I agree with your analysis and that of Jonathan. Perhaps this was the reason why they stopped publishing TLEs for NRO objects shortly after this incident. I think they may have decided publishing no info was a better alternative to publishing bad info that could undermine trust in the TLEs in general. ------- Brian Weeden Secure World Foundation +1 202 683-8534 On Jan 13, 2013, at 16:58, "Ted Molczan" <ssl3molcz@rogers.com> wrote: > Jonathan McDowell wrote: > >> I have now analysed the orbital data in the declassified document >> 54.pdf in this collection. >> It confirms previous rumours that the saved TLEs for the A object at >> http://www.planet4589.org/space/elements/13000/S13040 >> are NOT CORRECT - they are fine through Apr 28 but from Apr 28 to May >> 23 they refer to a DIFFERENT OBJECT >> (or maybe something invented). On Apr 28 1982-06A moved to a low 150 x >> 308 km orbit and seems to have >> been untracked by NORAD for almost a month. More details at >> http://planet4589.org/space/jsr/latest.html >> (permalink will eventually be planet4589.org/space/jsr/back/news.673) >> >> I solicit analysis of the Apr 28-May 23 published TLEs for 13040 >> (which I obtained from Allen Thomson's collection). >> What is this slowly decaying object? Does it later get retagged as >> something else? > > This is highly interesting. > > The apparent transition from reliable to doubtful TLEs occurs between epochs 82117.177 and 82118.130. Here they are as > recorded in Jonathan's archive: > > 1 13040U 82117.17705877 .00013321 14937-2 1601 > 2 13040 97.2339 195.5378 0008193 314.9290 45.0548 14.86887207 14136 > > 1 13040U 82118.13027880 .00010471 14937-2 1613 > 2 13040 97.2339 196.3828 0008194 311.8286 48.2226 14.76834731 14273 > > At face value, the orbit was raised about 32 km in the interim, which would have required two manoeuvres. The time of > closest approach between the two orbits should be the approximate mid-point between the manoeuvres, but it occurs one > day too early, near 11:54 UTC (epoch 82116.4958). > > Also of interest is that the TLEs spanning epoch days 82118 through 81142 appear to be represent the identical orbit > propagated to different epochs. Note the constant value of inclination and B* throughout, which was carried over from > epoch 82117 TLE. I tested this hypothesis by propagating the epoch 82118.130 TLE to the epoch of four subsequent > official TLEs, using a routine that extracts the mean elements generated internally within SGP4: > > Archived TLE > 1 13040U 82124.63437970 .00010505 14937-2 1652 > 2 13040 97.2339 202.2153 0008201 290.4308 69.6023 14.76971116 15235 > > Propagated 82118.13027880 TLE: > 1 13040U 82006A 82124.63437500 .00010510 00000-0 14937-2 0 05 > 2 13040 97.2339 202.2152 0008201 290.4193 69.5920 14.76971112 06 > > Archived TLE > 1 13040U 82130.52820390 .00010536 14937-2 1675 > 2 13040 97.2339 207.5015 0008207 271.0654 88.9617 14.77095082 16105 > > Propagated 82118.13027880 TLE: > 1 13040U 82006A 82130.52820602 .00010540 00000-0 14937-2 0 02 > 2 13040 97.2339 207.5015 0008207 271.0189 89.0330 14.77095078 09 > > Archived TLE > 1 13040U 82137.91172475 .00010564 14937-2 1715 > 2 13040 97.2339 214.1254 0008215 246.8489 113.1858 14.77250892 17199 > > Propagated 82118.13027880 TLE: > 1 13040U 82006A 82137.91172454 .00010579 00000-0 14937-2 0 09 > 2 13040 97.2339 214.1254 0008215 246.7153 113.3563 14.77250890 01 > > Archived TLE > 1 13040U 82006A 82142.04344872 .00010596 00000-0 14937-2 0 1734 > 2 13040 97.2339 217.8327 0008220 233.3163 126.7324 14.77338330 17806 > > Propagated 82118.13027880 TLE: > 1 13040U 82006A 82142.04344907 .00010601 00000-0 14937-2 0 09 > 2 13040 97.2339 217.8327 0008220 233.1156 126.9921 14.77338332 07 > > The propagation employed a version of SGP4 that closely conforms to the Center for Space Standards & Innovation version > as of Fall 2008. Propagation was to the nearest second of time of the epoch of the official TLE. > > Given the vagaries inherent in the natural evolution of orbits, and the imperfections in the orbital model and tracking > data, the negligible differences between the propagated and purported actual elements would be virtually impossible. > > As another test, I computed the separation between the official epoch 82118 and 82142 TLEs, and found that in the > interim any difference was almost entirely along-track, ranging between zero and 8.45 km, which is improbably small. > Moreover, the difference evolved gradually, suggesting that it resulted mainly due to a slight difference between the > propagators underlying the TLEs, and the one used for the test. > >> Is it really possible that NORAD failed to notice a 4.5 tonne polar >> LEO satellite for several weeks, or is this the first known instance >> of deliberate TLE disinformation? > > It is highly unlikely for the GAMBIT satellite to have gone untracked for so long. The orbits in question do not > correlate with the four known debris objects, based on comparison with their near-contemporaneous TLEs. Deliberate > disinformation seems a possibility. > > I offer the following speculation for discussion. > >> From launch through epoch 82117, the apogee and perigee of 82006A did not resemble that of any previous Gambit or > Hexagon mission, which could have been at least somewhat confusing to the Soviets. They might have wondered whether it > was an imaging or a SIGINT satellite. Certainly, they would not have known that the object was intended to eventually > lower its orbit to the standard Gambit dimensions. > > I recall (source escapes me at the moment) that one motivation behind the later stealthy Misty IMINT satellite was the > Soviet ability to track the KeyHoles, which facilitated deception and denial. The sudden manoeuvre by 82006A to the > standard Gambit orbit might have served as a test of how quickly the Soviets would detect the change, as well an > opportunity to collect some imagery in the interim, against targets (hopefully) not practicing the usual deception and > denial. > > I do not know how long it took U.S. TLEs to reach the Soviets in those days, but perhaps the bogus TLEs were intended to > prolong their hoped for confusion. The results could have informed the development and argument in support of Misty, > which reportedly was approved in Spring 1983. > > Alternative ideas welcome. > > Ted Molczan > > > _______________________________________________ > Seesat-l mailing list > http://mailman.satobs.org/mailman/listinfo/seesat-l _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l
This archive was generated by hypermail 2b29 : Sun Jan 13 2013 - 23:13:48 UTC