[amsat-bb] A bit of history please.

Tom Schuessler tjschuessler at verizon.net
Sat Jan 1 21:51:57 PST 2011

Hello to the AO51 team,

Since I am new to the Amateur Satellite world and have only been active for
about 7 months now, I have a few historical questions about AO51 and also

We are now moving into these eclipse periods and I see from the graphic that
appears in the 2010 version of AMSAT's' "Getting Started With Amateur
Satellites", that the advent of long duration eclipses is a recent
phenomenon and was not so in the early days of the orbit.  If the orbit has
been drifting since initial insertion as sun synchronous, I am curious how
much has the orbit shifted since release?  Right now it seems that an AZ of
90 degrees (Perfect overhead) would happen at about 11:15Z.  How much has
this changed since insertion?  How much orbital decay has occurred since

AO-27 is much older and somewhat lower also I think.  Has it drifted in time
as compared to what it was following launch?  How much orbital decay has
occurred with it in 17 years?

Such is the fate of a satellite that does not have any means of on board
orbital maneuverability.  Perhaps if the methods for micro propulsion being
tested by the U. Texas folks with their FastTrack satellites might be
adaptable to future cubesat designs to help prolong sun synchronous orbits
and thus mission lifetimes.

Many thanks to all the operational teams for all the satellites on their
labor-of-love efforts to keep the birds running in the best possible


Tom Schuessler

More information about the AMSAT-BB mailing list