Update on IGS 1B (10 June 2012)

We are slowly getting closer to the uncontrolled re-entry of the 1.2 tons malfunctioned Japanese spy satellite IGS 1B (2003-009B). The satellite's orbit has by now dropped below 340 km altitude (see second diagram below, perigee/apogee values from orbits calculated by Mike McCants based on amateur observations including mine). That is well below the ISS orbital altitude (ISS is currently in a 392 x 406 km altitude orbit). A mere month ago it was still considerably higher, in a 366 x 368 km orbit: it lost over 25 km or orbital altitude since. It is dropping fast, and the rate increases (see diagram below).

Using the latest amateur orbital elements for the object and Alan Pickup's SatEvo software with the current 10.7 cm solar flux, re-entry is currently estimated to occur between mid-July and early August 2012.