TLE

ISS (ZARYA)
1 25544U  98067A    06052.34767361   .00013949   00000-0  97127-4 0   3934
2 25544 051.6421 063.2734 0007415 308.6263 249.9177 15.74668600414901

The bundle of numbers above is called a TLE (Two-Line Element Set). A TLE is a two line file containing mostly orbit element data that computers read to enable the orbit propagation necessary to generate ephemerides for the satellite in question.

Scroll over or click on a number (highlighted by its colour) to determine what each of these numbers mean.

Sometimes, this file can be called the "Three-Line Element Set". In this case, there is a "Line 0" in which normally reserved for the common name of the satellite. This assists the user in cross-referencing the NASA catalogue number with the satellite's common name. Some orbit propagating software (like TheSky, by Software Bisque) requires the use of Three-Line Element Sets to work properly with the orbit element data. Many propagators take little or no notice of this line and can use two and three-line elements sets interchangeably.