UARS update 21 Sept am
All eyes of the satellite world are now firmly on UARS. Unfortunately, I have no visible passes here these last few days of its existence.
The predictions for the moment of re-entry keep fluctuating between late September 23 and early September 24. Using Alan Pickup's SatEvo software and a 10.7 cm solar flux value of 145 plus this morning's latest elset, the nominal prediction is for the early hours of September 24 but this time still has an uncertainty of up to half a day.
Below diagram shows the changes in apogee altitudes (blue) and perigee altitudes (red) of UARS over September, plus a forecast of the future evolution of them (grey) untill re-entry.