A new twoline element set has been posted by Ted Molczan to the SEESAT-L newsgroup for the dead USA 193/NROL-21 radar spy satellite. According to this latest element set USA 193 is still on a collison with earth something around March 19, 2008, plus or minus one week.Below is the complete post from Ted.
- - - - - - - - - - - - - - - - - - - -
Alberto Rango has reported a new observation, which I used to update the orbital
elements:
USA 193 5.0 2.5 0.0 4.3 v 260 X 268 km
1 29651U 06057A 08040.19031987 .00154186 00000-0 23822-3 0 09
2 29651 58.4879 79.7345 0006557 83.6022 276.5824 16.03599602 00
Arc 2008 Feb 04.28 - 09.21, WRMS residuals = 0.039 deg
Mean rate of altitude decrease over the past five days was about 850 m/d (metres
per day).
Definition of 2-line elements format:
http://spaceflight.nasa.gov/realdata/sightings/SSapplications/Post/JavaSSOP/SSOP
_Help/tle_def.html
Using the above elements and a 10.7 cm solar flux of 71, Satevo v0.51 estimates
decay from orbit on 2008 March 19, in reasonable agreement with earlier
estimates. The uncertainty is at least one week.