[amsat-bb] Re: Can we get them to fix AO-40 first then?

[Peter Guelzow]

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-refractor-telescope/
>> 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 at hotmail.com> wrote:
>>   
>>     
>>> I think both those things are accurate.
>>>
>>> Robert WB5MZO
>>>
>>>     
>>>       
>>>> Date: Wed, 14 Oct 2009 21:31:30 -0400
>>>> From: mat_62 at netcommander.com
>>>> To: amsat-bb at 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
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>>   
>>     
>
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