Re: [amsat-bb] eagle costs

["John B. Stephensen" <kd6ozh@xxxxxxxxxxx>]

The rocket engine explosion on AO-40 had nothing to do with the complexity of
the electronics or the number of transponders. It was caused by human error on
the ground.

There are only two types of satellites that AMSAT can deploy because they must
orbit either under or over the Van Allen radation belts. Anything in between
will not last long:

LEO satellites can be small and simple as they are placed into their final 800
km orbit by ICBMs that were paid for years ago by taxpayers in the Soviet Union.
AMSAT could afford to fly lots of these satellites but the communications range
of each one is limited by the low altitude. You could link a number of these via
dedicated Earth stations and the Intenet, but it would require scores of
satellites to provide anything close to continuous coverage.

HEOs provide coverage of close to 1/2 the Earth at any given time. However, they
must fly on large, expensive rockets that are paid for at the time of launch.
They are put into a parking orbit and must then boost themselves into the final
40,000 km apogee orbit. They need transmitters with 2500 times the EIRP of LEOs
plus the solar panels to power them and fuel many times the weight of the panels
and transponders to get them into the proper orbit. This determines the size of
the satellite. Since each launch has a very large fixed cost, you may as well
put lots of transponders on board as they don't weigh much and this increases
the reliability by providing spares. However, AMSAT does not receive enough
money to do this very often.

73,

John
KD6OZH

----- Original Message -----
From: "Diane Bruce" <db@db.net>
To: "KC6UQH" <kc6uqh@cox.net>
Cc: "Jim Sanford" <wb4gcs@AMSAT.Org>; "wa6fwf" <wa6fwf@pacbell.net>; "amsat-bb"
<amsat-bb@AMSAT.Org>
Sent: Sunday, 05 September, 2004 12:52 UTC
Subject: Re: [amsat-bb] eagle costs


> On Sat, Sep 04, 2004 at 10:29:14PM -0700, KC6UQH wrote:
> > Guess I will throw in my two cents.
> ...
> >
> > KISS and build what works sounds good , but what about learning something
> > new, and maybe advancing the state of the Radio Art? Have we forgot the
> > purposes of Amateur Radio as outlined in Part 97.1?
>
> http://www.arrl.org/FandES/field/regulations/news/part97/
>
> (a) Recognition and enhancement of the value of the amateur service to the
> public as a voluntary noncommercial communication service, particularly with
> respect to providing emergency communications.
>
> How does building more and more complex sats that blow up or burnup
> satisfy 97.1a ?
>
> For AMSAT to grow, there have to be satellites in the sky that can
> attract, and more importantly keep amateurs. There also has to be a system
> of satellites that is actually useful to satisfy part 97.1a
>
> There will be plenty of room still for experimentation once this
> is achieved.
>
> - Diane VA3DB
> ----
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