An Atlas 5 rocket will launch MMS, the Magnetospheric Multi-Scale mission on March 13th, between 02:44 and 03:14UT, from CCAFS. The mission overview booklet shows that the Centaur upper stage will insert the payload into a 585x70169 km orbit inclined at 28.77 degrees, after the stack has coasted in a LEO orbit to the first ascending node. http://www.ulalaunch.com/uploads/docs/Mission_Booklets/AV/av_mms_mob.pdf Based on the time, latitude and longitude of the MECO-2 and MMS-1 separation events, I use the known perigee, apogee and inclination to fit the RA of the ascending node, argument of perigee and mean anomaly. The fit yield the following orbital elements, which are valid from MECO-2 to the MMS-1 separation: MMS GTO Coast (02:44UT launch) 1 84001U 15999A 15072.11388889 .00000000 00000-0 00000-0 0 00 2 84001 28.7700 29.0124 8332309 25.8172 339.9766 1.01758185 09 MMS GTO Coast (03:14UT launch) 1 84002U 15999A 15072.13472222 .00000000 00000-0 00000-0 0 08 2 84002 28.7700 36.5268 8332309 25.9621 340.0397 1.01758185 05 These elements span the start and end of the launch window. The payload consists of four identical spacecraft (MMS-1 to 4), which will be released in 5 minute intervals after insertion into the GTO type orbit. The following table gives the UTC timings from the mission overview, and the shadow entry and exit as per the elements. Event 84001 84002 ================================ Launch 02:44:00 03:14:00 MECO-2 04:02:11 04:32:11 MMS-4 sep 04:16:11 04:46:11 MMS-3 sep 04:21:11 04:51:11 MMS-2 sep 04:26:11 04:56:11 MMS-1 sep 04:31:11 05:01:11 -------------------------------- Shadow entry 04:36:14 04:57:11 Shadow exit 05:17:14 05:31:31 As of yet there are no broadcast warnings that suggest that the Centaur upper stage will be deorbited. This may mean it will be inserted into Solar orbit. For either possibility, it is expected that the Centaur will perform a Contamination and Collision Avoidance Maneuver (CCAM), followed by the dumping of the remaining fuel. The ground track from the mission overview shows that the separation of the payloads and the subsequent CCAM and fueldump should be visible from North America. Note though that the payloads and upper stage will enter the shadow around the times specified in the above table. Regards, Cees _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-lReceived on Tue Mar 10 2015 - 11:05:40 UTC
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