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Day 5, part 3: The Manual Course Correction Burn Journal Home Page Day 5, part 5: Starting the Battery Charge

Apollo 13


Day 5, part 4: Wobbles and Bursts

Corrected Transcript and Commentary Copyright ©2020 by W. David Woods, Johannes Kemppanen, Frank O'Brien, Alexander Turhanov and Lennox J. Waugh. All rights reserved.
Last updated 2020-04-21
The fifth day of the mission of Apollo 13 continues. A manual course correction has made the spacecraft crew as well as Mission Control more confident that they will be re-entering the Earth atmosphere in an angle that will result in a successful landing. With 38 hours to go, they are drifting towards the Earth with a slowly increasing speed as the gravitational pull grows stronger. With the ground working to finish up the details of the procedures for returning to the Command Module, the crew must patiently wait, while also looking out for any additional trouble springing up.
This is Apollo Control. Flight Director Milton Windler has completed checking the status with each of his flight controllers at this time, and the general tenor all the way around was that we're in very good shape at the present time. A couple of the significant items discussed, the surgeon reported that the lithium hydroxide, the makeshift lithium hydroxide canister appears to be doing an excellent job. We're presently reading a carbon dioxide level of 1.2 millimeters of mercury. The LM TELCOM, reported that they're beginning to see the effects of the engine burn heat soak back into the helium tank and related rise in pressure in the helium, which would indicate that the burst disk may go a bit earlier than originally predicted, although the heat soak back had been expected. The plot that we have on the pressure rise in the helium tank would indicate the burst disk going sometime between 107 and 108 hours, ground elapse time. The range on the burst disk is 1,881 pounds per square inch to 1,970 pounds per square inch and somewhere between this pressure range we would expect the burst disk to go relieving the pressure on the super-critical helium tank. The flight dynamics officer reported that when we get the burst disk rupture, they will be observing what they call Doppler shift, to see what effect the venting from the helium tank has on the trajectory. If there is no effect on the trajectory, we would expect to have a preliminary data on the effects of the midcourse correction within about 2 hours. That would be about 2 hours after the burst disk ruptures. If on the other hand, there is some change in velocity as a result of the burst disk rupture, the flight dynamics officer said that it would be at least 5 hours before we had a preliminary estimate on the trajectory, the new trajectory. We've noted that the communications has gotten somewhat noisier. This is related to the power down of the lunar module. One of the items that is turned off in the power down is the communications power amplifier. This increases the noise with respect to the signal and we do expect the communications to remain more or less noisier than they have been. This condition will vary as the spacecraft attitude changes and as the position of the antennas changes with respect to the tracking antennas on Earth. The Flight Plan at this time calls for the Command Module pilot Jack Swigert and the Lunar Module Pilot Fred Haise to get about 6 hours of rest. Jim Lovell will stay on the watch in the lunar module. At 106 hours, 16 minutes, Apollo 13 is 149,706 nautical miles from Earth, traveling at speed of 4,509 feet per second. And the clock in Mission Control counting down to entry shows that we have 36 hours, 24 minutes until Earth entry. This is Apollo Control at 106 hours, 17 minutes.
Their distance from Earth is 277,256 km, speed is 1,374 m/s.
Flight Director Milton Windler photographed at his station in Mission Control.
106:33:40 Lousma: Aquarius, Houston. How do you read?
106:33:45 Swigert: I read you loud and clear, Jack.
106:33:48 Lousma: Okay, Jack. What's your status, who's sleeping, and who's working?
106:33:55 Swigert: Well, right now we're all three kind of working. Do you have any recommendations?
106:34:04 Lousma: Yes, looks like to us from here that you and Fred ought to get some sleep, and that you ought to eat in about 6 hours. And that the Skipper ought to go to bed about 113 hours.
106:34:23 Swigert: Okay.
The crew has slept very poorly since the accident, due to the shock and stress, as well as the very uncomfortable sleeping quarters provided by the cold, unpowered Command Module. Although Mission Control attempted to set up a work rotation, the crew has not been completely adhering to it.
106:34:24 Lousma: I've got some other information. We shouldn't have some good dope on your trajectory for about 2 hours. Looked like to us that the burn was real good, however, and we're taking a close look at it, and we'll get back with you on that in about 2 hours from now. Another thing that we're expecting to have happen is that the SHe tank is going to reach its burst limit. The earliest time we predict this will happen will be at 107 hours on about 25 minutes. And the latest probable time is at 110 hours, and this is supposed to be a nonpropulsive vent, but you might hear it and you might see something.
106:35:06 Swigert: Okay. That's good news. We were wondering about that. And I'll relay all the other information you gave me.
106:35:14 Lousma: Okay. And if the SHe tank does burst during this time frame before we get trajectory info, why, that will delay our trajectory info somewhat. Your consumables, your rates is now good through 152 hours.
Mission Control is using the radio and radar tracking to establish 13's exact trajectory. Although the supercritical helium is designed to vent in a fashion that does not create a propulsive effect - like was the case with the leak from the O2 tank during the accident, for example - they still fear that it might disturb their trajectory and require correction further along the way home. In better news from Jack, they are not in danger of running out of power, water and oxygen, with projected lifetime reaching to 152 GET, or ten hours past their landing time at 142 GET.
106:35:32 Swigert: Jack, wait a minute. Let me copy some of this down.
106:35:34 Lousma: Okay. [Long pause.]
106:35:48 Swigert: Okay. I'm ready now.
106:35:54 Lousma: Okay. We're predicting that you still have more water than you need. And one thing we'd like for you to do is when you're going to sleep up there in the Command Module take a look through the optics and see if you can see any stars.
Jack is talking about the cooling water, not drinking water here.
106:36:17 Swigert: Okay, Jack, I will do. Jim and I were able to spot constellations from the windows of the LM when there's no venting taking place. Could you give me some time on these consumables, what you're predicting they're good for? I think you started to give them times, didn't you, or was I just hearing things.
106:36:56 Lousma: We started to give you some times. We think we might be able to give you some better ones pretty soon. But it looks like your water is good through 154 hours, and you've got O2 through 272 hours, plenty of lithium hydroxide, and your amp-hours ought to be good through 199 or 200 hours. Over. [Pause.]
With their stringent power down procedures and the LM's large supply of oxygen, the water still remains the bottleneck in the lifetime of the spacecraft.
106:37:34 Swigert: Okay; good. Copy that. [Pause.]
106:37:44 Lousma: We expect that your water rate is going to drop off and at the time, Delta will go up to 160 - 165 hours quite shortly. Another thing we're interested in is what's your status on rest and medication.
Normally, the crew reports on their physical condition and possible medication use twice a day, before and after bedtime. These formal reports have not taken place since the accident, and have been reduced to occasional comments instead.
106:38:03 Swigert: Okay. None of us, I know of, had any medications, and right now as far as rest, I suppose we're no tireder than normally in this situation. I'm going to relay the work-sleep cycle.
Although Jack says they haven't taken any medication, the post-flight report does indicate that medication was taken at some point after the accident as well. This includes Fred being heard on the radio loop asking for aspirin, which he is known to have taken before the accident for his headaches as well. Since the medical kit is in the Command Module, it is very much possible for crewmembers to take medicines from there without the astronaut in the LM knowing about this. It is possible that none had been taken at this point, that Jack simply didn't know or forgot to mention it, or he didn't want to talk about it on the open radio loop.
106:38:20 Lousma: Okay. And don't forget to look through the optics when you go up in the Command Module. [Pause.]
106:38:30 Swigert: [Laughter.] Okay. I'll do that.
Comm break.
106:40:04 Swigert: Jack, as luck would have it, we just now started to vent a little from the Command Module [Garbled] [Long pause.]
106:40:46 Lousma: Aquarius, Houston. Sorry about that but there's too much background noise to read you. I think we'll have to wait until you come up on a new antenna. Over.
106:40:58 Lousma: Okay, Aquarius. Go ahead now. I think can hear you.
106:41:03 Swigert: Okay. Okay, Jack. I was going to say, as luck would have it, the Command Module picked this time to start venting again, so I probably won't be able to get a good hack out of stars out of the telescope.
106:41:20 Lousma: Okay. Thank you. And if you can think of it, when the time comes up, when you're not venting, how about remembering to take a look through them and give us a word?
106:41:31 Swigert: Okay. Will do.
Long comm break.
106:44:04 Swigert: Houston, Aquarius. [Long pause.]
106:44:24 Lousma: Go ahead. Over. [Long pause.]
This is Apollo Control at 106 hours, 45 minutes. The...
106:45:01 Lousma: Aquarius, Houston. Did you call?
106:45:05 Swigert: Yes, Jack. I just got a question. How long are you predicting our Command Module LiOH canisters to last in here?
106:45:20 Lousma: Okay, Jack. We've got 14 cartridges that'll last 157 hours, plus we've got the LM primary cartridge with 23 hours, and we've got two PLSS cartridges with 7 hours apiece.
106:45:35 Swigert: Okay. I was just curious as to how much time we've got out of these two cartridges.
106:45:42 Lousma: Stand by 1. I'll get a prediction on that. By the way, I hope you're keeping track of the ones you've used and the ones you've not.
106:45:51 Swigert: Yes, right now, we have numbers 7 and 8 in the LM here.
106:46:00 Lousma: Roger.
106:46:03 Swigert: They were two brand new fresh ones.
Long comm break.
Judging by their canister changing schedule, numbers 5 and 6 were in the ECS during the accident. This means that they grabbed the next fresh ones on the list, to take down to the LM.
This is Apollo Control. The participants for the Change of Shift Press Briefing are leaving Mission Control now. We estimate that the briefing will begin in about 10 minutes, in the MSC main auditorium in the News Center.
While we're waiting for the information which Jack Swigert requested on the expected lifetime of the two current lithium hydroxide canisters, we might recap some of the conservation between Swigert and CapCom Jack Lousma. Jack Swigert reported the crew had taken no medication and he said as far as rest they're no more tired than normally in this situation. He said they planned to switch to a rest cycle as indicated in the Flight Plan as soon as it's convenient. Now we passed up a consumable status to the crew. Also the status on the super critical helium tank burst disk we expect will be within the range where the disk could rupture within a matter of minutes. We're presently showing the super critical helium tank pressure at 1,874 pounds per square inch. We'll hit the lower limit of 1,881 pounds per square inch shortly and we'll be advising the crew when that level is reached. Jack Lousma advised them that they likely will hear the disk rupture and may see something from the LM at the time it ruptures.
106:50:13 Lousma: Aquarius, Houston. In regards to the CO2 canisters, by the way the PCO2 is reading 1.6 down here now. We expect that we can get 6 more hours out of the two canisters that we have there - 6 hours at least. However, at 112 hours, when we've got several people up, we're going to rig up two more and we have the new simplified procedure for doing this. However, in the meantime, should we need to have a canister change, we plan to switch to the LM primary canister. Over.
106:50:52 Swigert: Okay. Copy that, Jack. [Long pause.]
106:51:08 Lousma: And, Aquarius, how's your PTC holding up?
106:51:14 Swigert: Well, we got a little bit off Jack. The - It starts high in the LMP's window and goes low in the CDR window. [Long pause.]
106:51:37 Swigert: So we've got a little bit of a wobble on it. Of course, the Command Module venting doesn't help, either.
Very long comm break.
107:02:44 Swigert: Houston, Aquarius.
107:02:46 Lousma: Go ahead, Aquarius.
107:02:50 Swigert: Jack, in reference to your question about the PTC, on this last complete revolution, the Sun first appeared in the very top right corner of the LMP window, passed over the CDR window, and was visible through the overhead window, and now the Moon is - came pretty well through the center of both windows this last time. [Pause.]
107:03:20 Lousma: Okay. Thank you, Jack. Good copying that.
Long comm break.
107:07:23 Lousma: Aquarius, Houston. We'd like to get a little better idea of how PTC is going. So, what we'd like for you to do is what we did last time. That is to give us a reading on the center of the Earth and the center of the Moon on the - on the LPD.
107:07:49 Swigert: On the LPD. Okay, It's shifted. Let's see, the Moon's gone by and the Earth didn't come into the LPD last time. [Pause.]
107:08:03 Lousma: Okay. But when it goes by the plane of the LPD, tell us where it was. Okay?
107:08:10 Swigert: Okay. Will do.
Very long comm break.
They are again using the markings on the LM window to see if their motion relative to the Earth or the Moon is changing.
This is Apollo Control at 107 hours, 11 minutes. Our displays based on telemetry information from the spacecraft currently show that we have pressure in the supercritical helium tank of about 1,889 pounds per square inch. This is within the range where the burst disk on the tank could rupture. The range is roughly between 1,881 pounds per square inch and 1,970 pounds per square inch. During the last 10 or 15 minutes there's been a huddle around the Flight Director's console. The subject of the discussion is what procedure we use if the burst disk does not rupture as expected. The pressure in the tank should not go above about 2,000 pounds per square inch. If the burst disk does not rupture, we would need to use an alternative method of depressurizing the tank. These alternatives involve either depressurizing by venting all at once or by venting in stages, a little at a time. And a decision has not been made at this time on how the tank will be vented in the event it is necessary. But those are the options that we have as it appears right now. You've also heard Jack Swigert aboard the LM reporting the relative position of the Earth and the Moon and the Sun as the spacecraft rotates in the Passive Thermal Control mode. As these bodies come into view through the windows, we've asked him to give a relative position of the Earth and Moon on the Landing Point Designator, the grid on the LM window which is calibrated and will give us a bit more precise information on how the spacecraft is maintaining it's Passive Thermal Control attitude. At the present time now we show Apollo 13 to be 147,186 nautical miles from the Earth.
Distance, 272,588 km to go.
Venting the tanks of helium would not be an especially difficult task, as this procedure is performed shortly after the LM landing. In the procedure, the pyro batteries are brought online, and the vent valves are opened by a pyrotechnic charge. Individually, the fuel and oxidizer tanks on the commander's Panel 8 are vented.
Explosive Devices switches, including the fuel and oxidizer vents, on Panel 8 in the LM. Original scan courtesies of heroicrelics.org.
While the procedure is quite straightforward, the effects on the spacecraft attitude is not. The propellant tank vents are not designed to be "non - propulsive", that is, there are no means to limit a particular directional force on the spacecraft. They are, after all, intended to be used after landing, where the impulse of the escaping helium would be moot.
The two options, venting the helium all at once, or in stages is the debate currently ongoing at Flight Director Milton Windler’s console. If the burst disk fails to open the tank vent, completely dumping the contents of the SHe tank might induce a trajectory change. Dumping helium in stages, however, would minimize and attitude or trajectory effects, but the pressure would have to be constantly monitored and vented periodically.
Vents in the Descent Stage of the Apollo 14 LM Antares. Photo and editing courtesies of Frank O'Brien.
107:13:34 Swigert: Okay, Jack. This pass, the Earth came into view at the top left-handcorner of the LMP's window and was going down. However, when it passed it wasn't as high up as the last pass. It did pass into view at the CDR window, but too high up to get an LPD reading.
107:13:57 Lousma: Roger. Understand it went high in both windows then.
107:14:04 Swigert: Yes, last time it wasn't even visible in the CDR's window; this time it was visible if you squatted down, but too high up to get an LPD reading.
107:14:14 Lousma: Okay, Jack. That's good. Thank you.
Very long comm break.
107:21:51 Swigert: Okay, Houston; Aquarius.
107:21:53 Young: Go ahead. Over.
107:21:57 Swigert: Okay. The Moon came into view at the middle of the LMP's window, passed through the CDR's window at an LPD of 5 degrees.
107:22:11 Young: Roger. Understand.
Very long comm break.
This is Apollo Control at 107 hours, 31 minutes. We're presently reading a pressure on the supercritical helium tank of 1,897 pounds per square inch. Our LM Control officer just advised the Flight Director that he expects the most likely time for the burst disk on the supercritical helium tank to rupture would be within the next 15 minutes or so. At that time our indication in Mission Control that the disk has ruptured would be a drop in the tank pressure to zero. We presently show a current on the spacecraft Electrical Power System of anywhere from 10 to 12 amps. This is well below the minimum that we'd like to stay under. We'd like to keep it down to at least 14 amps and since the spacecraft is then powered down, we've been well below that figure.
107:35:55 Swigert: Houston, Aquarius.
107:35:58 Lousma: Go ahead, Aquarius.
107:36:02 Swigert: Okay, Jack. On this pass, the Earth came into the view at the top part of the LMP's window, and we got an LPD angle on it as it passed through the CDR's window of a minus 4 degrees.
107:36:18 Lousma: Okay. A minus 4. Thank you, Jack ...
107:36:19 Swigert: It's - it's above the - Okay. Are you familiar with the minus 4 being halfway through the sky part, huh?
107:36:28 Lousma: Affirmed.
Very long comm break.
107:44:43 Swigert: Okay, Houston; Aquarius.
107:44:47 Lousma: Go ahead, Aquarius.
107:44:51 Swigert: Okay. On this pass, the Moon came into view at the top part of the LMP's window, came across higher. Jim estimates the LPD angle at a minus 15 degrees.
107:45:09 Lousma: Okay. A minus 15 on the Moon, and sounds like it's set up pretty well. [Pause.]
107:45:21 Swigert: Everybody's happy with it down there? [Long pause.]
107:45:55 Lousma: Aquarius, it's a little too early to tell exactly how the PTC is going. We'd like to get a few more points, so keep reading them off, and we're still looking for that Supercrit to go anytime. [Long pause.]
107:46:08 Swigert: Okay.
Very long comm break.
107:59:10 Lovell: Houston, Aquarius.
107:59:13 Lousma: Go ahead, Aquarius.
107:59:17 Lovell: The Earth was just fairly high in the LMP's window and across the 14 degree LPD line.
107:59:27 Lousma: Okay, Skipper; 14 degrees. Thank you.
Very long comm break.
This is Apollo Control at 107 hours, 59 minutes. That report on the relative position of the Earth and Moon through the spacecraft windows is coming from Jim Lovell. That's the first time we've heard from Lovell recently. A check with the Flight Surgeon. As far as we know at this time, all 3 crewmen are still up. However, the fact that Lovell is now on watch might indicate that Jack Swigert and Fred Haise are planning to begin a rest period. In Mission Control, Flight Director Milt Windler has been discussing the situation with the supercritical helium tank and what options we've got if the burst disk does not rupture as it is expected it will. And as we've mentioned before, at that time it appeared the options were either to vent the super crit - vent the pressure from the supercritical helium tank at a series of small vents or to vent it all at once. After looking at the situation, it's been decided that the procedure, should it be necessary to relieve the pressure by venting would be to vent it all at once. In this event it is felt that the fuel in the fuel heat exchanger would be frozen and we would not be able to thaw it out again. This would render the Descent Propulsion System unusable for further maneuvers, however, we have adequate consumables in the LM ascent stage, adequate propulsion in the ascent stage. It's also felt that if a subsequent midcourse was needed probably closer into the Earth entry, we would be able to perform this midcourse using the ascent propulsion stage of the Lunar Module. The present pressure on the supercritical helium tank as read from telemetry data here in Mission Control is 1,913 pounds per square inch. The rise rate has slowed down somewhat. Recapping again the predicted range for the burst disk rupture is between 1,881 pounds per square inch and 1,970 pounds per square inch. We wouldn't begin to get concerned about the pressures on the supercritical helium tank until it got up around 2,000 pounds per square inch. And the LM Control officer anticipates that we would not get up around the 2,000 pounds per square inch in the event the burst disk does not rupture until about 114 or 115 hours Ground Elapsed Time. Experience we've had with ground tests on the supercritical helium burst disk indicates that it should be rupturing around the pressure we've got now, in the low 1,900's. And we're continuing to watch that. The LM power is continuing to run as it has since power-down, between 10 and 12 amps, and we look very good in that respect. There's also been no change in the status of any of the other consumables aboard the spacecraft. They all continue to look quite good at this time. Apollo 13 is presently 144,958 nautical miles from the Earth, traveling at a speed now 4,613 feet per second. We're now 34 hours, 37 minutes until Earth entry. At 108 hours, 4 minutes; this is Mission Control, Houston.
Earth is now 268,462 km away. Their velocity is 1,406 m/s.
The freezing of the fuel line spoken of by the PAO was first seen during Apollo 11. At a frigid -445°F (-265°C, 8°K), the supercritical helium needs to be warmed and converted to a gas, lest it freezes the fuel and oxidizer when it is introduced into the propellant tanks. A heat exchanger wraps the helium line around the fuel line, and uses the heat in the fuel for warming the helium into a gas. In this exchanger, the fuel is also cooled, but is in little danger of freezing as fresh, warm fuel is always passing through the heat exchanger when the engine is firing. It is only when the descent engine has stopped that fuel freezing becomes an issue. Venting helium will quickly freeze the stagnant Aerozine-50 fuel, leaving it in a state that is potentially explosive. Unlike Apollo 11, where the still warm descent engine melted the fuel, no such heat source is available on Aquarius. Aside from the potential danger that a frozen slug of fuel presents, the descent engine is now rendered unusable. This is not considered a major constraint, as their trajectory is very good, and any minor midcourse correction can be performed by the LM RCS system.
108:08:45 Lovell: Houston, Aquarius.
108:08:47 Lousma: Go ahead, Aquarius.
108:08:51 Lovell: The Moon went by the LPD at 6 degrees, plus 6 degrees.
108:08:56 Lousma: Okay. The Earth at plus 6. Thank you.
108:09:02 Lovell: That's the Moon, the Moon.
108:09:04 Lousma: Okay. The Moon. Thank you.
Very long comm break.
108:23:30 Lovell: Houston, Aquarius.
108:23:33 Lousma: Go ahead, Aquarius.
108:23:37 Lovell: The Moon passed by at a minus 8 degrees on the LPD. No, that's the Earth. The Earth passed by at a minus 8 degrees.
108:23:48 Lousma: Okay. The Moon went by at a minus 8 degrees. [Pause.]
108:24:02 Lousma: Okay, Jim. We got it. The Earth went by at a minus 8 degrees. On a basis of the data ...
108:24:08 Lovell: That's right.
108:24:09 Lousma: On the basis of the data we have so far, your entry angle is 5.99. The block data we gave you on the PAD for a no-Comm midcourse-7 last night is no longer valid because we made this midcourse. [Long pause.]
108:24:38 Lovell: Okay. Understand, the no-Comm PAD is no longer valid because of the midcourse. Entry angle based on the last 2 hours' tracking is 5.99, and I take it you're going to keep tracking for some time now to see whether we need another midcourse or not.
108:24:55 Lousma: That's affirmative. [Pause.]
108:25:05 Lovell: Are you planning any no-Comm midcourse at 134 and change anyway right now, or are you going to wait?
108:25:14 Lousma: We're discussing that now, Jim, and it looks like we're going to wait on the tracking. For the time being, since you're in the corridor, why, there's no need to pass it up. But we're going to keep looking at the tracking, and we'll probably come up with one.
Their entry angle is good enough that correction is not vital at this point, although this may be done in the future, should the tracking indicate that it is necessary.
108:25:34 Lovell: All right. I'm not too sure what the venting is going to do to us so - when this SHe tank ruptures, what it's going to do for us.
108:25:47 Lousma: Roger. We don't presently expect the SHe tank to have any effect on your trajectory, and the pressure's up to 1921 now. [Pause.]
108:25:59 Lovell: Hey, it's going a lot better than we ever expected. What a way to get a data point? [Long pause.]
108:26:35 Lovell: And, Jack, just think. You thought you we're going to sleep through all your watches.
108:26:41 Lousma: Say again, Jim. [Pause.]
108:26:48 Lovell: I said, you thought you were going to sleep through all you watches. [Pause.]
108:26:58 Lousma: Well, you keep waking me up.
108:27:04 Lovell: Sorry about that.
Very long comm break.
Jack's first two shifts coincided with the crew sleep period, hence giving him very little to do in terms of actually communicating with them. This all changed with the accident. Since then someone has always been up in Aquarius, and both the CapCom and the crewman on duty have taken the opportunity to chitchat.
This is Apollo Control at 108 hours, 52 minutes. The Flight Dynamics Officer hopes to have a preliminary set of numbers on the effects of the midcourse correction. At about 109 hours, 30 minutes or a little over 37 minutes from now, the burn was targeted to give the spacecraft a flight path angle of minus 6.52 degrees at Entry Interface. Now we won't have a confirmation of this, of course, until the Flight Dynamics Officer is able to complete the tracking and compilation of data to come up with some preliminary numbers. But the targeted value of that course was to give us a flight path angle of minus 6.52 degrees. The entry corridor which is the width of the flight path angle that we feel we can withstand is about minus 5.25 degrees to about minus 7.4 degrees of flight path angle. We're still watching the supercritical helium pressure aboard the LM descent stage increase gradually. The pressure is now reading 1,937 pounds per square inch. I would like to cover again the procedures which we mentioned have been worked out in the event that the burst disk did not rupture as it is expected to do. The burst disk, of course, is in there to relieve pressure on the tank, on the supercritical helium tank when the pressure gets above a certain specified limits. The disk is designed to rupture at between 1,881 pounds per square inch and 1,970 pounds per square inch. In the event the disk does not rupture, Flight Director Milton Windler as flight controller has worked out a procedure that will be followed to relieve the pressure on the tank, and we see the pressure dropping at this time. The Control Officer reports that the burst disk has ruptured. We - just as we were making this announcement...
108:54:31 Lousma: Aquarius, Houston. You notice anything?
108:54:37 Lovell: Yes, Jack. I was just about ready to call you. Underneath quad 4, I noticed a lot of sparklies going out.
108:54:50 Lousma: Can you hear or feel anything?
108:54:54 Lovell: No, I sure can't, but I think it changed our - it changed out PTC. Let me check and see what the drift is. [Pause.]
108:55:09 Lousma: Okay. She's going down through 600 now. [Pause.]
108:55:18 Lovell: I think we're probably going to have to reestablish PTC. Yes, we got pretty fast yaw drifting, Jack. [Long pause.]
108:55:57 Lovell: Houston, Aquarius. What are your plans?
108:56:01 Lousma: We're thinking about them right now. Did you say it yawed some? [Pause.]
108:56:08 Lovell: Yes, I was in a right yaw and now I'm in a left, yaw; at a much faster rate than the one we put in PTC. [Pause.]
108:56:28 Lousma: Okay, Jim. We're talking it over. Stand by. [Long pause.]
While we're waiting for conversation to resume between the CapCom and Jim Lovell aboard Aquarius, we'll summarize the situation as we were talking about the procedure that would be followed in the event the burst disk did not rupture. Lo and Behold the disk ruptured. That occurred at a pressure of about 1,937 pounds per square inch at 108 hours, 54 minutes 40, seconds Ground Elapsed Time. We saw...
108:57:20 Lovell: What's the SHe tank down to now, Jack?
The helium pressure display in the LM is powered down, hence Jim has to resort to asking Lousma for the telemetered value instead.
108:57:24 Lousma: Okay, Jim. It's going through 125 pounds now. And we understood you to say...
108:57:30 Lovell: Okay
108:57:31 Lousma: ...that it reversed your yaw. Is that affirmative?
108:57:37 Lovell: Sure did, Jack. It reversed my yaw completely and put in a little pitch, I think. [Long pause.]
108:57:53 Lovell: But more than anything, it reversed my yaw.
108:57:56 Lousma: Roger. Have you effectively established PTC in the opposite direction then?
108:58:04 Lovell: Well, you could say that. I'm not too sure just what kind of pitch or roll I've got, coupled with the yaw. I just saw the Earth go by the LMP's window here, not too long ago at a rather faster rate than we had going the other direction. [Long pause.]
108:58:38 Lovell: Perhaps you can tell how fast I'm having to shift Omnis.
108:58:42 Lousma: Yes, we can tell the Comm cycling back and forth. [Pause.]
108:58:52 Lovell: Is that what they call a nonpropulsive vent?
108:58:56 Lousma: Right. I'd hate to see a propulsive one.
108:59:01 Lovell: You and me both.
The burst disk, one of the most talked about components of the LM during the mission. There are actually two of them inside the device, each set to be burst by a spring-loaded punch when the pressure rises to its set level.
108:59:04 Lousma: It's going through 50 pounds now. So, are you seeing fewer sparklies?
108:59:12 Lovell: Yes. Much fewer. Not any at all, now. I'm not sure whether that vent gave me reverse yaw and roll - left roll - that's - if that's what it gave me.
108:59:34 Lousma: You say you think it might have given you some left roll as opposed to opposite yaw. [Pause.]
108:59:45 Lovell: I'm sure it gave me the yaw, Jack, but I'm not too sure [Garbled]
108:59:50 Lousma: Okay. We'd kind of like to watch it, see what happens for a little while before we make a recommendation. However, we'll need some inputs from you on that.
109:00:02 Lovell: Well, we're in no trouble up here as far as - as far the yaw goes. Everything's fine. It's faster than we had set up before. We just wanted to get into proper thermal constraint, and it's going to take me 15 minutes to get the thrusters up anyway. [Long pause.]
109:00:58 Lousma: Okay, Skipper. We don't see any thermal problems as a result of this change. If we see some communications problems, we may have to do something different, but so far, so good. And we'd kind of like to hear from you on LPD numbers, if you get anything going by the window.
109:01:28 Lovell: Okay. Will do. [Long pause.]
The helium venting has caused them to reverse the PTC, and spin up faster than earlier. For the moment, they don't want to do anything about it, since that would be a time and power-consuming effort.
109:02:03 Swigert: Okay, Jack. The Earth just went through at an LPD of 26 degrees.
109:02:09 Lousma: Okay. The Earth went through at 26 degrees going the opposite direction this time - left to right. Is that right?
109:02:17 Swigert: From left to right. That's affirmative. [Long pause.]
109:02:32 Lousma: Of course, the only other thing that we'd be concerned about is what change in your velocity this might have had and what Delta-V it imparted, and we'll have to look at that for a while before we are able to determine it. And, if there is no significant change, why, we prefer just to leave it the way it is.
109:02:54 Swigert: Okay, Jack. We're going to get a time on a revolution here, and maybe that'll help you out.
109:03:02 Lousma: Right. And, for your information, the tank went at 1937.
109:03:11 Swigert: That's two thousand - 1937?
109:03:14 Lousma: Right. [Long pause.]
109:04:12 Swigert: Okay, Jack. The Earth went through again at 18 degrees on the LPD.
109:04:19 Lousma: Okay. Earth at 18. Thank you.
109:04:23 Swigert: Okay. And we didn't see the Moon that time.
Comm break.
109:05:41 Swigert: Okay, Jack. The Moon went through that time at 32 degrees on the LPD.
109:05:46 Lousma: Roger. Moon at 32. Thanks.
Long comm break.
109:08:27 Swigert: Okay, Jack. Well, we didn't get the Earth that time. The Moon came back through at about 10 degrees, and now we're getting to the Earth again. Stand by. [Long pause.]
109:09:08 Swigert: Okay. The Earth came through the LPD at 62 degrees that time. And the total time for the two revolutions, - I missed the Earth revolution before, but the total time for the Earth's two revolutions was 3 minutes and 50 seconds. [Pause.]
109:09:33 Lousma: Say again the time and the - and also the LPD number. You're in the background noise, Jack.
109:09:39 Swigert: Okay. Okay, Jack. LPD that time was 62 degrees and that was for two revolutions, being at that distance we missed the Earth - The time before we didn't see it. And the time was 3 minutes and 50 seconds.
109:09:59 Lousma: Okay. Three minutes and 50 seconds. Is that rate uncomfortable for you? [Long pause.]
109:10:34 Swigert: Jack, Jim said it isn't uncomfortable. It's a little annoying as for the Omni switching, and also he said it's kind of - He said this Earth/Moon relationship's kind of [Garbled] because he doesn't know when to [Garbled]
109:10:50 Lousma: Roger.
Long comm break.
109:13:30 Swigert: Okay, Jack. We've got a Master Alarm and we've got a battery light flickering.
109:13:36 Lousma: Okay. Copy a battery light. What battery? [Long pause.]
109:14:16 Lousma: Aquarius, how about cycling the power temp monitor to find out which battery it is, please.
109:14:25 Haise: Yes. That's in work, Joe. [Pause.]
109:14:39 Haise: Okay. It's that same old [Garbled]. [Long pause.]
109:14:54 Lousma: Okay, Fred. I can hear you now. Say again, please.
109:15:01 Haise: Okay. It's the same old - same old one. The only light I'm getting is on Bat 2. [Long pause.]
Battery status displays on LM Panel 14. The Bat Fault light comes on if a malfunction state is detected in any of the batteries. To check the batteries, the rotating Power/Temp Mon switch is moved through each position to view the volts and amps on the gauges, and to see whether the fault indicator light comes on. It has now been illuminated upon Fred selecting Battery 2. Original scan via heroicrelics.org.
109:15:35 Lousma: Okay, Fred. We copy - copy your same old friend, battery 2. Could you give us high bit rate for a while, please? [Long pause.]
109:16:13 Lousma: Aquarius, Houston. High bit rate, please.
109:16:19 Haise: How you getting it now, Jack?
109:16:23 Lousma: We got it.
Long comm break.
That's rotation and communications officer reports we have high bit rate now. We're taking a look at the battery here in Mission Control to see if we see anything unusual. Battery 2 earlier in the - earlier yesterday caused a Master Alarm to go off. We took a look at it at the time and could see nothing wrong with it. The battery was put back on the line and at the time it was felt that the problem was a sensor problem rather than a problem with the battery itself.
The initial comment about rotation in this PAO transcript is somewhat puzzling.
109:20:54 Lousma: Okay, Aquarius. You can go low bit rate, Power Amp, Off and Down Voice Backup now. Voltages and currents look normal on battery 2; so ignore the battery light.
109:21:12 Haise: Okay, Jack. Power Amp, Off, back to low bit rate, and I'll go back to sleep.
109:21:21 Lousma: The battery light staying on? [Pause.]
109:21:30 Haise: Yeeah. We got a steady on Bat 2, Bat Fault Light and the battery caution light. [Long pause.]
109:21:49 Lousma: Okay. And is the Skipper in the sack now?
109:21:56 Haise: Aah - say again?
109:21:57 Lousma: Is the Skipper in the sack now? [Pause.]
109:22:08 Haise: Okay. Hold on a minute, Jack.
Long comm break.
109:24:17 Lousma: Aquarius, Houston.
109:24:22 Lovell: Go ahead, Houston.
109:24:24 Lousma: Okay, Jim. Since the antenna switch is kind of annoying, we've talked them into buying only half of the data. If it gets too troublesome for you to switch antennas, why, just leave it on one antenna and we'll listen to you half of the time.
109:24:43 Lovell: Okay. It's not really much trouble. That's all we're doing about it. We'll try to keep up with it. And you're satisfied with this attitude so far. I guess you're going to watch the thermal and find out whether perhaps we're going to some other PTC attitude.
109:24:55 Lousma: Roger. Thermal appears to be no problem. We're looking at what Delta-V might have been imparted due to this, and it looks like we're not going to change the PTC attitude.
109:25:14 Lovell: Okay. Then Delta-V was a part of it; I hope it raised that angle a little bit. [Long pause.]
109:25:44 Lousma: Yes. We'll be looking at the data here, and give you a better answer in next 30 minutes or so.
109:25:52 Lovell: Okay. Meanwhile, back to the drawing board about nonpropulsive vents. [Pause.]
109:26:06 Lousma: And, with your kind of luck, it probably lowered the angle some more.
109:26:13 Lovell: Thanks for the confidence. [Long pause.]
109:26:43 Lousma: And, Jim, we're going to have a handover here pretty soon, about 3 minutes, we may lose uplink for 30 seconds or a minute.
109:26:54 Lovell: Okay.
Long comm break.
This is Apollo Control at 109 hours, 27 minutes. CapCom Jack Lousma was advising Jim Lovell that we'll be handing over from the tracking site at Goldstone, California to the Honeysuckle, Australia site in about 3 minutes. During this handover, for a period of about 30 seconds to a minute, we will not be able to up-link to the spacecraft. At about 109 hours, 13 minutes the crew reported a Master Alarm and a battery light flickering. We had them turn up the, turn on the power amplifier and give us high bit-rate data so that we could look at the batteries here on the ground. After a look at them they telemetered the LM electrical systems engineer in Mission Control. He said that he was confident the problem was the same one that we'd seen yesterday, in which we probably have a sensor problem rather than a problem with the battery itself, and the sensor is triggering the alarm. The crew is advised to put the battery back on line and leave it there. The supercritical helium Burst-Disk ruptured at about 108 hours, 54 minutes, 40 seconds after reaching a pressure of 1,937 pounds per square inch. Lovell reported at the time seeing particles coming off, and also the pressure of the escaping gas, which was thought ahead of time to be a - was predicted to be a non-propulsive vent, turned out to be a very much a propulsive vent. Lovell said that the spacecraft stack which had been rotating about its longitudinal axis at a rate of about 3 revolutions per hour. This rotational rate was stopped by the vent and started up again in the opposite direction, and it is now rotating about one revolution every 2 minutes. One revolution a little less than every 2 minutes, as compared with a revolution every 18 or 19 minutes in the opposite direction prior to the vent. So, that was very much a propulsive vent. Hence, the remarks from Lovell, back to the drawing board on non-propulsive vent. The crew asked if there was any problem with the rotational rate they had as far as the structure of the vehicle and the temperatures on board. After a review of this situation in the SPAN engineering room, it was reported that there would be no problem, either with vehicle temperatures or structure, leaving this rotational rate as it is, and we advised the crew to let it continue to rotate at that rate, and the only problem might be in switching from one antenna to the other. Now, this of course, is function...
109:30:30 Lousma: Aquarius, Houston. We're handed over. How do you read?
109:30:36 Lovell: Read you loud and clear, Jack.
109:30:42 Lousma: Okay. I'm hearing you now, and the noise has come up again, but it will go down. [Pause.]
109:30:52 Lovell: How do you read now?
109:30:53 Lousma: Okay. That's a lot better, and we figure your battery glitch was just that thermal switch triggered a mal - a Caution and Warning, just cycled once, and triggered a Master Alarm again. We'll watch the batteries for you, since you don't have any Caution and Warning on now.
109:31:13 Lovell: Okay. Appreciate. that.
Very long comm break.
This is Mission Control. As we were saying, the only problem we, potential problem that we could see with the rapid rotation rate or the more rapid rotation rate of one revolution every 2 minutes might be that the crew would have to switch from one antenna to the next and it was felt that this might be troublesome, however, Lovell reported that it would be no problem and they would attempt to keep up with it. In the event that they miss an antenna switch we would lose data for perhaps 1 minute while the spacecraft rotated around in a position for the other antenna to be received on the ground. At the present time, Apollo 13 is 140,934 nautical miles from the Earth. Our velocity is up now to 4,700 feet per second. The very gradual velocity buildup we've been seeing since crossing the sphere of influence line, the imaginary line in which the Earth's gravitational force becomes the dominant gravity force acting on the spacecraft, and we begin to see at that point a gradual acceleration due to Earth's gravity.
Distance to go, 251,001 km, velocity 1,432 m/s.
109:43:33 Lousma: Okay, Jim. Your luck is holding. Tracking shows that your entry angle has gone up to minus 6.24. This is on the basis of all the data we've collected between the midcourse up to the time the SHe tank went. So, we'll continue to look at it, and see if SHe tank did anything to it at all. So it's - The data has gone from 5.9 to a minus 6.24.
109:44:07 Lovell: That sounds pretty good. We're really getting in there.
Very long comm break.
110:00:53 Lousma: How are you doing, Jim?
110:00:59 Lovell: Not bad. Not bad at all. [Pause.]
110:01:10 Lousma: Is Jack in the sack, or is he with you?
110:01:16 Lovell: Jack and Fred both are going to sleep. It's sort of humorous; Fred's sleeping place now is in the tunnel, upside down with his head resting on the ascent engine. Jack is on the floor of the LM, with a restraint [Garbled] wrapped around his arm to keep him down there.
110:01:39 Lousma: You say Jack is on the floor, and Fred is with his head on the ascent engine.
110:01:46 Lovell: That's right, with his feet up into the tunnel.
Very long comm break.
Lovell, from 1970 Technical debrief: "Actually, Fred, you got some good sleep?"
Swigert, from 1970 Technical debrief: "Yes,I did."
Lovell, from 1970 Technical debrief: "Yes. You slept that one time in the tunnel very well."
Swigert, from 1970 Technical debrief: "And one time in the CM. I think you got about 4 or 5 hour's good sleep."
Haise, from 1970 Technical debrief: "My sleep was very sporadic."
Haise, from 1970 Technical debrief: "I would sleep in the tunnel next to the ECS unit. This was the warmest place. And I got in the sleep restraint and slept upside down in the tunnel with my face back towards the hatch. I zipped up my sleep restraint and used a string on it to hook myself to the hatch handle on the LM hatch so I wouldn't drift away. It must have looked very strange."
Jack Swigert seen floating 'down' the docking tunnel and into the LM. Onboard 16 mm film. JSC.
This is Apollo Control at 110 hours, 2 minutes. That was Jim Lovell reporting that Fred Haise is sleeping at present time in a rather unusual position. Fred sleeping with his feet up into the docking tunnel, and his head is resting on the ascent engine cover which is on the floor of the LM. Relatively upside-down as you in a normal standing position in the LM. Jack Swigert sleeping on the floor of the LM.
This is Apollo Control at 110 hours, 8 minutes. We estimate that the amount of velocity change imparted to the combined stack of vehicles by the disk rupture and the super critical helium tank was about 2/10 of a foot per second. This amount of velocity, Delta V addition to the spacecraft, was able to stop the rotational rates in one direction and start them up in another. The rotational rate had been about 1 revolution every 18 - 19 minutes.
110:08:18 Lousma: Okay, Skipper. Your luck is really hanging in there. Your water's good up to 161 hours now.
110:08:26 Lovell: Hey, that sounds great. [Long pause.]
Their powerdown has reduced the water usage in the LM and extended the expected lifetime of the system considerably.
Jack Lousma just advised Jim Lovell that current estimates of water would indicate that he's got - the crew has sufficient water on the LM for 161 hours.
110:08:40 Lousma: That doesn't include PLSS water or Command Module water. [Pause.]
110:08:49 Lovell: Okay. Jack, I'd just like to know what - what plans or thoughts being contemplated for the PLSSs or the OPS, whether we're going to use their LiOH canisters or take the devices back in the Command Module with us, or just what will be your plans.
110:09:15 Lousma: Yes. We're talking all that over now. We haven't decided. [Pause.]
110:09:22 Lovell: Okay.
Very long comm break.
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