[amsat-bb] Working TLE set for Sputnik 1

andy thomas andythomasmail at yahoo.co.uk
Sat Sep 29 08:15:07 PDT 2007


The TLE set for Sputnik-1 below works in STS+ when the
simulated date is set to 5 October 1957.

Please note the spacing is critical (takes me back to
the days of FORTRAN!!).

Thanks to John G7HIA for help and to Sil and Farrell
for encouragement.

For the record,, I varied the keps from those given in
Sil's reference on the amsat-bb  (they are the best I
have seen):

http://www.satobs.org/seesat/Aug-2007/0239.html

I then:

a) Accept the coefficient of drag taken from Gerhard
HOLTKAMP's observations

b) accept his model of Epoch time, Mean motion and
RAAN (they all fit together - so I have to accept his
epoch time as well)

c) Change to the RAE observed values of eccentricity,
argument of perigee and inclination, and calculate
mean motion by dividing the sidereal day in minutes
(1436 divided by by the RAE observation of the period)

d) calculate the checksum accordingly (John sent me in
the right direction here!)

My prediction programme STS+, which runs under good
old DOS, allows me to enter a Simulated Time. I MUST
set it to 5 October 1957 before running the prediction
or map features.

Please note I have written <CR> where there must be a
line break, you should not include the characters
"<CR>" when you prepare the text file for your
program. I can't speak for other prediction progarms,
just good ol' STS+

SPUTNIK 1<CR>
1 00002U 57001B   57277.80972234  .00352343  00000-0 
15670-2 0     0<CR>
2 00002  65.1000 339.9400 0520000 058.0000 334.6900
14.92723492     6<CR>

This is for the satellite not the rocket.

Many thanks to all for help and encouragement. Let's
see how she works!

73 de andy G0SFJ




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