Re: Can we get them to fix AO-40 first then?
With all of the chatter lately in regards to HEO's (people putting their eggs in one basket with a hole in it) etc., it still brings up the point that even though the satellite doesn't work now, maybe it just "might" if the solar panels were attempted to be opened. I've received several emails in regards to that particular command & why it wouldn't work, but we will never know if AO-40 is in the proper attitude since it is off. If we could attempt to recover the satellite & just get SOME telemetry to see what's going on, we're in better shape than just letting it sit up there & "hope" the short goes away or that she "wakes up". Imagine if the "event" damaged a circuit by putting it to ground that is causing everything to short out, and moving a panel releases the short due to vibration! How many of you have hit your TV set to fix a jumpy screen? Or better yet, an analog meter to get the needle to move? Hopefully the transmitter comes back on the air sending telemetry once more if this could happen. It doesn't seem right that there's a battery up there that's only what, 2 years old, and it developed an internal short? I am by no means an aerospace expert, but I have batteries for my HT's that are older than that & still work fine. If this is what happened, I hope newer designs are including circuitry to prevent the total failure of the sat if this was to happen again. After the "event", there was talk about AO-40 possibly not being in one piece - was there a definite answer? I don't remember, nor did I check the archives.
My final thought on this is - if you can't get the receiver to decode commands, it's a loss, end of story. If it will receive, make it open the panels to get more power to the bird. Once the satellite is fully illuminated by the sun during its rotation, then try to work on stabilizing the satellite. Until that is tried, I personally feel that not every last attempt at reviving AO-40 has been attempted, and we could very possibly have an operating (although partially crippled) HEO in orbit. Besides, if the propellant is still there, what's to say it won't leak out between now & whenever she decides to "wake up"? Who's going to be able to control it in 20+ years? Won't it be useless to hams then too?
I'm not looking to start any heated arguments - this is all just my opinion. I haven't read every book there is on satellites, nor do I even remotely work close to the industry. I'm just an average ham who enjoys the sats from time to time, and would love to see someone "tinker" with AO-40 to get her back on the air!!!!!
73's... Larry N1MIW
...LEO's are satellites too!!!!!
Larry. (these are just my thoughts, and mine alone...I dont work with the "command team" or anything).
There is no doubt that AO-40 is spinning...radar and optical observation of it shows that. I also believe that it is "wobbling" as well (I cannot see how it would not be wobbling, I dont think that there is a nutation damper and with all the events that have occurred with it, well it would be hard to imagine it is not...and some observations would lead to that conclusion...)
If it is spinning and wobbling then opening the solar panels, if they could be opened would be dicey. Some vehicles in the past have been designed to open while spinning (Pioneer V for instance) but I would bet money that 40's are not. The first concern I would have is "would they stay on" followed quickly by what is going to happen to the attitude of the vehicle (since it cannot be controlled) as they open......things could get worse rapidly.
All that might be problematical as I doubt that anyone's "RF" is getting through.
Two things that I have read recently (like in the last week) surprise me.
The first is that apparently the command team had no real "QRH" (quick reference handbook) for either normal or abnormal or emergency situations. Layfolks call this a "checklist" and it is standard "stuff" on complex machines...for instance if the same situation were to happen in a transport category airplane the pilots would have "boldface items" which they would perform and then reference printed and thought out procedures.
OK QRH's take time to develop and all...but as a second thing.....I am kind of surprised that with all the events that happen to AO-40 someone didnt think that thhe battery might be a "problem area". Then game out what could/would happen as time moved on and have those procedures ready for the "command team". (as an aside I am surprised that the relay for the battery failed "closed" with a short or undervolt...I dont know what lead the designers to do this, it is required fare in airplanes that battery contractors with an undervolt fail open...)
Once it became clear that AO-40 was going to have a hard time transitioning to a three axis vehicle from a "spinner" and that with substantially less power from the arrays then expected. It surprised me that .someone didnt think long and hard as to what that would do to battery life and develop in place procedures for all the command team to execute with a drop in battery voltage.
All this and the problems at its birth point to a vehicle that was far to complex for the team to manage both in prep, normal and abnormal/emergency procedures.
There is in my view a better chance of AO-10 returning to life then 40...I bet you that vehicle looks like one of my classmates A-10 warthog after he tangled with a "zipper" (ZSU-23) ie it is probably full of holes.
As we say here in Texas, it lived hard and died young
(what do I do? I am a test pilot for the US government)
Robert WB5MZO
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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
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Rocky Jones