"Pseudo-MPEC" for ExoMars1a = 2016-017C = NORAD 41390
Created 2016 Mar 17 13:04:00 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 ExoMars1a, and more than 0.20 degrees from ExoMars2a. So most likely, ExoMars1a is the fuel tank (which is the way I currently have things labelled). This seems really likely, though admittedly 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:
ExoMars1a TC2016 03 14.72567718 11 45.805-49 10 24.24 10.7 R 467
ExoMars1a TC2016 03 14.72592018 12 26.628-49 06 30.12 10.9 R 467
ExoMars1a TC2016 03 14.72627918 13 26.968-49 00 41.63 11.0 R 467
ExoMars1a tC2016 03 14.72628918 45 42.558-47 19 31.74 11.0 R Q64
ExoMars1a TC2016 03 14.72677718 14 49.917-48 52 37.50 11.0 R 467
ExoMars1a TC2016 03 14.72737818 16 30.305-48 42 43.72 10.9 R 467
ExoMars1a TC2016 03 14.72837418 19 15.966-48 26 04.83 11.7 R 467
ExoMars1a TC2016 03 14.73467018 36 36.784-46 31 53.76 10.5 R 467
ExoMars1a TC2016 03 14.73578118 39 37.964-46 10 15.50 9.9 R 467
ExoMars1a TC2016 03 14.73793418 45 30.335-45 26 36.20 10.6 R 467
ExoMars1a TC2016 03 14.73954318 49 53.516-44 52 36.63 10.4 R 467
ExoMars1a TC2016 03 14.74145318 55 03.468-44 10 59.61 10.8 R 467
ExoMars1a TC2016 03 14.74258718 58 08.401-43 45 20.32 9.7 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: ExoMars1a = 2016-017C = NORAD 41390
Perigee 2016 Mar 15.091746 +/- 0.000532 TT = 2:12:06 (JD 2457462.591746)
Epoch 2016 Mar 15.0 TT = JDT 2457462.5 Find_Orb
M 233.667264 +/- 0.8 (J2000 equatorial)
n1376.978110801 +/- 1.31 Peri. 99.530734 +/- 0.27
a 17271.05293 +/- 11 Node 323.774901 +/- 0.047
e 0.58946022 +/- 0.00219 Incl. 51.539559 +/- 0.027
P 376.47m H 26.9 G 0.15 U 12.9
q 7090.454266 +/- 34.8 Q 27451.65159 +/- 51.6
From 13 observations 2016 Mar. 14 (24.4 min); mean residual 5".563
Residuals in arcseconds: 160314 467 7.50+ 4.36+ 160314 467 4.02+ 2.39+ 160314 467 7.97+ 5.79+ 160314 467 7.84+ 4.69+ 160314 467 .340- .611- 160314 467 5.69- 4.31- 160314 467 9.21+ 5.52+ 160314 467 7.23+ 5.11+ 160314 467 2.93- 2.53- 160314 Q64 12.6- 8.09- 160314 467 2.37- 1.43- 160314 467 4.83+ 2.94+ 160314 467 0.99+ .937+ Ephemerides (geocentric): Date (UTC) HH RA Dec delta r elong mag " sig PA ---- -- -- -- ------------ ------------ ------ ------ ----- --- ---- --- 2016 03 14 00 20 13 35.947 -24 07 56.79 18296 0.9942 53.5 12?? 3091 42 2016 03 14 01 02 13 08.327 +49 36 32.75 7298 0.9942 62.0 10.0 492' 74 2016 03 14 02 11 34 34.814 -31 48 03.02 16609 0.9943 145.7 8.5 5449 134 2016 03 14 03 14 03 20.181 -49 08 45.80 24363 0.9943 119.5 10.1 1867 111 2016 03 14 04 16 09 46.848 -51 14 44.17 27351 0.9943 101.5 10.9 949 86 2016 03 14 05 17 58 53.155 -45 40 27.83 26212 0.9943 84.5 11.5 756 63 2016 03 14 06 19 41 38.335 -31 10 20.47 20707 0.9942 62.4 12.2 1537 44 2016 03 14 07 22 33 31.929 +17 13 57.48 9955 0.9943 25.2 15?? 196' 40 2016 03 14 08 10 42 11.266 -19 41 53.45 13482 0.9944 154.0 Sha 7216 140 2016 03 14 09 13 25 24.231 -46 39 49.77 22758 0.9944 125.6 9.8 1876 118 2016 03 14 10 15 36 56.487 -51 32 25.07 26951 0.9944 106.3 10.7 750 94 2016 03 14 11 17 30 21.040 -47 52 21.73 26934 0.9944 89.6 11.3 386 69 2016 03 14 12 19 12 23.350 -36 26 45.62 22705 0.9943 69.8 11.9 617 47 2016 03 14 13 21 20 36.901 -04 50 06.82 13384 0.9943 34.5 14?? 4034 37 2016 03 14 14 09 29 38.486 +01 53 29.64 10055 0.9944 147.8 Sha 178' 142 2016 03 14 15 12 45 40.386 -42 52 30.64 20772 0.9945 132.4 9.4 1929 125 2016 03 14 16 15 02 41.862 -51 15 05.49 26238 0.9945 111.3 10.5 573 103 2016 03 14 17 17 00 55.048 -49 32 44.56 27343 0.9944 94.5 11.2 89 86 2016 03 14 18 18 44 20.945 -40 32 54.59 24320 0.9944 76.2 11.7 31 169 2016 03 14 19 20 35 52.736 -17 57 43.29 16522 0.9944 47.7 13?? 1125 36 2016 03 14 20 06 45 15.429 +40 22 23.81 7339 0.9945 103.9 Sha 247' 125 2016 03 14 21 12 03 17.858 -37 10 26.79 18373 0.9946 140.3 8.9 2020 132 2016 03 14 22 14 27 02.092 -50 17 02.25 25202 0.9946 116.6 10.2 400 114 2016 03 14 23 16 30 19.957 -50 43 12.64 27445 0.9945 99.2 11.0 173 69