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Re: Phase 4 versus Eagle

N4HY stated
> We are spending a significant amount of money THIS YEAR producing a
> hardware frame for the Eagle spacecraft.  The electronic systems are
> very similar.  Intelsat will have more capability than Eagle as we
> currently understand what we THINK the situation is because we will have
> a) a better antenna platform and b) much more power.
One thing the members should realize is that the "amateur radio" portion
of the satellite programs constitutes only about 10% of the programmatic
effort. IMHO, if things go in the direction I'd like to see, the
GEOstationary P4 possibility has several other advantages to be added to
Bob's list:

c) A major portion of the P3 satellite effort, going all the way back to
P3A (that achieved an aquatic orbit way back in 1980), has involved the
need for us to become real "rocket scientists" by flying our own
propulsion systems to achieve the HEO orbit. With the GEO P4possibility,
someone else worries about the motors. That lops off (at least) 30-40%
of the 90% non-radio overhead (and helps to prevent ulcers among the
volunteer builders).

d) Flying as a piggyback on somebody else's spacecraft means that they
will handle all the attitude control problems. This removes the need for
earth sensors, magnetorquers and an incredibly labor intensive effort to
use the magnetorquers to actually point the spacecraft (remember that
you are trying to push a gyroscope and all pushes cause the spin axis to
precess). We had to be really good at pointing the spacecraft because
the spin axis has to be properly aligned in the orbit plane in just the
right direction in order to fire the kick motor!

e) (expanding on Bob's item b) -- The current GEO plans would have the
main spacecraft provide us with power. The solar panels needed for EAGLE
would have cost us upwards of $2 million (unless we were to find a
really generous sugar-daddy). And the power levels we have been
discussing with the GEO supplier are about twice what we would have been
able to generate on EAGLE, meaning signals will be stronger.

f) There has been a lot of discussion here about launch availability and
cost. So far, we have had a hard time identifying an affordable launch
for a single EAGLE. It appears that the GEO piggyback may well cost LESS
than an EAGLE launch to GTO.

g) An even more important aspect of (f) is that these launches are a
renewable resource. Unless we blow the opportunity badly, we can launch
additional payloads every year or so. (Some info on the most recent
launch in October is seen at 
http://www.orbital.com/NewsInfo/release.asp?prid=629). The places we
might be able to get a ride to can be seen by clicking on either the
HTML or FLASH  item at http://www.intelsat.com/network/satellite/.

h) The pricetag for either EAGLE or a GEO P4 may well be more than we,
as amateurs, are able to raise. We are actively pursuing new funding
sources. Right now, one of the most promising is from the US Gov't under
the aegis of Homeland Security. Amateur Radio is well known as a very
competent "first responder" of communications services. The HS people
learned from Katrina that there is a need for 24/7 rapid response
capabilities that can cover a sizable area where the infrastructure has
collapsed. Some commercial sources have responded with multi-Billion
dollar proposals. We think that they will be responsive to a grant
request of a few percent of this, including the provision of ground
terminals which would be deployed at a number of locations around the
country (like at your QTH?).

As a Board member I have wholeheartedly embraced the P4 GEO concept as
the best (and perhaps only) act in town. I hope that the rest of the
AMSAT members are similarly enthusiastic about the idea. As of now, it
still is only an idea. It may not happen. But I can guarantee that we
are guaranteed to fail if we don't try; and to try we need to know that
the community is behind the effort. Remember that AMSAT is an
all-volunteer effort, and YOU ARE AMSAT.

Season Greetings and wishes for a successful 2008 -- Tom Clark, K3IO

Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author.
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