Human error is part of the reliability and only one P3 has made it to the intended orbit. Eagle orbital insertion was made simpler to minimize the possibility of such failures.
The cost of building the satellite depends on donations, but since Eagle is less than half the weight of P3E it should cost less to launch.
73,
John KD6OZH
----- Original Message ----- From: sco@sco-inc.com To: amsat-bb@amsat.org Sent: Sunday, September 10, 2006 13:16 UTC Subject: [amsat-bb] Re: S band, experience from UK
Please correct me if I am wrong. But AO-40 did not fail because of poor engineering workmanship. It failed because of HUMAN ERROR in the preparation of the satellite for launch. Are you saying that P3E will cost more to build and to launch than Eagle?
Les W4SCO
At 03:47 AM 9/10/2006, you wrote:
Since we want to do only one engine burn, Eagle will be at a lower
elevation
and WiFi interference will be greater than for P3E -- especially for
users
in Alaska. Consequently, Eagle is also lighter and less expensive and
less
likely to explode.
73,
John KD6OZH
----- Original Message ----- From: jules@g0nzo.co.uk To: amsat-bb@amsat.org Sent: Friday, September 08, 2006 18:30 UTC Subject: [amsat-bb] Re: S band, experience from UK
All
My station is in a built up area in the UK, which I would assume has
a
level of S band licence exempt traffic that is typical of most areas.
I
can
see 5 video senders on my ATV receiver and a 4 WLAN networks on my PDA
with
built in antenna. When I listened to AO40, I only had problems below 10 degrees
elevation.
This represents a small percentage of a pass, that it did not worry
me. (I
am aware that the orbit of Eagle may not be quite so favourable).
Also,
AO40
signals WERE rock crushing for me. With a 5ft dish, very non optimal
linear
feed and pretty average NF, I could hear VK stations as armchair copy
in
ssb, even at apogee. Often they were still copyable at LOS, unless I was
pointing
straight at the WLAN. I will try and make some quantive measurements and submit them, but my
gut
feeling is that S band is still a viable downlink in my location.
My 2 penneth worth.... I am not an AMSAT-NA member. Any donations I make go indirectly
through my
local AMSAT group. So I am not going to get into the politics of this. But... I expect that the decision to drop S-band was not taken lightly. The people who take on these satellite projects, do so at great
personal
and
sometimes financial expense. Given the great commitment that these
people
make, it seems a little discourteous to moan about not being able to
use a
small part of our stations. Our S-band capability will still be
useable
for
P3E. Also, by building an S-band station, you have already reaped the greatest reward, which is the experience of doing it, isn't that what Amateur Radio is all about.
In all hobbies, it seems that there is so much in-fighting, that
people
loose sight of the bigger picture. There are people in authority who
are
out
to get us. In this case it is the commercial pressure on our spectrum.
The
old adage, 'Use it or loose it', is very true here. So if the bit that
we
are able to use doesn't happen to match the box that we have on our
mast,
then we must adapt. Who knows, you may learn something on the way.
Jules G0NZO
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Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb