re: Raduga 33 not seen

Bjoern Gimle (
Sat, 24 Aug 1996 00:56:20 +0200 (MET DST)

Jim Varney wrote:

>The conclusion I come to after reading Spacetrack is that no prediction
>program based on SGP or SGP4 can handle high e / low p objects well.
>I'm not surprised now that Trakstar and Quicksat diverged. 
>Are there any programs out there that implement SGP8?  I'd be interested
>in playing with it.

So would I!

Thanks for your analysis. I raised a similar question when Interball 1
was new ( Interball 2 is due soon ) In that case, (high e, "high" p)
the answer probably is that SDP8 (or SDP4) should be used. I am not
sure if any known program does that, but what (still) surprises me
is that none of 4-5 programs that claim to use SGP4 agreed.
The differences where up to 40 minutes, and 5 degrees cross-track,
even after compensating for the time lapse, at 10000 km height !

I was not capable of finding it, using only a 7*50, so I was hoping 
someone with more powerful instruments would observe it, and help us
determine which program is reliable for this kind of orbit.

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