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 AO27.

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 insertion?

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 condition.

73

Tom Schuessler N5HYP