Re: ISS TLE's

Björn Gimle (b_gimle@algonet.se)
Sat, 28 Nov 1998 11:12:46 +0100

>That means that projected surface in v-direction changes permanently
>and this in turn causes the drag term to change. Interesting effect.
>
This wouldn't make it negative.=20
>2 25544  51.5893 148.2555 0056731  63.3832 297.2474 15.74087737   611
..
>1 25544U 98067A   98329.57169160 -.00146458  00000-0 -18619-2 0   398
>2 25544  51.5964 140.8358 0009347 223.7905 136.2350 15.59090576   841

The major cause is the MM decrease ( a raise of about 40 km)
Often, the USSPACECOM/OIG elsets show a negative drag, probably
because measurements before/during the maneuvre are included to
estimate drag factors.