New observations have been reported recently by David Brierley and Russell Eberst. As David reported, 07027A remained bang on time this morning; 07027C, shows signs of a very small manoeuvre between Feb 19 and 24. Here are updated elements: NOSS 3-4 (A) 0.0 0.0 0.0 4.9 v 1 31701U 07027A 08060.17558750 .00000006 00000-0 10095-4 0 08 2 31701 63.4058 94.2756 0130340 148.3013 212.5944 13.41266969 08 Arc 2008 Feb 13.16 - 29.20, WRMS residuals = 0.022 deg NOSS 3-4 (C) 0.0 0.0 0.0 4.9 v 1 31708U 07027C 08060.17567822 .00000006 00000-0 10000-4 0 01 2 31708 63.4046 94.4659 0129343 147.8739 213.0251 13.41267934 06 Arc 2008 Feb 24.42 - 29.20, WRMS residuals = 0.021 deg At the epoch, C trailed A by 7.8 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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