In my previous post, the Iridium satellites as suspected to have failed contained an error: Instead of 11, 18, 21, 27, 22, 46 and 71; it should have said 11, 18, 21, 27, 44, 46, 71. The correct text is now listed below. > Observers of Iridium satellites should be very careful to note that I and > others have been confusing the common names of the satellites that we are > observing. This confusion is derived from the OIG data that comes from > USSpace Command. I reported yesterday that Iridium 46 was tumbling and in > fact, it is really Iridium 24. This has been known for some time and is > not a new failure. However, the reason for this is the coding that is > produced when we get our element sets from OIG. When I print out my > predictioins, the common name that comes from OIG is printed out and I use > it just as everyone else does. > > Apparently, there are a total of 7 Iridium satellites that are not > operating normally from what we have observed and from the technical > information that has been provided to us on the net. There are two types > of observations that tend to confirm that a satellite has possibly become > unstable: a) slow tumbling, b) rapid tumbling. Iridium satellites that we > have identified as 11, 18, 21, 27, 44, 46, and 71 seem to be failed. These > numbers are based on the Iridium numbers listed in the OIG data base. What > OIG calls Iridium 20 is apparently the real Iridium 18 (as identified by > Iridium LLC) and vice versa just as Iridium 46 is probably the real > Iridium 24 and vice versa. There are possibly 6 other objects for which > the names and identities are not correct. All this is caused by the > movement of the satellites from engineering to operational orbits and the > tracking problems by USSpace Command when two Iridium satellites in > similar orbits pass close to each other in the sky. > > We are hoping that Iridium will be able to post a comprehensive list that > will let all space trackers know the correct identities in the very near > future. It would hopefully tabulate the satellite number within the > designated plane, the USSpaceCommand catalog number, the international > designator and the common name (e.g. Iridium XX). > > The observations that I and others make are strictly our own observations > and opinions based upon the information that we use from OIG (or other > sources). We attempt to be as accurate as we can; however, under the > conditions that exist with satellite maneuvers and with two satellites > passing close to one another on various occasions, it should be expected > that this confusion will continue. Anyone who may choose to act on any > information posted on this net would be well advised to check and double > check the facts with the posters before jumping to any conclusions. > Paul D. Maley > > tel. 281-244-0208; fax: 281-244-1140 > email: paul.d.maley1@jsc.nasa.gov > latitude 29.6049 north, longitude 95.1086 west, elev 6m > >