Russell Eberst's observations of 2007 Jul 27 UTC revealed that 07027A and C have raised their orbits again. Both were about 10 s late relative their epoch 07207.286 orbits. Recent manoeuvres have increased the orbital period between 3.6 and 4.2 s, averaging near 3.8 s. Here are their approximate new orbits, assuming a 3.8 s increase in period: NOSS 3-4 (A) 0.0 0.0 0.0 4.9 v 1 70001U 07208.02129679 .00000018 00000-0 20000-4 0 09 2 70001 63.3500 296.1195 0212300 149.6510 211.7019 13.60976000 07 NOSS 3-4 (C) 0.0 0.0 0.0 4.9 v 1 70002U 07208.02314820 .00000017 00000-0 20000-4 0 03 2 70002 63.3618 296.1414 0200300 150.3181 210.9399 13.61002000 05 Prediction time uncertainty will be about 5 s per 24 h since epoch. Observations of 07027B by Daniel, Lucille and Russell, result in the following improved elements: NOSS 3-4 r 0.0 0.0 0.0 5.0 v 1 31702U 07027B 07208.17709442 .00000023 00000-0 10000-4 0 03 2 31702 63.2474 285.2552 0145701 194.1648 165.5309 14.17698600 02 Arc 2007 Jul 24.23 - 27.19, WRMS residuals = 0.034 deg 1 31702U 07027B 07208.17710651 -.00000272 00000-0 -12072-3 0 05 2 31702 63.2835 285.2888 0140762 194.9531 164.7350 14.17700966 02 Arc 2007 Jun 15.73 - 27.19, WRMS residuals = 0.069 deg The longer arc demonstrates the close agreement between the recent observations and the data extracted from Babak A. Tafreshi's images of the propellant blow-down. I would not expect exact agreement, mainly because of: - approx 1 s uncertainty in times of the Tafreshi images - apparent effects of subsequent out-gassing on the orbit - perturbing effects of the Earth's odd zonal harmonics on eccentricity of orbits near 63.4 deg inclination Ted Molczan ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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