ATTENTION:

For space shuttle flights element sets are updated rather frequently. 
It is certainly possible to keep only the latest two-line element set
in the respective file, like 'sts-68.dat' for STS-68, that would 
contain only the following three lines:

STS-68
1 23285U 94062A   94280.68166896  .00019593  12460-4  96455-5 0   106
2 23285  56.9938  43.3425 0009162 269.6198  90.3824 16.25130079  1182

The author's policy is to keep all element sets that are distributed 
and to place them all in the respective file, as shown below. However, 
to insure that the most recent TLE set is being read by 'tlexgen' and 
'sattrack', that particular element set needs to be copied to the top 
of the file, as shown below: the first TLE set is therefore identical 
to the last one, in this case 'STS-68 F'. For reference see also 
'sattrack.doc' in the 'doc' directory. 

STS-68
1 23285U 94062A   94280.68166896  .00019593  12460-4  96455-5 0   106
2 23285  56.9938  43.3425 0009162 269.6198  90.3824 16.25130079  1182
STS-68 A
1 23285U 94062A   94273.71398473  .00126891  00000-0  63979-4 0    40
2 23285  57.0074  76.9956 0009327 267.4500  92.5492 16.19853975    52
STS-68 B
1 23285U 94 62  A 94274.82461727  .00202885  22808-3  11661-3 0    58
2 23285  57.0042  71.6434 0008860 272.7255  87.2792 16.20264410   233
STS-68 C
1 23285U 94 62  A 94276.12007817  .00177240  13808-4  93117-4 0    64
2 23285  57.0041  65.3969 0009364 282.2179  77.7835 16.20748183   445
STS-68 D
1 23285U 94 62  A 94276.67518413  .00136094  11322-4  71939-4 0    73
2 23285  57.0063  62.7154 0009256 276.8039  83.1971 16.20939096   537
STS-68 E
1 23285U 94062A   94279.63427997  .00194408  17535-4  92636-4 0    92
2 23285  56.9923  48.4133 0008893 293.0041  67.0089 16.22197025  1013
STS-68 F
1 23285U 94062A   94280.68166896  .00019593  12460-4  96455-5 0   106
2 23285  56.9938  43.3425 0009162 269.6198  90.3824 16.25130079  1182


Two-line element sets for space shuttle flights are also distributed 
by the U.S. Space Command. That means there is an entry for e.g. STS-68
in tle.dat, the file transferred from 'archive.afit.af.mil'. Program 
'tlexgen' will discard this entry and rather uses the first one from 
'sts-68.dat' if the 'sts-68.dat' is listed before 'tle.dat' in 
the input file 'tlelist.dat' in 'SatTrack/data', which is the input 
file for 'tlexgen'. If you rather want to use the U.S. Space Command 
data set, reverse the order of the file names listed in that input file. 
Remember to always run 'tlexgen' after any kind of change was made to 
these data files, in order to update the resource file 'tlex.dat'.

Typically, after a shuttle mission has been completed, the last TLE set is 
also saved in 'sts.dat'. 

