Two Line
Element Set Format
Example of a 2 line element set for the International Space Station:

1 25544U 98067A   18258.87806760  .00016717  00000-0  10270-3 0  9036
2 25544  51.6413 286.7600 0004466 162.8037 197.3268 15.53868139 12613
1 xxxxxu xxxxxaaa xxxxx.xxxxxxxx +.xxxxxxxx +xxxxx-x +xxxxx-x x xxxxx
2 xxxxx xxx.xxxx xxx.xxxx xxxxxxx xxx.xxxx xxx.xxxx xx.xxxxxxxxxxxxxx
Line 1
Line number of element data
Lines 03-07
Satellite number
Line 08
Classification (U=unclassified)
Lines 10-11
International Designator
(last two digits of launch year)
Lines 12-14
International Designator
(launch number of the year)
Lines 15-17
International Designator (piece of the launch)
Lines 19-20
Epoch Year (las two digits of year)
Lines 21-32
(day of the year & fractional portion of day)
Lines 34-43
First time derivative of the mean motion
Lines 45-52
Second time derivative of mean motion
(decimal point assumed)
Lines 54-61
BSTAR drag term
(decimal point assumed)
Line 63
Ephemeris type
Lines 65-68
Element number
Line 69
Checksum (Modulo 10) (Letter, blanks,
periods, plus signs = 0; minus signs = 1)
Line 01
Line number of element data
Lines 03-07
Satellite number
Lines 09-16
Inclination (degrees)
Lines 18-25
Right ascension of the ascending node
Lines 27-33
Eccentricity (decimal point assumed)
Lines 35-42
Argument of perigee (degrees)
Lines 44-51
Mean anomaly (degrees)
Lines 53-63
Mean motion (revolutions per day)
Lines 64-68
Revolution number at epoch (revolutions)
Line 69
Checksum (modulo 10)
Line 1
Line 2
A Two Line Element Set or (TLE) is a data format encoding a list of orbital elements of an Earth-orbiting object for a given point in time
.  Below is the designated format used by NASA and other organizations, as well as amateur satellite trackers to predict the
orbital elements of a man made satellite.