Uuuupsss...
Just a short remark - "However, there is no reason to believe that the satellite disintegrated, since there are *now* other objects tracked around it."
Indeed I meant there are *no* other objects around AO-40 ;-)
Thanks to Graham for pointing this out...
73s Peter DB2OS
Peter Guelzow wrote:
Hi Samudra et all,
very interesting article and links you've sent out. So far, I did not heard about attempts to take photographs, at least not in the public. However, there is no reason to believe that the satellite disintegrated, since there are now other objects tracked around it.
The command stations regularly sent commands to AO-40 in the last years, but I guess with larger time between those attempts now. AO-40 was launched with the IHU "hot", that means: After separation and release of the safety/separation switch, the 24V power for the transmitter was switched ON and after some waiting time, the Beacon was commanded ON by the IHU (integrated housekeeping unit). The electronics were designed that way, if for example the IHU crashes, the I/O ports will remain in their last state and the transmitter would be kept on. However if there is a complete power loss (as we expect with the battery shortened), all Output ports will indeed reset to their default state, which is "all off"... (The BCR's default values normaly should still produce enough power) For this reason, the command stations prepared a small boot-block for the IHU to configure the BCR (battery charge regulator) and the Trasmitter status, for example S-band Beacon On. If this would be successful, command stations could start to reload the IHU, etc.. We also still plan to use our 20m dish in Bochum to uplink commands with high power or listen for some week signals.
73s Peter DB2OS
Samudra Haque wrote:
Has there been any serious attempt to take a photograph of the damaged bird using ground based optical telescopes while it is in sunlight ? With modern telescopes such as http://www.refractortelescopes.co.uk/reviews/orion/orion-shorttube-80-a-refr... or similiar and a modern digital camera and a known RA/DEC co-ordinate of the satellite at any point in its orbit, it should be possible get a fairly decent picture of what is still up there...
Note RA / DEC are astronomy co-ordinates which should be able to be calculated from AZ/EL or TLE, but I may not be able to do it myself.
We don't need to track it, but just to image it in several consecutive frames. From: http://www.emergentspace.com/pubs/AIAA_GNC_2002_AMSAT_A040.pdf
Table 1. Nominal Orbit Parameters for AO-40 Orbit Parameter Value Semimajor Axis (km) 36,245 Perigee Height (km) 1,042 Apogee Height (km) 58,691 Eccentricity 0.797 Inclination (deg) 6.04 Period (hours) 19.1
On Wed, Oct 14, 2009 at 9:49 PM, Rocky Jones orbitjet@hotmail.com wrote:
I think both those things are accurate.
Robert WB5MZO
Date: Wed, 14 Oct 2009 21:31:30 -0400 From: mat_62@netcommander.com To: amsat-bb@amsat.org Subject: [amsat-bb] Re: Can we get them to fix AO-40 first then?
I guess I need to go back and read the archives because what I remember reading didn't give me any hope AO-40 would ever be back. Wasn't there something about that they believed the spacecraft was leaking corrosive fuel? Doesn't sound to conducive to any type of recovery of anything where electronics are involved.. I also thought there was talk of a "catastrophic explosion". Michael, W4HIJ _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Hotmail: Powerful Free email with security by Microsoft. http://clk.atdmt.com/GBL/go/171222986/direct/01/ _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb