Corrected STS 107 Two-line Orbital Elements

Most of the elements on this page are corrected versions of those originally issued by NASA/OIG. Many of the originals have unrealistic decay terms - generally too low - especially during Jan 19-27, when decay terms typically were one half to one third their correct values.

The errors most likely are due to imprecise conversion from the sophisticated orbital model used to track and navigate the shuttle, to the much simpler SGP4 model underlying the 2-line orbital elements; therefore, they would not have had any impact on STS 107, but do need to be considered by third parties.

The least accurate of the original elements result in a prediction time error of about 8 s, one day after the epoch; 30 s after two days; and more than 1 min after three days. The corrected decay terms reduce these errors by about 90 percent.

Ted Molczan corrected the ndot/2 and B* decay terms to more realistic values. The corrected ndot/2 is one half the slope of the linear regression of mean motion against epoch. The regression typically was performed on about 5 element sets, spanning about a one day arc, roughly centred on the epoch of the elset to be corrected. Coefficient of determination, r^2, typically was close to 0.95.

The corrected B* was estimated from the corrected ndot/2, using a formula derived by Molczan.

The decay rate of elements issued soon after launch has not been corrected, because they span too short an arc to analyze with confidence, and because the elements may not have settled down to realistic values. The decay rate of the elements of epoch 03021.88472222 has not been corrected, because of their completely erroneous RAAN.

The decay rate of the elements of epoch 03023.13938657 also has not been corrected, because they appear to be erroneous; they suggest a manoeuvre to a higher orbit, but subsequent elements disagree. Such errors are not unusual among 2-line elements.

To avoid the corrected elements becoming confused for the offical elements, they bear a dummy catalogue number (70000) and no international designation.

The meaning and format of the 2-line orbital elements is explained here.

1 27647U 03003A   03016.64683704  .00000000  00000-0  00000-0 0    14
2 27647  39.0169 229.2417 0012696 352.7112   7.4097 15.97530540    04

1 27647U 03003A   03016.68225256  .00003946  53936-5  12004-4 0    16
2 27647  39.0143 229.0079 0012750 352.8980 211.2024 15.97522778    02

1 27647U 03003A   03016.77184272  .00000011  00000-0  23134-7 0    27
2 27647  39.0155 228.4112 0011670 352.4999   7.6176 15.97484470    25

1 27647U 03003A   03016.91666667  .00054847  65730-5  12014-3 0    41
2 27647  39.0161 227.4537 0012387 351.4208 122.8318 15.97536570    49

1 27647U 03003A   03017.25000000  .00054621  65661-5  11929-3 0    50
2 27647  39.0167 225.2307 0012713 353.9884 240.2008 15.97583932    96

1 70000U          03017.33503472  .00068256  00000-0  14405-3 0    79
2 70000  39.0160 224.6631 0012452 356.0600   7.9315 15.97593448   107

1 70000U          03017.58333333  .00062299  00000-0  13125-3 0    94
2 70000  39.0149 223.0048 0012360 355.7135 358.5111 15.97626761   144

1 70000U          03017.91666667  .00066557  00000-0  13986-3 0   108
2 70000  39.0169 220.7872 0012322 359.5348 114.7574 15.97673882   197

1 70000U          03018.25000000  .00068057  00000-0  14274-3 0   129
2 70000  39.0161 218.5631 0012449   1.9742 232.4243 15.97705154   248

1 70000U          03018.58333333  .00070822  00000-0  14815-3 0   138
2 70000  39.0133 216.3335 0011875   4.3438 350.2564 15.97764745   308

1 70000U          03018.91666667  .00070822  00000-0  14777-3 0   142
2 70000  39.0152 214.1161 0011997   8.1414 106.6913 15.97808187   358

1 70000U          03019.25000000  .00075495  00000-0  15704-3 0   156
2 70000  39.0165 211.8944 0012187  10.7063 224.4093 15.97858440   407

1 70000U          03019.58333333  .00197261  00000-0  40635-3 0   168
2 70000  39.0138 209.6653 0011722  14.6597 340.8914 15.98042145   467

1 70000U          03019.91666667  .00198278  00000-0  40350-3 0   178
2 70000  39.0153 207.4484 0011753  18.6024  97.6665 15.98257209   510

1 70000U          03020.58333333  .00182662  00000-0  36880-3 0   188
2 70000  39.0142 202.9932 0011031  25.0418 332.9930 15.98413253   629

1 70000U          03020.91666667  .00183057  00000-0  36679-3 0   190
2 70000  39.0151 200.7739 0010853  29.2311  89.8564 15.98551741   670

1 70000U          03021.25000000  .00232524  00000-0  46199-3 0   205
2 70000  39.0177 198.5463 0010919  30.2299 210.1596 15.98699125   725

1 70000U          03021.58333333  .00203464  00000-0  40054-3 0   237
2 70000  39.0150 196.3161 0010641  34.4432 327.4057 15.98867113   788

1 27647U 03003A   03021.88472222  .00061450  69206-5  12476-3 0   216
2 27647  39.0150 305.1132 0010641  34.4432 327.4057 15.98867113   820

1 70000U          03021.91666667  .00213046  00000-0  41552-3 0   256
2 70000  39.0152 194.0946 0010629  38.2905  85.1745 15.99030647   832

1 70000U          03022.25000000  .00114512  00000-0  22139-3 0   266
2 70000  39.0183 191.8655 0010774  39.3027 206.0050 15.99181374   888

1 70000U          03022.58333333  .00121966  00000-0  23504-3 0   280
2 70000  39.0164 189.6316 0010349  44.8390 322.4470 15.99247182   944

1 70000U          03022.91666667  .00114512  00000-0  21948-3 0   296
2 70000  39.0164 187.4117 0010771  46.9330  82.4006 15.99332732   994

1 27647U 03003A   03023.13938657 -.00041453  59924-5 -76813-4 0   300
2 27647  39.0009 185.9559 0009515  50.4960 283.0279 15.99270825  1027

1 70000U          03023.25000000  .00145164  00000-0  27786-3 0   313
2 70000  39.0198 185.1824 0010531  47.7070 203.7036 15.99361520  1040

1 70000U          03023.58333333  .00180354  00000-0  34254-3 0   326
2 70000  39.0181 182.9490 0010131  53.3203 320.2998 15.99505912  1107

1 70000U          03023.91666667  .00203951  00000-0  38410-3 0   330
2 70000  39.0168 180.7267 0010521  54.3083  81.7080 15.99644473  1163

1 70000U          03024.25000000  .00183765  00000-0  34317-3 0   344
2 70000  39.0212 178.4953 0010487  57.4073 201.2606 15.99792437  1205

1 70000U          03024.58333333  .00175836  00000-0  32660-3 0   358
2 70000  39.0191 176.2618 0009888  62.5387 318.8176 15.99898093  1261

1 70000U          03024.85080602  .00111353  00000-0  20608-3 0   360
2 70000  39.0193 174.4765 0009693  60.7174  63.5232 15.99965312  1305

1 70000U          03024.91666667  .00126618  00000-0  23346-3 0   371
2 70000  39.0170 174.0377 0010253  62.6900  81.5207 16.00017748  1314

1 70000U          03025.25000000  .00160021  00000-0  29526-3 0   385
2 70000  39.0219 171.8059 0009658  68.1463 198.8724 16.00017976  1366

1 70000U          03025.52951389  .00166481  00000-0  30574-3 0   392
2 70000  39.0183 169.9354 0010025  71.2728   8.2436 16.00091785  1411

1 70000U          03025.58333333  .00186061  00000-0  33999-3 0   403
2 70000  39.0205 169.5730 0009334  76.4571 313.5805 16.00191933  1423

1 70000U          03025.91666667  .00181008  00000-0  32867-3 0   419
2 70000  39.0175 167.3476 0009757  75.8853  77.3447 16.00292745  1472

1 70000U          03026.25000000  .00197166  00000-0  35536-3 0   429
2 70000  39.0215 165.1161 0009303  78.6343 197.9428 16.00429896  1530

1 70000U          03026.58333333  .00206950  00000-0  37161-3 0   432
2 70000  39.0197 162.8803 0009250  89.2127 310.7427 16.00495152  1582

1 70000U          03026.91666667  .00189888  00000-0  33597-3 0   448
2 70000  39.0167 160.6524 0009301  88.6622  74.9412 16.00747948  1637

1 70000U          03027.25000000  .00185998  00000-0  32773-3 0   453
2 70000  39.0193 158.4178 0009060  92.2921 195.1280 16.00823552  1692

1 70000U          03027.58333333  .00118415  00000-0  20767-3 0   468
2 70000  39.0184 156.1829 0009369  99.7923 311.5781 16.00898656  1749

1 70000U          03027.78299251  .00118415  00000-0  20668-3 0   471
2 70000  39.0184 154.8450 0008940  99.7289  24.0962 16.00987862  1771

1 70000U          03027.91666667  .00048468  00000-0  84683-4 0   495
2 70000  39.0155 153.9527 0009451  98.6440  76.7487 16.00960614  1793

1 70000U          03028.25000000  .00048468  00000-0  84572-4 0   505
2 70000  39.0185 151.7164 0008975 103.0922 196.3708 16.00992267  1856

1 70000U          03028.58333333  .00048468  00000-0  84446-4 0   510
2 70000  39.0184 149.4847 0009267 110.3182 313.2464 16.01012192  1907

1 70000U          03028.82182454  .00056284  00000-0  97834-4 0   513
2 70000  39.0178 147.8897 0009270 110.4262 249.8073 16.01052275  1952

1 70000U          03028.91666667  .00060966  00000-0  10595-3 0   538
2 70000  39.0154 147.2544 0009194 108.5056  79.1935 16.01056794  1954

1 70000U          03029.25000000  .00058468  00000-0  10122-3 0   540
2 70000  39.0181 145.0181 0008868 113.6837 198.2353 16.01129397  2013

1 70000U          03029.91666667  .00054110  00000-0  93454-4 0   562
2 70000  39.0165 140.5537 0009128 119.7864  80.6426 16.01164488  2113

1 70000U          03030.25000000  .00050090  00000-0  86200-4 0   579
2 70000  39.0175 138.3186 0008887 124.8999 199.8904 16.01230509  2174

1 70000U          03030.58333333  .00063421  00000-0  10895-3 0   582
2 70000  39.0192 136.0861 0009733 129.8103 319.3549 16.01244440  2220

1 70000U          03030.91666667  .00058506  00000-0  10023-3 0   590
2 70000  39.0175 133.8526 0009498 129.8557  83.7393 16.01294859  2278

1 70000U          03031.25000000  .00063421  00000-0  10836-3 0   607
2 70000  39.0171 131.6143 0009349 134.5071 203.5906 16.01343716  2330

1 70000U          03031.58333333  .00082756  00000-0  14046-3 0   611
2 70000  39.0189 129.3811 0009380 140.9902 321.6925 16.01456723  2385

1 70000U          03031.91666667  .00177492  00000-0  29918-3 0   624
2 70000  39.0174 127.1480 0008759 140.2063  87.2128 16.01585528  2439

1 70000U          03032.25000000  .00179417  00000-0  29922-3 0   630
2 70000  39.0164 124.9099 0008781 145.1170 207.2382 16.01765594  2492

1 70000U          03032.53523148  .00179417  00000-0  29906-3 0   681
2 70000  39.0193 122.9937 0009207 143.3143  56.1711 16.01767039  2535