[Chaos-l] [Medoc-mountain-men] last night

[Alexey Toptygin]

On Sun, 23 Sep 2012, Robert Nielsen wrote:

> And I just looked at my planetarium program (SkySafari) and looked at 
> what was near that point in the sky at that time last Friday night.
>
> The geosynchronous orbit for satellites isn't very far from there, just 
> a little higher in the sky (between Albali and Sadalsuud or Beta 
> Aquarii).  So if one had malfunctioned and moved slightly, it could have 
> appeared in that area.  But there were also some satellites that were 
> supposed to be in that area itself (MSAT M1 and LES 9 or perhaps 
> INMARSAT 4-F3 or ICO G1). Given your description, it was moving the 
> right way, from Albali towards Deneb Algedi.  So I'm pretty sure it was 
> either a functioning satellite, or a piece of one.
>
> In fact, if I had to pick a particular satellite that matches your 
> description, I would pick AMC-14.  But there are lots of them in the 
> general area.

I don't think it can be in a geosynchronous orbit like the ones you 
mention are, because while it is in the right plane it was moving too 
slowly against the background stars. Geosynchronous sattellites by 
definition move at 15 degrees/hour, the same as the rotation rate of the 
earth, but this sattellite appeared to me to move only 3-4 degrees in the 
45 minutes that I was looking at it. Granted my timing measurement was 
very imprecise, so I can believe it was as fast as 7.75 degrees/hour, the 
rate that it would move if it was near the apogee of a GTO orbit (an orbit 
with apogee at the altitude of geosynchronous orbits and perigee close to 
the earth's surface); in this case it could be a discarded booster stage 
from a launch to geosynchronous orbit that was made before disposal of the 
booster became mandatory. I found an interesting set of slides about 
boosters like that here:

http://www.congrex.nl/11c01proceedings/Papers/2168175%20Finkleman.pdf

But my gut feeling is that my timing wasn't _that_ wrong, which means the 
apogee has to be higher than geosynchronous orbit (about 51000km as 
compared to the 42000km apogee of GEO/GTO). I don't know of any satellites 
that are intentionally launched that high.

 			Alexey