hi all, After discussions with Jonathan McDowell and Ted Molczan, I have slightly revised my orbit estimates for USSF-52 OTV 7, which should launch in about 6 hours from now, around 1:14 UTC (12 December). I used the fact that the Navigational Warning for the apparent second stage deorbit area south of Alaska was later re-issued as NAVAREA XII 854. This NavWarning contains a time constraint that the original did not have (the original opened at launch time): it opens at 12:53 UTC (Dec 11). With the 4-minute shift in launch time between Dec 11 and Dec 12, that becomes 12:49 UTC (Dec 12). So I constructed an orbit that arrives over the area of NAVAREA XII 854 around 12:49 UTC. This means I had to increase the apogee altitude from 35188 km to 37700 km. The resulting orbit has a daily precession of 4m 22s, matching the 4-minute shift in launch time (from 1:18 to 1:14 UTC) between 11 and 12 December, as Ted Molczan noted in a private communication. This is the resulting estimated elset: USSF-52 OTV 7 for launch on 12 Dec 2023 01:14:00 UTC 1 70000U 23999A 23346.07013889 .00000000 00000-0 00000-0 0 06 2 70000 074.0000 325.5453 7407989 135.5462 360.0000 02.15472011 09 I also slightly revised the initial low orbit USSF-52 is launched into before doing the dogleg into HEO. My initial estimate with ~48 degrees orbital inclination was based on the azimuth of area A from NAVAREA IV 1414. After comments by Jonathan, I tried to get something that better fits Areas B and C as well, and arrived at 51.5 degrees orbital inclination: USSF-52 initial orbit for launch on 12 Dec 2023 01:14:00 UTC 1 70001U 23999A 23346.05138889 .00000000 00000-0 00000-0 0 03 2 70001 051.5000 354.4138 0011414 048.2332 322.9851 16.30015116 06 Note that this all strongly hinches on whether the area south of Alaska is indeed related to USSF-52 and not something else. This is not 100% sure. The elsets should be treated as ballpark figures only, and there is always the possibility of subsequent further orbital adjustments of the payload post-release. - Marco ----- Dr Marco Langbroek - SatTrackCam Leiden, the Netherlands. e-mail: sattrackcam_at_langbroek.org launchtower: http://launchtower.langbroek.org Station (b)log: http://sattrackcam.blogspot.com Twitter: _at_Marco_Langbroek ----- _______________________________________________ Seesat-l mailing list https://lists.seesatmail.org/mailman/listinfo/seesat-lReceived on Mon Dec 11 2023 - 10:51:36 UTC
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