Hi Satelliters,   Using Keps from Space-Track for ARISSat-1  (37772)  I have been plotting various parameters including Mean Motion. Rrecent results were unexpected.   From day 328to 334 the daily change in Mean Motion has been exactly the same. The orbital decay is going at a very steady rate. This is completely different from earlier observations where there is quite a bit of daily variation.   My interpretation is that the atmospheric density along the orbital track has been remarkably unchanged over 6 days or so. This is something I have not seen before.   73 John G7HIA