push
them back on station. A process calling for specialist human geosat
jockeys . Who like fuel and thrusters,do not come cheaply.