The following elements have been derived through analysis of observations by Cees Bassa, Russell Eberst, David Hopkins, Marco Langbroek, Mike McCants, Brad Young, and myself. 20712A 569 X 580 km 1 99567U 20712A 20215.37143580 .00000592 00000-0 50000-4 0 07 2 99567 53.9762 208.3911 0007782 335.8979 24.1653 14.97640824 08 Arc 20200730.92-0802.4 WRMS resid 0.020 totl 0.011 xtrk 20712B 569 X 580 km 1 99568U 20712B 20215.37219574 .00000591 00000-0 50000-4 0 04 2 99568 53.9801 208.4150 0007764 331.4180 28.6390 14.97579140 04 Arc 20200730.92-0802.4 WRMS resid 0.019 totl 0.013 xtrk 20712C 570 X 580 km 1 99569U 20712C 20215.37353899 .00000264 00000-0 22418-4 0 03 2 99569 53.9759 208.3996 0006726 333.5641 26.5012 14.97459196 02 Arc 20200726.98-0801.92 WRMS resid 0.020 totl 0.014 xtrk 20712D 572 X 579 km 1 99570U 20712D 20215.37704080 .00000584 00000-0 50000-4 0 00 2 99570 53.9632 208.3939 0005000 332.2108 27.8621 14.97128365 00 Arc 20200801.92-0802.4 WRMS resid 0.003 totl 0.003 xtrk 20712E 573 X 579 km 1 99571U 20712E 20215.37762384 .00000584 00000-0 50000-4 0 02 2 99571 53.9738 208.4272 0004552 315.3101 44.7528 14.97097456 05 Arc 20200801.92-0802.4 WRMS resid 0.010 totl 0.008 xtrk Objects D and E arrived several seconds late last night, indicating that they have manoeuvred. Their preliminary post-manoeuvre elements show a reduction in the difference in their mean motion, perhaps an indication that they are entering into a permanent formation. Time will tell. The emerging consensus is that 20712C is the Minotaur 4th stage, based on optical characteristics. Additional evidence is found in the elements. The satellite deployments occurred shortly after orbital insertion, which was near apogee. First E, then D, appear to have separated in the direction of the velocity vector, which raised their perigee relative the 4th stage. It appears that the 4th stage rotated 180 deg before ejecting A and B, which lowered their perigee relative the 4th stage. There is precedent in the launch STPSat-2 and 5 other payloads, which were launched on a Minotaur IV: https://www.nasaspaceflight.com/2010/11/live-minotaur-launch-multiple-satellites/ "Once the fourth stage has burned out, payload separations will begin. STPSat-2, the primary payload, will be the first to separate and will do so sixteen minutes and thirty nine seconds into the mission. One minute later, RAX will be ejected from a PPod CubeSat dispenser at the rear of the fourth stage, followed a minute later by O/OREOS from another rear-mounted dispenser. About a minute after O/OREOS separates, the fourth stage will make a 180 degree turn, in order to deploy FASTSAT against the direction of flight. FASTSAT will separate two minutes later, and a minute after that the fourth stage will manoeuvre to an attitude offset from its direction of flight by 150 degrees, and aligned with the elevation of its velocity vector. Four minutes later, FalconSat-5 will separate from the rocket, followed five minutes later by both FASTRAC satellites, which will be deployed together as one spacecraft. Thirty seconds later the rocket will manoeuvre back to align with its direction of flight, and 150 seconds later the HAPS will separate from the fourth stage." Ted Molczan _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-lReceived on Sun Aug 02 2020 - 12:38:54 UTC
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