"Pseudo-MPEC" for ExoMars2a = booster + spacecraft
Created 2016 Mar 17 13:04:58 UT using Find_Orb
This is astrometry for the ExoMars mission before going to heliocentric orbit. (467) and (Q64) tracked two objects in elliptical orbits, which I'm calling ExoMars1a and ExoMars2a. One of them is the combined ExoMars probe and booster that accelerated it into heliocentric orbit, and the other is a discarded fuel tank. But NORAD has now provided TLEs (two-line elements) for the fuel tank, which has received the designation 2016-017C = NORAD 41390. That TLE gives positions within 0.04 degrees of ExoMars1, and more than 0.20 degrees from ExoMars2. So most likely, ExoMars1 is the fuel tank (which is the way I currently have things labelled). This seems really likely, though not 100% certain.
The astrometry for ExoMars1a and ExoMars2a is better than it may seem. The problem is that the times for the (467) observations were recorded to the nearest second, and the objects were moving at about 21 arcseconds per second. So simply rounding the time to the nearest second could introduce up to 10.5 seconds of error. The "cross-track" residuals are all under half an arcsecond, bolstering the conclusion that we're really just seeing timing error here.
After the ExoMars spacecraft and booster accelerated and left the Earth/Moon system for Mars, they were also tracked, and links are provided to the data for those objects below.
Astrometry: ExoMars2a TC2016 03 14.72567718 10 55.687-49 14 27.17 11.5 R 467 ExoMars2a TC2016 03 14.72592018 11 36.471-49 10 35.02 11.6 R 467 ExoMars2a TC2016 03 14.72627918 12 36.699-49 04 49.40 11.5 R 467 ExoMars2a tC2016 03 14.72628918 44 55.903-47 24 25.54 11.3 R Q64 ExoMars2a tC2016 03 14.72648718 45 26.718-47 21 06.83 11.3 R Q64 ExoMars2a TC2016 03 14.72677718 13 59.485-48 56 49.49 11.4 R 467 ExoMars2a TC2016 03 14.72737818 15 39.699-48 47 00.48 11.5 R 467 ExoMars2a TC2016 03 14.72837418 18 25.047-48 30 29.20 12.9 R 467 ExoMars2a TC2016 03 14.73467018 35 43.908-46 37 16.93 11.9 R 467 ExoMars2a TC2016 03 14.73578118 38 44.759-46 15 50.10 11.5 R 467 ExoMars2a TC2016 03 14.73793418 44 36.473-45 32 32.32 11.4 R 467 ExoMars2a TC2016 03 14.73954318 48 59.147-44 58 49.83 11.4 R 467 ExoMars2a TC2016 03 14.74145318 54 08.442-44 17 34.62 10.9 R 467 ExoMars2a TC2016 03 14.74258718 57 12.917-43 52 08.87 11.5 R 467 Station data: (467) Auckland Observatory (S36.9079 E174.7766) New Zealand. Observer G. W. Christie. Measurers M. Micheli, G. W. Christie, K. Merz, D. Koschny. 0.40-m f/10 Schmidt-Cassegrain + CCD. (Q64) Siding Spring-LCOGT B (S31.27307 E149.07078) Australia/NSW. Observers A. Tripp, S. Roberts. Measurers M. Micheli, A. Tripp, K. Merz, D. Koschny. 1.0-m f/8 Ritchey-Chretien + CCD. Orbital elements: ExoMars2a = booster + spacecraft Perigee 2016 Mar 15.092507 +/- 0.000531 TT = 2:13:12 (JD 2457462.592507) Epoch 2016 Mar 15.0 TT = JDT 2457462.5 Find_Orb M 232.832057 +/- 0.8 (J2000 equatorial) n1374.678998696 +/- 1.33 Peri. 99.502374 +/- 0.28 a 17290.30446 +/- 11.2 Node 323.771407 +/- 0.048 e 0.58994151 +/- 0.00221 Incl. 51.540987 +/- 0.028 P 377.10m H 27.7 G 0.15 U 12.9 q 7090.036106 +/- 34.8 Q 27490.57282 +/- 52.9 From 14 observations 2016 Mar. 14 (24.4 min); mean residual 6".255
Residuals in arcseconds: 160314 467 9.77+ 5.62+ 160314 467 7.16+ 4.12+ 160314 467 1.59+ 1.34+ 160314 467 10.4+ 5.94+ 160314 467 6.36+ 3.78+ 160314 467 8.37+ 6.20+ 160314 467 11.7+ 6.83+ 160314 467 1.76+ 1.58+ 160314 467 5.92- 4.59- 160314 Q64 9.04- 5.65- 160314 467 7.99+ 5.67+ 160314 467 4.21- 3.34- 160314 Q64 8.35- 5.46- 160314 467 1.61- 1.40- Ephemerides (geocentric): Date (UTC) HH RA Dec delta r elong mag " sig PA ---- -- -- -- ------------ ------------ ------ ------ ----- --- ---- --- 2016 03 14 00 20 16 30.927 -23 24 34.10 18075 0.9942 52.7 13?? 3382 41 2016 03 14 01 02 51 07.131 +50 58 03.74 7198 0.9942 67.5 10.4 528' 81 2016 03 14 02 11 38 28.132 -32 33 52.51 16865 0.9943 144.9 9.4 5463 134 2016 03 14 03 14 06 04.133 -49 17 29.30 24503 0.9943 119.1 10.9 1905 110 2016 03 14 04 16 11 48.993 -51 12 33.67 27406 0.9943 101.2 11.8 985 85 2016 03 14 05 18 00 24.483 -45 32 14.75 26194 0.9943 84.2 12.3 804 62 2016 03 14 06 19 43 05.375 -30 52 33.64 20612 0.9942 62.1 13.1 1653 44 2016 03 14 07 22 38 34.783 +18 37 39.04 9795 0.9943 25.6 16?? 213' 40 2016 03 14 08 10 44 52.341 -20 25 00.52 13647 0.9944 153.8 Sha 7272 140 2016 03 14 09 13 26 52.858 -46 47 01.85 22858 0.9944 125.3 10.6 1913 118 2016 03 14 10 15 37 52.859 -51 32 27.88 27007 0.9944 106.2 11.6 772 93 2016 03 14 11 17 30 52.716 -47 50 14.38 26958 0.9944 89.5 12.2 407 69 2016 03 14 12 19 12 42.316 -36 23 34.05 22701 0.9943 69.8 12.8 656 47 2016 03 14 13 21 21 04.515 -04 41 14.28 13355 0.9943 34.4 15?? 4231 37 2016 03 14 14 09 30 29.490 +01 37 11.07 10091 0.9944 148.0 Sha 182' 142 2016 03 14 15 12 45 46.766 -42 53 25.72 20805 0.9945 132.4 10.2 1969 125 2016 03 14 16 15 02 26.543 -51 14 55.42 26271 0.9945 111.3 11.3 583 103 2016 03 14 17 17 00 23.748 -49 34 17.61 27385 0.9944 94.5 12.0 90 86 2016 03 14 18 18 43 38.769 -40 38 29.46 24379 0.9944 76.4 12.6 31 170 2016 03 14 19 20 34 45.474 -18 16 00.41 16612 0.9944 48.0 13?? 1135 36 2016 03 14 20 06 36 23.841 +41 31 27.65 7299 0.9945 102.1 Sha 255' 124 2016 03 14 21 12 01 49.879 -36 56 33.53 18307 0.9946 140.5 9.7 2070 132 2016 03 14 22 14 25 29.019 -50 13 36.84 25188 0.9946 116.8 11.1 401 114 2016 03 14 23 16 28 40.661 -50 46 12.94 27481 0.9945 99.5 11.8 186 70