[amsat-bb] Re: Remembering a part of AMSAT's History

i8cvs domenico.i8cvs at tin.it
Fri Dec 5 04:46:00 PST 2008

----- Original Message -----
From: "Tom Clark, K3IO" <tom.k3io at gmail.com>
To: "AMSAT BB" <amsat-bb at amsat.org>; "Phil Karn" <karn at ka9q.net>
Cc: "AMSAT BoD" <bod at amsat.org>; "senior-officers"
<Senior-officers at amsat.org>
Sent: Friday, December 05, 2008 5:15 AM
Subject: [amsat-bb] Remembering a part of AMSAT's History
> There is another story in those newsletters. In the early 1980's, a few
> amateurs were learning about computers. The pre-1980 LEO  satellites
> could be tracked using only the time of equator crossing and a simple
> plotting board. However the HEO Phase-3 satellites in elliptical orbits
> made the job a lot harder. In Orbit #6 (see
> http://www.ka9q.net/AMSAT-ORBIT-6.pdf) I started AMSAT on the "open
> source" software track by publishing the source code (in BASIC) for a
> the algorithms needed to do the job on a personally owned computer; at
> the time, the detractors said
>       "Why waste all this space in the magazine. Only a few amateurs
> will ever own
>        computers with enough horsepower to do these calculations!"
> I held fast and we published the article anyway. In the next 5-10 years,
> clones and graphical adaptations of "IWI Orbits" by others for many
> computers were added. AMSAT's "sales" of copies of the many variants of
> my open-source software put nearly $100,000 into the till to build AO-10
> and -13.
> My thanks to Phil & Ralph for giving me the chance to reminisce one more
> time!
> 73 de Tom, K3IO (ex W3IWI)

Hi Tom, K3IO

I remember that before to publish your article " Basic Orbits " into the
ORBIT magazine March/April 81 you sent to me by regular post the
listing of your software written in North Star Basic because at that
time waiting for P3A I had developed a new type of maps and overlay
to track a HEO satellite using the old equator crossing method.

I still have your letter and it helped me a lot to develope a software for
the Texas Instruments  programmable calculators TI-59 and SR-52 

I would like to point out that your software was the first one in the
amateur radio community to introduce the concept of Keplerian Elements
and use the CELESTIAL coordinates system instead of the GEOCENTRIC
coordinates system based on satellite ephemeridis and equator crossing.

Your software was the "cromosome" for the following programs
circulating in the future.

By the way at that time in the early 1980's the future was very brigth for
all of us HEO satellite users but unfortunately things are now changed
a lot.

Tank's for your effort Tom

73" de

i8CVS Domenico

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