Walter Nissen wrote: > PROGRESS M-45 oig > 1 26890U 01036A 01233.77072885 .00199884 25346-4 70872-3 0 56 > 2 26890 51.6382 118.5983 0014078 346.5632 91.3524 15.88457051 60 > > If a drag factor is too high, the object will arrive late. Hmm, it should exactly be the opposite in orbital motions. If an object loses height because of high drag, it travels faster and arrives sooner at your point of observation. Btw: Can someone explain how to derive the ballistic coefficient B (mass/(drag factor*cross-sectional area)) from the Bstar drag term in the 2line elsets? The Spacetrak report says something like: B=rho/(2*Bstar) with rho=2.461*10^-5 kg/m^2/Earth radii. But with the Progress TLE above (Bstar=0.70872*10^-3 in 1/Earth radii) I realy don't think that B=0.017.. kg/m^2 is right! The ballistic coefficient of a Progress freighter should be around 200 kg/m^2 in the worst case. Cheers, Sebastian ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Wed Aug 22 2001 - 13:52:08 PDT