October 2009 - AMSAT-BB - mailman.amsat.org

Re: Can we get them to fix AO-40 first then?
by Larry 17 Oct '09

17 Oct '09

Just out of curiosity, have any of the command stations tried to open the solar panels to give AO-40 another chance at life? I mean, if the "event" caused some damage to the satellite with the solar panels retracted, what's to say that opening the panels wouldn't possibly provide just enough power to the CPU to get some telemetry flowing (if the commands could be received, and the panels aren't damaged)? What else do we have to lose - she's been off for how many years now without any signs of coming back? If the command stations were to try something, might I suggest announcing a date first so the big stations ( if any are left) can possibly assist in listening for any type of signal? Just a thought I've had for some time now, and thought this might be an appropriate time / thread to finally say something. 73's ...Larry N1MIW

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OT: USB - RS-232 Adapter
by Josh Smith 17 Oct '09

17 Oct '09

Everyone, I know this is slightly (mostly??) off topic but I am in the market for a USB to RS-232 adapter for use with my radios (ft-897d and th-d7ag). My main requirement be that it works with Linux. Can any of you make a recommendation? Thanks, Josh Smith KD8HRX email/jabber: juicewvu(a)gmail.com phone: 304.237.9369(c)

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Re: Can we get them to fix AO-40 first then?
by Michael Tondee 17 Oct '09

17 Oct '09

Michael Tondee wrote: > Wow, interesting to see you admit you don't have a clue about > something Robert! Judging by the post I've been reading from you the > past few days, I thought you knew it all. > Michael, W4HIJ > Rocky Jones wrote: >> >> >>>> >>> On a more practical note, could there be some sort of failsafe "battery >>> went phut so disconnect it" device? I'm guessing a perfectly ordinary >>> inline fuse would be too simple, but perhaps some sort of mechanical >>> latch that would just pop the battery terminal if it lost power would >>> work. >>> >>> Gordon MM0YEQ >>> >>> _______________________________________________ >>> Sent via AMSAT-BB(a)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 >>> >> >> that is fairly common in many spacecraft (I have checked a few >> designs) and most transport category airplanes. I dont have a clue >> why it wasnt put into AO-40 >> >> Robert WB5MZO >> >> _________________________________________________________________ >> > >

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On the possibility of imaging AO-40 with earth bound telescopes...
by Mark VandeWettering 17 Oct '09

17 Oct '09

> 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-ref… > 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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Re: Why do hamsats? (Or anything else...)
by G0MRF＠aol.com 17 Oct '09

17 Oct '09

In a message dated 17/10/2009 04:37:16 GMT Standard Time, orbitjet(a)hotmail.com writes: I dont know how the "education" thing got into ham radio, but I imagine it is one of the virus that we got when we started interfacing with NASA for ham radio. There is no justification for human spaceflight (and I am not the only one that thinks that...the Augustine Commission agrees there is not) so NASA and its groupies try everything to justify it including "education". Ohhh. Who proded the troll again?

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AMSAT at Fort Wayne Hamfest
by Doug Kuitula 17 Oct '09

17 Oct '09

For those going to the Ft. Wayne, Ind. Hamfest, Nov. 14-15. There will be an AMSAT Forum on Sat. the 14th at 1:15pm. There is also an APRS forum on Sun. 15 Nov. at 10 am. More info can be found at: www.fortwaynehamfest.com 73 de Doug KA8QCU

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AO-51 in JOTA mode
by Andrew Glasbrenner 17 Oct '09

17 Oct '09

Jamboree on the Air repeater is now on, 145.88/435.15 @ 780 mw, JOTA QSOs only please! 145.92/435.3 is on for general use @ 450mw 73, Drew KO4MA

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What Are Others Using
by Joel Black 17 Oct '09

17 Oct '09

Years ago, when I first started operating the satellites, I used an IC-821. I "graduated" up to an FT-847. I don't ever remember using software to tune the rig (the IC-821 or FT-847) only software to steer the antennas. For the life of me, I cannot seem to find my downlink using the FT-847 and *any* tuning software with the linear birds (AO-7 and VO-52). It works fine with the "fixed" freq FM birds which, understandably, is easier for it to track. I am just wondering, does *anyone* use tuning software with the linear birds or do you just tune it manually? 73, Joel, W4JBB

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Re: Patrick on Saturday
by Clint Bradford 17 Oct '09

17 Oct '09

>> ... As for AO-51 in the evening - passes around 2318 and 0054 UTC ... I'll be working that 0053 GMT pass on the JOTA repeater pair from Victor Valley, CA. I'll try to move over to your repeater and have some kids talk to you! Clint, K6LCS http://www.work-sat.com

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Ares 1-X in highbay 3
by Joseph Armbruster 17 Oct '09

17 Oct '09

The subject of this email says it all. This is too incredible not to share with you all and an interesting look inside! http://nasatech.net/Ares1-Xmid091015/ Enjoy, Joseph Armbruster

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