Bogus Mir elsets?

Ed Cannon (ecannon@mail.utexas.edu)
Sat, 01 Mar 1997 03:13:44 -0600

What's going on with the Mir elements tonight?  I had used elset #1 below 
to generate predictions for next week for my folks, and it yielded a 
Quicksat time error of .8 minute after only 9 days!  So I decided to go 
get the last 5 elsets from OIG.

SATNO = 16609
Element set number = 1
1 16609U 86017A   97059.07924160  .00056468  00000-0  66860-3 0   879
2 16609  51.6505 274.3828 0011764 122.9249 237.3208 15.60613928629999
Element set number = 2
1 16609U 86017A   97059.52748769  .00013719  00000-0  16818-3 0   889
2 16609  51.6502 272.1260 0011444 122.9987 237.2104 15.60596947630061
Element set number = 3
1 16609U 86017A   97058.82309409 -.00000282  00000-0  29824-5 0   846
2 16609  51.6538 275.6695 0011673 121.6731 238.5390 15.60578749629954
Element set number = 4
1 16609U 86017A   97058.82309432 -.00000281  00000-0  29820-5 0   858
2 16609  51.6477 275.6713 0011349 119.3726 240.8410 15.60579081629954
Element set number = 5
1 16609U 86017A   97058.88713023  .00001987  00000-0  29820-4 0   862
2 16609  51.6499 275.3530 0011703 120.8929 239.3100 15.60569345629960

Elset #1 above yielded these predictions:

  29.400  98.640  600.   San Antonio, Texas  2000  1.6 23 F F T T T
 
***  1997 Mar   9  Sun morning  *** Times are AM CST  ***  1920  610
 
 H  M  S  Tim Al Azi C Dir  Mag Dys F  Hgt Shd  Rng  EW Phs  R A   Dec
 
16609 Mir Complex    86 17A  32.7 4.2     360 1.2  -1.0 
 5 51 55   .8 25 181   303  -.3   9 6  244 122  515 1.9  81 1622 -35.7
 5 52 34   .8 33 162   292  -.8   9 7  244 150  416 2.2  94 1731 -25.2
 5 53 12   .8 39 132 C 271  -.8   9 7  243 175  374 2.1 113 1851  -8.9
 5 53 50   .8 34 101   250  -.1   9 7  243 195  407 1.5 130 20 8   8.3
 5 54 29   .8 26  81   238   .9   9 7  243 212  499 1.0 140 2111  20.0
 
Compare those with the following predictions, which are SEVERAL MINUTES 
later (as well as varying widely in time error, altitude and azimuth):

  29.400  98.640  600.   San Antonio, Texas  2000  1.6 23 F F T T T

***  1997 Mar   9  Sun morning  *** Times are AM CST  ***  1920  610

 H  M  S  Tim Al Azi C Dir  Mag Dys F  Hgt Shd  Rng  EW Phs  R A   Dec

16609 Mir Complex    86 17A  32.7 4.2     360 1.2  -1.0 
 5 57 23   .1 38 169   298 -1.1  10 7  245 159  381 2.5  89 1711 -22.0
 5 57 43   .1 43 153   287 -1.3  10 7  245 171  349 2.6  99 1753 -13.7
 5 58  2   .1 45 133 C 272 -1.2  10 7  245 183  336 2.4 109 1838  -4.0
 5 58 21   .1 44 112   256  -.9  10 7  245 193  344 2.1 119 1922   5.8
 5 58 41   .1 39  95   244  -.4  10 7  245 203  373 1.7 128 20 5  14.3
 
These predictions were produced by the following elset from the most 
recent (360.n21) molczan.tle:

Mir Complex     32.7  4.2  0.0  1.6 v
1 16609U 86017  A 97 58.50291158  .00002891  00000-0  34121-4 0   822
2 16609  51.6504 277.2794 0011316 120.0427 240.1665 15.60579821629905

This sort of thing could cause missed observations!  (After almost a year
at this, my inclination is to trust the half-day-older Molczan elset.)

Ed Cannon
Austin, Texas, USA
30.308N, 97.728W