New observations have been reported by Tony Beresford, Russell Eberst and myself. Here are updated elements: NOSS 3-4 (A) 0.0 0.0 0.0 4.9 v 1 31701U 07027A 08055.40398441 .00000012 00000-0 20000-4 0 01 2 31701 63.4061 106.4521 0129778 148.0192 212.8793 13.41266933 02 Arc 2008 Feb 13.16 - 24.43, WRMS residuals = 0.019 deg NOSS 3-4 (C) 0.0 0.0 0.0 4.9 v 1 31708U 07027C 08055.40407689 .00000012 00000-0 20000-4 0 03 2 31708 63.4052 106.6473 0128266 147.8322 213.0611 13.41269129 02 Arc 2008 Feb 19.20 - 24.43, WRMS residuals = 0.015 deg The observational arc of 07027C is short; therefore, its elements may still be a bit rough, despite the low residuals. I fixed the value of inclination in the differential correction, in an effort to prevent the solution from straying too far from reality. At the epoch, C trailed A by 8 s at the ascending node, and the closing rate was nearly zero; therefore, the observed nominal separation for 3rd generation NOSS, about 8 s appears to have been achieved. Eventually, the pair will manoeuvre to synchronize their mean motion to that of the other operational NOSS groups, currently about 13.40515 rev/d. The NOSS 3-4 pair appear to have more or less completed their manoeuvres to compensate for the under-burn of the Centaur upper stage that inserted them into too low an orbit, during launch on 2007 June 15 UTC. Over the past 7 months, both spacecraft have made in excess of 50 corrective manoeuvres. Here is a plot of their manoeuvre history, expressed as the percentage of completion of the approximate required altitude-raising: http://www.satobs.org/seesat_ref/NOSS_3-4/NOSS_3-4_altitude_progress_3.pdf Additional information on the NOSS satellites is available here: http://www.satobs.org/noss.html Ted Molczan ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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