Updated elements

From: Ted Molczan (ssl3molcz@rogers.com)
Date: Tue Oct 02 2012 - 17:24:55 UTC

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    Russell Eberst contributed the observations used to update the following element sets.
    NOSS 3-6 (A)                                           1009 X 1201 km
    1 38758U 12048A   12276.14811054  .00000000  00000-0  00000-0 0    01
    2 38758  63.4434 355.3764 0128473 179.6221 180.4923 13.40854523    05
    Arc 20121001.12-1002.16 WRMS resid 0.019 totl 0.008 xtrk
    NOSS 3-6 (P)                                           1010 X 1202 km
    1 38773U 12048P   12276.14777423  .00000000  00000-0  00000-0 0    09
    2 38773  63.4506 355.2433 0127740 179.1067 181.0210 13.40584005    04
    Arc 20121001.12-1002.16 WRMS resid 0.031 totl 0.020 xtrk
    Object 12048A has reduced its altitude to enable it to overtake 12048A, which raised its orbit very slightly. If they
    behave the same as the NOSS 3-5 pair, then once 12048A has moved ahead of 12048P by about 8 s, 12048P will lower its
    orbit to match the mean motion of 12048A. The above elements place this event early on 2012 Oct 04, perhaps about 04:00
    UTC. If the plan is for 12048P to remain the leader, then 12048A will make its manoeuvre on Oct 03, around 9 UTC.
    Once they have achieved the design along-track spacing, they will drift for some time, possibly months, then manoeuvre
    to synchronize with the current NOSS constellation mean motion, about 13.4061 rev/d. 
    In my previous report, I stated that 12048P had reduced its RAAN by 0.2 deg relative 12048A, but the above solutions
    reveal a smaller difference, less than 0.14 deg. Mike McCants has them less than 0.08 deg apart. Considering the
    shortness of the arcs and small number of observations, that could be within the margin of uncertainty. At this point, I
    am not certain what the RAAN difference is, but it probably is not close to 0.2 deg. All five previous NOSS 3 pairs
    operate with the RAAN of the leader 0.2 deg less than that of the follower. On the NOSS 3-5 mission, the eventual leader
    of the pair manoeuvred to decrease RAAN by 0.2 deg soon after the design along-track spacing had been achieved.
    Additional information about NOSS: http://www.satobs.org/noss.html
    Ted Molczan
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