Jonathan T. Wojack wrote: > I did not see USA 86 (22251) at 01:01:15, considering my element sets > were 4 to 5 days old, and the object seems to manuever a lot. Bad > mistake # 1. To my knowledge, these are the latest elements, which were about 8 days old at the time of Jonathan's attempted observation: 1 22251U 92083A 00116.12243973 .00007000 00000-0 43321-3 0 09 2 22251 97.7240 150.5454 0371000 133.3341 226.6658 14.66971147 07 I estimate the prediction time uncertainty at less than 10 s; so the age of the elements should not have been a problem. More likely, I believe the object may have been difficult to see because it was low in the west and poorly illuminated, especially after culmination, at 1:01 UTC. Jonathan might have had better luck had he observed about 1 min earlier, in the SW, where its illumination was somewhat better. On the other hand, KeyHoles are known to flare briefly in the West and NW, so it could have become visible, despite the poor phase angle. As for manoeuvres, this object has made only one significant one since the spring of 1996. In early Nov'99 it decreased its apogee by about 50 km, and slightly increased its inclination. However, at 2706 days in orbit (as of the latest elements) it is getting old, so there is an increasing potential for it to be de-orbited, though that could still be years away. The two longest-lived KeyHoles to-date were 84122A, which remained in orbit for at least 3600 days; and 88099A, which remained in orbit for about 2745 days. Ted Molczan ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Thu May 04 2000 - 18:19:03 PDT