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Today's Topics:
1. Re: AMSAT Symposium News Posted to the Web (Ben Jackson)
2. Re: Can we get them to fix AO-40 first then? (Rocky Jones)
3. Re: Can we get them to fix AO-40 first then? (Rocky Jones)
4. Re: Can we get them to fix AO-40 first then? (Samudra Haque)
5. Re: Can we get them to fix AO-40 first then? (Rocky Jones)
6. Re: Can we get them to fix AO-40 first then? (Samudra Haque)
7. Re: Can we get them to fix AO-40 first then? (Rocky Jones)
8. Re: Passive Receive Antennas (Clint Bradford)
9. On the possibility of imaging AO-40 with earth bound
telescopes... (Mark VandeWettering)
10. Re: Can we get them to fix AO-40 first then? (Peter Guelzow)
11. Re: Can we get them to fix AO-40 first then? (Peter Guelzow)
12. Subject: It's on! (Road trip to FN56, FN57, FN66, FN67,
etc.) (Richard Crow)
13. Hudsonvalley Satcon Group Net Tonight On Echolink N2EYH-L
Oct.15 (Cotejaune2@xxx.xxxx
14. Re: Passive Receive Antennas (Nigel Gunn G8IFF/W8IFF)
15. Re: On the possibility of imaging AO-40 with earth bound
telescopes... (Tim - N3TL)
----------------------------------------------------------------------
Message: 1
Date: Wed, 14 Oct 2009 21:31:10 -0400
From: Ben Jackson <bbj@xxxxxxxx.xxx>
Subject: [amsat-bb] Re: AMSAT Symposium News Posted to the Web
To: "Sanford, Fred" <fred.sanford@xxx.xxxxxxxx.xxx>
Cc: 'Amsat BB' <amsat-bb@xxxxx.xxx>, "'n3tl@xxxxxxxxx.xxxxx
<n3tl@xxxxxxxxx.xxx>
Message-ID: <4AD67B5E.60704@xxxxxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Sanford, Fred wrote:
> I hope that AMSAT NA does not use an 70cm uplink, because that band
> is not available for transmitting in all areas of the US. I live
> near Cape Cod, MA and 70cm is not available for transmitting because
> of PAVE PAWS.
Hi Fred:
I don't think PAVE PAWS prohibits transmission, it only affected
repeater operation. At least I haven't heard anything regarding that,
and I was fairly active on 70cm until last Monday when W1WNS/R was PAVE
PAWSed.
~Ben
--
Ben Jackson - N1WBV - New Bedford, MA
bbj <at> innismir.net - http://www.innismir.net/
------------------------------
Message: 2
Date: Wed, 14 Oct 2009 20:43:34 -0500
From: Rocky Jones <orbitjet@xxxxxxx.xxx>
Subject: [amsat-bb] Re: Can we get them to fix AO-40 first then?
To: <n1miw@xxx.xxx>, Amsat BB <amsat-bb@xxxxx.xxx>
Message-ID: <COL106-W35B6F56B0791328E34B34AD6C50@xxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
Larry...
to add a few things to my post (and I admit this is speculation, someone
from the command team can shoot me down at anytime).
As a spinner -40 was in trouble power wise. I "dont know" but wonder if how
the "arrays" were folded they would produce power while folded? If not then
the vehicle was seriously out of power (I probably knew this at one point,
but it was a bit ago). Spinners (like the Pioneer 6-9 Venus Pioneer and a
lot of the communications satellites) are "sized" so that the part of the
array viewing the sun is enough to power the spacecraft without the battery.
The batteries are only used for eclipse periods (which on geo's are very
short). (as an aside I dug out my Pioneer 6-9 technical information and the
battery was designed to automatically disconnect with an undervolt...that is
one reason the probes are very long lived).
I bet you that in the spinner mode with the arrays folded -40 could only use
"some" (One?) of its array sides. That meant that for some part of the
"spin" the battery was discharging, then had to be recharged as the spin
continued then discharged etc. I bet the battery and the associated
circuitry were never designed for that.
If -40 were to "open" the battery, I wonder if there would be enough power
from whatever arrays are left to power the receivers (much less the
transmitters) during the complete spin cycle. IE without a battery I wonder
as the vehicle spun if the receiver(s) would stay powered long enough to
decode a command?
If the aux battery isnt any good and the vehicle is left in spin mode, the
next question would be (if they could get the command link up) is there
enough solar exposure to operate anything? (without a battery?)
It has been years ago (decades) so I have forgotten most of it, but when
they tried to reactivate Skylab before its doom...they had a similar
problem with keeping the command recievers powered long enough to orient the
arrays with thrusters and gyros.. As I recall they beat that by endlessly
sending commands...and eventually they got the solar arrays oriented for
real power.
In other words my speculation would be that -40 is useless without some type
of battery, as a spinner. I bet it is not much on three axis either since
the arrays probably do not articulate...
As I said in my previous post...the more I think about it (and its all
speculation) the less likely I think AO-40 will do a "Seven"
Robert WB5MZO
_________________________________________________________________
Hotmail: Free, trusted and rich email service.
http://clk.atdmt.com/GBL/go/171222984/direct/01/
------------------------------
Message: 3
Date: Wed, 14 Oct 2009 20:49:52 -0500
From: Rocky Jones <orbitjet@xxxxxxx.xxx>
Subject: [amsat-bb] Re: Can we get them to fix AO-40 first then?
To: <mat_62@xxxxxxxxxxxx.xxx>, Amsat BB <amsat-bb@xxxxx.xxx>
Message-ID: <COL106-W55EF098FB8119B5574EF5BD6C50@xxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
I think both those things are accurate.
Robert WB5MZO
> Date: Wed, 14 Oct 2009 21:31:30 -0400
> From: mat_62@xxxxxxxxxxxx.xxx
> To: amsat-bb@xxxxx.xxx
> 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@xxxxx.xxx. 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/
------------------------------
Message: 4
Date: Wed, 14 Oct 2009 22:08:22 -0400
From: Samudra Haque <samudra.haque@xxxxx.xxx>
Subject: [amsat-bb] Re: Can we get them to fix AO-40 first then?
To: Rocky Jones <orbitjet@xxxxxxx.xxx>
Cc: Amsat BB <amsat-bb@xxxxx.xxx>
Message-ID:
<d8c724880910141908j4775134brb77ef43e478058a7@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
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-refrac
tor-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@xxxxxxx.xxx> wrote:
>
> I think both those things are accurate.
>
> Robert WB5MZO
>
>> Date: Wed, 14 Oct 2009 21:31:30 -0400
>> From: mat_62@xxxxxxxxxxxx.xxx
>> To: amsat-bb@xxxxx.xxx
>> 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@xxxxx.xxx. 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@xxxxx.xxx. 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
>
------------------------------
Message: 5
Date: Wed, 14 Oct 2009 21:29:46 -0500
From: Rocky Jones <orbitjet@xxxxxxx.xxx>
Subject: [amsat-bb] Re: Can we get them to fix AO-40 first then?
To: <samudra.haque@xxxxx.xxx>
Cc: Amsat BB <amsat-bb@xxxxx.xxx>
Message-ID: <COL106-W566B2636DA7B44AE573C4BD6C50@xxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
The "national intellegence assets" which would be needed to get an image of
AO-40 that "showed things" are probably there...but if you see the pictures
they have to kill you (grin).
I know amateurs who have imaged -40 and done so enough to measure the light
curve from it.
Robert WB5MZO
_________________________________________________________________
Your E-mail and More On-the-Go. Get Windows Live Hotmail Free.
http://clk.atdmt.com/GBL/go/171222985/direct/01/
------------------------------
Message: 6
Date: Wed, 14 Oct 2009 22:39:42 -0400
From: Samudra Haque <samudra.haque@xxxxx.xxx>
Subject: [amsat-bb] Re: Can we get them to fix AO-40 first then?
To: Rocky Jones <orbitjet@xxxxxxx.xxx>
Cc: Amsat BB <amsat-bb@xxxxx.xxx>
Message-ID:
<d8c724880910141939q27745f7ese0e004fb68a915b5@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
There is no need for any specialised photo intelligence assets, simple
telescopes with enough F/D and gain will do, there are many amateur
astronomers who have imaged craters on the moon (e.g.., google
astrophotography) also see
http://www.footootjes.nl/Astrophotography_Lunar/Astrophotography_Lunar.html
Question is do we have any amateur astronomer who is also amsat enthusiast ?
On Wed, Oct 14, 2009 at 10:29 PM, Rocky Jones <orbitjet@xxxxxxx.xxx> wrote:
> The "national intellegence assets" which would be needed to get an image of
> AO-40 that "showed things" are probably there...but if you see the pictures
> they have to kill you (grin).
>
> I know amateurs who have imaged -40 and done so enough to measure the light
> curve from it.
>
Hope to hear from them if they are on the list..
------------------------------
Message: 7
Date: Wed, 14 Oct 2009 21:43:03 -0500
From: Rocky Jones <orbitjet@xxxxxxx.xxx>
Subject: [amsat-bb] Re: Can we get them to fix AO-40 first then?
To: <samudra.haque@xxxxx.xxx>
Cc: Amsat BB <amsat-bb@xxxxx.xxx>
Message-ID: <COL106-W3830E85EE917CE75A1929BD6C50@xxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
I bet that is not enough resolution
Robert WB5MZO
> From: samudra.haque@xxxxx.xxx
> Date: Wed, 14 Oct 2009 22:39:42 -0400
> Subject: Re: [amsat-bb] Re: Can we get them to fix AO-40 first then?
> To: orbitjet@xxxxxxx.xxx
> CC: mat_62@xxxxxxxxxxxx.xxxx amsat-bb@xxxxx.xxx
>
> There is no need for any specialised photo intelligence assets, simple
> telescopes with enough F/D and gain will do, there are many amateur
> astronomers who have imaged craters on the moon (e.g.., google
> astrophotography) also see
> http://www.footootjes.nl/Astrophotography_Lunar/Astrophotography_Lunar.html
>
> Question is do we have any amateur astronomer who is also amsat enthusiast ?
>
> On Wed, Oct 14, 2009 at 10:29 PM, Rocky Jones <orbitjet@xxxxxxx.xxx> wrote:
> > The "national intellegence assets" which would be needed to get an image
of
> > AO-40 that "showed things" are probably there...but if you see the
pictures
> > they have to kill you (grin).
>
>
> >
> > I know amateurs who have imaged -40 and done so enough to measure the
light
> > curve from it.
> >
> Hope to hear from them if they are on the list..
_________________________________________________________________
Hotmail: Free, trusted and rich email service.
http://clk.atdmt.com/GBL/go/171222984/direct/01/
------------------------------
Message: 8
Date: Wed, 14 Oct 2009 22:57:26 -0700
From: Clint Bradford <clintbrad4d@xxxxxxxxx.xxx>
Subject: [amsat-bb] Re: Passive Receive Antennas
To: amsat-bb@xxxxx.xxx
Message-ID: <00E53FD2-348D-4A07-9173-46008459981A@xxxxxxxxx.xxx>
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
>> ... Has anyone ever heard of a passive loop antenna indoors? About
36" square and quite good for receive...
For receive only on that unit, just string a long wire high 'round the
room.
Sony made one - the AN-LP1. But for my clients, a long wire worked
just as well. AGAIN - FOR RECEIVERS ONLY.
Clint, K6LCS
http://www.work-sat.com
------------------------------
Message: 9
Date: Wed, 14 Oct 2009 23:57:40 -0700
From: Mark VandeWettering <kf6kyi@xxxxx.xxx>
Subject: [amsat-bb] On the possibility of imaging AO-40 with earth
bound telescopes...
To: amsat-bb@xxxxx.xxx
Message-ID:
<d8eb7a910910142357x40cc9312u89d865b653f3fbe@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
> Has there been any serious attempt to take a photograph of the damaged
> bird using ground based optical telescopes while it is in sunlight ?
It's not going to work. AO-40 just isn't big enough. For fun,
let's worth through
some of the details.
> With modern telescopes such as
>
http://www.refractortelescopes.co.uk/reviews/orion/orion-shorttube-80-a-refrac
tor-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
Let's look at a couple of potential telescopes. The short tube
refractor that you linked to has an 80 mm (roughly 3 inch) aperature.
According to the Rayleigh criterion, that scope should be able to
resolve angles as small as about 1.5 arc seconds. At perigee, the
resolving power is 1042000 * tan(1.5 arc seconds), or about 7.5 meters
(or 25 feet). To increase the resolution by a factor of 2, you need
to to double the aperature. To get resolutions down to 1/2 a foot,
you need an aperature 50x larger, or 150 inches.
This doesn't take into account any effects of atmosphere either.
it's actually fairly rare to get sub arcsecond resolution from any
earthbound telescope without using adaptive optics. This limits the
practicality of high resolution imaging.
Impressive photos of the space shuttle, ISS and HST have been taken
using amateur equipment, but these objects are both closer and an
order of magnitude larger than AO-40. While we might be able to
measure spin rate and the like by measuring the brightness curve,
actual imaging of the satellite isn't likely.
73 Mark K6HX
------------------------------
Message: 10
Date: Thu, 15 Oct 2009 12:11:16 +0200
From: Peter Guelzow <peter.guelzow@xxxxxx.xx>
Subject: [amsat-bb] Re: Can we get them to fix AO-40 first then?
To: Samudra Haque <samudra.haque@xxxxx.xxx>
Cc: Amsat BB <amsat-bb@xxxxx.xxx>
Message-ID: <4AD6F544.2070605@xxxxxx.xx>
Content-Type: text/plain; charset=ISO-8859-1
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-refrac
tor-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@xxxxxxx.xxx> wrote:
>
>> I think both those things are accurate.
>>
>> Robert WB5MZO
>>
>>
>>> Date: Wed, 14 Oct 2009 21:31:30 -0400
>>> From: mat_62@xxxxxxxxxxxx.xxx
>>> To: amsat-bb@xxxxx.xxx
>>> 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@xxxxx.xxx. 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@xxxxx.xxx. 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@xxxxx.xxx. 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
>
>
------------------------------
Message: 11
Date: Thu, 15 Oct 2009 13:13:09 +0200
From: Peter Guelzow <peter.guelzow@xxxxxx.xx>
Subject: [amsat-bb] Re: Can we get them to fix AO-40 first then?
To: Samudra Haque <samudra.haque@xxxxx.xxx>
Cc: Amsat BB <amsat-bb@xxxxx.xxx>
Message-ID: <4AD703C5.9090507@xxxxxx.xx>
Content-Type: text/plain; charset=ISO-8859-1
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-refrac
tor-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@xxxxxxx.xxx> wrote:
>>
>>
>>> I think both those things are accurate.
>>>
>>> Robert WB5MZO
>>>
>>>
>>>
>>>> Date: Wed, 14 Oct 2009 21:31:30 -0400
>>>> From: mat_62@xxxxxxxxxxxx.xxx
>>>> To: amsat-bb@xxxxx.xxx
>>>> 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@xxxxx.xxx. 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
>>>>
>>>>
>>> _________________________________________________________________
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>> _______________________________________________
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>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
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------------------------------
Message: 12
Date: Thu, 15 Oct 2009 07:33:11 -0400
From: Richard Crow <rfcrow@xxxxxxxxx.xxx>
Subject: [amsat-bb] Subject: It's on! (Road trip to FN56, FN57, FN66,
FN67, etc.)
To: amsat-bb@xxxxx.xxx
Message-ID: <830a3cdfaabad29ea23db63d334d5c7e@xxxxxxxxx.xxx>
Content-Type: text/plain; charset=US-ASCII; format=flowed
Currently, the National Weather Service is forecasting sunny weather
for Saturday October 17th and Sunday October 18th in Caribou, Maine.
So Plan A, the N2SPI "grid-square DXpedition" to northern Maine, is on!
See schedule below.
====================================================
N2SPI's Planned Schedule for Saturday, October 17th:
Likely
AOS LOS Operating
Sat UTC UTC Grid Location Notes
----- ----- ----- ---- -------------- ---------
AO-51 12:02 12:14 FN53 Topsham, ME Note 2
AO-27 19:11 19:25 FN56 "OnTheRoad", ME
AO-51 21:38 21:52 FN66 Caribou, ME Note 2
AO-51 23:19 23:30 FN66 Caribou, ME Notes 2,3
====================================================
N2SPI's Planned Schedule for Sunday, October 18th:
Likely
AOS LOS Operating
Sat UTC UTC Grid Location Notes
----- ----- ----- ---- -------------- ---------
AO-51 11:21 11:34 FN67 Van Buren, ME Note 2
**** Note 4 **** Note 4 **** Note 4 **** Note 4
SO-50 15:10 15:19 FN57 Stockholm, ME
VO-52 15:49 16:00 FN56 New Sweden, ME Note 5
====================================================
Note 1: The AOS/LOS times are for my operating locations as indicated.
Note 2: I'll be using AO-51's 145.920 MHz_uplink/435.300 MHz_downlink.
Note 3: I'll work this nighttime pass only if I can find a suitable
location to work this in the dark.
Note 4: On the morning of October 18th, I may work other passes of
SO-50 and VO-52, as the opportunities present themselves.
Note 5: Look for my VO-52 downlink around 145.910 MHz, +/- Doppler.
====================================================
73,
Richard, N2SPI
------------------------------
Message: 13
Date: Thu, 15 Oct 2009 07:59:18 EDT
From: Cotejaune2@xxx.xxx
Subject: [amsat-bb] Hudsonvalley Satcon Group Net Tonight On Echolink
N2EYH-L Oct.15
To: amsat-bb@xxxxx.xxxx roi@xxxxxxxxx.xxx
Message-ID: <cbc.4d2a28e2.38086896@xxx.xxx>
Content-Type: text/plain; charset="US-ASCII"
Please join us tonight at 8PM ET for net. This is our second Net in our
fourth year. Share your satellite experience with the net. Hope
to hear you there.
73
Gary WA2AQH
------------------------------
Message: 14
Date: Thu, 15 Oct 2009 12:33:14 +0000
From: Nigel Gunn G8IFF/W8IFF <nigel@xxxxx.xxx>
Subject: [amsat-bb] Re: Passive Receive Antennas
To: Clint Bradford <clintbrad4d@xxxxxxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Message-ID: <4AD7168A.3060405@xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8; format=flowed
Aren't the majority of antennas passive?
You don't state the frequency.
A 36" square is (roughly) a half wabe on 2M. If "centre" fed, it's called a
squarelo.
Clint Bradford wrote:
> >> ... Has anyone ever heard of a passive loop antenna indoors? About
> 36" square and quite good for receive...
>
------------------------------
Message: 15
Date: Thu, 15 Oct 2009 05:57:59 -0700 (PDT)
From: Tim - N3TL <n3tl@xxxxxxxxx.xxx>
Subject: [amsat-bb] Re: On the possibility of imaging AO-40 with earth
bound telescopes...
To: k6hx@xxxx.xxxx amsat-bb@xxxxx.xxx
Message-ID: <645164.4099.qm@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=iso-8859-1
Please see Page 19 of the May-June 2008 issue of The AMSAT Journal.
Patrick Seitzer, WA4DSR, provided a photo of AO-40 taken by the University
of Michigan's Curtis-Schmidt Telescope at Cerro Tololo Inter-American
Observatory in Chile. Following is information from a University of Michigan
Web page about the telescope:
"The Curtis-Schmidt telescope is a 0.61 meter aperture f/3.5 Schmidt
telescope located at the Cerro Tololo Inter-American Observatory, about 500
km north of Santiago, Chile. This telescope was originally installed at the
University of Michigan's Portage Lake Observatory in 1950, and moved to the
much clearer skies of north central Chile in 1966.
It is named for Heber D. Curtis, Director of the University of Michigan
Observatories from 1930 until 1942.
The telescope is dedicated to optical studies of artificial space debris for
NASA's Orbital Debris Program Office at the Johnson Space Center. Projects
include optical surveys for debris and follow-up observations to determine
orbits and photometric properties of recently discovered debris."
?
If you find the Journal photo, you'll see a field with dozens of blurred
stars and one sharp litttle white dot, which is AO-40.? I believe it's safe
to say that obtaining an image with the detail necessary to try assess
damage is impossible.
?
73 to all,
Tim - N3TL
________________________________
From: Mark VandeWettering <kf6kyi@xxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Sent: Thursday, October 15, 2009 2:57:40 AM
Subject: [amsat-bb] On the possibility of imaging AO-40 with earth bound
telescopes...
> Has there been any serious attempt to take a photograph of the damaged
> bird using ground based optical telescopes while it is in sunlight ?
It's not going to work.? AO-40 just isn't big enough.? For fun,
let's worth through
some of the details.
> With modern telescopes such as
>
http://www.refractortelescopes.co.uk/reviews/orion/orion-shorttube-80-a-refrac
tor-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
Let's look at a couple of potential telescopes.? The short tube
refractor that you linked to has an 80 mm (roughly 3 inch) aperature.
According to the Rayleigh criterion, that scope should be able to
resolve angles as small as about 1.5 arc seconds.? ? At perigee, the
resolving power is 1042000 * tan(1.5 arc seconds), or about 7.5 meters
(or 25 feet).? ? To increase the resolution by a factor of 2, you need
to to double the? aperature.? To get resolutions down to 1/2 a foot,
you need an aperature 50x larger, or 150 inches.
This doesn't take into account any effects of atmosphere either.
it's actually fairly rare to get sub arcsecond resolution from any
earthbound telescope without using adaptive optics..? This limits the
practicality of high resolution imaging.
Impressive photos of the space shuttle, ISS and HST have been taken
using amateur equipment, but these objects are both closer and an
order of magnitude larger than AO-40.? While we might be able to
measure spin rate and the like by measuring the brightness curve,
actual imaging of the satellite isn't likely.
73 Mark K6HX
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------------------------------
_______________________________________________
Sent via amsat-bb@xxxxx.xxx. Opinions expressed are those of the author.
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End of AMSAT-BB Digest, Vol 4, Issue 540
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