Derek Breit, Russell Eberst, Kevin Fetter, Alberto Rango, Greg Roberts, Brad Young, and I, contributed observations used to determine one or more of the following element sets. Russell has discovered Helios 2B, trailing 2A by one half of a revolution. Soon after its launch in 2004, 2A manoeuvred to trail 1A by one half rev, which was maintained until day 09266, when 1A manoeuvred to decrease mean motion to 14.6004 rev/d, allowing 2A to catch-up. By day 09273, 1A resumed the standard mean motion, establishing the present spacing of 0.0188 d (28 percent of a rev). This clearly was in preparation for the launch of 2B, then less than three months away. I guessed that 2B would trail 1A by half a rev, but Russell's discovery reveals that it trails 2A by that amount. Helios 1A 675 X 680 km 1 23605U 95033A 10239.08915179 .00000127 00000-0 24323-4 0 02 2 23605 98.1136 173.4544 0003659 153.3293 206.8098 14.63841131 08 Arc 20100708.08-0827.11 WRMS resid 0.055 totl 0.019 xtrk Helios 2A 675 X 680 km 1 28492U 04049A 10239.10795028 .00000138 00000-0 26547-4 0 02 2 28492 98.1192 173.8900 0003583 31.4254 328.7162 14.63827744 08 Arc 20100724.09-0827.13 WRMS resid 0.028 totl 0.022 xtrk Helios 2B 676 X 680 km 1 36124U 09073A 10239.07282622 .00000000 00000-0 00000-0 0 02 2 36124 98.1220 173.9535 0003000 68.3825 291.7697 14.63824605 08 Arc 20100827.10 fit to single point The elements of 2B are preliminary, but should be accurate to within a few seconds per day since epoch. Helios 2B r 625 X 661 km 1 36125U 09073B 10239.05546938 .00000082 00000-0 12203-4 0 06 2 36125 98.0581 177.1281 0025623 331.1013 28.8775 14.74856750 01 Arc 20100822.13-0827.08 WRMS resid 0.039 totl 0.033 xtrk Alberto reported two new positions of X-37B OTV-1, and Kevin made a video, from which I extracted a couple more: 36514 10 015A 1775 G 20100827082311151 36 25 0413751-060286 28 S+033 05 36514 10 015A 1775 G 20100827082315656 36 25 0421390-055175 97 S+033 05 OTV-1 434 X 444 km 1 36514U 10015A 10239.33327521 -.00000880 00000-0 -19158-4 0 06 2 36514 39.9880 301.0482 0007547 32.7343 327.3931 15.43344492 08 Arc 20100822.1-0827.35 WRMS resid 0.027 totl 0.012 xtrk Ted Molczan _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l
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