Dramatic increase of space debris peak density since 2006 seen at ESR

Markkanen, J.

EISCAT Scientific Association, Sodankylä, Finland

In March and July 2006, EISCAT collected about 160 hours of space debris measurements at ESR. The 2006 measurements provide a convenient reference point for the debris measurements to be done during the IPY in 2007 and 2008. The IPY debris measurement commenced in March 12, 2007 at ESR, and immediately revealed a large increase of daily peak debris detection rate. In March 2007, in the altitude zone 780-980 km, during the UT hours 6 and 12, between 70 and 110 events per hour were regularly observed, while in other hours of the day, the event rate typically is between 10 and 20. In 2006, the daily peak hourly event rate in that altitude zone varied between 20 and 30. The enhanced debris density is consistent of being due to the ESR 42m antenna beam crossing the debris cloud originating in a Chinese antisatellite test performed in January 11, 2007. The cloud has been claimed by NASA to be “the most severe orbital debris cloud in history”. The EISCAT IPY debris campaign offers a good opportunity to observer the expected gradual spreading-out of the cloud day by day.