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Project Apollo Beta 7.0 released!
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Author Topic: LEM Panel Status Report  (Read 23326 times)
lassombra
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« Reply #30 on: December 16, 2007, 06:08:09 PM »

No, I'm not getting it confused.  It happened about halfway HOME after all the other drama and caused a decent stir in mission control.  Realistically it only had the effect of reducing the flow from that battery by about 25%. 

Apparently, because they were already running under budget on the LEM amps, it turned out to not be a problem, but it was occasionally triggering an alarm in the c/w system.

Strictly speaking, I'm not sure it's worth modeling, and I only know that it happened between 95 and 105 hours.  I could do some more research if anyone is truly interested, or we can just let it go.

EDIT: Ok, here's some more info I turned up:

at 97:13 Ground Elapsed Time, Fred Haise reported the "thump"

Haise: "I just heard a little thump, sounded like down in the descent stage, and I saw a new shower of snowflakes come up."

    [The thump and the venting were related to an apparent short circuit in the LM descent battery 2, this was not directly related to the CSM or to the accident.]

According to the book "Lost Moon" the problem was that the reaction in the batteries that provided the power gave off oxygen and hydrogen as byproducts.  Ordinarily the quantities of these would simply not be enough to do anything by the time the LEM left the moon.  On Apollo however, the LEM was being asked to provide more power and for longer than it's descent batteries had ever been designed to.  Enough pressure built up in battery 2 and caused the problem when a spark occurred.  It never totally crippled the battery, and since the LEM was actually designed to be able to run on 3 batteries (running on four for safety and backup), the problem was minimal.  What it DID mean was that battery 2 would trigger a master alarm quite frequently, and they had much narrower margins for amps.  It also caused the guys in mission control to start budgeting for 3 batteries in case battery 2 went out completely.  It also made them regret the partial power up and systems check of the CM they had done the previous day.

Some good info on Apollo 13 can be found here: http://myweb.accessus.net/~090/as13.html#toc

« Last Edit: December 16, 2007, 08:57:45 PM by lassombra » Logged

My current Project Apollo work:

Quickstart to the Moon initiative (Quickstart_to_the_Moon): Done through earth orbit.  Working on new method of calculating TLI.

Checklist Controller: 
  • MFD Interface 99%(Minor cleanup and future features remain)
  • Panel Interface 99%
  • Excel interface and logic 99%
  • LEM Event code.0%
  • DSKY Interface code. Framework complete, creating "buttons"
  Approximately 80% done. (Checklist Controller
jc121081
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« Reply #31 on: December 16, 2007, 09:08:01 PM »

Well, as the old saying goes, you sure do learn something new every day...
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NoName
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« Reply #32 on: December 16, 2007, 09:19:22 PM »

Well, it's hard to find information (within the original Apollo documents and Lunar Surface Journal) about an exploding LEM battery. So I'm not sure if it's really something of significance, if it really should have happened. The only information I got is about several master alarms and caution lights concerning LEM battery 2. It is mentioned (in the Apollo 13 mission report) that the alarms were caused by a sensor and that the master alarm circuit breaker was opened to prevent recurring alarms. So, I'm a little bit confused now.

But of course, for maximum realism we could simulate all that detailed stuff, if you would like to work on it Wink It's up to you... Happy  
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lassombra
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« Reply #33 on: December 17, 2007, 12:23:10 AM »

Well, as I said, according to the book by Jim Lovell the event regarding the battery happened (and if we could find the original transcript, I bet we can find the explanation given to the crew as well.  And it did cause the repeated master alarms.  I DIDN'T know about pulling the circuit breaker, and that seems a little suspect to me, unless the ground just intended to monitor all the systems themselves.
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My current Project Apollo work:

Quickstart to the Moon initiative (Quickstart_to_the_Moon): Done through earth orbit.  Working on new method of calculating TLI.

Checklist Controller: 
  • MFD Interface 99%(Minor cleanup and future features remain)
  • Panel Interface 99%
  • Excel interface and logic 99%
  • LEM Event code.0%
  • DSKY Interface code. Framework complete, creating "buttons"
  Approximately 80% done. (Checklist Controller
lassombra
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« Reply #34 on: December 17, 2007, 02:55:53 AM »

Alright, I found what I THINK is the original transcript. http://www.jsc.nasa.gov/history/mission_trans/apollo13.htm  I went through it at about the time when the battery supposedly blew, and we've got some nice conversation to build some conclusions from.

Ok, apparently at 99:53 they turned battery 2 off completely until houston could tell them what was going on.

At 99:57 the best guess of "over temp" for bat 2 was given to the crew.

99:57:56 Capcom said: Jim, on the battery problem, we have determined that it is not overcurrent or reverse current.  We suspect it's over-temp, but donrt know for sure, so we're going to watch it for awhile.

100:50:15 Capcom: Jim, regarding your number 2 battery, we think that it's probably a sensor failure, a temperature sensor failure that's caused this alarm, rather than an actual overtemp of the battery; the reason being that we haven't seen any higher temperatures in the glycol loop. We expect to put the battery back on about 101 hours. That'll be about 10 minutes, and then we'll look at it some more there. Over.

101:02:47 The battery was brought back online, which resulted in master alarm again.

At this time, part of the warning system was blocked.

101:05:09 Capcom: Jim, it looks to us like your battery is good, that this is in fact a sensor problem; therefore, request you close the CROSS TIE BAL LOADs on - circuit breaker on panel 16. Advise that you will not have any malfunction indication on any of your batteries now, but we can watch it from the ground. Over.

So yes, they did intend to watch it from the ground as I suspected to be potential explanation in my earlier post.

109:13:30 Jim Lovell: Okay, Jack. We've got a MASTER ALARM and we've got a battery light flickering.

They went on to realize that bat 2 was acting up again.

Interestingly along everything that was happening, Battery 2 was putting out tolerable numbers.  It seems that it's biggest problem was an annoyance factor.

There is no further discussion about the battery except to reiterate what has already been said.

There are a few pages that mention in passing the explosion of the battery.  This page mentions a CM battery, but I believe they might mean the LM battery, though I suppose it could have happened in the CM also.  http://www.super70s.com/Super70s/Tech/Space/Missions/Apollo_13.asp

This site is, on the whole, a religious site, and one that I have a few problems with myself, despite being quite religious, but it does mention the LM battery, and apparently in the words of a mission control worker.  http://www.ghg.net/woodfill/TRACT13.html


All in all, I think there is reasonable evidence that something DID happen to that battery other than just an instrumentation error (though that could have happened as well), and I'd be very curious to see any nasa documentation on it.
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My current Project Apollo work:

Quickstart to the Moon initiative (Quickstart_to_the_Moon): Done through earth orbit.  Working on new method of calculating TLI.

Checklist Controller: 
  • MFD Interface 99%(Minor cleanup and future features remain)
  • Panel Interface 99%
  • Excel interface and logic 99%
  • LEM Event code.0%
  • DSKY Interface code. Framework complete, creating "buttons"
  Approximately 80% done. (Checklist Controller
NoName
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« Reply #35 on: December 17, 2007, 01:25:56 PM »

This is what the Apollo 13 mission report describes:



It seems that the battery problem wasn't really something of significance in relation to the explosion of the SM oxygen tank. At least it's not significant enough to be mentioned on Wikipedia, the Apollo 13 movie as well as several TV documentaries of Apollo 13 I saw in my life. Until you started talking about it, I even didn't know about it. And you seem to know about it because of reading "Lost Moon" (which I still have to read by the way Happy ).

No matter what really happened to the battery (an explosion or just a sensor issue...), there were even more little things going wrong during that mission, concerning instrumentation. The question is what should be simulated and what not. Everything or just the oxygen tank explosion and battery issue? I'm not sure. But I wouldn't vote against simulating such things of course. It's really up to you. If you would like to include such things it's great since it increases realism Wink But I would guess simulating it as described in the mission report (master alarms - caution lights and opening of the master alarm circuit breaker, because an explosion is not really mentioned in several NASA documents).

But feel free to work on it, I have absolutely no doubts Thumbs Up
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lassombra
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« Reply #36 on: December 17, 2007, 04:03:31 PM »

I don't want to include too much "instrumentation" failures personally simply because we're talking about crossing the line between realistic representation and nitpicking.  As far as I'm aware though, only one instrumentation failure (other than the quantity sensor on the O2 tank 2) really got the crews attention.  Reading through the transcript, the only major error they were getting, other than the CO2 on the way home was bat 2.

It might be fun to implement.  And I certainly think we should implement the CO2 quantity getting to 13 before settling down.

Also, I never found any evidence of the master alarm circuit breaker being bulled till much later when both the crew and the ground were absolutely fed up that NOTHING they had done that should have isolated the master alarm was succeeding.
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My current Project Apollo work:

Quickstart to the Moon initiative (Quickstart_to_the_Moon): Done through earth orbit.  Working on new method of calculating TLI.

Checklist Controller: 
  • MFD Interface 99%(Minor cleanup and future features remain)
  • Panel Interface 99%
  • Excel interface and logic 99%
  • LEM Event code.0%
  • DSKY Interface code. Framework complete, creating "buttons"
  Approximately 80% done. (Checklist Controller
movieman
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« Reply #37 on: December 17, 2007, 04:39:37 PM »

I don't want to include too much "instrumentation" failures personally simply because we're talking about crossing the line between realistic representation and nitpicking.

I disagree. The most important failures should come first, but these are things the crew had to deal with on real flights.

Quote
And I certainly think we should implement the CO2 quantity getting to 13 before settling down.

Well, that will happen automatically as the CM and LEM are shut down so the CO2 builds up. The real question is how to simulate the jury-rigged CO2 scrubber they built.
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lassombra
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« Reply #38 on: December 17, 2007, 04:46:42 PM »

I was thinking that a switch internally would detect the, I think it was 13.3 ppm of the CO2, at which they hooked up the new unit and we can then just simulate the unit internally.
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My current Project Apollo work:

Quickstart to the Moon initiative (Quickstart_to_the_Moon): Done through earth orbit.  Working on new method of calculating TLI.

Checklist Controller: 
  • MFD Interface 99%(Minor cleanup and future features remain)
  • Panel Interface 99%
  • Excel interface and logic 99%
  • LEM Event code.0%
  • DSKY Interface code. Framework complete, creating "buttons"
  Approximately 80% done. (Checklist Controller
NoName
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« Reply #39 on: December 17, 2007, 06:00:18 PM »

Well, I finally found out the facts concerning the bat 2 event. There indeed was a thump sound and things going on...

Just jump to page 136:

http://www.hq.nasa.gov/alsj/a13/A13_MissionReport.pdf

Now, I think that we should simulate the thump and snowflakes since it really happened after all.
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lassombra
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« Reply #40 on: December 17, 2007, 07:05:41 PM »

It's a question of work versus reward.  Mission wise it triggered a series of master alarms, but nothing major.  I suppose it can be considered part of the atmosphere of Apollo 13 (SCARY!).  I don't know, I'd rather focus on getting the LEM panel wired up, but I don't know what should be wired up where.
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My current Project Apollo work:

Quickstart to the Moon initiative (Quickstart_to_the_Moon): Done through earth orbit.  Working on new method of calculating TLI.

Checklist Controller: 
  • MFD Interface 99%(Minor cleanup and future features remain)
  • Panel Interface 99%
  • Excel interface and logic 99%
  • LEM Event code.0%
  • DSKY Interface code. Framework complete, creating "buttons"
  Approximately 80% done. (Checklist Controller
NoName
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« Reply #41 on: April 12, 2008, 07:12:33 AM »

After some break for the LEM instrument panels I'm working on a new and also the final "face" of the panels, related to the latest photos I found. We get new real looking switches and rotaries and another few changes...



Note that the real photo on the left hand side doesn't show the transparent plastic-cap on the SLEW RATE switch which seems removed.



I don't want to commit anything before all the people here including the dev-team say that it looks okay. Just let me know what do you think... Happy





« Last Edit: April 12, 2008, 07:29:46 AM by Moonwalker » Logged
bluespace88
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« Reply #42 on: April 12, 2008, 07:15:36 AM »

I think it looks great  Thumbs Up
spot on with the picture on the bottom.
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lassombra
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« Reply #43 on: April 13, 2008, 08:47:07 AM »

looks great.

Point me in the right direction and I'll start wiring it up after I finish what I'm doing with the checklist mfd.
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My current Project Apollo work:

Quickstart to the Moon initiative (Quickstart_to_the_Moon): Done through earth orbit.  Working on new method of calculating TLI.

Checklist Controller: 
  • MFD Interface 99%(Minor cleanup and future features remain)
  • Panel Interface 99%
  • Excel interface and logic 99%
  • LEM Event code.0%
  • DSKY Interface code. Framework complete, creating "buttons"
  Approximately 80% done. (Checklist Controller
mikaelanderlund
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« Reply #44 on: April 13, 2008, 09:56:14 AM »

Very, very cool Thumbs Up Thumbs Up Thumbs Up

Mikael
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