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