----- Original Message ----- From: "Tom Clark, K3IO" tom.k3io@gmail.com To: "AMSAT BB" amsat-bb@amsat.org; "Phil Karn" karn@ka9q.net Cc: "AMSAT BoD" bod@amsat.org; "senior-officers" Senior-officers@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