Geostationary satellites
Philip Chien (kc4yer@amsat.org)
Mon, 18 Mar 1996 04:15:45 -0400
Greg Roberts <grr@da.saao.ac.za> said:
>I find the mail referring to geostationary satellite visual observations
>of great interest. For the past 20 years I have been observing these
>satellites using either a 30 inch or 20 inch reflector at our Sutherland
>observing outstation of the South African Astronomical Observatory.
<snip>
>Norad catalog numbers 19688,21139,22653,23331 and 23686 corresponding to
>ASTRA 1A,1B,1C,1D and 1E. Objects 19688 and 23331 appear to be the
>brightest and are suspected of being the two that merge every night. I
>suspect the faintest satellite is #22653. However I would imagine these
>satellites are all of similar if not identical size so the variations in
>brightness amongst them are due to reasons other than physical size.
Actually they are different models and do vary greatly in size.
Astra 1A is a GE-4000 spacececraft bus
Astra 1B is a GE-5000
Astras 1C through 1F (1F scheduled for launch in a couple of weeks on a
Proton) are based on the Hughes HS-601 bus.
There are different variations in the HS-601, and at least one Astra has
much larger solar panels than the others in the series.
The satellites are all basically box-shaped with fold-out solar wings in
the up/down direction, and two large circular antennas - one for
transmitting and one for receiving.
Philip Chien, Earth News - space writer and consultant PCHIEN@IDS.NET
__ __^__ __________
| \ +---/ \---+ (=========
|____\___________ +---\_____/---+ //
>____)| | \__ \ \______//___
>/ |________| \ [ _____\
>|____________________\ \_______/
Roger, go at throttle up CHR$(32) the final frontier