99099A correlates with 99028A Titan IV launch
Ted Molczan (molczan@home.com)
Thu, 17 Jun 1999 19:57:50 -0400
The orbit of 99099A does not appear in NASA/OIG's catalogue - a strong
indication that it may be related to one of the classified U.S. launches. As
a result of an analysis of several quasi 60 deg inclination, classified
launches, I have found an apparent correlation between the orbit of 99099A,
and the recently launched 99028A mission.
I also analysed 90019B (USA 53 / AFP-731), and the three NOSS 2 launches
(90050A, 91076A, 96029A). I did not find a close correlation with any of the
orbits (insertion, parking, operational) that were known to have been
occupied by various components of those launches. My analysis concentrated
on the early stages of those missions, through payload deployment. In the
case of 90019B, I also looked for a correlation around the time of its
disappearance on 5 Nov 90.
I have also considered the various U.S. launches into Molniya orbits;
however, I do not see how any of them could have accounted for a large
object in a MEO orbit like that of 99099A - unless some of them did not go
to Molniya, which I have no way of knowing.
A correlation may be suspected between two objects, if their orbits were
coplanar (or nearly so) around the time of some meaningful event, such as
launch or orbital manoeuvres. This method is not infallible, because we
probably do not know about all of the meaningful events of the launches in
question, and because of uncertainties inherent in calculating the
precession of orbital planes over many years.
The correlation between 99099A and the mission of 99028A, is based on an
analysis of the following orbital elements:
Titan IV 2nd stage, 211 X 305 km
1 25745U 99028B 99144.30720100 .00701775 79230-5 54019-3 0 10
2 25745 63.3944 95.8512 0070863 171.1785 189.0195 16.08930044 06
Small object, 390 X 404 km
1 25744U 99028 A 99155.48763000 .00090000 00000-0 10662-2 0 06
2 25744 63.4100 55.4400 0011000 350.0000 10.0000 15.60800000 07
Large object, 2700 X 3136 km
1 99099U 99099 A 99167.90066188 .00000000 00000-0 00000-0 0 05
2 99099 63.4395 65.9713 0234713 291.3036 67.5185 9.69752369 01
The 99028B elset was issued by NORAD and downloaded from NASA/OIG. The
elsets of 99028A and 99099A are based on observations by amateurs,
previously reported on SeeSat-L.
On 22 May 99, at about 9:45 UTC, 99028B was inserted into a 63.4 deg, 216 X
314 km orbit. The payload probably separated from it soon after.
On 23 May 99, at about 8h UTC, the orbits of 99028A and 99028B were
coplanar, suggesting that this was the approximate time of two manoeuvres by
99028A that raised its orbit to 390 X 404 km.
I have considered two possible routes 99099A could have taken to reach its
2700 X 3136 km orbit:
1. On 24 May 99, at about 22h UTC, the orbits of 99099A and 99028B were
coplanar. Therefore, if 99099A manoeuvred independent of 98028A, then this
was the time of its manoeuvres.
2. On 25 May 99, at about 2 h UTC, the orbits of 99099A and 99028A were
coplanar. Therefore, if 99099A and 99099A were together in the 390 X 404 km
orbit, then this was the time of its manoeuvres.
I favour explanation #2, because the apparent large size of 99099A is more
consistent with the single payload catalogued (so far), and the capacity of
the Titan IV.
Based on its visual magnitude, 99099A could easily have accounted for
virtually the entire volume of the 15 X 5 m payload fairing used on the
99028 launch. In contrast, Mike McCants found 99028A's visual magnitude
consistent with a size of about 1 m, more likely to be one of the 9 pieces
of debris catalogued by NORAD.
If this analysis is correct, then we may eventually rename 99099A as 99028A,
and rename 99028A as 99028C. However, I do not believe we should rush to do
so. One reason, is that both 99028A and 99099A have been seen to be slowly
varying in brightness, which is more characteristic of debris than payloads.
Perhaps further observations of both objects will help decide whether or not
they are payloads or debris.
It is particularly important that 99028A be observed before it decays. It is
now entering evening visibility for S. Hemisphere observers, and should not
be too difficult to find using the elements above, making a reasonable
allowance for the uncertainty of its rate of decay.
Ted Molczan