Sebastian Stabroth wrote: > could it be that USA 144 exploded? There are at least nine > debris objects (#25746-25749, #25751-25755). One of them > decayed already. I can hardly believe that all of them > are/were mission related. I have always been suspicious of the large amount of debris generated by this launch, all of which has been officially attributed to the payload. It might be useful to review the chronology of this launch (times approximate): 1999 May 22 09:36 UTC lift-off of Titan IVB from VAFB 1999 May 22 09:45 UTC insertion into 63.4 deg, 210 x 316 km initial orbit 1999 May 23 08:30 UTC manoeuvre to 310 x 404 km transfer orbit 1999 May 23 11:30 UTC completed manoeuvre to 389 x 404 km parking orbit 1999 May 25 02:00 UTC manoeuvred from 389 x 404 km orbit to 2705 x 3129 km orbit A source I trust, who prefers not to be named, told me that all of the debris was shed in the insertion orbit, the transfer orbit and the parking orbit. Hobbyists tracked an object in the parking orbit that was initially thought to be the payload. Here is Mike McCants' elset: 1 25744U 99028A 99159.07478761 .00062000 00000-0 71960-3 0 00 2 25744 63.4100 42.4565 0010000 349.9893 10.0106 15.61344808 08 Its standard magnitude (1000 km, 90 deg phase angle) was 6.9, which suggests that it was about 1 m across. It was rotating with a period of about 17 s. Official elements for another piece were issued during is final weeks in orbit. This was its orbit about 24 d prior to decay: 1 25752U 99028H 00026.23500801 .00233793 80000-5 20103-3 0 64 2 25752 63.3782 246.1198 0047700 353.9531 6.3471 16.10435036 18133 The 220 x 283 km altitude suggests that it was one of those shed in the 310 x 404 km transfer orbit. It is uncommon for modern spacecraft to shed any debris, but this one seems to have left a trail throughout its initial LEO orbits. Judging by their rates of decay, they were reasonably dense, so I suspect they were operational debris. Can anyone think of a practical reason for manoeuvring to the 400 km parking orbit, only to spend 1.6 days there and leave behind debris? Why not manoeuvre directly from the insertion orbit to the high orbit? Turning to the high object, certain facts argue that it is a payload: apogee is at 56 deg north latitude, providing the greatest dwell time over the traditional areas of interest. This led some of us to speculate that this was the "8X" satellite, which supposedly was going to provide wide-area, long-dwell time coverage. The ground track nearly repeats every 3 days - the U.S. favours 2 to 4 day nearly repeating tracks for its LEO imagers. On the other hand, the small difference between perigee and apogee does not seem to justify use of the 63.4 deg orbit. Some have speculated that the payload was bound for a Molniya orbit and either became stranded in a transfer orbit or left behind some debris there. The problem with that idea is that the orbit of the high object does not look much like a Molniya transfer orbit - its perigee seems far higher than necessary. If the high object is the payload, then it must be presenting a solid area of at least 500 m^2 to the sun. Some have suggested an antenna, but why would it be aimed at the sun? A solar array makes more sense, but one that large would generate on the order of 100 kW (based on gallium arsenide, at end of life). What needs that much power? A Lacrosse-like SAR, perhaps? The rotation presents another problem, since most satellites are three-axis stabilized. I note that some of the U.S. LEO elints appear to rotate rapidly. Could this be a heavy-elint sat? If so, why the large area facing the sun? Turning back to the debris, this mission reminds me of Misty, aka AFP-731, aka 90019B. It was shuttle-deployed into a low 62 deg orbit. A week later, Russia reported that it had vanished, leaving behind only debris. Speculation was that it had exploded. Seven months later, Russell Eberst, Daniel Karcher and Pierre Neirinck found it in a 65 deg, 800 km orbit. Soon after, in early Nov 1990, it disappeared again. Ten years later, I discovered that Russell Eberst probably observed it as an unknown three times during 1996-97. It had manoeuvred to a 66.1 deg, 736 km orbit, apparently to create a 3 day repeating ground track, probably to optimize its revisit rate in support of Operation Desert Storm. Here is an accurate orbit derived from Russell's obs: 1 20516U 90019B 97284.23458324 .00000027 00000-0 70436-5 0 01 2 20516 66.1631 65.2852 0005248 187.8717 231.2307 14.48751217 03 It is now generally accepted that Misty was the first U.S. LEO stealth satellite. It is believed that hobbyists were able to see it easily until early Nov 1990 because its optical stealth mechanism was active only when in sight of Russian optical tracking stations. It had been assumed that there were no other "detection threats" elsewhere in the world. Since the manoeuvre to the 736 km orbit took place within days of the hobbyist's sighting having been made public, it is reasonable to guess that the optical stealth mechanism was activated against the hobbyist's known locations. That would explain why the otherwise bright object was not seen for years, and was faint during Russell's chance sightings in 1996-97. Thorough searches by Greg Roberts in 2001 and 2002 failed to turn up the object. Most likely because it had exceeded its useful life and been de-orbited. Could 99028A be Misty 2, or something similar? Perhaps. If so, then I suspect the high object is debris, and that all of the debris would have been intended to create confusion. The payload could have remained in the insertion orbit until near decay, only to vanish while out of range of Russian tracking stations. Or it could have manoeuvred to its final orbit shortly after launch. One problem with this idea is the notion of using decoys in long-lived orbits, such as the high object. If deception and denial is a concern, then it is not a good idea to have adversaries hiding from decoys. Imagine several decoys in orbits like that of the high object from 99028A. One would almost always be above the horizon everywhere on Earth, leading adversaries to hide as much as possible all of the time, leaving little for the real recon sats to see. I am not arguing that USA 144 is stealthy; but it is food for thought. Certainly, USA 144 remains more mysterious than ever. Ted Molczan ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www.satellite.eu.org/seesat/seesatindex.html
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