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- Approaching the Moon

Apollo 8

Day 3: The Maroon Team

Corrected Transcript and Commentary Copyright © 2003-2021 by W. David Woods and Frank O'Brien. All rights reserved.
Last updated 2021-02-27
Frank Borman, Jim Lovell and Bill Anders are further from the surface of Earth than any human in history and are only thirteen hours from a rendezvous with Earth's natural satellite as their spacecraft, Apollo 8, begins its fall towards the Moon. Though they don't know it yet, they have just passed another historic milestone by passing a point between Earth and the Moon where the gravity of the two planets balance. Now the Moon is exerting the greater pull as they become the first people to enter the gravitational realm of another world.
In Mission Control, it is three o'clock in the afternoon, nine in the evening by Greenwich Mean Time. A new shift of flight controllers, the Maroon Team, have just taken over in the MOCR (Mission Operations Control Room) led by Flight Director Milt Windler. Everyone is settling down after a television transmission from the spacecraft during which the crew transmitted a grainy but very recognisable view of Earth from 325,000 kilometres distance.
Still frame from the first live TV images of Earth sent by humans.
This was an important event, as much for its cultural significance as the engineering prowess that made it happen. Not only are three explorers reaching out like no other, they are able to share their unique vantage point with a sizable portion of the citizens of the planet.
056:10:06 Borman: Houston, Apollo 8.
056:10:09 Mattingly: Go ahead, Apollo 8.
056:10:12 Borman: Hey, Jerry, how much water does this - the water dispenser in the Lower Equipment Bay, the one that puts out hot and cold water - how much comes out of that with each shot?
Jerry Carr is not due to take the CapCom seat until the next shift change.
056:10:23 Mattingly: Stand by. I'll take a check on that. And, by the way, welcome to the Moon's sphere.
056:10:32 Borman: The Moon's fair?
056:10:34 Mattingly: The Moon's sphere - you're in the influence.
056:10:39 Borman: That's better than being under the influence. [Long pause.]
And it was with this quip that humankind, for the first time in its evolution, did depart the timeless grip of Earth and come under the stewardship of a celestial body.
Witticism aside, it could be argued that this moment, though somewhat arbitrary, carries a significance of a similar magnitude to Neil Armstrong's first step on the lunar soil.
056:11:00 Borman: Hey, Jerry?
056:11:03 Mattingly: Go ahead, 8.
056:11:07 Borman: My handy LMP had his schematics out at the drop of a hat and informs me that it's one ounce per cycle.
056:11:29 Mattingly: Apollo 8, looks like the flying EECOM and the ground EECOM [Charles Dumis] came to a dead heat on that one.
At the same time, both Bill Anders (the "flying EECOM"), and Charlie Dumis (the "ground EECOM") have come to the same conclusion: that the water dispenser releases one ounce (about 30 grams) per "squirt".
056:11:39 Borman: They did?
056:11:40 Mattingly: Roger. We got the same answer at the same time. [Pause.]
056:11:53 Borman: I'll have Bill put it on the tape recorder and send it down to you.
Very long comm break.
056:37:05 Mattingly: Apollo 8, Houston.
056:37:11 Anders: Go ahead, Houston. Apollo 8.
056:37:13 Mattingly: Okay, 8. We want to run a little exercise on the ground here to make sure that we're able to dump the tape and bring the voice portion back to Houston in a timely manner. So we plan to dump your tape, and we're going to exercise the procedures on the ground to get it back here and take a listen to it. We believe that we have something on the tape already unless you have recorded over it after the last dump. Just to make sure, we'd like to have you just say a few words, give us a short count or something on the tape and anything else that you might want to put on there. And we're going to do this in the next 5 minutes before we get away from Madrid. That's the site we want to exercise, so we'll go ahead and do that, and we'll tell you before we make the dump.
056:38:05 Anders: Roger.
Long comm break.
Apollo 8 will spend 20 hours around the Moon making ten full two-hour orbits in that time. For one hour and fifteen minutes of each orbit, Mission Control will be able to receive data from the spacecraft's systems, letting flight controllers keep an eye on the critical systems that will keep the crew alive and bring them back home. For the rest of each orbit, about 45 minutes, the spacecraft is behind the Moon and out of radio communication. All three engine burns, two of them absolutely critical, will take place during these times so there is a strong desire to record engineering data while the crew are behind the Moon. This is achieved with the DSE (Data Storage Equipment), a tape recorder that records data from the many sensors around the spacecraft as well as voice from the crew. It can be controlled either by the crew or remotely by Mission Control so that when the spacecraft reappears around the Moon's limb, all its far-side telemetry can be dumped to the ground. There is a separate channel within the S-band radio link to carry this data as well as the live data from the spacecraft.
As the voice and data from the DSE are sent to Earth, they are recorded at the ground station that received the signals. This is usually Goldstone in California, Madrid in Spain or Honeysuckle in Australia. Once the engineers at the station have recorded the contents of the DSE onto tapes, these can be replayed to Houston on dedicated lines, either voice or data. Mission Control want to exercise the ground station at Madrid in the procedures for carrying out this task. In the meantime, Bill has begun recording voice comments on the spacecraft's DSE.
056:39:44 Anders (onboard): ...hazy, so we haven't really taken too many pictures on the way out. Every now and then we have taken a shot with the 70-millimeter camera and 80-millimeter lens at f/11, 1/250th, but it's questionable how good these - will be, because of the haze on the windows.
056:40:14 Anders (onboard): Another problem has been trying to record the development of the smear on the windows. Seemed to come pretty quick on window number 3. And the technique of - of taking a picture when the Sun's 85 degrees incidence is not possible, because the window frames are so thick that you can't get any Sun on them with an 85-degree incidence. What pictures have been taken, have been taken about 60 to 70 degrees incidence with various f-stops.
056:41:03 Anders (onboard): Anybody else have anything for the record?
056:41:07 Borman (onboard): No.
056:41:08 Anders (onboard): Jim?
056:41:09 Lovell (onboard): Yes, you might mention about this hard thing to open here.
056:41:13 Anders (onboard): One point we might mention is that the foodbox doors are hard to close. Looks like the foodbox has split out a little bit on the left....
056:41:23 Lovell (onboard): The handle's bent.
Food is stored in two cabinets. One is below the optics control panel in the LEB (Lower Equipment Bay), the other being a little to its left.
056:41:24 Anders (onboard): ...left side. And in - look's like we've gotten the handle bent in trying to close the door. We're able to lock it on one side now, on the right side, but not on the left. The food has generally been good, particularly the last meal: butterscotch pudding, beef stew, grapefruit drink, and chicken soup. Notable...
056:41:53 Lovell (onboard): Hot wa...
056:41:55 Borman (onboard): ...the notable, mainly notable ones were the grapefruit drink and butterscotch pudding.
056:42:02 Lovell (onboard): Well, Bill, you might mention the hot water makes a big improvement, too.
Frank and Jim already have the longest yet space mission under their belts, having spent two weeks in the Gemini VII spacecraft. Compared to its cramped accommodation, the Apollo cabin is relatively luxurious and one of the major luxuries is the availability of hot water.
056:42:06 Anders (onboard): Jim Lovell says the hot water makes a big improvement. The meals I've had have been quite tasty though none of us have really gone overboard for the little bread cru - cubes and cereal cubes.
056:42:33 Anders (onboard): Also, I'd like to suggest that if they ever fly one of these TV cameras again, they put a - some kind of a sight on it. Sort of ridiculous to have a 9-degree field-of-view lens with no way of aiming it except for looking down the side or putting some chewing gum on the top.
056:42:57 Anders (onboard): Also might tell Doc Frome that his toothpaste tastes pretty good. I don't know what kind of job it does on your teeth, but it's nice for settling your stomach after dinner.
"Edible toothpaste" was a special foamless toothpaste that was swallowed, rather than expectorated. As there are no practical washbasins in the spacecraft, and spitting into towels would simply generate a large trash problem, and swallowing is really the only option. Edible toothpaste was tested many years ago as a consumer item for children, but never took off (and regularly swallowing fluoridated toothpaste is never a good idea). Regardless, edible toothpaste for dogs and cats still survives.
056:43:10 Anders (onboard): Anything else, Frank?
056:43:11 Lovell (onboard): We used it for frosting on the fruitcake.
056:43:18 Anders (onboard): Jim Lovell is be - engaged in an activity which I shan't describe, so I think I'll cut this short and get my oxygen mask.
056:43:24 Lovell (onboard): But that could be improved, also [laughter].
056:44:20 Anders: Houston, Houston, this is Apollo 8. Over.
056:44:24 Mattingly: Go ahead, Apollo 8.
056:44:29 Anders: Okay. Ken, we put a few comments on the last of the tape after we heard from you, and it's being rewound now, and you can have it as soon as we get it back to the beginning.
056:44:38 Mattingly: Okay. We'll have to wait. It looks like you are going out of the attitude to use High Gain. We'll catch it next time around and then dump it.
The HGA (High Gain Antenna) is unable to point at Earth for about half of the time that the spacecraft is rotating in Passive Thermal Control. Since it takes about an hour for one complete rotation, the HGA should come back into view in about half an hour.
056:44:51 Anders: Okay. I know this would be better in high bit rate, so it will probably take quite a while.
056:44:55 Mattingly: Alright.
Very long comm break.
The DSE is capable of three speeds: 3.75, 15 and 120 inches per second (9.5, 38, 304 cm/s). If data is recorded from the spacecraft at high bit rate, 51.2 kilobits/second, then the recorder runs at the fastest of these speeds. If only low bit rate data, at 1.6 kbps, is being recorded, then the slowest of these speeds is used. Since the ratio of speeds and data rates are both 32:1, then the density of data on the recorded tape is the same regardless of the recording speed. Whichever speed is being used, the crew's voices are also recorded on one of the fourteen tracks.
This arrangement with the DSE has a consequence for any crew chat recorded on the voice track. When the tape is dumped to Earth, it always sends at full speed such that all data, whether recorded at high or low rate, is sent at high rate. A side effect of this is that any voice recorded during low bit rate recording will be replayed to the ground thirty two times faster than normal, raising the pitch by five octaves and rendering the voice unintelligibly fast. Since Mission Control asked the crew to add their voices to the DSE, they have done so at high bit rate so that they will be intelligible once Madrid have replayed their recording to Houston. According to John Saxon, an engineer who manned the Australian ground station at Honeysuckle, it was possible to replay the speeded up voice to Houston at 1/32nd speed, restoring its intelligibility.
Frank and Jim settle down for some sleep. It will be the last they get before they reach lunar orbit.
This is Apollo Control at 57 hours, 11 minutes into the flight. Here in Mission Control Center, we've completed the change of shift and Flight Director Milton Windler has gone through the status of the mission with his flight controllers. Now, at the present time, we are preparing for a midcourse correction. This will be the second performed on this translunar leg of the Apollo 8 flight. That first maneuver was, of course, performed with the Service Propulsion System engine. Midcourse maneuvers number 2, numbers 2 and 3, now which had been included in the Flight Plan, were not performed because of the small amount of correction needed and our estimate, at this point, is that midcourse correction number 2 [means four] will be for about 3 feet per second [1 metre/second] and will occur at the nominal time in the Flight Plan of about 61 hours. We've had two brief conversations with the crew since our last report. We'll play those back for you now.
... At the present time, Apollo 8's velocity, as it moves toward the Moon now, is 4,011 feet per second [1,223 m/s], so we are beginning to see an increase in velocity as the spacecraft comes under the influence of the Moon's gravity and begins to accelerate toward the Moon. Our height above the Moon is also showing a continued decrease and now reads 30,021 nautical miles [55,599 km]. Marilyn Lovell, Apollo 8 Command Module Pilot Jim Lovell's wife, was in the viewing room at Mission Control Center for about 30 minutes, viewing activities here in the Control Room and talking with Dr. Robert Gilruth in the viewing room. And she heard the rather brief conversations with the spacecraft during that period of time and she has now left the Control Center. At 57 hours, 16 minutes into the flight of Apollo 8; this is Mission Control, Houston.
057:16:44 Mattingly: Apollo 8, Houston.
057:16:49 Anders: Go ahead, Houston.
057:16:51 Mattingly: Roger. Do you think you're in a position where you could use the High Gain?
057:16:57 Anders: I'll give it a try.
057:16:59 Mattingly: Okay.
Comm break.
057:19:05 Mattingly: Apollo 8, Houston. We're dumping at this time.
057:19:12 Anders: Roger. Tape voice is probable. [Pause.]
057:19:21 Anders: We ought to also get a check on it at low bit rate for DSE voice, Ken.
057:19:31 Mattingly: Apollo 8, are you saying that everything that's on there now is in high bit (rate)?.
057:19:38 Anders: That's where my switch was.
057:19:40 Mattingly: Okay. We'll take a look at it then. If there wasn't anything that was previously recorded in low bit, then we'll come back and maybe take a look at that, too.
057:19:52 Anders: Okay. We might get [garble] if maybe we can get in a little closer to the Moon to put as big a strain on it as we can.
Long comm break.
Bill had recorded the voice with the tape going at its fastest speed. The Madrid station will have no problem with the intelligibility of the voice track as the tape is replayed to Earth at that speed. Had he recorded something at the low speed, this would have provided a test of how Madrid handles the unintelligible voice. Bill suggests that such a test might be carried out closer to the Moon so that the overall system is tested to its operational limit.
057:28:24 Mattingly: Apollo 8, Houston.
057:28:30 Anders: Go ahead, Houston.
057:28:31 Mattingly: Okay. We've completed the dump, and the tape recorder's back to you. You can use it any way you want. We may want to dump that thing again, and if we do we'll go ahead and use the same information unless you have something else that you specifically wanted to put on there later. Listening to the voice quality - it sounds real good. We're coming up on a midcourse [correction]-4 and right now it's - talking about doing it on time, and you can anticipate the burn in the neighborhood of three foot per second [one metre per second]. We're considering, and would like for you to think about, the possibility of doing this burn using the onboard vector and just have us update the vector in the LM slot, so that you will have the MSFN [Manned Space Flight Network] vector on board. But it looks like it won't have any big effect on the burn results, and it might prove interesting. So if you think about that one for a bit and let us know if you have any suggestions or thoughts on the subject.
057:29:39 Anders: Roger. You say it uses the onboard vectors and leaves the MSFN vectors on the LM slot.
057:29:45 Mattingly: That's affirmed, if that's what you would like to do, right. We considered it, and it looks like that would be a reasonable thing.
057:29:55 Anders: Roger. Frank and Jim are asleep now, and I'll bring this up to them when they wake up.
Although Apollo 8 is the first manned flight to the Moon, the quality of its navigation is excellent and belies the pioneering nature of the mission. This is especially true for Jim Lovell's separate and parallel attempt to navigate autonomously. His results are accurate enough that the trajectory flight controllers cannot tell whose numbers are better, theirs or Jim's. Performing the burn based on Jim's numbers would be a great confidence builder for the mission.
The numbers are collectively called a state vector. It consists of six numbers that define the spacecraft's velocity and position at a certain time and, combined with a knowledge of the Solar System, it defines their trajectory. There are spaces for two state vectors in the computer; one for the CSM and the other for the Lunar Module. Of course, on this mission there is no LM so these slots are available. Mission Control are using the LM slots to store a state vector that has been calculated from ground-based tracking. The CSM slots are used to hold the vector that Jim has derived from his observations of Earth, Moon and stars.
As an exercise, Mission Control are considering using Jim's vector as the basis for calculating the size of Apollo 8's final adjustment to their trajectory.
057:30:03 Mattingly: Okay. Real fine. [Long pause.]
057:30:48 Mattingly: Apollo 8, Houston. How about stirring up the oxygen.
057:30:56 Anders: Okay. Stand by.
Very long comm break.
This is Apollo Control at 57 hours, 32 minutes into the flight of Apollo 8. Now we are in contact with the spacecraft at this time and Bill Anders reports that both Frank Borman and Jim Lovell are sleeping at the present time. And we have passed up some preliminary information to the crew on the midcourse correction that they will be performing at 61 hours in their flight. We will ... stand by for any live communication with the spacecraft.
This is Apollo Control and it appears that we have no more communications with Bill Anders during this period. We would also judge that the crew is following the advice of the ground given out yesterday that they set their own pace and sleep when they feel they need it. As you heard, Anders reports both Borman and Lovell are sleeping at the present time. Apollo 8 is continuing now to accelerate toward the Moon. The current velocity reading is 4,018 feet per second [1,225 m/s] now - that's up about 10 feet per second [3 m/s] in velocity in the past 30 minutes. And our current altitude now stands at 29,048 feet or rather 29,048 nautical miles [53,797 km] above the Moon, This is Apollo Control at 57 hours, 40 minutes.
This is Apollo Control at 58 hours into the flight of Apollo 8. We've had no communications with the spacecraft since our last report, and here in Mission Control it has also been rather quiet. At the present time, the spacecraft is at an altitude of 28,225 nautical miles from the Moon and velocity reads 4,024 feet per second. Coming up, in just a little under 3 hours, we have a midcourse correction maneuver scheduled. This is listed as midcourse correction number 4 in the Flight Plan and will actually be the second midcourse correction on route to the Moon. Midcourse corrections 2 and 3, which were listed in the Flight Plan, were such low values that they were not performed and we anticipate that midcourse correction coming up will be for about 3 feet per second, a burn of about 3 feet per second using the spacecraft Reaction Control System. At 58 hours, 1 minute; this is Apollo Control.
058:06:38 Mattingly: Apollo 8, Houston.
058:06:43 Anders: Go ahead, Houston.
058:06:45 Mattingly: Okay, Bill. I guess I want to delay [may mean belay] my last about using the onboard state vector for MCC-4. After looking at it some more on the ground, they've got to get going on making the PAD's and doing all their computations, and rather than put it off or do it twice, we're going to go ahead and go with the procedures we've been using all along.
In other words, Mission Control have elected to use the ground-generated state vector for working out the details of the upcoming burn. Otherwise they would want to make the calculations twice for backup purposes and don't have that time.
Mattingly (continued): On the lunar orbit stuff, we've been looking it over and we got several guys - Jack Schmitt and company in the back room - looking at what effect your windows have. And, basically, it looks like there's two options that will make an impact on that Rev 2. One of the options, of course, will be just to have you and Jim change seats and let Jim look out and get his SAM that way, and another option will be to roll the bird over and let Jim point the optics as far forward as he can get them and take his SAM through the telescope. And I guess we'd like to have any thoughts that you folks have on what you think you can do with the windows; if you have anything, we'd like to factor it into our thinking and go ahead and firm up our plans as early as we can. We'd like not to put it off so that we have none of these things to do after midcourse. You folks can probably tell us more about what you can do with those windows. So if you have any thoughts, go ahead and sing out with them, and we'll see what we can do about factoring that in.
With only the two small forward-facing rendezvous windows clear of the fogging that has affected the other windows, it would seem that for lunar observation and photography, all they have to do would be to aim the spacecraft at whatever they want to view. However, changing the attitude of the spacecraft from what was planned has consequences for the aiming of the HGA the avoidance of gimbal lock, not to mention the consumption their RCS fuel.
058:08:25 Anders: Okay. With reference to the midcourse, I think that's generally agreed upon, that we do it like we've always been doing it. Now, with respect to the windows, center windows, essentially, are usable. The two side windows are - may be alright for observation, and the problem with the rendezvous windows is that they're pretty small. And I just thought we'd have to play the window game by ear almost. Not really sure what capability we're going to have. And we'll give you some more thoughts on this later.
058:09:02 Mattingly: Okay. How about exercising the idea of rolling over and having Jim do his polarization through the telescope because if we have to change attitudes we'd like to go ahead and start thinking about what effects that'll have on such things as antenna orientation and all that.
058:09:24 Anders: Okay. We'll, I'll mention it to them when they wake up.
Very long comm break.
This is Apollo Control at 58 hours, 12 minutes. We have just been in touch with the spacecraft and received a status report from Bill Anders on the condition of the spacecraft windows at this time. We'll ... stand by briefly, for any further communications with the spacecraft.
And it appears that we'll have no further communication at this time with Bill Anders, aboard the spacecraft. We're continuing to monitor the velocity and altitude as it approaches the Moon. At the present time, our velocity reading is 4,030 feet per second [1,228 m/s] and we're at an altitude above the Moon of 27,575 nautical miles [51,069 km]. Our predictions in Mission Control Center are that the velocity will, of course, continue to accelerate as we approach the Moon rather slowly for the next 7 hours or so and we anticipate that by about 65 hours, the velocity will be somewhere around 4,350 feet per second [1,326 m/s]. That would be an increase of about 300 feet per second over what we're showing now. The dramatic increase in the velocity will come between 65 hours and 69 hours, at the point of Lunar Orbit Insertion, when the velocity will just about double, going from 4,350 feet per second up to about 8,420 feet per second [2,566 m/s]. At 58 hours, 18 minutes into the flight; this is Apollo Control, Houston.
058:30:34 Mattingly: Apollo 8, Houston.
058:30:40 Anders: Go ahead, Houston.
058:30:42 Mattingly: Okay. Apollo 8, we'd like to update your CMC clock. This is not to correct errors which we have now but just to make up for some effects that we're going to have in lunar orbit. And what we'd like to have you do is go to P00 and Accept and let us update the clock time.
058:31:04 Anders: Stand by. [Long pause.]
058:31:23 Anders: Okay. You got P00 and Accept.
058:31:25 Mattingly: Roger. Thank you.
Long comm break.
By placing the computer in program 00 and throwing the Up Telemetry switch to the Accept position, Mission Control are given direct access to the computer. In this case, the registers that hold the current value for time are being updated.
Readers should note that the CMC clock is not the same as the mission clock or timer. They are very separate things. One is concerned with time with respect to the motions of the planets while the other is purely concerned with how the crew and Mission Control schedule their work. Indeed, on some missions, the mission timer would be altered to compensate for a late launch, allowing the crew to return to their original schedule.
This is Apollo Control at 58 hours, 37 minutes. At the present time, our spacecraft velocity is 4,037 feet per second [1,230 m/s] and we are at an altitude now of 26,764 nautical miles [49,567 km] above the Moon. We had one rather brief conversation with Bill Anders in the past 15 minutes or so and have not heard from the spacecraft since. During that conversation, we passed up to the spacecraft an update to the computer driven clock aboard the spacecraft and that pretty much summarized the content of that communication. We'll ... pick up live with conversations that are going on at the present time.
058:38:07 Mattingly: Apollo 8, Houston.
058:38:13 Anders: Go ahead, Houston.
058:38:14 Mattingly: Okay. We're completed with the clock update, and the computer is yours.
058:38:21 Anders: Roger. Going to Block.
058:38:28 Mattingly: Roger.
Very long comm break.
Bill places the Up Telemetry switch in the Block position, inhibiting further access by the ground.
058:49:50 Mattingly: Apollo 8, Houston.
058:49:56 Anders: Go ahead, Houston.
058:49:56 Mattingly: How about an O2 purge?
058:50:04 Anders: Okay.
058:50:07 Mattingly: Thank you.
Comm break.
Bill passes oxygen gas through the fuel cells to flush out contaminants from their reactive surfaces.
058:51:26 Anders: There's number 1.
058:51:30 Mattingly: Roger.
Very long comm break.
This is Apollo Control at 59 hours, 22 minutes into the flight. At the present time Apollo 8 is at an altitude of 25,036 nautical miles [46,367 km] above the Moon and traveling at a speed of 4,053 feet per second [1,235 m/s]. Since our last report, we have only had one very brief conversation with the spacecraft. That was a request from the ground that Bill Anders begin a fuel cell purge, supposedly one of the routine bits of housekeeping that the crew will - is carrying out throughout the flight, at specified time intervals and part of this procedure to remove any contaminants that build up inside the fuel cells and could begin to degrade their performance. We will ... stand by for any possible call to the crew.
059:42:19 Mattingly: Apollo 8, Houston.
059:42:24 Anders: Houston. Apollo 8. Go ahead.
059:42:26 Mattingly: Okay. We'd like to update CMC. The order that we'll update will be the LM state vector, the CSM state vector, and then the external Delta-V and the REFSMMAT. So any time you're free with it, we can have P00 and Accept; we'll go ahead with it.
The mission is at page 2-43 in the Flight Plan. In the right-hand column for MCC-H actions, these updates are listed. The first item, P27, is the program the flight controllers will use to alter the computer's memory. They can activate it once the crew have selected P00 and placed the Up Telemetry switch to Accept. After the state vectors are updated, the next item is a Target Load. This is simply the planned Delta-V for the upcoming MCC-4 manoeuvre.
The final item in Mattingly's list is the REFSMMAT update. Up to now, Jim has been using the orientation of the launch pad at Kennedy Space Center at the precise time of launch as the reference orientation for the guidance platform. Each time he has realigned the platform, it has been to return it to the way it was oriented at launch.
Now, as they approach the Moon, they are about to change the orientation of the platform and for this, Mission Control has to send up a set of numbers that define this new orientation with respect to the stars. Before MCC-4 is carried out, Jim will make sightings on the stars to carry out this realignment. The new REFSMMAT is defined as being the spacecraft's predicted attitude at the time of the second LOI (Lunar Orbit Insertion) burn, if it were to be facing heads up in a prograde (pointy end forward) attitude. Since the burn is actually retrograde, the spacecraft would be flying engine-first and so the displays would read 0°, 180°, 0°. This REFSMMAT will be used throughout the lunar orbital phase of the mission. Once the crew are on their way home to Earth, they will use a third reference orientation for the journey home that is relevant to re-entry.
The reason for changing to this REFSMMAT is to make the monitoring of a critical burn easier. The LOI-2 burn is intended to lower their orbit to 110 km circular. It is an important burn to get right as there are scenarios that could cause them to impact the Moon less than an hour after ignition, so there would be little time for bailing out of an incorrect trajectory. Note that during the LOI-1 burn, the FDAIs will not read 0,180,0, but something similar to it. The idea of monitoring using the LOI-2 REFSMMAT is more critical, because the margins for error are smaller.
059:42:53 Anders: I understand you're going to update LM state vector, CSM state vector, and external Delta-V and the REFSMMAT.
059:43:00 Mattingly: Affirmative. And I'll have one, two, three PAD's to read to you.
One of the three PADs will definitely be used - it is the MCC-4 PAD. The other two are abort PADs, to be used in an emergency only to return home without entering lunar orbit.
059:43:12 Anders: Stand by. Okay. You've got P00 and Accept.
059:43:18 Mattingly: Okay, thank you. And just a minute, I'll be with you on the PAD's. They'll be three minute maneuver PAD's, one of them MCC-4.
Comm break.
059:45:19 Anders: Houston, this is Apollo 8. We're ready to copy, if you read.
059:45:22 Mattingly: Okay. Stand by.
059:45:27 Anders: Okay. I thought maybe we had lost comm here for a second.
059:45:31 Mattingly: No, I'm just behind. [Long pause.]
This is Apollo Control at 59 hours, 46 minutes. Capsule Communicator Ken Mattingly has just put a call into the crew. We'll ... follow the conversation live.
059:46:26 Mattingly: Okay. Apollo 8, let me just read you midcourse correction number 4.
059:46:38 Anders: Okay.
059:46:42 Mattingly: Alright. Midcourse correction number 4: the RCS/G&N; 62888; November Alpha, November Alpha; 060:59:54.30; minus 0001.2, minus 0001.1, plus 0001.2; 031, 008, 323; November Alpha, plus 0061.8; 0002.0, 0:11, 0002.0; 17, 296.5, 30.8; Alpha Centauri, up 07.3, left 3.4. For the stars, it will be the primary, Sirius; secondary, Rigel; 129, 155, 010. Over.
The PAD is interpreted as follows: Unusually, there are no additional notes to this PAD.
059:49:25 Anders: Roger. MCC-4, RCS/G&N; 62888; N/A, N/A; 060:59:54.30; minus 0001.2, minus 0001.1, plus 0001.2; 031, 008, 323; N/A. Are you with me so far?
059:50:02 Mattingly: Keep going.
059:50:06 Anders: Plus 0061.8; 0002.0, 0:11, 0002.0; 17, 296.5, 30.8; Alpha-Centauri, up 07.3, left 3.4; primary, Sirius; secondary, Rigel; 129, 155, 010. Over.
059:50:48 Mattingly: That's correct, Apollo 8. [Long pause.]
059:51:05 Anders: And what else have you got?
059:51:07 Mattingly: Okay. I've got one for pericynthion plus 2, and it's a minimum Delta-V solution.
059:51:24 Anders: Roger. Ready to copy.
059:51:29 Mattingly: Okay. That's pericynthion plus 2. RCS/G&N; 62871; November Alpha, and stand by one. Okay. We'll pick up with a pitch trim and yaw trim of Not Applicable; time, 071:07:22.16; minus 0046.8, plus 0025.4, plus 0018.1; 173, 101, 027; November Alpha, plus 0018.7; 0056.3, 5:15, 0056.3; 01, 316.9, 19.8; 044, down 04.4, left 4.5; plus 11.00, minus 025.00; 1296.7, 36198, 137:01:53; primary, Sirius; secondary, Rigel; 129, 155, 010; four jets plus-X. This assumes execution of midcourse correction number 4 and uses the same alignment as midcourse correction. Over.
The PAD is interpreted as follows: The next five parameters all relate to re-entry, during which an important milestone is "Entry Interface," defined as being 400,000 feet (121.92 km) altitude. In this context, a more important milestone is when atmospheric drag on the spacecraft imparts a deceleration of 0.05 g. The additional notes are that the burn will be made using the four RCS jets that aim in the same direction as the SPS engine and whose thrust is along the plus-X axis. Also, the calculations for this PAD assume that MCC-4 has already taken place and that the guidance platform is still oriented to the LOI-2 REFSMMAT.
059:54:33 Anders: Roger. Pericynthion plus 2, minimum Delta-V; RCS/G&N; 62871; N/A, N/A; 071:07:22.16; minus 0046.8, plus 0025.4, plus 00181; 173, 101, 027; NA, plus 0018.7; 0056.3, 5:15, 0056.3; 013, 16.9, 19.8; 044, down 04.4, left 4.5; plus 11.00, minus 025.00; 1296.7, 36198, 137:01:53; primary, Sirius; secondary, Rigel; 129, 155, 010; four jets plus-X; assumes MCC-4 with same alignment. Over.
059:56:10 Mattingly: That is correct, Apollo 8. [Long pause.]
059:56:28 Anders: Houston, Apollo 8. Confirm that boresight star and SPA are exactly the same number and not typographical error.
059:56:47 Mattingly: Roger, Apollo 8. They are checking that. Apollo 8, the computer is yours. You can take it back.
059:57:00 Anders: Roger. Going to Block.
059:57:02 Mattingly: Thank you.
Comm break.
059:59:06 Mattingly: Apollo 8, Houston. [No answer.]
059:59:26 Mattingly: Apollo 8, Houston. [Pause.]
059:59:35 Anders: Houston, this is Apollo 8. Do you copy?
059:59:37 Mattingly: I do now, loud and clear. I've got one more PAD for you, and the confirmation that those boresight star number and the pitch angle are correct at 44.
059:59:54 Anders: Roger. And we are ready to do our P52 preferred alignment at this time. Are you ready?
060:00:02 Mattingly: Affirmative. [Pause.]
060:00:14 Anders: Okay. We are ready to copy.
060:00:17 Mattingly: Okay. This is a pericynthion plus 2 for a fast return. This will be SPS/G&N; 62871; minus 1.61, plus 1.29; 071:06:42.07; plus 4522.4, minus 0621.6, minus 1871.2; 001, 287, 351; November Alpha, plus 0018.7; 4933.6, 6:03, 4911.8; 11, 203.8, 29.6; Earth, up 01.0, right 3.7; plus 14.75, plus 065.00; 1323.9, 36913, 106:09:23; primary star, Sirius; secondary, Rigel; 129, 155, 010; no ullage, assumes execution of midcourse correction 4 and uses the same alignment. The time for MCC-5 for GERU determination - that's Golf Echo Romeo Uniform - this will be a GET of 83:02; use P37 NC-4, steps 1 through 10 and NC-8, steps 3 and 4. I say again, use P37 November Charlie 4, steps 1 through 10, and November Charlie (eight), steps 3 and 4; velocity 400K for corridor control chart, 36507. Over.
The PAD is interpreted as follows: The next five parameters all relate to re-entry, during which an important milestone is "Entry Interface," defined as being 400,000 feet (121.92 km) altitude. In this context, a more important milestone is when atmospheric drag on the spacecraft imparts a deceleration of 0.05 g. The additional notes are that since the SPS tanks would still be full if this burn were executed, there is no need for a so-called ullage burn to settle the propellants to the bottom of their tanks. Also, the calculations for this PAD assume that MCC-4 has already taken place and that the guidance platform is still oriented to the LOI-2 REFSMMAT.
The execution of this burn implies that the crew have lost comm and must determine their own midcourse correction burns using P37, a "Return to Earth" program. However, a glitch in this program makes it unsuitable for working outside Earth's sphere of influence. The PAD included a time when using P37 is recommended (83 hours, 2 minutes GET) and gives the steps from the No-Comm checklist they should use. It also gives the velocity at 400,000 feet altitude they should use when referring to a chart as part of controlling the angle they re-enter at. This is 36,507 fps (11,127 m/s).
060:04:28 Anders: Houston, Roger. This is Apollo 8. You copy?
060:04:32 Mattingly: This is Houston. No joy.
060:04:40 Anders: Roger, Houston. This is Apollo. How you read?
060:04:42 Mattingly: Okay. Loud and clear, Bill.
060:04:47 Anders: Okay, Ken. Pericynthion plus 2, fast return; SPS/G&N; 62871; minus 1.61, plus 1.29; 071:06:42.07; plus 4522.4, plus 0621.6, minus 1871.2; 001, 287, 351; N/A, plus 0018.7; 4933.6, 6:03, 4911.8; 11,2, 038, 296; Earth, up 01.0, right 3.7; plus 14.75, plus 064.00; 1323.9, 36913, 106:09:23; primary, Sirius; secondary, Rigel; 129, 155, 010; no ullage, assume MCC-4, same alignment, MCC-5 GERU determination GET 83:02, P37 NC-4, 0 through 10 and copy NC-8, 3 and 4. Velocity at 400K, 36507. Over.
060:07:10 Mattingly: Okay, Apollo 8. That's correct with one exception: in the PAD format under longitude Noun 61, that is plus 06500. Over. [Pause.]
060:07:31 Anders: Roger. That's what I have, plus 06500.
060:07:38 Mattingly: Okay. That's correct, Apollo 8. [Long pause.]
060:07:52 Anders: And we're ready to copy whatever else you have. [Pause.]
060:08:03 Mattingly: Apollo 8, let's go back and confirm on your minimum Delta-V pericynthion plus 2 that the pitch column is 101; that's the fifth block down.
060:08:19 Anders: Roger. Pitch - Roger, pitch 101.
060:08:25 Mattingly: Okay. Thank you very much. And the item we have left to go is that we'd like to get with you on how you want to handle the problem with windows on Rev 2. [Long pause.]
060:08:59 Anders: Okay: Houston. Stand by on that, please.
060:09:01 Mattingly: Roger.
060:09:02 Anders: Houston, this is Apollo 8. We want you to come up with a suggested redline for RCS usage during lunar orbit, also, please.
060:09:12 Mattingly: Roger. That's in work. [Pause.]
Both the ground staff and the crew are thinking about the repercussions of the fogged-up windows during lunar orbit. The expectation is that they will have to do a lot more manoeuvring to bring the clear rendezvous windows into use and this will cause more RCS propellant to be used up than planned. Bill is asking Mission Control for a quantity reading that they must not go beyond as they perform these extra manoeuvres. There must be sufficient propellant left over to safely carry out the rest of the mission, including emergency contingencies.
060:09:21 Anders: And for your information, Houston, when the Sun is shining on window 5, it's pretty hazy; window number 1 is a little bit better.
060:09:34 Mattingly: Okay. Thank you. [Long pause.]
060:10:10 Anders: Houston, this is Apollo 8. [No answer.]
Jim is about to realign the guidance platform using Program 52 in the computer. For the first time in the mission, the alignment reference, the REFSMMAT, is being changed. Instead of aligning to the launch pad orientation, they will use the calculated ideal orientation of the LOI-2 burn as the basis of the new REFSMMAT (a so-called "preferred" orientation).
The first stage of completely realigning the platform is to call up the platform angles of the new orientation, based on the current orientation. In other words, the platform is at the launch pad orientation and it is to be set to a new orientation that can be expressed in terms of its current orientation.
060:10:20 Anders: Houston, Apollo 8.
060:10:23 Mattingly: Apollo 8, go ahead.
060:10:26 Anders: Roger. We tried to get this realignment. We need - Do you have a maneuver to get us some gimbal angles so we don't get gimbal lock when we get the preferred alignment? [Pause.]
Early in the alignment process, a check is made of the middle gimbal angle the new orientation would yield. If this angle exceeds 70°, the computer shows an error code, 401, which means that at their current attitude, if Jim were to realign the platform to the new REFSMMAT, he would make the gimbals line up in such a way that a condition called gimbal lock may ensue.
The MIT lab who designed the Apollo G&N system borrowed heavily from their previous work on Polaris missiles which had used three gimbals to mount a guidance platform. This saved weight by excluding a fourth gimbal and was less prone to drift. It could also be shown that a 3-gimbal arrangement could do everything required of the mission, as long as care was taken in its operation to avoid a nuisance called gimbal lock.
Gimbal Lock is a notoriously difficult concept to describe verbally, and it benefits from some drawings to help the reader visualise what is going on. Stripped to its essentials, the IMU consists of a stabilised platform (grey with yellow dot in our diagram) mounted within three freely-rotating gimbals; the outer (red), middle (green) and inner (blue) gimbals. Each is connected to the other by bearings which are at right angles to each other.
Gimbal Lock Figure 1
Figure 1 shows the arrangement. The spacecraft structure is represented by the square frame and the three axes are labelled 1, 2 and 3. In figure 2, we imagine that the spacecraft rotates around axis 1.
Gimbal Lock Figure 2
We can see that the bearings at axis 1 accommodate the rotation to permit the platform to maintain its orientation. Return to the arrangement in figure 1 and instead, imagine a rotation around axis 3, as shown in Figure 3.
Gimbal Lock Figure 3
Once again, the bearings on a single axis accommodate the rotation, keeping the platform correctly oriented. Again, starting from figure 1, we will now rotate the spacecraft around axis 2. This is shown in figure 4.
Gimbal Lock Figure 4
As the rotation is taken up by axis 2, notice that the axes 1 and 3 have lined up. For the moment, the platform has maintained its orientation but there is no axis to take up a further rotation like that shown in figure 5.
Gimbal Lock Figure 5
In this situation, the gimbals have "locked" and the platform has moved; the arrangement is no longer able to maintain its orientation. Axis 2 serves the middle gimbal, and so crews talk about making sure the angle on the middle gimbal does not get too large. Angles above about 70° are avoided and this is marked in red on the FDAI (Flight Director Attitude Indicator).
A fourth gimbal to supply the missing axis would have overcome the condition but instead, careful flight planning is used to work around the problem. The computer is even programmed to warn the crews if it is being asked to take the spacecraft towards gimbal lock. In itself, the condition is not dangerous. It simply requires that the platform be laboriously realigned. In extreme circumstances, the crew have the backup orientation from the BMAGs and Gyro Assemblies to fall back on.
060:10:41 Mattingly: Stand by on that.
060:10:45 Anders: Thank you.
060:10:49 Lovell: Houston, on our present position, we'll go into gimbal lock, I figure, to try and get the preferred angle.
060:10:57 Mattingly: Say again, Apollo 8.
060:11:01 Lovell: In running through Program 52, we got a Program Alarm 401 which would indicate that if we continued, we'd drive it into gimbal lock.
060:11:12 Mattingly: Roger. I understand. [Long pause.]
060:12:11 Mattingly: Apollo 8, Houston. This should be an Option 1 like Option 3. [Pause.]
060:12:23 Lovell: Houston, we're doing an Option 1 like Option 3. We keep getting a 401 alarm, which says desired ICDU yields gimbal lock.
060:12:34 Mattingly: Roger. Stand by.
Long comm break.
ICDU is Inertial Coupling Data Unit. This is the encoder that measures the angle of each gimbal. As Mission Control contemplates the gimbal lock alarm, Jim manoeuvres the spacecraft to a different angle to work around the problem and continues with the P52. He is working from page G-56 and 57 in his G&C checklist.
060:19:14 Mattingly: Apollo 8, Houston. It appears that you have maneuvered around the gimbal locks system.
060:19:22 Borman: Roger. Roger.
060:19:25 Mattingly: Okay. Sorry we were late on that answer.
060:19:30 Borman: Thank you.
Comm break.
This is Apollo Control. During that series of conversations with the spacecraft, among the numbers passed up to the crew and then verified and read back down from the spacecraft, was the information that will be used for the midcourse correction coming up at 61 hours. That maneuver is scheduled to be an RCS maneuver using the four Reaction Control System jets on the Service Module, each of those having a thrust of about 100 pounds. So we'd have a total of 400 pounds of thrust. The burn duration is scheduled for 11 seconds and with that much burn time and that much thrust acting on the weight of the vehicle, which is estimated to be at 62,888 pounds, it gives a Delta-V, a change in velocity, of about 2 feet per second. And that velocity change would be in the retrograde direction. It would slow the spacecraft down slightly, having the effect of lowering the perigee, or perilune, at the point the spacecraft passes closest to the Moon. Our computations on the ground give the low point above the surface of the Moon at present, without the maneuver, as 69 nautical miles [127.8 km], The nominal altitude would be 61.5 [113.9 km], and this burn is designed to give us that altitude at pericynthion. The spacecraft will be pitched down and yawed right slightly in the burn, making it retrograde and slightly out of grade. We're now back in conversation with the spacecraft, and we'll pick that conversation up now.
060:21:20 Lovell: Houston, Apollo 8.
060:21:22 Mattingly: Go ahead.
060:21:26 Lovell: Well, we stopped and went through coarse align of P52 and then we got fine align, and pick-a-pair, pick Capella, but she drove and didn't get to any place. I didn't pick Capella, and I can't recognize any out there right now. Can I recycle here and go back and pick a pair? [Pause.]
060:21:54 Mattingly: That's affirmative, Apollo 8.
Long comm break.
Jim's exchange is a little awkward . The term 'coarse align' is usually part of P51, and is done when the platform's orientation is lost, or as part of its initial alignment when it gets powered up.
Having rotated the platform to approximately the correct alignment, Jim then wants to bring it to the precise alignment (a fine align). First, the computer suggests a pair of suitable stars which should be visible in the optics. When he has entered the code for the first star he wants to sight on, he asks the computer to aim the sextant at it. If the coarse alignment of the platform is sufficiently accurate, he can see the star in the instrument's field of view. In this case, the procedure has not worked and he wants to take the program back to an earlier step and try again.
Lovell, from the 1969 Technical debrief: "One glitch that we did see concerned getting the preferred alignments just prior to MCC-4. This was an area which we had never duplicated in the simulator. We had always, in the simulator, started out at that particular spot with the alignment for LO1-2 and we had always ended up in the simulator with the alignment for the REFSMMAT. We have never gotten to do one. It turned out when we went through the preferred alignment technique, prior to MCC-4, we got a program alarm 401. Now, we kept the spacecraft from rolling. We rolled up again until we [garble, possibly 'bypassed'] the alarm. The course alignment which we did, fine align to Capella, and at least that was in the sextant field of view. We [garble] and noticed on Aldebaran and Rigel that a big change was required. The star was very large, and we did not accept this. We again selected the P52, and at the same time we cycled the optics to Zero pitch. I think we came up with number 10 and it drove to the other side of the compass to the proper spot. Then we also got number 12 and we figured that the REFSMMAT and optics were operating correctly, and we did get our preferred alignment."
060:25:27 Lovell: Houston, Apollo 8.
060:25:30 Mattingly: Go ahead, Apollo 8.
060:25:33 Lovell: My plan is to go back into re-enter Program 52 - well, it did not drive to Capella, and I can't recognize it in the scanning telescope. My plan is to go back into recall P52.
060:25:50 Mattingly: Okay. Stand by one.
060:25:54 Mattingly: Apollo 8, can you confirm that you zeroed the optics prior to starting?
060:26:02 Lovell: Roger. That's affirmative. We zeroed the optics. [Long pause.]
060:26:32 Mattingly: Apollo 8, Houston. You have a Go for a second try in P52 with an Option 3.
The software for Program 52 allows one of four optional orientations when realigning the guidance platform. These options are the first thing the crewman selects when he begins with P52.
060:26:43 Lovell: Okay. I now have Aldebaran in the scanning telescope; I might want to call that one instead of Capella.
060:26:50 Mattingly: Okay.
060:26:51 Lovell: I'll see what it comes up with first, though.
Long comm break.
This is Apollo Control. We have just now passed the 30-minute mark in the clock counting down to the midcourse correction maneuver. Now that clock currently reading 28 minutes 35 seconds until the burn, and at the present time, Apollo 8 is at an altitude of 22,211 nautical miles [41,135 km] above the Moon, traveling at a speed of 4,085 feet per second [1,245 m/s]. We'll continue to stand by for any conversation from the spacecraft or the ground to the spacecraft.
060:32:23 Borman: Houston, Apollo 8. We came up with an unacceptable difference in our stars; we're going to have to recycle.
The crucial stage in realigning the platform is to measure the apparent position of two stars in the sky. As a check of Jim's sighting accuracy, the measured angle between them is compared to the known angle. Frank is reporting that, for some reason, this angle does not match expectations. This implies a problem with the sightings as Jim's record in marking the stars is otherwise exemplary.
060:32:29 Mattingly: Roger.
060:32:33 Borman: If we don't get this midcourse in, what will that do to our pericynthion?
060:32:40 Mattingly: Stand by. We'll... [Long pause.]
060:32:59 Mattingly: Apollo 8, Houston. In the event that we don't get this midcourse in, we'll still go for an LOI, and it's been suggested you might try Mirfak which is octal 10.
060:33:12 Borman: That's the one we're trying now.
060:33:13 Mattingly: Roger.
Very long comm break.
If they miss the opportunity to make their midcourse correction, they can still enter lunar orbit, albeit at a higher altitude than planned though this is not a desirable scenario. Mission Control suggest that instead of using Capella or Aldebaran, they try using Mirfak (Alpha Pegasi) which they do along with Rigel (Beta Orionis).The platform realignment goes ahead with no further problems reported.
This is Apollo Control at 60 hours, 40 minutes into the flight; and we're continuing to countdown to our midcourse correction - now 19 minutes, 57 seconds from that maneuver. At the present time the crew is somewhat behind in the Flight Plan, and we suspect they are involved in aligning the inertial measurement unit in the Guidance and Navigation equipment. We just heard from the Guidance Officer that it appeared that that operation was proceeding well at this time. We'll continue to follow activities and monitor for any conversation between the ground and the spacecraft.
This is Apollo Control at 60 hours, 46 minutes. Now we're continuing to monitor for conversations between the ground and spacecraft. It's been a very quiet period what with the crew busily involved in getting ready for the midcourse correction maneuver. That burn is scheduled to occur now in 14 minutes and to resummarize that will be using the spacecraft Reaction Control System thrusters. It will be an 11 second burn giving us a change of velocity of 2 feet per second. That velocity change will primarily be retrograde slowing the spacecraft down by about 2 feet per second in order to lower the pericynthion or point at which the spacecraft passes closest to the Moon. And the burn will also be performed with the spacecraft yawed slightly out of plane. At 60 hours, 47 minutes; this is Apollo Control.
060:51:50 Borman: Houston, Apollo 8.
060:51:52 Mattingly: Go ahead.
060:51:56 Borman: We are all set up and counting down at 8 minutes.
060:52:00 Mattingly: Roger. [Pause.]
060:52:08 Mattingly: Apollo 8, our data is down right now; appreciate making sure you have the tape recorder on.
060:52:19 Borman: Roger. I am going to go - I'll have to go Command Reset. You've got control [of the tape recorder].
Comm break.
This is Apollo Control at 60 hours, 54 minutes. We just heard from the spacecraft. Jim Lovell [means Frank Borman] advised that they are set and apparently ready to go at this time for their midcourse correction maneuver. We will ... stand by for further communications with the spacecraft.
060:53:52 Borman: Houston, Apollo 8.
060:53:57 Mattingly: Go ahead.
060:54:00 Borman: Roger. You have some pitch and yaw angles for our PTC extra burn. [Pause.]
060:54:14 Mattingly: Okay, Apollo 8. That's pitch, 348; yaw, 315.
060:54:25 Borman: Pitch, 348; yaw, 315.
Once the midcourse correction burn is out of the way, the Flight Plan calls for the PTC (Passive Thermal Control) mode to be re-established to keep temperatures on the spacecraft's skin moderated.
060:54:30 Mattingly: That's affirmative. And would you give us another hack on your countdown time?
060:54:39 Borman: It's 5:18, 17, 16, 15, 14.
060:54:45 Mattingly: Thank you.
Comm break.
060:55:51 Borman: Houston, I will give you a mark at 4 minutes.
060:55:53 Mattingly: Alright. Thank you.
060:55:54 Borman: 3, 2, 1...
060:55:57 Borman: Mark. Four minutes.
Comm break.
We are coming up now on 3 minutes until our midcourse correction maneuver. You will note a slight time delay from the time when the spacecraft is counting back and we're watching our clocks here. That's about one and one half second delay one way. Here is another call to the crew.
060:57:05 Mattingly: Apollo 8, Houston. How about switching the Biomed switch over to the left.
060:57:12 Borman: Roger. 3, 2, 1...
060:57:16 Borman: Mark.
060:57:18 Borman: Switched.
Long comm break.
Coming up on 2 minutes now. Still looking good for that maneuver. At the present time, the spacecraft is at an altitude of 21,144 nautical miles above the Moon and traveling at a speed of 4,100 feet per second. We're now coming up on 1 minute, 30 seconds until that midcourse correction maneuver.
The DSE or tape recorder is started as the crew are at the bottom of page G-52 in the G&C checklist, less than a minute away from the burn.
060:59:10 Anders (onboard): DSKY blanks at minus 35 seconds.
The displays on the DSKY (Display and Keyboard) go blank for five seconds before showing the velocities that are to be gained in three components. This confirms to the crew that the program is running correctly in the computer. When the displays return, the Guidance system is in the "Average G" mode where it is integrating the accelerations it senses.
060:59:14 Lovell (onboard): Alright, stand by.
060:59:17 Lovell (onboard): DSKY blank.
060:59:19 Lovell (onboard): Okay.
060:59:20 Anders (onboard): Limit Cycle, Off.
060:59:23 Borman (onboard): Limit Cycle, Off.
060:59:24 Anders (onboard): EMS Mode, Auto.
060:59:25 Borman (onboard): Auto.
060:59:28 Anders (onboard): Okay, at zero [i.e. ignition] [Verb] 16 [Noun] 85, null VGX, Y. and Z. Null component. Tell me when you're going to burn.
In other words, when the count reaches zero, the computer should flash Verb 16, Noun 85 and display three velocity components, VGX, VGY. and VGZ. These are the velocities to be gained in each of the three axes and the engine firing should bring them all to zero.
This is Apollo Control at 60 hours, 59 minutes, 41 seconds; and we're counting down now the last 10 seconds to our maneuver. We should have the beginning of that 11-second Reaction Control System maneuver at this time. We will stand by for confirmation here on the ground. We show the burn completed at this time."
060:59:43 Borman (onboard): Okay, stand by.
060:59:47 Borman (onboard): At the flash.
060:59:50 Anders (onboard): 4, 1...
060:59:55 Lovell (onboard): Burn.
060:59:58 Borman (onboard): 11 seconds.
061:00:00 Anders: Burning.
061:00:01 Lovell (onboard): 11 seconds.
061:00:09 Lovell (onboard): Should be Off by now.
061:00:12 Borman (onboard): [Garble.] That's good.
061:00:13 Anders (onboard): Okay, 12 seconds.
061:00:15 Lovell (onboard): 12 seconds?
061:00:16 Anders (onboard): Okay, record Delta-V Counter, residuals; Tape Recorder is going to Stop
061:00:55 Lovell (onboard): Okay, now do Verb 66, Enter.
061:00:57 Anders (onboard): Verb 66, Enter.
Verb 66 moves the state vector to the LM slot.
061:01:02 Lovell: Houston, Apollo 8.
061:01:05 Mattingly: Go ahead.
061:01:08 Lovell: Roger. Burn on time, angles nominal, burn time about 12 seconds, 0.2 feet per second after the Delta-VC, 0 in VGX. We have transferred the results of the burn over to the LM slot with Verb 66.
The crew had two velocity displays in front of them during the burn. The prime display was the DSKY showing the three components as determined by the G&N system. The other was the Delta-V display on the EMS which based its value on its own accelerometer. It provides a backup display of the progress of the burn.
The burn has modified the spacecraft's state vector, stored in an area of memory set aside for it. Jim has made a copy of it in another area, one normally set aside for the Lunar Module's state vector.
061:01:30 Mattingly: Roger. And got a couple of items to clean up. We will get you an RCS budget. We've got one redline now; we are trying to get some firmer numbers for you, and we'll have those in a little bit. Right now your use - your PTC usage is right on the Flight Plan line, so everything looks pretty good there. We want to get a crew status report from you. We'd like to firm up the Rev 2 Flight Plan idea; and sometime at your convenience, we'd like to take a reading of the PRD [Personal Radiation Dosimeter] for the Commander and CMP and then have you swap them. We are trying to isolate the - what the possible reason is for the discrepancies or the disparity in the two readings.
061:02:29 Borman: Roger. [Long pause.]
061:02:58 Borman: And we are maneuvering to the PTC attitude, Houston.
061:03:01 Mattingly: Roger.
Comm break.
061:05:17 Mattingly: Apollo 8, Houston. Could you give us the sign of that Z residual? [Long pause.]
061:05:40 Lovell: Stand by, Houston.
061:06:05 Lovell: Alright, Houston. Looks like we didn't record just the Z. We recorded Delta-VC, which is minus two tenths.
061:06:16 Mattingly: Okay. Understand.
061:06:17 Lovell: And Z was one tenth 0.1, but we didn't get the sign.
061:06:24 Mattingly: Roger. Understand that was Delta-VC was minus 0.2. I copied Delta-VZ; Zulu is 0.2. Is that incorrect?
061:06:39 Lovell: Roger. It was 0.1, but we didn't get the sign.
061:06:44 Mattingly: Okay. Thank you.
061:06:46 Anders: We can get it. We have it on the tape, Houston, whenever you want to dump it.
061:06:54 Mattingly: Roger. Thank you.
061:06:57 Anders: It'll be about the last 5 minutes worth.
061:07:00 Mattingly: Roger. [Long pause.]
061:07:59 Anders: Okay, Houston, for the PRD's: CDR is 0.07, CMP is 0.64, LMP is 0.80. Note that the CMP's hasn't changed since we started and the Commander's hasn't changed much. We have swapped PRDs; Commander has LMP, CMP has Commander's, and LMP has CMP's PRD. Over.
061:08:27 Mattingly: Okay. Thank you.
Comm break.
Since the last report of PRD readings eight and a half hours ago, Frank's meter has registered 0.01 rads, a dose equivalent to about a tenth of what a human would receive from a chect x-ray. Jim's PRD has not changed and Bill's seems to be amiss, having jumped. Mission Control have noted the disparity and are working the problem.
This is Apollo Control. Based on this information passed back from the crew on that midcourse correction, and our figures here on the ground, it appears that the maneuver was within about 0.2 of a foot per second of being right on the nominal and that would put us very close to the preplanned pericynthion of 61½ nautical miles. We, of course, will be tracking the spacecraft following this maneuver to determine just exactly what effect it did have. But that was the preplanned (Delta-V). That maneuver would have had the effect of lowering the pericynthion by about 6 or 7 nautical miles. At 61 hours, 10 minutes into the flight, Apollo 8 is currently at an altitude of 28,676 nautical miles [53,108 km] and traveling at a speed of 4,107 feet per second [1,252 m/s]. This is Apollo Control, Houston.
061:09:53 Lovell: Houston, Apollo 8.
061:09:57 Mattingly: Go ahead.
061:10:01 Lovell: Roger. Crew status report as follows: water, the Commander has about 50 clicks so far today; CMP, 43; and the LMP is 44. We've eaten two meals so far today. Day 3, meal A and B; consumed most of it except for the - the hard, hard bites, which no one cares for. Pudding was outstanding. [Pause.] We're at a gain of pericynthion now of plus 63 [nautical] miles [117 km]. [Pause.] Commander and CMP have had a rest period just before the midcourse 4 of about 2 hours.
061:11:07 Mattingly: Roger.
Long comm break.
One of Jim's last tasks related to the burn is to calculate their new pericynthion using P21, the ground track determination program based on their revised state vector.
061:16:11 Lovell: Houston, Apollo 8.
061:16:13 Mattingly: Go ahead.
061:16:18 Lovell: We're at a gain of about 20,500 miles from the Moon at 61:14. How does that agree with what you figure?
Comm break.
Using P21, Jim enters a time (in this case, 061:14) and the computer replies with a position above the Moon's (or Earth's) surface and an altitude. Mission Control will reply in about 4 minutes to Jim's request for a comparison with the ground's tracking.
061:19:18 Mattingly: Apollo 8, Houston. Looks like you're on the secondary loop. We would like to run that for about 5 minutes.
Bill is going through a check of the ECS (Environmental Control System) per page S-6 to ensure it is all working before committing the spacecraft to lunar orbit. Jim also carries out a check of the Service Module's RCS system per page S-1.
061:19:28 Borman: Roger. We're doing the ECS redundant component check.
061:19:31 Mattingly: Roger. We'll follow.
061:19:32 Borman: Getting any data now Houston? Guess you are. Okay. See you stopped my tape then. I've been running for about 3 extra minutes here to record the check.
061:19:45 Mattingly: Roger. We have data now. That was a temporary loss. [Pause.]
061:19:55 Borman: What's the matter? Was it chow time down there?
061:19:58 Mattingly: Rog. [Pause.] Didn't know you could smell it that far away. [Pause.]
061:20:13 Borman: Give me a call when you're satisfied with the secondary loop; it's stabilized out here pretty well.
061:20:18 Mattingly: Wilco, and you might tell Jim that RTCC is about 4 miles off; we had 20,496 [nautical miles, 37,959 km].
061:20:34 Lovell: Fine. [Long pause.]
This shows the incredible accuracy of the onboard and ground navigation systems. At a distance of approximately 200,000 nautical miles, the difference between the two is only 4 miles or 0.002 per cent.
061:21:07 Borman: We just put compressor 2 on AC2.
Comm break.
061:22:23 Borman: Houston, Apollo 8. Do you show battery B as voltage dropped some from the post-charge value? Over. [Long pause.]
061:23:51 Mattingly: Apollo 8, Houston. Confirm that battery B is a little bit lower, and this is attributed to the parasitic loads that are on there.
061:24:06 Anders: Okay. I just didn't see the same kind of drop for A. So if you think it's okay, it's fine.
061:24:11 Mattingly: That's affirm. You don't have the same parasite loads on that; B is actually drawing some.
061:24:20 Anders: Okay. I guess that's the radiators, huh? [Long pause.]
061:24:39 Mattingly: Apollo 8, Houston. We've seen enough of the secondary evaporator. We would like for you to wait about 2 minutes between the time you go to Reset and the time you turn the pump off.
061:24:53 Anders: I agree; good idea. [Pause.] And we plan to leave the water control in Auto.
061:25:09 Mattingly: Roger.
Long comm break.
This is Apollo Control at 61 hours, 29 minutes. A preliminary figure on the effects of that midcourse correction performed at 61 hours indicates that our height of perigee will be 62.3 nautical miles [115.4 km] as a result of that maneuver. Now we have been shooting for something on the order of 61.5 [113.9]. 62.3 is very good, and the flight controllers here in Mission Control Center are quite happy with that figure. The spacecraft also computed height of pericynthion following the maneuver and we heard from Lovell - their onboard computation was that the maneuver would have placed their pericynthion at 63 nautical miles. So we have very close agreement between the ground computer figure in that case and the onboard computation. We'll ... stand by for any communications that should develop. ...
061:31:30 Mattingly: Apollo 8, Houston.
061:31:34 Borman: Go ahead, Houston. Apollo 8.
061:31:37 Mattingly: Okay. Looking over the - our redundant component check, it appears we have not yet checked the integrity of the secondary loop radiators; and if you haven't done that, some time we would like to open up the secondary radiators but not flow through them and just measure the accumulator pressure.
061:32:03 Borman: Stand by. [Long pause.]
The pipes of the secondary loop radiators actually run through the same radiator panel as the primary pipes while being a separate set of pipes.
061:32:42 Borman: Houston, we don't show that in our pre-LOI check, but we're willing to go ahead and do it if you want to.
061:32:50 Mattingly: Rog. We just noticed that it isn't there, and, yes, we would like to. [Pause.] You understand that we are not proposing that you flow, but merely we check for any pressure decay.
061:33:10 Borman: Roger. Wait 'til I get my trusty assistant here to help me.
Comm break.
The trusty assistant is Bill whose particular responsibility on this flight is the spacecraft systems including the ECS.
061:34:20 Borman: Okay, Houston. We're going to blow the secondary - or we're gonna open the secondary RAD for 30 seconds now.
061:34:27 Mattingly: Roger. [Pause.]
061:34:38 Borman: Looks pretty good.
061:34:40 Mattingly: Sure does. [Long pause.]
061:35:05 Borman: Okay. They're closed now.
061:35:07 Mattingly: Okay. Thank you. Looks good.
061:35:11 Borman: Roger. No meteoroids yet.
Long comm break.
Almost certainly this is a check to see if the secondary radiators are in good shape, with no leaks caused by meteorites or whatever.
This is Apollo Control. During that conversation with the crew, Jim Lovell gave us a status report on the eating and drinking and sleeping that they've done recently. And he said that they have logged 50 clicks of water for the Commander, and 33 clicks for the Command Module Pilot, and 44 clicks for the Lunar Module Pilot. That translates into one half ounce per click which would be about 25 ounces for the Commander; about 21 or 22 ounces for the Command Module Pilot and about the same amount of water for the Lunar Module Pilot. Lovell noted that they have all had two meals today. And found the pudding particularly palatable to them, and also you heard Lovell relay the onboard figure for the height of pericynthion, the closest approach of the spacecraft to the Moon following that midcourse correction maneuver. We'll continue to monitor for any conversations with the crew, and if we don't pick up communications in a minute or so, we'll take the circuit down and standby to come up again when there are further conversations.
The crew get their water from three sources. Drinking water comes from the potable tank via a dispenser which delivers in half-ounce (14-gram) spurts. Two spigots at the food preparation station deliver hot or cold water for mixing with dehydrated food. This water is dispensed in one-ounce (28-gram) increments.
061:38:48 Mattingly: Apollo 8, Houston. You take your tape recorder to stop, why, we'll reset it then and give it back to you.
061:39:00 Borman: Roger. It's stopped.
061:39:02 Mattingly: Thank you.
Very long comm break.
This is Apollo Control at 61 hours, 41 minutes; and at the present time we show 7 hours, 17 minutes until our Lunar Orbit Insertion maneuver. I will pass along to you information on that maneuver as soon as it is available. In the meantime we anticipate things will be quieting down somewhat both here in Mission Control Center and aboard the spacecraft. The Flight Plan is relatively quiet for the next several hours. It doesn't begin to pick up activity again until about 3 hours prior to the Lunar Orbit Insertion maneuver at which time the crew will begin checking out the guidance and navigation equipment and running through their systems checks and preparation for that maneuver. And here on the ground, they will be passing up the information needed to carry out the maneuver and the crew will be checking this against their onboard figures and against the information that is automatically loaded into the computer from the ground. We'll continue to stand by for any communications that should develop. As I said we do expect that the insuing several hours will be quiet. At 61 hours, 43 minutes; this is Apollo Control.
061:53:18 Mattingly: Apollo 8, Houston.
061:53:23 Borman: Go ahead.
061:53:25 Mattingly: Okay. We still need to talk about the Rev 2 attitudes we're going to use to work around the fact that you have a fogged center window. Whenever that's convenient, we'd like to go over what your thoughts are on the subject so we can make sure we can get our Flight Plan squared away.
061:53:47 Borman: My thoughts are to make to do with the best with what we have. We are not interested in changing a lot of things right now, Ken.
061:53:55 Mattingly: Okay. The one proposal that sounds like it has some advantage to it: if we let Jim do his evaluation through the telescope, you do everything exactly the same except you turn and roll over 180 degrees so that your head's up, and let Jim do his tracking through the telescope and you'll still be a yaw right when you go to pick up your TV and that type of thing. It looks like that probably will cover everything. We can do that or we can just go as is and just have to let some of that tracking evaluation go by. Another alternate would be to have Jim look out the right-hand rendevous window, and you may have to change your attitude in order to get the same picture there also. [Long pause.]
On page 2-53 of the Flight Plan, 72 hours GET, there is a call for Jim to make a visual sighting of a pseudo landing site 150 km east of the crater Maskelyne in Mare Tranquillitatis using the hatch window. This window is now badly fogged up and Mission Control suggest using the scanning telescope on the opposite side of the spacecraft instead.
061:55:08 Borman: I think we'll try to do that, but I don't - this is one of the things that we'll work out when we get there.
061:55:16 Mattingly: Okay. The reason we were looking into it in the Flight Plan is, if you do want to try rolling over and flying heads up or something of that nature, we can help Bill get a little more out of his photography by giving him new film settings and that type of thing. We'll have something like that available; in case you do fly heads up, why, we'll have some numbers we can call up for film settings.
061:55:45 Borman: Thank you.
Comm break.
If the crew were to be lying on the couches, the spacecraft windows would be near their heads with their feet facing the Lower Equipment Bay and the spacecraft optics. Therefore, to fly in a "heads up" attitude means the optics will be facing the lunar surface while the hatch window will be facing out into space.
061:57:15 Borman: Houston, Apollo 8.
061:57:17 Mattingly: Go ahead. [Pause.]
061:57:22 Borman: Roger. We are going to have to dump some urine here shortly. Will this bother your tracking? [Long pause.]
061:57:42 Mattingly: Apollo 8, we're checking on that with the tracking people now. [Long pause.]
061:58:01 Borman: Houston, just give us the time when we can start on it, and we'll hold off until you say so.
Expelling anything from the spacecraft imparts a minute thrust. This is especially true for watery liquids where there is rapid expansion as they meet the vacuum of space. The thrust causes very small perturbations in their trajectory and may affect the accuracy of the spacecraft tracking from Earth.
061:58:06 Mattingly: Okay. And you can anticipate a handover between stations here on the hour, and you might get a slight glitch as we go through. I'll give you a call when we get back.
061:58:21 Borman: Thank you, Ken. What station are we going to be going to, Ken?
061:58:32 Mattingly: Okay. We'll be going to Honeysuckle.
061:58:37 Borman: Thank you. [Long pause.]
This is Apollo Control at 61 hours, 58 minutes; and at the present time Apollo 8 is at an altitude of 18,733 nautical miles [from the Moon, 34,693 km], traveling at a speed of 4,139 feet per second [1,262 m/s]. Since our last report we've had a couple of conversations with the crew in which we've discussed the - some of the methods for working around the fogged windows that the crew has on the spacecraft in order to carry out the planned tasks in lunar orbit. And we'll ... continue to stand by for live conversations from the spacecraft.
061:59:31 Mattingly: Apollo 8, Houston. You're cleared for a dump at this time, and I understand this is the last gas station for a long time.
In other words, it is their last opportunity to get rid of urine until they make lunar orbit in seven hours time. Mattingly's play with words refers to long trips in cars where the only available toilets were in refuelling stations along the way (gas is gasoline or petroleum).
061:59:42 Borman: You mean you don't want us to dump after this for a while?
061:59:45 Mattingly: That's affirm. Due to the tracking as you approach the LOI, they would like to minimize any of these type of perturbations.
Long comm break.
062:04:06 Mattingly: Apollo 8, Houston through Honeysuckle.
062:04:11 Anders: Roger. Houston through Honeysuckle. We read you loud and clear.
062:04:15 Mattingly: Okay. Good morning.
062:04:20 Anders: Good morning.
062:04:23 Mattingly: Thought you went to sleep.
062:04:25 Anders: You got off over to Australia - you got over to Australia pretty fast.
062:04:30 Mattingly: Rog. [Pause.] That gas station call wake you up?
062:04:41 Anders: Man, I've been all eyeballs and elbows here for the last several hours.
We would guess that Bill means he is wide awake and moving about.
062:04:57 Mattingly: I'll bet. If you've got nothing else to do, I do have two charts in your LOI table that I need to give you more update numbers on.
062:05:04 Anders: Standby. [Long pause.]
062:05:21 Anders: We'll get our LOI tables man [i.e. Jim] on the line here. Houston. Stand by.
062:05:25 Mattingly: Rog. [Long pause.]
062:06:07 Lovell: Okay; Houston, CMP here. I understand you have some updates for me.
062:06:12 Mattingly: Yes, sir; I've got a couple of charts in your chart book under LOI, and I have some numbers to fill in, one of them being the chart of LOI Delta-V magnitude versus abort Delta-V.
062:06:35 Lovell: Okay. Stand by, and I'll get it out.
062:06:37 Mattingly: Roger. [Long pause.]
062:07:04 Lovell: Okay, I have the chart out. Go ahead.
062:07:06 Mattingly: Alright. Mode 1, 5 hours; roll, 1.38; pitch, 7.89; yaw, 357.37. Mode 1, 15 minutes; roll, 180.73; pitch, 29.46; yaw, 1.65. Over.
062:08:11 Lovell: Roger. The new attitudes for the Mode 1, 5-hour, Mode 15 minute are as follows: roll; for the one - Mode 1, 5-hour; roll, 1.38; pitch, 7.89; yaw, 357.37. Mode 1, 15 minute; roll, 180.73; pitch, 29.46; yaw, 1.65.
062:08:43 Mattingly: Okay. That is correct. Now I also have to give you a couple of points to plot on that curve. The present curve you have drawn is based on a 60-mile perigee or perilune, and you right now have a 62-mile pericynthion; and the reason that your target is for 62 miles is to pass over the landing site, so I have five sets of coordinates for you to copy.
062:09:16 Lovell: Is this to go on the same chart to redraw the curve?
062:09:19 Mattingly: That's affirmative.
062:09:24 Lovell: Okay. Go ahead.
062:09:27 Mattingly: Okay. We'll go in on the LOI Delta-V magnitude, 1600; abort Delta-V, 2450, two-four-five-zero. [Long pause.]
062:09:59 Lovell: Okay. LOI Delta-V magnitude, 1600; abort Delta-V, 2450. Stand by just one. [Pause.] I have it; continue.
062:10:20 Mattingly: Okay. The next one is the LOI Delta-V, 2000; abort Delta-V, 3130. [Long pause.]
062:10:47 Lovell: Roger. I've got that plotted.
062:10:51 Mattingly: 2400, LOI Delta-V; abort Delta-V, 3880, three-eight-eight-zero. [Long pause.]
062:11:18 Lovell: I've got it plotted.
062:11:20 Mattingly: 2800, LOI; abort Delta-V, 4700. Over. [Long pause.]
062:11:46 Lovell: Roger. I have that one plotted, too.
062:11:50 Mattingly: Alright. The last one is LOI Delta-V, 2990; abort Delta-V, 5114. That is almost directly into the end of the present curve; 5114. [Pause.]
062:12:20 Lovell: Say again the LOI Delta-V magnitude, please.
062:12:24 Mattingly: Okay. LOI Delta-V, 2990.
062:12:31 Lovell: Roger. 2990. [Long pause.] Okay. I have it plotted.
062:12:49 Mattingly: Alright. And on the next one, you should have a chart, number 10, and we have three numbers to go in there for a Mode 3 gimbal angle. [Long pause.]
062:13:06 Lovell: Roger. Go ahead with the Mode 3 gimbal angles.
062:13:12 Mattingly: Roll, 180.87; pitch, 42.31; yaw, 1.65.
062:13:36 Lovell: Mode 3 gimbal angles are as follows: roll, 180.87; pitch, 42.31; yaw, 1.65.
062:13:48 Mattingly: Roger. That's correct.
062:13:56 Lovell: Could you please send up a French curve for me?
062:14:00 Mattingly: Rog.
For those not versed in technical drawing of the period (prior to Bezier curves on computer screens), a French curve was a template with an outline consisting of various curves with which lines of almost any curvature could be drawn.
062:14:03 Borman: Send up a couple.
062:14:07 Mattingly: The only one I have is about 6 foot. [Pause.]
062:14:18 Borman: Houston, could you give us some gimbal angles to point at the Moon? I never have seen it the whole trip, and I'm wondering which way it is from us now.
062:14:26 Mattingly: Roger. 180.
Comm break.
062:16:35 Lovell: Houston, Apollo 8. Radio check.
062:16:38 Mattingly: Roger. Loud and clear.
062:16:42 Lovell: Roger. [Pause.]
062:16:47 Mattingly: We are getting ready to give you a rundown on your systems. We're going over all the final steps, and we will tell you what we see in the way of trajectory and systems information. And once again, Dr. Joe Kerwin has brought over all the latest news, and we can read that up to you a little bit at a time if you don't go to sleep.
062:17:12 Borman: What's he going to do, read out of the AMA [American Medical Association] Journal?
062:17:20 Mattingly: Roger.
Joe Kerwin became an astronaut in 1965 as part of the fourth group selected by NASA, all drawn from the scientific community. A physician and naval aviator, Kerwin entered space on 25 May 1973 with Pete Conrad and Paul Weitz as part of the first Skylab crew.
062:17:23 Lovell: Go ahead. We are all ears.
062:17:25 Mattingly: Okay. Here is one: the previously scheduled 72-hour cease fire by the Viet Cong went into effect today, 17 hours before the allied truce was to begin.
062:17:57 Borman: You lost us on the numbers there. What was that again?
062:18:04 Mattingly: The gist of it was that the VC went into a cease fire earlier than the truce that we had planned on, as a Christmas holiday type.
062:18:25 Borman: Roger. Good.
Long comm break.
This is Apollo Control at 62 hours, 24 minutes; and at the present time, Apollo 8 is traveling at a speed of 4,159 feet per second [1,268 m/s] or presently at an altitude of 17,657 nautical miles [32,701 km] above the Moon. We have some preliminary information on the Lunar Orbit Insertion maneuver. We anticipate that this information will be refined and updated as we get additional tracking information on the spacecraft. At the present time we anticipate that the maneuver will be performed at about 69 hours, 8 minutes Ground Elapsed Time and the burn will be a total duration of about 4 minutes, 2 seconds and it will slow the spacecraft [by] about 2,990 feet per second [910 m/s]. We anticipate that the velocity at the beginning of the burn will be about 8,400 feet per second [2,560 m/s]. This will give us a velocity following the maneuver of about 5,400 feet per second [1,650 m/s]. We have had some conversations with the spacecraft since our last report. We are in communication with the crew at the present time. We'll pick ... whatever live communications are going on ...
062:21:36 Borman: Houston, how do you read? Apollo 8.
062:21:38 Mattingly: Loud and clear. Sorry to have stepped on you there. We are going over the summary of the systems data.
062:21:49 Borman: Okay.
Long comm break.
062:31:19 Mattingly: Apollo 8, Houston.
062:31:24 Borman: Go ahead, Houston. Apollo 8.
062:31:26 Mattingly: Okay. I have a rundown on your systems here, G&C status. Everything looks real...
062:31:38 Borman: Just a minute.
062:31:42 Mattingly: Go ahead. [Pause.]
062:31:52 Borman: I want to wait until the LMP gets on the head set, Houston.
062:31:55 Mattingly: Roger.
Comm break.
062:33:11 Anders: Okay, Houston, go ahead. EECOM's on the line.
Bill's specialisation on spacecraft systems has earned him the nickname of EECOM, the term given to the flight controller with similar responsibility on the ground.
062:33:19 Mattingly: Okay. We'll just start with EECOM business, then. I'll give you a summary of your batteries; battery A, we calculate 38.3 amp-hours. battery B...
062:33:36 Anders: Stand by a second, Ken. [Pause.]
062:33:46 Anders: Let me get my chart out.
062:33:49 Mattingly: Roger.
062:33:53 Anders: Go ahead now.
062:33:55 Mattingly: Okay. Battery A, 38.3; battery B, 36.9; battery C, 38.5. That's looking pretty good. It looks like we got all the things back in that we took out, and we're running right along prediction. We would like to get a battery C voltage from you if you can just reach over there and switch it. [Pause.]
062:34:28 Borman: Roger. Thirty-seven volts, on battery C.
062:34:34 Mattingly: Rog. Thirty-seven volts. Okay. The predicted cryo quantities at [CM/SM] Sep: on oxygen tank 1, 170 [pounds, 77 kg]; oxygen tank 2, 170 [pounds, 77 kg]; hydrogen 1, 19.5 [pounds, 8.8 kg]; and hydrogen 2, 10.0 [pounds, 4.5 kg]. You essentially have single cryo tank capabilities all the way at full power now.
062:35:14 Anders: Fine.
The mission could continue with full electrical power using only one oxygen and one hydrogen tank all the way to Earth re-entry.
062:35:17 Mattingly: The secondary coolant loop really looked good. Looks like you had a nice tight radiator and everything else on there was working right along the performance curves. Your main oxygen regulators both filled at 104 psi during our check. Looking at the lunar orbit, expect to be doing a water boil of about 1 pound per hour, and this is just an approximation; there's quite a variety of estimates as to what the water boiling requirements may be, might go anywhere from boiling lots to not boiling at all.
Systems engineers in Mission Control can estimate the cooling requirements of the spacecraft while in lunar orbit, and the ability of the radiators to dissipate that heat in the lunar environment. Those estimates lead to a determination of how much excess heat needs to be lost using the evaporator, a device that removes heat by evaporating water and which only comes into play when the radiator does not do the whole job. Mattingly points out that there are many unknowns in this estimate that make it rather tentative.
Mattingly (continued): The next water dump will be coming up after TEI (means LOI), so you don't have to worry about any of that until you get through. Communications predictions are looking good, possibly a little bit better than what we had hoped for, and looks like we're going to get high bit rate on Omni's with our 210-foot dish at Goldstone. This will be working for us on the first couple of rev's, and then we'll be switching sites, so we'll go back to using Omni's [means the HGA] for high bit. The voice quality on DSE is good. Your fuel cells have been running above nominal for the entire flight, and they really look nice and stable. [Pause.] There's been some destratification...
062:37:04 Anders: [Garbled] on normal voice, doesn't it? [Pause.]
062:37:11 Mattingly: Okay. Looks like may not be able to hack the normal voice. On the cryo tanks, we've had quite a bit of destratification, particularly in the oxygen, and you notice this during the fan cycles and Delta-V's, so we're going to be sure and we'll remind you again to stir up the oxygen prior to LOI.
After a long period of weightlessness, the contents of the cryogenic tanks, both oxygen and hydrogen, begin the settle into layers of differing density around the probe that senses tank quantity. The erroneous quantity reading that results only comes good when something happens to disturb this "stratification", either when internal fans are used to stir the tanks or an engine burn applies a temporary g-force.
Mattingly (continued): CMC [Command Module Computer] is running along like clockwork. G&C tells us that the RCS quantities are looking good. You're using the same amount as predicted for your PTC and for your alignment. What we have in the way of a redline: we're going to tell you that you can use 30 percent per quad in lunar orbit. Now this is quite a bit of fuel to play with, and you can take 30 percent and subtract that from what you have to completion of LOI, and that will be a good number.
062:38:27 Mattingly: On the SPS, the oxidizer and fuel feed line temperatures are 75 [degrees Fahrenheit, 24°C] and holding steady. The Service Module RCS quad package temps are cycling and holding between 120 and 140 [degrees Fahrenheit, 49°C and 60°C], and looks like we're getting good normal heater operations. We plan to have you in a 60-[nautical] mile [111 km] circular orbit after LOI-2. [Pause.] And we should have some PAD's for you on the LOI burn at about 67 hours. [Long pause.]
062:39:30 Borman: Roger. We got all that.
062:39:32 Mattingly: Okay. We're still going through the tracking, and as you know, we're going to hold down on the water dumps and so forth during the last couple of hours in and out, sort of aid the tracking procedures. Everything's running along the line normally now. Do you have any other specific questions? We are looking for an angle on the Moon. I guess that about summarizes the system. Everything looks Go right now.
To track the spacecraft from Earth, engineers measure both the velocity of the spacecraft and its range with respect to the ground antenna. The velocity is derived by carefully monitoring how the Doppler effect alters the frequency of the received radio signal. Though it gives only a radial velocity (that which is towards or away from the antenna) it is enough for the computers to use in their trajectory calculations. Measuring the distance between the spacecraft and the Earth station (i.e. range) is achieved by timing the return trip for the signal. A code is embedded into the signal which is delayed by the length of the round trip. Accurate measurement of this delay yields the range. These measurements are exquisitely accurate and are particularly important to ensure the spacecraft arrives at the desired altitude around the Moon's far side for the LOI burn. Unwanted small thrusts from water dumps are avoided for now to maximise this accuracy.
Mattingly also informs the crew that they are working on a set of attitude angles to which the crew can manoeuvre so they can view their approaching quarry, the Moon.
062:40:06 Borman: Okay, Ken. Thank you. We just completed day 3, meal C, and now we're going to break up and each take a rest period before LOI.
062:40:18 Mattingly: Okay, real fine. Everybody wanted to ask if you wouldn't try and get some sack time here before we go in. It's going to be a big day.
062:40:31 Borman: Roger.
Very long comm break.
This is Apollo Control. At the present time, the spacecraft is traveling at a speed of 4,176 miles - rather, feet per second [1,273 m/s], and the altitude [above the Moon] is 16,814 nautical miles [31,139 km]. You heard the crew advise they do hope to get some rest now before activity picks up leading toward the Lunar Orbit Insertion maneuver. According to the Flight Plan, they'll have about 3 hours of relative quiet in which they will be able to get some rest prior to picking up activities leading toward that maneuver. Such things as preparing the guidance and navigation system, checking out the spacecraft systems, and getting set up for that maneuver. We'll continue to monitor for any conversation. We do anticipate that it will be relativly quiet, and we'll come back up in the event that we hear anything from the crews and we'll give you periodic status reports. At 62 hours, 46 minutes; this is Apollo Control.
062:58:21 Mattingly: Apollo 8, Houston.
062:58:26 Borman: Go ahead.
062:58:28 Mattingly: Finally found out where the Moon is, and (at) your present PTC attitude - if you happen to look out the right window [window 5, beside Bill's couch] as you go by - roll attitude of 320, it should be there.
062:58:46 Borman: Thank you.
Long comm break.
If they do see the Moon, it will be a very thin crescent as they are approaching the night side of the Moon.
This is Apollo Control at 63 hours, 4 minutes. At the present time our spacecraft is at an altitude above the Moon of 100 - rather 16,035 nautical miles [29,697 km], and our velocity continuing to increase - still increasing rather slowly but steadily. Our speed is now 4,194 feet per second [1,278 m/s]. We would expect this relatively slow velocity build up to continue to about 65 hours. At that point, the spacecraft will be some 11,000 nautical miles [20,400 km] from the Moon, and from that point on, the acceleration will begin to build up quite rapidly so that within about 4 hours from 65 hours at the point where we do the insertion maneuver from that - in that 4-hour period of time the velocity would just about double, going from some 4,350 feet per second [1,326 m/s] up to about 8,450 feet per second [2,576 m/s]. We have some further information on the Lunar Orbit Insertion maneuver as a result of the midcourse correction that was done at 61 hours, and we have the refinement also on the effects of that miscourse correction. Prior to our midcourse maneuver, we computed that our pericynthion, or point of closest approach to the Moon, would have been about 66.5 nautical miles [123.2 km]. As a result of the burn, it was lowered to about 61.8 nautical miles [114.5 km]. The Lunar Orbit Insertion maneuver using the Service Propulsion System engine is scheduled to occur at 69 hours, 8 minutes Ground Elapsed Time. The burn duration would be 4 minutes and 2 seconds. This would give us an orbit about the Moon with a low point of about 60 nautical miles [111 km] and a high point of about 170 nautical miles [315 km], We've had one brief conversation with the spacecraft since our previous report, and we advised the crew that they should be getting a good view of the Moon as they continue through their Passive Thermal Control mode with the spacecraft rolling at the rate of about 1 revolution per hour. At a certain specified degree of roll they should acquire the Moon through one of the windows of the spacecraft. During this period of time the spacecraft will be coming into a much better view of the Moon with a larger part of the lighted surface becoming visible to the crew. We'll ... pick up with the conversation that is developing right now between CapCom Ken Mattingly and the crew.
063:06:13 Anders: Houston, Apollo 8.
063:06:15 Mattingly: Go ahead.
063:06:20 Anders: Roger. Bill would like to ask the doctor for permission to take a Seconal [sleeping pill].
063:06:25 Mattingly: Okay. Standby.
Comm break.
063:08:06 Anders: Houston, this is Apollo 8. Did you call? We lost track for a minute.
063:08:10 Mattingly: Okay, Apollo 8. You're cleared to go ahead with that pill. Take - Surgeon recommends a small one.
063:08:21 Anders: Small one. Roger.
Comm break.
063:10:12 Mattingly: Apollo 8, Houston. If you can, we'd like to have you stir up the oxygen cryo.
063:10:19 Borman: Okay, I'll do that right now. Two minutes each. Just the oxygen?
063:10:26 Mattingly: Okay. We want to get both the oxygen and hydrogen.
063:10:29 Borman: You say just the oxygen, Ken?
063:10:30 Mattingly: No, sir; both the oxygen and the hydrogen.
063:10:33 Borman: Okay. Start, starting with the hydrogen.
063:10:36 Mattingly: Thank you.
Long comm break.
Each of the four cryo tanks are stirred for two minutes each to improve the accuracy of quantity measurement.
063:20:01 Borman: Okay. Houston, Apollo 8. We've cycled through all of the cryo fans.
063:20:04 Mattingly: Okay. Thank you.
Very long comm break.
This is Apollo Control at 63 hours, 43 minutes. At the present time Apollo 8 is traveling at a speed of 4,236 feet per second [1,291 m/s], and their altitude is 14,399 nautical miles [26,667 km] above the Moon. Since our last report, we had one brief conversation with Frank Borman aboard the spacecraft. It's been relatively quiet on the spacecraft as we would anticipate. The crew indicated that they would attempt to get some rest between the midcourse correction, which was performed at about 61 hours and the starting of activities leading up to the Lunar Orbit Insertion maneuver at 69 hours and 08 minutes Ground Elapsed Time. There will be a period of a couple of hours before their activity picks up in preparation for that burn. Beginning at about 66 hours in the Flight Plan they will begin burn preparations of the systems checks and Guidance and Navigation preparation that they will do for that maneuver, and until then, the Flight Plan is relatively quiet. So we, in line with that, do expect that we'll be hearing very little from the crew. In a previous conversation we heard Bill Anders request permission to take a Seconal tablet, one of the short acting sleeping pills that the crew carries onboard, and the Flight Surgeon recommended that he take a smaller tablet. They carried two different sizes. One a 50 milligram tablet and the other 100 milligram tablet, and the recommendation was that Anders take the 50 milligram tablet. We'll ... stand by for any further communication from the crew.
The Flight Plan shows that Jim and Bill should be resting just now. This seems to be the case as Frank is the only crewman currently talking to Mission Control.
It appears that we'll have no further communication with the crew at least for the moment. Here in Mission Control at the present time, activity is beginning to pick up as we near our change of shift. Flight Director Glynn Lunney and his team of flight controllers are coming on at this time receiving briefings from the previous shift headed by Flight Director Milton Windler. The activity on the boiler control, sounded, as you would expect, like a beehive at the present time. At 63 hours, 48 minutes; this is Apollo Control, Houston.
063:54:56 Borman: Houston, Apollo 8. How do you read?
063:54:58 Mattingly: Loud and clear, Apollo 8.
063:55:03 Borman: Okay. Thank you.
063:55:05 Mattingly: Roger. We had a momentary loss there.
063:55:07 Borman: How is the tracking?
063:55:09 Mattingly: Looking great.
063:55:10 Borman: How's the tracking data look, Ken?
063:55:13 Mattingly: Looking great.
063:55:16 Borman: Roger.
Very long comm break.
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- Approaching the Moon