ISS Elsets

Mir16609@aol.com
Mon, 3 May 1999 22:15:31 EDT

Here are the last 5 for the ISS:

ISS             20.0  4.0  0.0  1.0 d            389 x 382
1 25544U 98067A   99123.88537204 -.00004731  00000-0 -49965-4 0  5407
2 25544  51.5937  61.0365 0005292  61.9733 298.1784 15.60548296 25686
ISS             20.0  4.0  0.0  1.0 d            389 x 382
1 25544U 98067A   99123.43711243 -.00041328  00000-0 -48721-3 0  5394
2 25544  51.5945  63.2947 0005100  67.8395 292.3099 15.60530968 25617
ISS             20.0  4.0  0.0  1.0 d            390 x 382
1 25544U 98067A   99122.79673654  .00017573  00000-0  21456-3 0  5383
2 25544  51.5935  66.5165 0005553  64.5313 295.6239 15.60525188 25519
ISS             20.0  4.0  0.0  1.0 d            390 x 382
1 25544U 98067A   99121.83615349  .00017628  00000-0  21550-3 0  5379
2 25544  51.5932  71.3570 0005543  60.7103 299.4420 15.60490912 25367
ISS             20.0  4.0  0.0  1.0 d            390 x 382
1 25544U 98067A   99121.13171392  .00017302  00000-0  21186-3 0  5360
2 25544  51.5927  74.9066 0005522  58.0183 302.1353 15.60464083 25250

The drag term in the 2 most recent elsets are negative (-.00004731,  
-.00041328)  .  I associate this (in my own mind, anyway) as an orbit boost, 
yet the apogee and perigee remain essentially unchanged.  What causes the 
drag term to go negative? 

Cheers
Don Gardner  39.1796 N, 76.8419 W, 34m ASL
Homepage: http://hometown.aol.com/mir16609/
Space Day - 6 May 1999; http://www.spaceday.com/