The Upper Atmosphere Research Satellite is a now defunct (and passivated) satellite in orbit around the Earth.

Upper Atmosphere Research Satellite (Wikipedia)

Video about UARS and its Science (Youtube)


Re-entry clock will be removed shortly as the Gadget may not cater for the timezone correctly (even though it may look correct for some).

The major portion of the 5.7 metric tonne satellite is due for re-entry on the 23 or 24 September 2011 (UT).  The majority of this satellite will burn up on re-entry, however there will be fall-out from this satellite.  The track over which the debris will fall is around 800 kilometers (500 miles).

The inclination of this orbit is identical to the International Space Station - any region which can have a direct fly-over of the ISS has a chance of the re-entry taking place over it.

Predicting re-entry of any object is difficult, as an example; a recent solar flare caused the space station to rapidly loose 30km in altitude (over and above its normal decay rate).

Depending on the F10.7 levels (and therefore air density) and the orientation of the decaying satellite, the current best estimate is only a range at this stage - 23 September 2011 20:36 UT +/- 20 hours.



Predictions & Detail

  • Perigee : Closest approach to Earth (within a particular orbit)
  • Apogee : Furthest from Earth

Tweet and Diagram Explanation

see Twitter Account @UARS_Reentry

The gadget spec URL could not be found

Orbit and Position Tweet

Time (UT) Orbital Period (in minutes) / Apogee / Perigee / Latitude / Longitude (instantaneous) / age of data elements for prediction

#UARS Wed 21 Sep 2011 10h:05m UT orbit 88.58 minutes  195.7 x 211 km (121.6 x 131.1 mi)   Lat  3.4N Long 126.5E [age 0.24d]

Orbital Decay - Altitude Prediction Graph

The prediction graph is a plot of perigee & apogee over time (thus dual lines) actual altitude oscillates 16 times per day.
There are three pairs of lines, the original prediction pair, the revised prediction (f=1.5) and the actual observed.

UARS 20110921-2-v21 10d