Re: Can we get them to fix AO-40 first then?
I would want to take the "chance" of trying to open those 4 solar panels, even if it was to "see what happens". I don't know the exact layout of the equipment on board, but opening those panels just might trigger something good to happen. At this point, there really isn't anything to lose. Who knows? Opening the panels might expose the batteries to more heat from the sun, which could possibly cause them to "open" quicker, or if the orientation of AO-40 is off, the extra panels might receive enough light to get that IHU working again. Or if there's a short due to the "event", moving the panels may remove the short (or fix an open). Do any of the command stations want to elaborate on why the panels have remained retracted? Has this been discussed? Of course, this is all depending on if the receiver will accept the command in the first place...
I would wonder about the sensors picking up light inside the spacecraft too. Doesn't sound possible that telemetry would still be able to report this if there's holes in the craft.
I'm only questioning opening the panels because it seems like it's the only possible thing left to try to resurrect the bird, but nobody wants to make the decision - "just in case", which is understandable too. But I'd say go for it since there's nothing else to try & she's been silent for a while now.
Just my 2 cents worth. Keeping my fingers crossed that AO-40 comes back!... Larry
Four of the solar panels are retractable but not released. Please see some old pictures. As the orientation of AO-40 is not known it is better that the panels are kept around the satellite. If they still exists... There is enough power from a single panel to run IHU and some beacon if the bus wires and electronics are not damaged. Some sensors indicated that sun is shining into the satellite so there may be big hole(s) in it. Not sure about that raport though. Have to check out that. The beacons were loud with the omnis and data was easily received with rubber duck and hand held radio. Miss that fine telemetry sound.
I have allways said that the world would be different if AO-40 were alive.
Jari, OH3UW
The thing is, running the spacecraft with the panels open only works if the satellite is fully stabilized so that the panels continually point towards the sun. Stabilization only works if lots of things, pretty much everything in fact, is working on the spacecraft. I'd say that we've pretty much determined that is not the case.
Let's follow the first rule of medicine (and spacecraft management), and "do no harm", until something changes and we know more about what's going on up there. I, too, am anxiously awaiting that magic day when AO-07 gets a sibling.
Greg KO6TH
From: n1miw@cox.net To: amsat-bb@amsat.org Date: Mon, 12 Oct 2009 02:26:36 -0400 Subject: [amsat-bb] Re: Can we get them to fix AO-40 first then?
I would want to take the "chance" of trying to open those 4 solar panels, even if it was to "see what happens". I don't know the exact layout of the equipment on board, but opening those panels just might trigger something good to happen. At this point, there really isn't anything to lose. Who knows? Opening the panels might expose the batteries to more heat from the sun, which could possibly cause them to "open" quicker, or if the orientation of AO-40 is off, the extra panels might receive enough light to get that IHU working again. Or if there's a short due to the "event", moving the panels may remove the short (or fix an open). Do any of the command stations want to elaborate on why the panels have remained retracted? Has this been discussed? Of course, this is all depending on if the receiver will accept the command in the first place...
I would wonder about the sensors picking up light inside the spacecraft too. Doesn't sound possible that telemetry would still be able to report this if there's holes in the craft.
I'm only questioning opening the panels because it seems like it's the only possible thing left to try to resurrect the bird, but nobody wants to make the decision - "just in case", which is understandable too. But I'd say go for it since there's nothing else to try & she's been silent for a while now.
Just my 2 cents worth. Keeping my fingers crossed that AO-40 comes back!... Larry
Four of the solar panels are retractable but not released. Please see some old pictures. As the orientation of AO-40 is not known it is better that the panels are kept around the satellite. If they still exists... There is enough power from a single panel to run IHU and some beacon if the bus wires and electronics are not damaged. Some sensors indicated that sun is shining into the satellite so there may be big hole(s) in it. Not sure about that raport though. Have to check out that. The beacons were loud with the omnis and data was easily received with rubber duck and hand held radio. Miss that fine telemetry sound.
I have allways said that the world would be different if AO-40 were alive.
Jari, OH3UW
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Greg D. wrote:
The thing is, running the spacecraft with the panels open only works if the satellite is fully stabilized so that the panels continually point towards the sun. Stabilization only works if lots of things, pretty much everything in fact, is working on the spacecraft. I'd say that we've pretty much determined that is not the case.
Let's follow the first rule of medicine (and spacecraft management), and "do no harm", until something changes and we know more about what's going on up there. I, too, am anxiously awaiting that magic day when AO-07 gets a sibling.
Greg KO6TH
And taking Greg's analogy a bit further, imagine a comatose patient lying in his bed. Does the doctor stand at the bedside and scream at the patient, "Tell me what's wrong with you so I can treat you!!!" -- I don't think so. If that analogy seems too gruesome to you, then perhaps another one that many parents of small children have experienced first-hand will work. Your 3-year-old child wanders into the bathroom to investigate all the pretty things inside, and she pushes the door closed behind her. Then she plays with the doorknob and accidentally pushes the lock button. Parents frantically stand outside the locked bathroom door and plead with the child to please open the door, while imagining all the dangerous objects on the other side of the barrier, such as sharp scissors, scalding hair rollers, a large porcelain fixture full of water to drown in, etc. "Please open the door! Mommy and Daddy aren't mad! Please just open the door!" while the child on the other side has no idea what mommy and daddy are babbling about...
In case you miss my point, with essentially no power making it to the IHU or the receivers, how is the spacecraft supposed to "hear" a command to open the panels, or even if it heard the command, execute it with no electrical power?
Long before AO-40 went comatose (silent) for the last time, it had already been determined after long and careful deliberation that without the ability to properly steer the spacecraft attitude to keep the panels in the sun, they would do more good in the folded configuration, and so it was decided to NOT deploy them. There was some discussion on this point on the mail list. You could dig back through the archives to find that discussion if you were so inclined.
Indeed, it would be wonderful if the patient "woke up" from her long sleep like AO-7 did. There's no harm in wishing, even when the odds of success are so slim...
73 de WØJT
At 07:52 AM 10/12/2009, John P. Toscano wrote:
Indeed, it would be wonderful if the patient "woke up" from her long sleep like AO-7 did. There's no harm in wishing, even when the odds of success are so slim...
73 de WØJT _______________________________________________ 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
John,
I have had discussion on this topic with Drew and I believe that periodically commands are transmitted in the off chance that they might be received. I do not recall what band the command is on but I will soon have a very large L-band station (16-foot dish (34.5 dBi gain) and 300w at the feed) that could make some attempts with commanding. This is an eme station, of course. I hope to be QRV by December. I also wonder how good the Keps are for AO-40. My L-band beamwidth is only 2.5 deg.
73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com 500-KHz/CW, 144-MHz EME, 1296-MHz EME DUBUS Magazine USA Rep dubususa@hotmail.com ======================================
I hope to be QRV by December. I also
wonder how good the Keps are for AO-40. My L-band beamwidth is only 2.5 deg.
73, Ed - KL7UW, WD2XSH/45
BP40IQ 500 KHz - 10-GHz www.kl7uw.com 500-KHz/CW, 144-MHz EME, 1296-MHz EME DUBUS Magazine USA Rep dubususa@hotmail.com ======================================
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Ed. Norad/spacetrak keep pretty close tabs on just about everything including AO-40. I have classmates at large "tracking/radar" facilities and on "fun time" they have "pinged" the satellite...the keps are right on
Robert WB5MZO _________________________________________________________________ Hotmail: Powerful Free email with security by Microsoft. http://clk.atdmt.com/GBL/go/171222986/direct/01/
participants (5)
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Edward Cole -
Greg D. -
John P. Toscano -
Larry -
Rocky Jones