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Apollo 8

Day 3: The Green Team

Corrected Transcript and Commentary Copyright © 2003-2021 by W. David Woods and Frank O'Brien. All rights reserved.
Last updated 2021-02-27
Mike Collins has taken over at the CapCom console at the start of the Green Team's third shift in the MOCR (Mission Operations Control Room, normally just called Mission Control in this journal), where it is just after eight in the morning, 14:07 Greenwich Mean Time. The date is 23 December 1968 and the Apollo 8 spacecraft has covered about three quarters of the distance to the Moon.
Bill Anders is on watch while Frank Borman and Jim Lovell try to catch up on some sleep. However, it is evident that Frank is awake and listening to the conversations.
This is Apollo Control, Houston and at 49 hours, 18 minutes, we've just tagged up with the crew, and Mike Collins is reading the morning edition of the Interstellar Times. Here's how it's going.
049:16:34 Collins: Apollo 8, Houston. [No answer.]
049:17:07 Collins: Apollo 8, this is Houston. Over.
049:17:13 Anders: Go ahead, Houston. Apollo 8.
049:17:15 Collins: Roger. I just wanted to let you know we still have voice contact, and we have the morning news for you. We can give it to you now or some time later. Your choice.
049:17:27 Anders: How about right now?
049:17:29 Collins: Very good. This is the 23rd of December edition of the Interstellar Times a la Paul Haney.
Paul Haney is the Public Affairs Office announcer occupying the PAO console on the Green Team.
Collins (continued): We would like to let you know that there are only 2 more shopping days until Christmas. He says your TV transmission was a real big hit yesterday. Mickey Herskowitz is doing double duty for the Post. He's written a couple of columns on your launch in addition to his other sports columns, and, Jim, your Mom certainly appreciated that birthday greeting. Twenty one convicts broke out of a prison in New Orleans yesterday, and President Johnson went home last night from Bethesda Naval Hospital after his bout with the flu. He sends you guys a special message - not what to do for the flu - but congratulations on the flight. Are you reading me so far?
Mickey Herskowitz is a sports journalist and author. He was the co-author for astronaut Walter Cunningham's autobiography The All American Boys.
049:18:25 Anders: You're very clear, Mike.
049:18:27 Collins: Good. Well, we had a big blizzard down here in the midwest; I don't know if you can see that from up there or not. And in Houston, as a matter of fact, it's getting pretty chilly, about 35 degrees [Fahrenheit, 2°C]. And we would like to know who you like next Sunday, Baltimore or Cleveland? Baltimore defense looked pretty tremendous yesterday. They put on a great pass rush, and it sounds to CapCom like Haney is trying to con you guys into a bet. Over.
049:18:57 Anders: I like Baltimore.
049:19:01 Collins: Are you giving points?
049:19:05 Anders: Negative. I don't bet.
049:19:09 Collins: I guess you don't if you don't give points.
049:19:14 Anders: Not with you anyway.
Journal Contributor Dave Hardin - "The Baltimore Colts would go on to win the 1968 National Football League championship six days later, 34-0 over the Cleveland Browns, with the strong Baltimore defense that Mike Collins referred to carrying the day. Baltimore would go on to lose the third Super Bowl to the New York Jets, 16-7, on January 12, 1969, the first Super Bowl win for a team from the newer American Football League and a game considered one of the biggest upsets in the history of American football."
049:19:19 Collins: Okay. That's about the size of the news. Houston, standing by.
049:19:24 Borman: How are the families doing, Mike?
049:19:29 Collins: They are doing just great, Bill; just talking to Valerie a few minutes ago.
Valerie is Bill Anders' wife. Mike Collins has not picked up the change in voice yet.
049:19:37 Borman: That was Frank.
049:19:40 Collins: Oh, well, likewise with Susan [Borman]. I have not talked to her since last night.
049:19:48 Borman: Roger.
Comm break.
It is notable that at the time of writing, 34 years after the event, all three crewmen have remained with their first wives. In the high pressure world of American astronauts in the pioneering years, few marriages survived.
Apollo Control here. We got a little lull on the conversation. That may be resumed. We will take advantage of the lull to give you the altitude which is 163,920 [nautical] miles [303,579 km] and our velocity; 3,514 feet per second [1,071 m/s]. If you take three-fourths of that, you can get the distance [means velocity in miles per hour] - I'll read that - it's something like 26 - 26 hundred miles per hour, call it. We'll stand by - here is more conversation.
049:21:16 Borman: Mike, this is Frank again. Would you tell the doctors I got about 5 hours of good sleep yesterday?
049:21:21 Collins: Roger. Thank you, Frank; we were wondering about that, about 5 hours of good sleep.
049:21:29 Borman: Right. [Pause.]
049:21:37 Collins: How is everything going up there, Frank; all three of you guys feeling okay this morning?
049:21:43 Borman: Feel fine. Jim went back to sleep. Bill and I are having breakfast and everything seems fine.
049:21:48 Collins: Good; glad to hear it.
Very long comm break.
By the Flight plan, all three crewmembers were to be eating a meal just now. Instead, due to the difficulties of trying to sleep in a tiny cabin where others are talking, the crew are taking naps when they can so that they can be as rested as possible for tomorrow's rendezvous with the Moon.
This is Apollo Control here. Apparently we are wrapping up, the crew is now eating and we doubt that we will get any additional conversation for at least the next few minutes. The eat period extends up to 50 hours [Ground] Elapsed [Time]. We are at 49 hours, 29 minutes. The spacecraft meanwhile has - it's about to complete its second - let's back off that statement and put it this way. The Earth is about to complete its second revolution under the spacecraft. The spacecraft now, in relation to the Earth, is over Africa and that is its second revolution since the second rev when suddenly the spacecraft left the Earth out over the central Pacific. Our flat map projection follows this trace and it's running at about 10 degrees south latitude very steady and coming back across, if for map purposes it appears that it's coming - going from east to west across the face of the map. Of course, the spacecraft is quite steady and the Earth is turning under it. At 49 hours, 30 minutes into the flight; this is Apollo Control, Houston.
050:07:18 Collins: Apollo 8, Houston. Over.
050:07:23 Borman: Go ahead, Houston.
050:07:24 Collins: Just checking in with you after about a 45-minute quiet break. Say, we notice on your High Gain Antenna, if you like, you can get a little bit more use out of it by switching to it from Omni when you have a yaw angle of 90 degrees and a pitch angle of minus 45 degrees. We are noticing that you are staying an extra 10 minutes on the Omni, which is fine; but you could get more use out of the High Gain if you use that procedure. Over.
050:08:00 Borman: Okay, thank you. It's a lot simpler for us, as long as the Omni isn't working. We've got it all wrapped up here on the eight-ball with the roll [garbled] pointing to an Omni number. We just switch it; it makes it a lot easier, if it is not bothering you.
At their current large distance, only the HGA (High Gain Antenna) gives a good enough link to Earth for high-bit-rate data to be sent from the spacecraft. When it is unable to get a lock on the Earth due to Apollo 8's rotation, the data link to Earth is maintained at a slower rate by one of four omnidirectional antennae around the CM. Mission Control have noticed that the crew could switch to the HGA earlier during this rotation. However, the crew seem to have set up a system whereby they use the roll angles displayed on the eight-ball or FDAI (Flight Director/Attitude Indicator) to let them know when to make the switch as the spacecraft rolls around in its Passive Thermal Control mode.
The FDAI, of which there are two, allows the crew to monitor the spacecraft's attitude relative to some reference.
Photograph of FDAI-1 onboard Apollo 13's Command Module Odyssey.
This photograph is of one of the FDAId within the Apollo 13 Command Module Odyssey. Pitch and yaw angles are read directly from the graticule at the centre of the ball. A graticule around the ball and an associated pointer, currently showing 40°, give the current roll angle. The crew may have marked around this display to indicate when to switch antennae.
050:08:13 Collins: Okay. That is fine. We are presently happy with the comm, Frank. We are just trying to be helpful.
050:08:25 Borman: Thank you very much. It's unusual that Mike Collins tries to be helpful, but nevertheless, thank you very much.
050:08:30 Collins: Good; aerospace first, Frank.
050:08:35 Borman: Say hello to Howard Tindall for us, will you? His procedure seemed to be working.
Among Apollo historians, Howard W. Tindall's reputation is legendary, for he left behind a rich collection of memos that are utterly distinctive in style, dictated as they were in a manner that sounded just like he talked. They are clear, concise and uniquely readable unlike so many government memoranda and so are most useful to those trying to understand them years later. It can be argued that he is the only government employee whose memos have achieved cult status.
Bill Tindall (for that was how he was known) was at the core of departments that looked into overall mission planning or the details of the development of the spacecraft's computer programs. He summarised the results from those meetings in memos affectionately called "Tindallgrams", that reflected the way he spoke and all around him loved it. Those of us who study Apollo do too. For example, a four page memo was given the tongue-in-cheek subject title, "Fifth 'D' Mission Rendezvous Mission Techniques Meeting---don't miss paragraph 51, it's great." Another had a paragraph bemoaning the lack of definition in Lunar Module programs and the time it was taking for documents to arrive, "We'll eat 'em raw when they get here!"
Tindall often invoked not-so-subtle sarcasm in order to make a point stick. In a classic memo, he argued that the LM's fuel quantity light, when illuminated, should no longer trigger the spacecraft master alarm with its loud annunciator. The argument was that during the most critical part of the landing, the last thing the crew needed to be distracted with was an alarm that regularly went off. Specifically, he worried that the first words from the surface of the Moon would be, "Gee, that master alarm really startled me!".
The procedure Frank is talking about may be the use of the roll needle to help the crew know when to switch antenna.
050:08:39 Collins: Sure will. [Long pause.]
050:08:59 Borman: I hope that you have got everybody looking this thing over very carefully. One thing we want is a perfect spacecraft before we consider the LOI burn.
050:09:07 Collins: Apollo 8, Houston. We concur, and we are doing that.
050:09:13 Borman: Okay. [Long pause.]
Frank and his crew are most certainly putting their lives on the line in this flight and Frank is not slow in letting the ground know that they must be sure of the integrity of his craft.
050:09:55 Borman: Houston, Apollo 8. The water is in the process of being chlorinated at this time.
050:09:59 Collins: Roger. Understand you're chlorinating the water at this time.
A port is included in the water system where the crew can periodically inject an ampule of chlorine-based disinfectant to help inhibit the growth of bacteria in the crew's drinking water. The port is on panel 352 on the Left-Hand Equipment Bay.
050:10:06 Borman: Roger. [Long pause.]
050:10:48 Collins: Apollo 8, Houston. Over.
050:10:53 Borman: Go ahead.
050:10:54 Collins: At your convenience, we would like the read-out of your Service Module RCS propellant quantities. We haven't gotten one of those so far this flight.
050:11:04 Borman: Alright. Stand by. We are just about to - need to change the antenna. I'll give them to you. [Long pause.]
050:12:14 Borman: Houston, Apollo 8. How do you read?
050:12:18 Collins: Go ahead, Apollo 8.
050:12:25 Borman: Okay. A, Service Module [quad] A. Are you ready?
050:12:30 Collins: Ready to copy.
050:12:34 Borman: The temperature is about 111 [degrees Fahrenheit], the helium pressure - Do you just want the quantity, or do you want the whole works?
050:12:41 Collins: Well, if you are reading, give us the whole works.
050:12:46 Borman: Okay. The helium pressure [on quad A] is about 37 [that is 3,700 psi, 25.5 MPa], the [fuel] manifold [pressure] is 182 [psi, 1,255 kPa], and the quantity is reading 80 [percent]. B has got the temperature about 112, the helium pressure about 36.5, the fuel pressure 180, and the quantity about 77. C has got the temperature of 140 - incidentally, those other temperatures should have been 120 instead of 110; I was looking at the wrong calibration here. The pressure is 37, the manifold pressure is about 182, and the quantity is 80. Temperature on D is 115, pressure is 37, the manifold pressure is 181, and the quantity is about 83.
Each of the four RCS clusters around the Service Module contain a helium tank, two fuel tanks, two oxidiser tanks and an external package containing the four engines. Four meters on the left side of Panel 2 allow four parameters of a single quad cluster to be monitored, with a selector knob mounted right in the middle of panel 2 allowing selection of which quad is being monitored.
The four parameters are:
A summary of Frank's read-outs with SI conversions is as follows.
Helium Tank
Fuel Manifold
Quad A120°F (49°C)3,700 psi (25.5 MPa)182 psi (1,255 kPa)80%
Quad B120°F (49°C)3,650 psi (25.2 MPa)180 psi (1,241 kPa)77%
Quad C140°F (60°C)3,700 psi (25.5 MPa)182 psi (1,255 kPa)80%
Quad D115°F (46°C)3,700 psi (25.5 MPa)181 psi (1,248 kPa)83%
Note that the actual quantity readings that Collins is about to read to them are lower than their on board read-outs.
050:14:02 Collins: Roger, Frank. I read you loud and clear. On the temperatures, quad A and B should both be 120. Roger.
050:14:11 Borman: Roger.
050:14:12 Collins: Thank you. [Long pause.]
050:14:36 Borman: I will trade all of that good information for a read-out of the actual quantities. If you will give us a minute, we will go ahead and plot them up, Mike.
050:14:45 Collins: Roger. We will stand by until we get them for you.
Comm break.
While the method of calculating the quantities from the temperature and pressure is rather clever, and the information is quite important, the real question is, "How much fuel do I have left?". For all it's sophistication, there was no way to measure the actual quantity of propellants in the RCS system. With the Teflon bladders used to pressurize the tanks, one cannot generalize how the fuel is distributed throughout the tank. Hence, traditional methods of measuring quantity, such as level sensors are ineffective. Other technologies, such as totalizers, would most likely be inaccurate, as the nature of RCS usage is in very small bursts, rather than a continuous flow.
050:16:34 Collins: Apollo 8, Houston. I have your Service Module RCS quantities available. Over.
050:16:43 Borman: Roger. We are ready to copy at 50 hours, 16 minutes.
050:16:47 Collins: Okay. I have them both in percent and pounds; I'll give you both numbers. The pounds are slightly more accurate for plotting on your chart. Quad A, 72 percent, 219 pounds; quad B, 76 percent, 233 pounds; quad C, 70...
050:17:10 Borman: Take it a little slower, Mike; whoa, whoa, whoa, whoa.
050:17:13 Collins: Okay.
050:17:15 Borman: Slow up. We just got quad A plotted. They are on separate charts.
050:17:20 Collins: Okay.
050:17:22 Borman: Okay for quad B.
050:17:24 Collins: Quad B; 76 percent, 233 pounds.
050:17:34 Borman: Okay. Quad C.
050:17:36 Collins: Seventy-six percent, 231 pounds.
050:17:49 Borman: Quad D.
050:17:50 Collins: Seventy-six percent, 229 pounds.
050:17:59 Borman: Okay. [Long pause.]
Mission Control have a more accurate idea of the propellant quantities based on thruster usage, helium pressure/temperature ratio, tank volumes, pressure regulator settings, sensor nonlinearities, system history, and applying sophisticated models of how the system should work. The following graph was derived from one printed in Bill's system checklist:
Diagram showing predicted RCS propellant usage throughout the flight, and actual usage at 50 hours GET.
The blue lines indicate the usage since the last read-out and they show that the crew's actual consumption is slowly converging with their predicted values.
050:18:15 Borman: Would you give us the O2 and H2 as long as we are plotting?
050:18:18 Collins: Roger. Stand by for O2 and H2.
Comm break.
050:19:58 Collins: Apollo 8, Houston. We have got those numbers in a percent. We are going to switch them over to pounds, and in the meantime, we are going to be changing our ground antenna in about another 2½ minutes. You can expect a comm glitch. Over.
050:20:14 Borman: Thank you.
Long comm break.
As an indication of the dearth of computer integration in late 1960s space flight, these values are not available at the "touch of a button". Even basic values such as RCS, oxygen and hydrogen quantities have to be computed by hand from the basic telemetry.
050:23:44 Collins: Apollo 8, Houston. Over.
050:23:52 Borman: Go ahead, Houston. Apollo 8.
050:23:55 Collins: Roger. I have your oxygen and hydrogen quantities when you are ready to copy.
050:24:02 Borman: Ready.
050:24:06 Collins: Oxygen tank number 1, 270 pounds, 270; oxygen tank 2, 267, 267 pounds. Over.
050:24:24 Borman: Roger. Thank you.
050:24:26 Collins: Roger. On the hydrogen, hydrogen tank 1, 19.7; hydrogen tank 2, 20.1. Over.
050:24:41 Borman: Understand; 19.7 and 20.1.
050:24:44 Collins: Roger. You are a little bit low on the line on your graph due to the fact that they started out low.
050:24:55 Borman: Roger.
Very long comm break.
Their oxygen quantity is slightly higher than predicted, hydrogen is lower, as Collins explains.
This is Apollo Control. We have apparently got a lull in the conversation. We have been listening to the exchange between Mike Collins and Apollo 8 live now, for nearly half an hour. Our present position in relation to Earth, is 166,116 [nautical] miles [307,646 km] from Earth. Our velocity in feet per second; 3,466 [1,056 metres per second]. And one-fourth [means three fourths, a quick means of converting feet per second to miles per hour] of that would be about 27 - 2,725 miles per hour. Velocity will continue to slow down to a value of 2,170 miles per hour, not feet per second.
As he later admits, the PAO announcer's simple conversion is somewhat poor and their speed is 2,363 statute miles per hour rather than the 2,725 given.
And at the point of lunar capture, or the point of lunar sphere influence - which we are rapidly approaching; and in fact reach, I believe, at 55 hours - we will begin to see a slight acceleration. I think the biggest thing that we will experience today, at least we will be filling in numbers in an unknown but at a predicted area, is the range of temperatures that the spacecraft will be seeing. The Earth - even in Earth orbit, the Earth exerts a temperature factor over spacecraft, even out at 100 or more miles. And the Moon, it's theorized, does the same thing because of its highly reflective quality. The area between the Earth and the Moon has no great reflector available. And, thus, a different temperature regime is experienced. This will be of considerable interest to the spacecraft builders and the spacecraft thermal planners, as we progress through this day. At 50 hours, 27 minutes, this is Apollo Control, Houston.
050:54:46 Borman: Houston, how do you read? Apollo 8.
050:54:48 Collins: Apollo 8, Houston. Loud and clear. How me? Over.
050:54:54 Borman: Loud and clear. I was just checking. Over.
050:54:57 Collins: Roger.
Comm break.
This is Apollo Control, Houston. 50 hours, 55 minutes into the flight. Mike Collins just put in a - I take that back. Apollo 8 just gave us a call a few minutes ago, I guess just to check and make sure our antennas are all switched around, which I believe they have been. We can expect some communication very shortly. We have had a number of calls on conversion charts. We would like to pass on to you these conversion tables. Earlier we had estimated that to get a handy grab on statute miles per hour, simply take three quarters of feet per second. Of course, the number is somewhere between three quarters and two thirds, so here are some more conversion tables. Before we do that, let's go now live to more communication.
050:56:09 Collins: Apollo 8, Houston. Over.
050:56:13 Borman: Go ahead.
050:56:15 Collins: Roger, Frank. Your 51-hour update of block data will be omitted. The block data you have on board is satisfactory. Over.
050:56:28 Borman: Understand. The block data we have aboard is satisfactory.
050:56:30 Collins: Right. That's for the flyby and pericynthion plus 2-hour block update.
During the outbound and lunar orbit stages, Mission Control always makes sure the crew have the data they need to get home in the event their communications with Earth fail. These are read up as "block data", each tailored for a particular get-home manoeuvre. Mike Collins is referring to two block data that were read up at 44 hours and which are still current in case of emergency; the flyby manoeuvre that refines their passage behind the Moon, and the pericynthion-plus-2 manoeuvre that would occur two hours after pericynthion to speed up their return.
Collins (continued): We would like also to get a current up-to-date report on all your windows. We are trying to make some alternate plans for using the center hatch window when you are in lunar orbit, and we would like to make sure we understand exactly what the condition of all five windows is. Over.
050:56:54 Borman: Okay, Roger. Window number 1 and number 5 are clouded, but they may be partially useful. The hatch window is very badly clouded. Window number 2 and 4 are good.
050:57:06 Collins: Okay. Understand the hatch window is unusable, 1 and 5 are partially usable, and the rendezvous windows are both good.
050:57:17 Borman: Right.
050:57:18 Collins: Okay.
Very long comm break.
The upshot of the fogging windows problem is that only the two tiniest windows in the spacecraft are of any real use. Because of their small size, positioning and being recessed into the Command Module structure, their field of view will be very limited and photography will be difficult. They are both intended for viewing along the spacecraft's longitudinal axis (in the same direction as the Command Module's pointy end) though they have a slight tilt away from that axis. Nevertheless, to be useful, they will require that the spacecraft be manoeuvred to aim them at any desired visual or photographic target.
Apollo Control here. We will take advantage here to go ahead and give you these conversion tables that we talked about earlier. If you have feet per second and you want statute miles per hour, you convert by multiplying feet per second times 0.6818. The resulting number - statute miles per hour. If you want knots, you take feet per second, and multiply by 0.5925, I repeat, feet per second times 0.5925 gives you knots per hour. If you want kilometers per hour, you take feet per second and multiply by 1.097, 1.097, and you get kilometers per hour. And one other factor to help, particularly our European, well to help all reporters who are other than U.S., if you have statute miles per hour and multiply by 1.609, you can get kilometers per hour. So much for the lack of a universal numbering system. We will go back and monitor the circuit now for any additional communications.
The PAO announcer might have added that to convert feet per second to metres per second, the fundamental scientific units for velocity under the SI (Systeme International) arrangement, you multiply by 0.3048.
Apollo Control here. CapCom Mike Collins is sitting back in his seat and apparently we will not have any communication unless it is initiated by Apollo 8. So we will take the line down now at 51 hours, even, into the flight and we are - they are 167,000 [nautical] miles [309,000 km] from Earth, moving at a velocity of 3,441 feet per second [1,049 m/s]. This is Apollo Control, Houston.
051:13:13 Collins: Apollo 8, Houston. Over.
051:13:18 Borman: Go ahead, Houston. Apollo 8.
051:13:20 Collins: Roger, Frank. We would like to ask you about the next few hours in the Flight Plan. We are inclined to let Jim go ahead and sleep and to slip the P23 that occurs at 52:15. On the other hand, we would think it would probably be a good idea if he returned more to the normal sleep rest cycle; and if you got him up nominally to do the 52:15 work, then perhaps he would be ready to go back to sleep at about 61 hours, when he nominally is expected to do so.
051:13:55 Borman: Okay. He's up now, eating. We are planning to go to normal procedures on the Flight Plan.
051:14:02 Collins: Okay. That - that's fine then. If - you know, there is no - it's not time critical that P23 be done at 52:15, but if you get up to do it then, that's just fine.
051:14:16 Borman: Well, we thought we might give it a try.
051:14:18 Collins: Roger. [Pause.]
The routine of taking short naps has been useful as a short term remedy for the crew, but as the spacecraft gets closer to the Moon, the sleep/wake cycles need to return to the Flight Plan schedule. Unfortunately, sleep on the outward bound portion of the flight will be fleeting.
051:14:23 Borman: This sleep cycle here is - we're just going to have to real-time it, I guess. I'm supposed to be asleep right now but, obviously - or I'm supposed to go to sleep here shortly, but I just got up. We are going to have to play this by ear.
051:14:39 Collins: Roger. Understand.
Comm break.
Frank's next planned sleep period is due to start at 52 hours.
051:17:39 Borman: Houston, Apollo 8.
051:17:41 Collins: Go ahead, Apollo 8.
051:17:46 Borman: Are the stars in the Flight Plan proper for this next exercise of P23?
Program 23 is the computer program Jim uses during his exercises in interplanetary navigation. To summarise, the spacecraft's position is determined from measurements of angles between the distant stars and the nearby worlds (i.e. Earth and Moon). A particular angle at a particular time can only be the result of a particular trajectory.
051:17:52 Collins: We would like to talk to Jim about it when he is ready to copy.
051:17:59 Borman: He's ready.
051:18:01 Collins: Okay.
051:18:03 Lovell: Good morning, Mike. How are you doing?
051:18:05 Collins: Fine, fine, Jim. You are sounding good this morning. We would like to give you a little rundown on these stars. As you can see in the Flight Plan, we've got you scheduled for a number 33, Antares, number 34, Atria, and number 40, old Altair. Now, the first of those, Antares, is in plane; the second two are out of plane. As you know, we would like to get a mixture of the in and the out of plane. Antares, number 33, is close to the Sun, and we expect that you are going to have difficulty getting those measurements on number 33. We would like very much for you to try, but if you are unable to do number 33, then we propose that you use number 42, which is Peacock, to the lunar far horizon. We realize Peacock isn't the greatest one available - greatest star in the sky - but it's about the only one available. Over.
Out of the countless numbers of stars across the celestial sphere, only a very few can be used for cislunar navigation. A range of constraints limits their usefulness. First, only the brighter stars are suitable, simply because of their visibility. However, there needs to be an even spread of stars across the heavens and, unfortunately, there are large areas of the sky devoid of really bright stars while other parts of the sky (for example, the constellation of Orion) are rich in them. Therefore, some lesser stars have to be included in the Apollo star list while bright ones, like Betelgeuse, are not.
For a particular sighting exercise, the acceptance angle of the sextant places a conical constraint that means only those stars within about 57° of the planet in question can be viewed. Additionally, if the planet, or in this case, the Moon is in the vicinity of the line of sight to the Sun, then a star's visibility can be further compromised by glare in the optical system.
A further constraint, being tested in this flight, depends on whether the star is 'in plane' or 'out of plane'. The orbit of the Moon around the Earth can be thought to lie on an imaginary geometrical flat surface, or plane. The spacecraft is travelling along this plane as it coasts from one world to the other. The apparent motion of the Earth or Moon against the background of stars (motion caused by the spacecraft's velocity) is primarily along this plane. Therefore, angular star/planet measurements taken with stars whose line of sight lie along this plane will have more relevance when determining their state vector. Measurements with stars above and below the plane will have less relevance because they don't change much as the spacecraft's position changes.
051:19:06 Lovell: Roger. Understand. I'll - we'll go to Antares first and try it. You know, we tried it last time, but I got one set before I lost the Moon completely in the white haze. I'll give it another try, and if it doesn't work out, we will go to Peacock and give it...
051:19:26 Collins: That ... that is affirmative, Jim, and if neither Antares nor Peacock work, well then, we just will be happy to go with Atria and with Altair. We would like then to increase the number of sets and do three on Atria, that is, number 34, and two on Altair, number 40; but that is only in the event that you can get neither Antares nor Peacock.
051:20:07 Collins: Apollo 8, Houston. Did you copy?
051:20:12 Lovell: Roger. This is 8. Copied. We'll increase the number 34 to three and the number set of 40 to two if we cannot get 33 or 42.
051:20:25 Collins: Yes, that's exactly right.
Very long comm break.
Before Jim begins the P23, he routinely realigns the spacecraft's guidance platform using P52 in the computer. To do this, he gives the computer an absolute attitude reference by sighting on star 7 (Menkar, or Alpha Ceti) and star 12 (Rigel, or Beta Orionis). Comparison of his measurements with what would be expected show that this sighting exercise was as perfect as the system will allow.
In the postflight debrief, Jim points out that it would be easier to calibrate the optics for the P23 exercise now, before turning them toward the Sun, where the Moon is.
Lovell, from the 1969 Technical debrief: "At this point in the flight, about 52 hours, it would be helpful to perform the optics calibration just after Program 52 when the spacecraft has been stopped from its Passive Thermal Control roll in an area where the scanning telescope does not have any light scatter. This is pretty important. Then we go through Program 52, and after that we zero the optics and pick one for our optics calibration."
This is Apollo Control, Houston. 51 hours, 41 minutes into the flight and just a very few minutes ago, the wife of Bill Anders, Valerie Anders, joined us here in the Control Center. She is seated in the viewing area, which overlooks the Mission Operations Control Room, chatting with Mr. James C. Elms, the director of the Electronics Research Center in Boston and Elms was formerly deputy director of this Manned Spacecraft Center. With her also is Neil Armstrong, backup Command Pilot for Apollo 8. This is the first of the wives to visit the Control Center during the mission. Later today we expect to see Jim Lovell's wife, Marilyn. ... Our distance right now; 168,829 [nautical] miles [312,671 km], we should - we are to pass into the lunar sphere of influence [at] 55 hours, 38 minutes; about 4 hours from now. Our velocity has slowed down to 3,408 miles [means feet per second, 1,039 m/s]. While we were talking, Mike Collins has put in another call. Let's go back to that.
051:47:55 Collins: Apollo 8, this is Houston. Over.
051:47:59 Borman: Go ahead, Houston. Apollo 8.
051:48:02 Collins: Roger. We're getting low bit rate from you, rather than high, and on this P23 work, for us to get our data, you're going to have to delay the DSKY display about 10 seconds when it comes up with Noun - Noun 87. Over.
Prior to each P23 exercise, Jim calibrates the sextant per the checklist on page G-27. This instrument has two lines of sight, fixed and movable (called LLOS and SLOS in the checklist [Landmark Line Of Sight and Star Line of Sight respectively]) and the angle between them is the known as the trunnion angle. The device, or encoder that measures this angle is prone to slippage over time so it is important to calibrate its central position prior to making the navigationally important star sightings.
Jim uses the sextant to superimpose the image of a star upon itself, thereby ensuring the trunnion angle is zero. He presses a button so the computer will record the angle reading from the encoder. This bias angle will be subtracted from subsequent readings to yield a true trunnion angle with respect to zero. He repeats the exercise until he has two bias angle readings that agree to within three thousandths of a degree. The bias angle is stored as Noun 87 and, as Mission Control are monitoring the readings on the DSKY (Display and Keyboard), they would like Jim to leave the bias angle up on the display for 10 seconds so they can be sure of coping its value down.
051:48:18 Borman: Roger. [Long pause.]
051:48:44 Collins: Apollo 8, Houston. We are past that [Noun] 87 display now. Did you write down what your trunnion bias was?
051:48:57 Borman: Negative.
051:49:00 Lovell: Houston, we haven't started [P]23 yet. Our Cal is zero.
Though he has not written down the trunnion bias angle, Jim is happy that the bias is properly set and begins rotating the spacecraft to the desired attitude for his sightings.
051:49:12 Collins: Roger. Understand. Thank you.
051:49:17 Lovell: We are in the process now to - to go to P23 attitude.
051:49:27 Collins: Roger. Thank you.
Long comm break.
051:53:42 Collins: Apollo 8, Houston.
051:53:47 Borman: Go ahead, Houston. Apollo 8.
051:53:49 Collins: Roger. Downlink data shows that on star 33, Jim is using the lunar far horizon when he should be using the lunar near horizon. Over.
When measuring the angle between a planet's horizon and a star, a celestial navigator has to use that part of the planet's horizon that is fully illuminated by the Sun. This may be on the side of the planet towards the star (the near horizon) or on the opposite side (the far horizon).
Diagram to show the difference between a near-horizon and a far-horizon measurement.
Whichever type of measurement is being made, the computer must be told so that it can appropriately factor the planet's radius into its calculations.
051:54:02 Borman: Okay. Thank you. 220?
051:54:07 Collins: Roger. 220.
As part of program 23, the computer asks for a set of three codes to be entered into three registers, the third of which defines whether the Earth or Moon is being used, and whether the near or far horizon is being used. 220 is the appropriate code for a lunar far horizon measurement and is therefore wrong in this instance. The third register should be set to 210 for a lunar near horizon measurement.
051:54:14 Borman: Let us check it.
051:54:16 Collins: Roger. [Long pause.]
051:54:58 Borman: You want the far horizon now, Houston?
051:55:01 Collins: Roger. Far horizon.
Collins is mistaken because Antares requires a near horizon measurement. However, the error is quickly trapped and rectified.
051:55:06 Lovell: We have far horizon in now, Mike, on 220. I will check again, though.
051:55:12 Collins: Yes. That is right. We are requesting the lunar near horizon as per the Flight Plan, the lunar near horizon. We show that you are using the lunar far horizon.
051:55:27 Lovell: Okay. Roger. I thought that you had copied up 220 to me. I will put it in the near horizon.
051:55:34 Collins: Roger.
Long comm break.
051:58:50 Anders: Houston, Apollo 8. Over.
051:58:52 Collins: Apollo 8, Houston. Go ahead.
051:59:03 Anders: Mike, it's getting kind of damp - we're getting a playback, Mike. It is getting kind of damp in here. It might be a good idea to go back into Auto on the temp in - the glycol temp in for a while to try and get some of this moisture out of the cabin.
As air is taken out of the cabin and into the suit circuit to be recirculated, it is cleansed, deodorised, scrubbed of CO2 then cooled in the Suit Heat Exchanger. As it is cooled, excess moisture condenses on a set of metal wicks from which it is collected and sent to the waste water tank. This operation depends on the coolant to the heat exchanger being cold enough, this being partly achieved by the evaporator which has not been operating properly. If the coolant going into the heat exchanger is too warm, it will not remove as much moisture from the air as it ought. This may be tied up with the fact that the cabin is relatively warm just now.
051:59:21 Collins: Roger. Stand by, Bill.
051:59:28 Anders: Roger. [Long pause.]
052:00:08 Collins: Apollo 8, Houston.
052:00:13 Anders: Go ahead.
052:00:14 Collins: We concur. We would like you to go back to Auto on the glycol temp inlet valve. Over.
052:00:22 Anders: Okay. When was our lowest radiator Out Temp during the last couple of hours while we have been in Manual?
052:00:28 Collins: I will get it for you.
052:00:33 Anders: And we are back in Auto.
052:00:35 Collins: Roger. Back in Auto, and 29 degrees (F, minus 2° C) is as low as we've seen.
052:00:43 Anders: Okay. We are showing a cabin temp of about 76. It is very comfortable, but we are getting a lot of condensation on the walls now.
052:00:54 Collins: Roger. Understand.
Long comm break.
052:05:00 Borman: Houston, Apollo 8.
052:05:04 Collins: Apollo 8, this is Houston.
052:05:08 Borman: Roger, Mike. While we are waiting for the spacecraft to maneuver to the Moon, I might note that as we get closer to the Moon, the light from the Sun comes right into the scanning telescope, and it is impossible to use. You have to rely on the sextant alone.
052:05:35 Collins: Roger, Jim. Understand that light from the Sun is coming into the scanning telescope making it impossible to use, and you have to rely on the sextant alone. Can you attach any angle to that?
052:05:55 Borman: Well, Mike, I am right now at the substellar point of [star] 33 [Antares]. I don't know where the Sun is exactly from there, but that is about the angle. We're - the optics are pointed right at the Moon now.
052:06:10 Collins: Roger. Understand.
Comm break.
The angle between Antares and the Sun is only about 22° just now. The wide acceptance angle of the scanning telescope (about 60°) means the Sun's light is flooding its optics.
052:08:47 Collins: Apollo 8, Houston. We are going to be changing our antennas in a couple of minutes. You can expect a comm switch-over.
052:08:57 Borman: Thank you.
Very long comm break.
Before Bill's next comm, Jim completes six angular measurements between Antares and the Moon's near horizon.
052:19:22 Anders: Houston, Apollo 8. Over.
052:19:26 Collins: Apollo 8, Houston. Go.
052:19:30 Anders: Roger. The LMP is going to take a little snooze here for a while. I am wondering, can you give me a quick - your view of the system status here before I depart, and, also, give me an idea of when the next cryo stir is due?
052:19:48 Collins: Roger, Bill. Will do; stand by. [Long pause.]
052:20:23 Collins: Apollo 8, Houston.
052:20:27 Anders: Go ahead.
052:20:29 Collins: Roger. Your systems remain unchanged. They are all looking good. You can go ahead and stir up the cryo starting right now.
052:20:38 Anders: Okay. Will do.
Long comm break.
While Bill goes ahead with two-minute stirs of the spacecraft's four cryogenic storage tanks, Jim takes another three marks on Antares.
This is Apollo Control, Houston. 52 hours, 21 minutes into the flight. ... Very shortly we expect to query the crew on their medical status. We have had some communication regarding the system status. That is reported to be in excellent shape. Dr. Berry, and his people on the medical console are wondering about the water intake and the food intake which seems to be off. We don't understand the sleep cycle, The crew are grabbing naps or better when they can. We don't have a very good plot of just how much sleep each man has had. So he has prepared a list of questions which I think will be relayed to the crew within the hour. I believe that brings us up to date. ...
052:25:19 Collins: Apollo 8, Houston.
052:25:23 Borman: Go ahead, Houston.
052:25:25 Collins: Roger. Before Jim makes his next mark [his last on Antares], could he call up Verb 1 Noun 91? We missed the last trunnion. Over.
052:25:36 Borman: Roger. The last trunnion was 10660.
052:25:41 Collins: 10660. Thank you.
Comm break.
As Jim takes a mark with the star's image superimposed on the Moon's horizon, the measured angle is displayed on the DSKY. Mission Control can see the contents of the display and are trying to copy the numbers. Verb 1 Noun 91 specifically calles up the current angles of the optics system.
052:26:53 Collins: Apollo 8, Houston.
052:26:59 Borman: Go ahead.
052:27:00 Collins: Roger. Before Bill gets his snooze, we would like him to give us a PRD read-out on all three crewmembers. Over.
052:27:12 Anders: Roger. CDR is 0.06, CMP is 0.64, and LMP is 0.64.
052:27:51 Collins: Roger. Thank you, Bill. [Pause.]
052:28:00 Borman: Looks like I'm the only one that is radioactive.
052:28:02 Collins: Understand. [Long pause.]
Journal Contributor Dave Hardin - "Since the start of the flight (at least according to the comm at 04:54:53), Borman's PRD has risen by 0.06 while Lovell's has stayed the same and I presume Anders' has, as well, but something is not consistent about the readings either here at 052:21 or at 004:54. Borman's PRD (according to an explanation Eric Jones gave in one of his journals), indicates he has received 0.06 rads of radiation throughout the flight. 0.10 rads is equal to the amount a human receives in a chest x-ray and humans pick up anywhere from 0.20 to 0.30 rads a year just living on Earth, according to medical textbooks."
052:28:18 Lovell: Okay. Houston, we got three sets [of marks] on 33 [the star Antaries]; we are going now to 34 [the star Atria] lunar far horizon for one set. Don't you agree?
052:28:26 Collins: We agree. Star 34, lunar far horizon, for one set.
Comm break.
052:29:48 Anders: Houston, the cryos have been stirred, and could you also give me a quick rundown on how the SPS line temps are doing?
052:29:58 Collins: Roger, Bill. Understand you stirred the cryos. Last time we checked, the SPS line temps were excellent; they were nice and warm. We will give you another number right now.
052:30:10 Anders: And a PU valve. [Long pause.]
The Propellant Utilization valve is part of the main CSM engine, the Service Propulsion System. This valve is manually manipulated by the Lunar Module Pilot to adjust the fuel mixture in the engine. By adjusting the mixture, fuel and oxidizer are evenly consumed.
The PU valve is an interesting idiosyncrasy of the Apollo system. This is known as an "open loop" mixture control, with there being no automatic feedback except the crewman's eyes and brain. Perhaps a closed loop system, using totalizers and automatic valves, would have complicated the engine to the point where the reliability might have been affected.
052:31:05 Collins: Apollo 8, Houston.
052:31:10 Anders: Go ahead.
052:31:12 Collins: Roger. On your SPS system, your oxidizer is running 75 degrees (F, 24°C); fuel, 74 degrees (F, 23°C); and PU valve between 78 and 82 (°F, 25.5°C and 28°C) depending on where we measured it. Over.
052:31:27 Anders: Real good. Everything really is working fine, Isn't it?
052:31:30 Collins: Yes, it's really humming along, Bill.
052:31:37 Anders: Okay. See you later.
052:31:39 Collins: Adios.
Long comm break.
Okay. Apollo Control, Houston. 52 hours, 33 minutes. We will just shut [the line] down to save wear and tear on the eardrums.
Jim makes three P23 measurements (one set) on star 34 (Atria, Alpha Trianguli Australis) to the Moon's far horizon.
052:37:57 Borman: Houston, Apollo 8.
052:38:01 Collins: Apollo 8, this is Houston.
052:38:05 Borman: I understand you want two sets on [star] number 40 [Altair], lunar near horizon. Is that right?
052:38:08 Collins: That's affirmative. Two sets on number 40, lunar near horizon.
Long comm break.
052:42:25 Collins: Apollo 8, Houston.
052:42:30 Borman: Go ahead, Houston.
052:42:32 Collins: Roger. We missed your last trunnion angle, Frank.
052:42:37 Borman: 21450.
052:42:41 Collins: Roger. 21450, and Paul tells me Valerie is over here and wishes Bill a happy nap.
052:42:52 Borman: Okay. Thank you. Tell her that he makes us tired sometimes too, will you?
052:43:13 Collins: Roger. I will deliver a modified version of the message.
052:43:20 Borman: Thank you. [Long pause.]
052:43:58 Collins: Apollo 8, Houston.
052:44:04 Borman: Go ahead, Houston.
052:44:07 Collins: Roger. On star number 40 that you are doing now, the Flight Plan only calls for one set of marks. You called down two sets, and it's really your choice. Only one is required. We are glad to have the data if you do a second set. Over.
052:44:24 Borman: We will only do one then, if you want to. Our Flight Plan has been updated to include two sets. That is why I called it down.
052:44:32 Collins: Roger. One set is - will suffice.
Comm break.
The post-flight guidance analysis shows that one set of three marks were taken on Altair.
052:47:28 Collins: Apollo 8, Houston. We missed the last trunnion [angle].
052:47:34 Borman: Very well, I will read it to you; 21455.
052:47:39 Collins: 21455. Thank you. Just a matter of interest: it is taking your voice about 1.6 seconds to get down to us.
052:47:51 Borman: I'm a little hoarse, that's why. [Long pause.]
052:48:19 Borman: Okay. Houston, do you want us to go back to the PTC attitude now and start the rotisserie again?
A common nickname for the Passive Thermal Control manoeuvre is the barbecue mode as the spacecraft is being slowly turned to even its heating from the Sun and chilling from exposure to deep space. Rotisserie is even more apt, being a food roaster with a rotating spit.
052:48:25 Collins: That is affirmative, Frank. We will have the PTC attitude for you in just a second here. [Long pause.]
052:48:48 Collins: Apollo 8, Houston.
052:48:53 Borman: Go ahead.
052:48:55 Collins: Roger. Those PTC attitudes remain pitch, 224 degrees; yaw, 020 degrees. On the next page, page 2-39 of your Flight Plan, those PTC numbers should be changed to reflect that.
052:49:12 Borman: Pitch 224 and yaw 20.
052:49:15 Collins: That's affirmative.
Long comm break.
052:52:23 Collins: Apollo 8, Houston. Over.
052:52:29 Borman: Go ahead, Houston. Apollo 8.
052:52:31 Collins: When you have a few minutes, we would like to hear the detailed crew status report from you.
052:52:40 Borman: Like what?
052:52:42 Collins: Well, like we would like to know, in the last 24 hours, has anybody had any symptoms similar to Frank's. We would also like to know - You know, we told you the other day to take Marezine as you like - we would like to know if anybody had taken any drugs, and then we would like to talk over there about sweet breads and water and such.
052:53:01 Borman: Okay. Nobody has taken any other drugs; nobody took any Marezine; nobody is sick. Bill took one of those pills, a sleep Seconal pill, last night. Everybody had breakfast this morning and ate most of a meal - 1 day 3 - meal a day 3. What else do you want?
052:53:31 Collins: We would like to tell you to drink plenty of water. We think that your water intake may be down. We copied your dosimeter readings. The only other thing is we just were wondering how in general you feel. We show you to have about 15 hours sleep total - Frank or Bill about 10 and Jim about the same, and we were wondering just how you are feeling in general.
052:53:58 Borman: We all feel fine; we are going to fix it now so that we all have one more rest period before the LOI.
052:54:04 Collins: Roger. Thank you. [Pause.]
052:54:11 Lovell: Happiness is bacon squares for breakfast.
052:54:18 Collins: If you don't eat them all, bring them back, and we'll polish them off here. [Long pause.]
One gets the impression that bacon squares are some of the crews favorites.
052:54:34 Borman: Okay, Houston. Apollo 8 here. I stand corrected, William had one Marezine. He didn't tell me about it; he snuck it.
052:54:40 Collins: Roger. Understand Lovell took the Marezine. Understand.
052:54:43 Borman: That's Bill Anders, and he took one when he took the - with the Lomotil, when the doctors told him to.
052:54:54 Collins: Roger. We copy that. Thank you.
052:56:06 Borman: Okay. We are back on the barbecue attitude, starting PTC.
052:56:10 Collins: Roger, Apollo 8. Thank you. [Pause.]
052:56:21 Borman: Mike, we ran the latest state vector we have through the P21, and it showed the pericynthion at 69.7 miles.
052:56:30 Collins: Yes, we were all having big talks about that down here. It looks like you are giving us a real good comparison on our system. Looking - looking extremely good.
Running the P21 ground track determination program in the computer is the final stage of Jim's navigation exercise. It lets the crew calculate forward in time and see how close they will get to the Moon. 69.7 nautical miles (129.1 km) is a good value and is in close agreement with Mission Control's figure of about 66 nautical miles (122 km).
052:56:45 Borman: We've got the navigator, par excellence.
052:56:50 Collins: I believe. [Long pause.]
052:57:28 Collins: Apollo 8, Houston.
052:57:33 Borman: Go ahead.
052:57:36 Collins: Roger. What was the time you used on that P21?
052:57:42 Borman: 69:10 [GET] there, Mr. Slide Rule.
052:57:46 Collins: Thank you. [Long pause.]
052:58:01 Borman: Mike, I wonder if Buzz wants us to change the time?
052:58:04 Collins: No, that is fine.
052:58:07 Borman: Oh, okay. Thank you.
Long comm break.
A bit of gentle ribbing towards Buzz Aldrin, known through the astronaut corps as "Dr. Rendezvous". Buzz's doctorate from MIT was in orbital mechanics, emphasizing rendezvous in particular. The reference is probably that P21, which gave a very accurate pericynthion of 69.7 nautical miles (129.1 km), would be improved if the time of closest approach is altered from the calculated time of 69:10. Of course, this is a flip statement, as the time is fixed by the speed and position of the spacecraft.
053:03:07 Borman: Houston, Apollo 8.
053:03:11 Collins: Apollo 8, Houston.
053:03:15 Borman: Roger. Are you going to give us an update for a maneuver PC plus 2 that does not assume a flyby maneuver?
053:03:26 Collins: Roger. Stand by.
Long comm break.
As part of the effort to keep the crew updated with information to get home in case of loss of communication, details of a flyby manoeuvre were read up at 44 hours, as were details for a further manoeuvre to hasten their arrival, the PC plus 2 burn.
Even without the flyby manoeuvre, the spacecraft's trajectory will bring them to Earth. The function of the flyby is to modify the trajectory such that the spacecraft will head for the prime recovery area. A burn 2 hours after their closest approach would hasten their approach.
This is Apollo Control, Houston. 53 hours, 5 minutes into the flight. The spacecraft is 171,360 odd [nautical] miles [317,358 km] from Earth. Its velocity, in feet per second; 3,356 [1,023 m/s]. We have heard from the crew in the last 20 minute time period, a rather complete medical status. They reported that Bill Anders had taken 1 Marezine. They say they are all feeling all quite well now as opposed to yesterday. They also explained their sleep and rest cycle. As a general reference, the spacecraft is proceeding on sort of a nose-down - in a nose-down attitude. If you consider in your mind's eye, the Earth, Moon and Sun all on a flat plane and along with the spacecraft of course. The spacecraft is proceeding in a nose-down attitude toward an intersection with the Moon and at the same time the spacecraft is rotating about 1 revolution per hour. It has held this attitude for some time and will continue in that attitude. ...
053:08:03 Collins: Apollo 8, Houston.
053:08:12 Lovell: Go ahead, Houston. Apollo 8 here.
053:08:14 Collins: Roger. Here is a rather brief summary of the updates that you will be getting. The one that you have now for PC plus 2 following an LOI minus 8 flyby maneuver is still good. That will not be updated. The next update you will get will be MCC [Mid-Course Correction]-4. After that, you will get two PC plus 2 maneuvers, that assume MCC-4 completed. One will be a minimum Delta-V, and the other will be a fast return. Do you copy?
Apollo 8's trajectory to the Moon has been very accurate and two of the three adjustments to its flight path so far have been cancelled due to the corrections being too small to be concerned with. As the spacecraft approaches the Moon, the effect of any error has been allow to build, to be taken out at the final opportunity, the MCC-4 burn. Therefore, unlike the previous PADs the crew have been given, the one for MCC-4 will definitely be used. It is not an abort contingency. The changes made to the trajectory by this burn will be taken into account for the next two contingency PADs, both of which would be used, if required, two hours after closest approach to the Moon.
053:08:50 Lovell: Roger. Understand, and also I take it for MCC-4 you are going to give us a new alignment. Is that correct?
053:08:57 Collins: That is affirmative.
Very long comm break.
At the very core of the Apollo spacecraft, at least as far as its guidance and control are concerned, is the IMU (Inertial Measurement Unit) with the platform at its centre. All the guidance measurements, attitude adjustments and engine burns are made with respect to the precise orientation of this platform. The physics of three gyroscopes mounted on the platform hold its orientation nearly constant with respect to the stars while the spacecraft is allowed to rotate around it.
All the way out to the Moon, the platform has been lined up with a reference orientation defined within the computer and set to match the precise orientation of the launch pad at Kennedy Space Center at the time of launch. Though the platform tends to drift slightly with time, regular comparisons with the stars have allowed the crew, usually Jim, to realign it to the reference. The numbers in the computer that describe this reference orientation are known as a REFSMMAT (Reference to a Stable Member Matrix) and throughout Apollo 8, three different REFSMMATs are used.
Pre-flight planning has stipulated that the alignment of the guidance platform will be changed to a new REFSMMAT prior to the MCC-4 burn. This orientation is defined according to one of the two engine burns that gets Apollo 8 into its final lunar orbit. The first burn, called LOI1 is a large one that gets the spacecraft into an elliptical orbit around the Moon. After two orbits, a second burn, called LOI2 makes the orbit circular. The new REFSMMAT is calculated to be the orientation the spacecraft would be in at the time of the LOI2 burn if it were flying facing forward in a "heads up" manner. Since the burn is 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 numbers that define the new REFSMMAT will be uplinked to the spacecraft's computer in a few hours time after which Jim will use them when he realigns the platform.
Readers might like to compare the three REFSMMATs used for the first manned lunar voyage, to the eight used during the more advanced Apollo 15 mission: The increasing sophistication of the planning and flight control teams in using the spacecraft's capabilities is apparent. Many of these REFSMMATs during Apollo 15 are to aid the crew when monitoring the spacecraft's attitude during crucial burns. By having the FDAI display zero in all three axes, deviations are much more apparent and easier to correct.
Apollo Control here. ... Our present distance, 171,699 [nautical] miles [317,986 km]. Velocity, in feet per second, 3,349 [1,021 m/s]. An update on the passage into the lunar gravitational field: that event to occur at an [Ground] Elapsed Time of 55 hours, 38 minutes, 46 seconds. The - our present weight of the spacecraft is 62,915 pounds, Earth pounds [28,538 kilograms]. At 53 hours, 16 minutes into the flight, this is Apollo Control, Houston.
053:26:31 Collins: Apollo 8, Houston.
053:26:36 Borman: Go ahead, Houston. Apollo 8.
053:26:38 Collins: Roger, Frank. I've got a lot of talking to do regarding TV cameras and brackets and what not. I would like to start in on it whenever you are ready to talk about it.
A television transmission from the spacecraft is scheduled in just under two hours time at 55:15 GET. Frank has been struck by the view of the Earth from their unprecedented altitude and is keen to televise it. However, during the first TV transmission at 031:10:23, the crew had great difficulty getting a clear image of the home planet. Using the wide angle lens, they got only a bright blob that threatened to burn the imaging tube. Their attempts to use the telephoto lens were unsuccessful.
053:26:52 Borman: Let me get a piece of paper out.
053:26:54 Collins: Okay. [Pause.]
053:27:06 Borman: Go ahead.
053:27:08 Collins: Okay. First a question. Are you planning to show us TV pictures of the Earth today?
053:27:18 Borman: Well, that is what we wanted to do. It seems that would be the most interesting thing we can show you, but we - you know, we had trouble with the lens.
053:27:25 Collins: Well, okay, that's good. All this procedure that I am going to give to you here is relative to what we hope are fixes to the lens and for looking out your rendezvous window at the Earth, and all the gimbal angles and all that good stuff is based toward looking out the window at the Earth rather than at the Moon. Over.
053:27:49 Borman: Roger.
053:27:50 Collins: Okay. First, unstow the red filter, the polarizing filter, the red and blue filter holder, and some tape. Over.
053:28:07 Borman: Okay. Let me write this down.
053:28:09 Collins: Roger. I'd suggest that. I've got a whole page full. [Long pause.]
053:28:33 Borman: Okay.
053:28:35 Collins: Alright. Tape the red filter to the telephoto lens. That red filter is the 25A red filter, not the one that is in the red and blue filter slider.
By suppressing the blueness of the Earth, the red filter will improve the contrast from their black and white camera. They may also be trying to reduce the brightness of the Earth's image
053:28:48 Borman: Roger.
053:28:49 Collins: Attach telephoto lens to the camera.
053:28:56 Borman: Okay. We can figure out how to do that. Roger.
053:29:00 Collins: Ensure that the automatic light control, the ALC switch on the camera, is in the In position. Over.
053:29:11 Borman: ALC In. Roger.
053:29:14 Collins: Roger. Attach camera to the adjustable TV bracket and attach the bracket to the TV mounting point on the Commander's side of the hatch to point out rendezvous window number 2.
053:29:41 Borman: Roger.
The two rendezvous windows, numbers 2 and 4, are designed to look along the spacecraft's plus-X axis as an aid to guiding the CSM when performing a rendezvous and docking with the Lunar Module. By attaching the camera to a bracket, the camera will be made to look along a well defined axis that is 30° away from the plus-X axis. Thus, the spacecraft itself becomes a steerable platform that can be used to aim the camera at the Earth in a controlled fashion.
053:29:43 Collins: Okay. There is a note here that says use dovetail on top of camera, rather than the side dovetail. Use the dovetail on the top of the camera for mounting to bracket and place the locking nut on the bracket down, and down means toward your minus-X direction.
053:30:16 Borman: Roger.
053:30:18 Collins: Okay. They say this step I just got through giving you is somewhat complicated. You might want to get the cameras set up early using the instructions I just gave you. When it's properly...
053:30:31 Borman: We are not reading you.
053:30:34 Collins: Roger. I say again, the instructions that I just gave you should end up having the camera looking out the window and about 30 degrees yawed left from your plus X-axis, so I suggest you get the camera set up that way early; and if there are any problems, come back to us; we will talk them over. These mounting instructions are sort of complicated.
053:31:00 Borman: Roger.
053:31:03 Collins: Okay. The next step: dim the interior lights. Over.
This will minimise reflections from the window.
053:31:12 Borman: Dim interior lights.
053:31:14 Collins: Roger. Next, stop Passive Thermal Control at gimbal angles pitch 224, yaw 020, roll 270. Over.
053:31:36 Borman: Pitch 224, yaw 020, roll 270.
The first two angles represent the orientation of the spacecraft's plus-X axis. During the PTC manoeuvre, the spacecraft rolls around this axis at a rate of 360° in an hour. The crew will wait until the roll angle reaches 270° then stop the roll.
053:31:41 Collins: Roger. Next, acquire on High Gain Antenna, switch to Auto Track, Narrow Beam upon acquisition. Over.
The HGA needs to use its narrowest beam width to give the best possible signal. Television, even the limited bandwidth version coming from Apollo 8, is demanding of the radio link, especially at the near lunar distances the spacecraft is at.
053:32:02 Borman: Got it.
053:32:04 Collins: Okay. Yaw spacecraft left to get good view of Earth in your rendezvous window number 2. You may have to pitch slightly as well, but primarily a left yawing maneuver to get a good view of the Earth.
053:32:20 Borman: Got it.
053:32:22 Collins: This maneuver is going to put you very close to your scan limits for the High Gain Antenna, so while you are making the maneuver, check your lights. If your scan limit light comes on, you still have got 15 degrees to play with. But the only message is, should you break lock, then you are going to have to go back and reacquire and do that maneuver over again, because you are going to be very close to the edge of your High Gain Antenna capability.
The spacecraft and the HGA will both be aimed in roughly the same direction. This takes the HGA very near the limits of its articulation and if it does reach that limit, it will lose its ability to automatically maintain its aim at Earth.
053:32:52 Borman: Thank you.
053:32:54 Collins: And then finally, now that you have got the spacecraft over there, aim the camera as required to include the Earth in the field of view, and do not touch the body of the lens while televising. Apparently, if you put your hands on the lens itself, it causes electrical interference. Over.
053:33:26 Borman: Okay. Aim camera and do not touch lens while televising.
053:33:30 Collins: Right. And in all this stuff in all these pictures using the ALC, it is important that you let the camera stabilize for at least 10 or 20 seconds, to let the ALC do its thing.
The ALC (Automatic Level Control) automatically adjusts the camera's exposure to ensure detail in the bright disc of the Earth is visible.
053:33:58 Borman: Stabilize for 10 to 20 seconds. Thank you.
053:34:01 Collins: Right. Now we have some additional instructions in case this does not work. They say a full 20, Frank, on that ALC. It requires a full 20 seconds undisturbed for the ALC to properly do its thing. Now if these procedures that I've given you do not work, then we will be giving you some more, and they have to do with other filters and various combinations thereof. So I'd have the polarizing filter and the red and blue filter holder at hand because we will be attempting to use those in addition to the red filters if this procedure doesn't work.
Collins' latter comment implies that part of the exercise is to try and reduce the brightness of Earth's image in the TV camera by adding numerous filters.
053:34:43 Borman: All very well, Mike.
053:34:46 Collins: That's all we have right now. We will have a few more remarks on the TV coming up to you later. I would suggest that you get set up for this early, and if you have any questions on it, shoot them down to us. We have a bunch of experts down here to help out.
053:35:03 Borman: Thank you; will do.
Very long comm break.
Happily, the second TV transmission from the spacecraft will manage to acquire good images of the Earth, considering the capability of the system.
This is Apollo Control, Houston at 53 hours, 34 minutes into the flight. Mike Collins is passing on a procedure to the crew, involving the use of that telephoto lens which we couldn't get to work yesterday. It will certainly be of interest to the broadcast media and hopefully, an interest to a lot of other people too. ...
054:06:18 Collins: Apollo 8, this is Houston. Over.
054:06:23 Borman: Go ahead, Houston. Apollo 8.
054:06:25 Collins: Roger. Just a voice check, Frank.
054:06:30 Borman: Roger. You're loud and clear.
054:06:32 Collins: Thank you.
Very long comm break.
054:18:50 Collins: Apollo 8, Houston.
054:18:55 Borman: Go ahead, Houston. Apollo 8.
054:18:57 Collins: Roger. We would like some high bit rate data when you can get it locked up on the High Gain. We haven't had any of that for a while.
When the HGA is in operation, data from a wider range of sensors aboard the spacecraft can be sent to Earth, giving the flight controllers in Mission Control a deeper insight to how well the spacecraft is working.
054:19:06 Borman: Roger. We will do that.
054:19:09 Collins: Thank you. How is that camera bracket thing working out?
054:19:13 Borman: We are doing it right now. [Long pause.]
054:19:53 Borman: Houston, this is Apollo 8 transmitting to you on the High Gain. How do you read?
054:19:57 Collins: Read you loud and clear, Frank. Thank you. [Pause.]
054:20:08 Borman: Apollo 8 transmitting on the High Gain Antenna.
054:20:11 Collins: Apollo 8, Houston. You are loud and clear. Thank you for the High Gain.
054:20:18 Borman: Roger.
Very long comm break.
This is Apollo Control, Houston back. During the television pass this afternoon, we don't know exactly what the crew is going to do, but you know from the earlier discussion that they are going to work with the telephoto lenses again with a filter application which we hope will enhance the image of the Earth and it is also entirely possible they will swing it around - swing that camera around and take a picture of the Moon. If we are successful we should see approximately about a quarter Moon - the eastern limb of the Moon - and in what detail, it is impossible for us to estimate. But those are the general plans to take a long look of the Earth and hopefully a quick look at the Moon. They will be about 45,000 [nautical] miles [83,000 km] away from the Moon at that time. They are presently 174,000 [nautical] miles [322,000 km] from Earth. They are moving at a velocity of 3,300 feet per second [1,000 metres/second]. This is Apollo Control, Houston.
054:32:59 Borman: Houston, this is Apollo 8. Are you getting high bit rate all right?
054:33:08 Collins: That is affirmative, Apollo 8. We are getting a good high bit rate.
054:33:14 Borman: Thank you. [Long pause.]
054:33:36 Collins: Apollo 8, Houston.
054:33:40 Borman: Go ahead.
054:33:42 Collins: Roger. I've got some more talking to do about the TV any time it's convenient for you.
054:33:48 Borman: Go ahead.
054:33:50 Collins: Okay. First thing, we've made no provisions in these instructions for taking pictures of the Moon. If you get some Moon shots after it's all over by looking out a different window or by making some small maneuver, of course, we would be happy to have them, but the show as scheduled is just out the window at the Earth only. Over.
054:34:15 Borman: Roger.
Frank will stick to the schedule. Though he has been impressed by the sight of the home planet at a distance, and is keen to present it to the people there, he is unwilling to extend spacecraft operations any further beyond that which is planned.
054:34:17 Collins: The second point is, of course, when you stop your Passive Thermal Control, you are about 90 degrees to the Earth line, so when you make that yaw left, you are going to have to yaw left until your middle gimbal angle is in the vicinity of 60 degrees. You will get the additional 30 degrees by offset between where the camera is pointed and your plus-X axis. But the two together are going to total up around 90. We just wanted to make sure that you understood you were going to be working with a large middle gimbal angle. Over.
The guidance platform at the centre of the IMU is supported by three gimbals whose axes of rotation are at 90° to those next to them, an arrangement with a drawback. If the spacecraft adopts certain attitudes where the middle gimbal angle is greater than about 70°, the outer and inner gimbal axes will nearly line up. If this happens, the assembly may lose its most important property, that of allowing the platform to hold a steady attitude, independent of the spacecraft's attitude. This condition is known as "gimbal lock" and all spacecraft manoeuvres are carefully chosen to avoid it.
A fourth gimbal would have avoided the gimbal lock problem but, despite having been used in the Gemini spacecraft, MIT did not implement it in Apollo for reasons of weight, complexity and reduced tendency to drift, despite the misgivings of astronauts. Instead, the decision was made to work around the property by careful mission planning. The crew can see when they are approaching the gimbal lock by referring to the FDAI or "8-ball" which has a red circle marking that indicates the danger area. Entering gimbal lock is not particularly dangerous providing it doesn't happen during the build-up to an engine burn. If it does occur, it only requires a platform realignment to restore correct platform attitude.
The procedures for getting TV pictures of the Earth will take the spacecraft near gimbal lock and Mission Control want the crew to be aware of it.
054:34:52 Borman: Roger. We understand that. We also are looking at the Earth right now, and there is a spectacular long thin band of clouds. Looks like it may be a jet stream. It's absolutely spectacular - going almost all the way - or halfway around the Earth.
054:35:12 Collins: Roger. Well, you might want to repeat that during the TV narrative, and we would like you, if possible, to go into as much of a detailed description as you poets can on the various colors and sizes of those things and how the Earth appears to you, in as much detail as you can possibly muster. Over.
054:35:36 Borman: Roger. I figure we will have to do that because I bet you - I won't bet - but I bet the TV doesn't work.
Frank's pessimism is misplaced as the camera works well. However, it is Jim who will turn poet, going against the tendency of test pilots to concentrate on procedures and numbers.
054:35:44 Collins: Well, we won't take that bet, but anyway, we are standing by for a nice, lurid description, and we would suggest that you talk a little bit slower than you did yesterday. Over.
054:35:56 Borman: Okay.
054:35:58 Collins: And the only other thing on this TV is that the experts tell us that - do not point - with the wide angle lens on the camera, do not point at either the Earth or the Moon. It comes close to damaging [the] interior of the instrument due to the fact that it's too bright. Over.
054:36:18 Borman: Understand.
054:36:20 Collins: Thank you.
Long comm break.
This is Apollo Control, Houston at 54 hours, 35 minutes into the flight. We have established contact and Frank Borman says, among other things, that they have a spectacular view of the Earth. He goes into some little detail regarding a jet stream that they are observing. Mike Collins tells him he hopes that will hold up for at least another hour so we can all see it on television. ...
054:41:23 Anders: Houston, Apollo 8. We're going to have to switch to an Omni.
Having established the HGA for sending high bit rate data to Earth, they must return to using low bit rate through one of the omni-directional antenna as the rotating spacecraft is taking the large antenna out of its range.
054:41:28 Collins: Roger, Apollo 8.
Very long comm break.
054:52:57 Collins: Apollo 8, Houston. Over.
054:53:03 Borman: Go ahead, Houston. Apollo 8.
054:53:05 Collins: Roger. Just checking the voice comm, Frank.
054:53:09 Borman: Thank you.
Long comm break.
This is Apollo Control, Houston. 54 hours, 50 -- almost 54 minutes into the flight and the spacecraft presently 174,800 nautical miles [323,700 km] from the Earth. A word or two here on a change in our charts and a change in our reporting procedure which will come up following the passage of what we call MSI or Moon Sphere of Influence. That event to take place in about a half an hour from now. We've been reading - the reporting we have given you on distance and velocity is coming from a chart called the Command Service Module Space Digitals and it presently uses, as a reference, the Earth. Now at some point shortly after we pass the - pass into the sphere of influence of the Moon, the reference will become the Moon and we will have rather sharp and dramatic change of the velocity reference. For instance, the velocity at - precisely at the passage in relative to Earth terms will be 3,261 feet per second [994 m/s]. Relative to the Moon, that same velocity reading will be 3,989 feet per second [1,216 m/s]. And from that point we will be giving you velocities in relation to the Moon, which will be exercising the gravitational effect at that point. Our present estimate is that at MSI, the Moon's sphere of influence point, the Moon will be 33,821 [nautical] miles [62,636 km] from the spacecraft and the spacecraft will be 176,275 [nautical] miles [326,461 km] from Earth. Both of those are nautical miles. In the last 10 to 15 minutes the crew has put in one call simply to establish communications. We have had nothing more than a 'Roger, we read you loud and clear.' And at 54 hours, 56 minutes into the flight; this is Apollo Control, Houston.
054:57:39 Collins: Apollo 8, Houston.
054:57:44 Borman: Go ahead, Houston.
054:57:46 Collins: Roger. We'll be switching antennas from Madrid to Goldstone in another 3 minutes. You can expect a glitch on your comm.
054:57:56 Borman: Thank you.
Long comm break.
055:02:38 Borman: Houston, how do you read? Apollo 8.
055:02:41 Collins: Apollo 8, Houston. We're reading you loud and clear through Goldstone. Over.
055:02:46 Borman: Okay. We have the television On now, and we're trying to maneuver to the - to the Earth.
055:02:55 Collins: Roger. Understand.
Comm break.
055:04:11 Lovell: Houston, Apollo 8.
055:04:15 Collins: Apollo 8, Houston. Over.
055:04:20 Lovell: Roger. We're maneuvering to position now for the TV. Bill's got it set up in Frank's left rendezvous window, and I'm over in Bill's spot looking out the right rendezvous window, and the Earth is now passing through my window. It's about as big as the end of my thumb.
055:04:45 Collins: About as big as the end of your thumb at arm's length, huh?
055:04:51 Lovell: That's right. I think what we see now is South America down below us.
This is the earliest reference to the idea of being able to obscure the entire Earth with your outstretched thumb, a powerful demonstration of the new view of the planet that was being afforded the pioneers of Apollo 8. When actor Tom Hanks played Jim Lovell in the movie Apollo 13, he repeated the act both on Earth and in the spacecraft to help bring home to the audience the scale of the distances involved.
055:04:55 Collins: Roger. Is the TV camera pointed about 30 degrees yaw left from the plus-X axis?
055:05:05 Lovell: Stand by a moment. We're checking it. We think we've got it in the right position. We're going into position now.
055:05:13 Collins: Okay. [Long pause.]
055:05:33 Anders: Houston, are you getting any sort of a picture? [Long pause.]
055:05:52 Collins: Apollo 8, Houston. Negative; not yet. [Long pause.]
055:06:32 Anders: Okay. Houston, Apollo 8. We should have...
Comm break.
The Network flight controller, George Ojalehto, reports to the Flight Director, Cliff Charlesworth, that a TV signal is arriving at Houston. The black screen being presented to Mission Control is black because the camera is aimed into space.
055:07:36 Borman: Hello, Houston; this is Apollo 8. We have the television camera pointed directly at the Earth now and have followed the instructions you gave us.
055:07:45 Collins: Roger, Frank. We're picking something up on our TV. It's not very good so far, but let it sit for a second, and we'll have more instructions for you. [Pause.]
This is Apollo Control, Houston. Frank Borman has come up a little bit earlier - a little earlier than anticipated, but let's buzz this picture out. It is - The bright blob on the upper right is the Earth.
055:08:00 Collins: Okay. It[Earth]'s coming into view now, Frank.
055:08:07 Borman: It is?
055:08:08 Collins: Yes. We have it in the corner of our screen. You're slightly off on your pointing, but we're getting a darn good look at the corner of it. [Pause.]
About one quarter of the Earth is in the top right corner of the picture.
055:08:21 Collins: It's moving off, Frank. It's moving off our - 3 o'clock on our TV screen. I have no idea what to tell you about which way to point. [Pause.]
055:08:32 Collins: It's moving further away. We've lost it now. [Long pause.]
The image is once again black.
055:08:57 Collins: Apollo 8, Houston. Receiving nothing now. Over.
055:09:03 Borman: Okay.
055:09:05 Collins: We're receiving the picture; we're just not seeing the view of the Earth.
055:09:11 Borman: Roger. I got you.
055:09:16 Collins: Okay. We are just picking it up at 3 o'clock on our screen.
055:09:21 Borman: Okay.
055:09:23 Collins: It is moving up toward 1 o'clock and in toward the center; keep it going in that direction.
055:09:29 Borman: Okay.
055:09:31 Collins: It's looking better. You're holding it about 1 to 2 o'clock. Looking better.
For a short time, a complete image of the gibbous Earth comes into the top right corner of the picture. The exposure is changed and detail becomes visible.
Collins (continued): Give us a little more in that same direction. You're down at 3 o'clock now. We see about half of what you see. Too much. It is disappearing at our 5 o'clock. Now it is coming back. It is half off - screen at our 2 o'clock. [Pause.]
055:10:05 Collins: And it's disappeared off to our 3 o'clock. There, it is coming back in now. It is headed toward the center of our screen.
055:10:14 Collins: Mark.
055:10:15 Collins: It is right in the center of our screen. Just hold her - hold her steady. It is really looking good. Okay. We have...
One can only imagine the frustration aboard Apollo 8, trying to maneuver the spacecraft at a target without a TV monitor to guide their progress. With the telephoto lens, the field of view is quite narrow (only 9 degrees), and so pointing must be precise. Yet the maneuvering directions are delayed by several seconds and are next to impossible to interpret ("it's at the 3 o'clock position... it's moving toward 1 o'clock") as the angle of the camera is offset from the spacecraft axis.
At last, the crew can be the first humans to send the live TV coverage of the whole Earth back to itself.
Still frame from the first live TV images of the Earth sent by humans.
In this image, lifted from coverage provided by www.spacecraftfilms.com, north is to the left. At a distance of about 325,000 km, the Earth appears about two and a quarter degrees across from pole to pole.
055:10:28 Lovell: What you're seeing, Mike, is a - Houston, what you are seeing is the Western Hemisphere. Looking at the top [left in this image] is the North Pole; in the center - just lower to the center is South America - all the way down to Cape Horn. I can see Baja California and the southwestern part of the United States. There's a big, long cloud bank going northeast, covers a lot of the Gulf of Mexico, going up to the eastern part of the United States, and it appears now that the east coast is cloudy. I can see clouds over parts of Mexico; the parts of Central America are clear. And we can also see the white, bright spot of the subsolar point on the light side of the Earth.
The Earth has drifted to the top edge of the picture, requiring a readjustment of their attitude to bring it back in.
055:11:28 Collins: Roger. Could you give us some ideas about the colors, and also, could you try a slight maneuver? It's disappearing. We're seeing about half of it. It's going off to our 12 o'clock. Now it is going off to our 3 o'clock. That is the wrong direction. Yes, that is a good direction. [Pause.]
055:11:50 Collins: We need another small correction to bring it to our center screen. If you could maneuver toward the terminator, that is the part of it we are missing. We are getting the lighted portion. There you go; that's fine. Stop it right there.
Judging by the final motion that brings the Earth into view, it seems the camera's aim has been adjusted in the bracket as well as a change being made to the spacecraft's attitude.
With the aiming directions referencing the view from the camera, moving the camera, rather than the entire spacecraft makes sense. Such manoeuvring also conserves RCS propellant, which is already above pre-flight estimates.
055:12:17 Lovell: Okay. For colors, the waters are all sort of a royal blue; clouds, of course, are bright white; the reflection off the Earth is - appears much greater than the Moon. The land areas are generally a brownish - sort of dark brownish to light brown in texture. Many of the vortices of clouds can be seen of the various weather cells, and a long band of - it appears cirrus clouds that extend from the entrance to the Gulf of Mexico going straight out across the Atlantic. The terminator, of course, cuts through the Atlantic Ocean right now, going from north to south. [The] southern hemisphere is almost completely clouded over, and up near the North Pole there is quite a few clouds. Southwestern Texas and southwestern United States is clear. I'd say there are some clouds up in the northwest and over in the northeast portion.
The Earth has again drifted towards the top of the image.
055:13:25 Collins: Roger. Could you maneuver toward the terminator again, please? [Pause.]
055:13:34 Collins: A little bit more. Stop her right there and hold it. [Pause.] It keeps slipping up a little bit; could you maneuver slightly more toward the terminator? [Pause.]
That is the North Pole at the lower left portion of the Earth. At about 8 o'clock.
055:14:02 Borman: How is that, Houston?
055:14:05 Collins: We are getting about half of the Earth, Frank. The top half - our top half which includes the dark portion it - is obscured.
055:14:19 Borman: How is the definition on the picture?
The GNC flight controller, likely Gary Coen, suggests to FLIGHT that the spacecraft be rotated to 347° in yaw. He reckons this will bring the Earth into the centre of the picture.
055:14:23 Collins: Looks pretty good.
Actually, the picture, by modern standards, is almost unintelligible, and Mike's comment is a bit generous. Still, the major features such as clouds are visible.
055:14:28 Lovell: Can you see cloud patterns at all?
055:14:31 Collins: That's affirmative. [Pause.]
055:14:36 Lovell: Good.
055:14:39 Anders: Are you still seeing it, Houston?
055:14:42 Collins: Yes, we are seeing it. We are missing the portion of the Earth that is over toward the terminator. The dark portion of the Earth is what we are not picking up. We are getting about three-quarters or four-fifths of the rest of it.
055:14:56 Anders: Roger. I will move it, and tell me when I am getting better or worse please.
055:15:01 Collins: Good. [Pause.]
055:15:08 Collins: Stop right there. That is worse, Bill. Go back where you were. You made it disappear to our 3 o'clock. Now it's coming back. [Pause.] Okay. Stop right there. Now you are back where you were, and we need a motion that is about 90 degrees to that last one you gave us. [Pause.]
The Earth smartly moves off the top of the picture.
055:15:38 Collins: That is the wrong 90 degrees. 180 degrees away from that one. [Pause.]
055:15:47 Collins: Stop right there. [Pause.] Okay. Now we have lost a different half of it. I need a motion 90 degrees to that last one. [Long pause.]
055:16:24 Collins: That is good right there, Bill. That is good right there. [Pause.]
055:16:42 Collins: Apollo 8, Houston. If you can stick your polarizing filter in front of the camera without disturbing anything else, it might improve the quality slightly.
055:17:02 Anders: Stand by.
055:17:04 Collins: Roger, Bill. [Pause.]
A slight dip in the image brightness betrays the placing of the polarising filter but once the brightness recovers, very little difference is visible. Note that no attempt seems to have been made to rotate this filter, an operation closely tied in to the way the filter works.
Light exhibits wave-like behaviour that can be likened to wiggling a long rope. For most light sources, though the direction of the "transverse" wiggle is at right angles to the direction of travel, the plane of the wiggle can be at any angle around that direction of travel. This is unpolarised light. However, it is possible to limit transverse waves so that the wiggle is preferentially along one axis, somewhat like someone shaking a rope only in the up/down direction rather than the left/right direction.
Certain circumstances in nature tend to polarise light. Light reflecting off objects at a low incidence angle becomes polarised, as does sunlight being scattered to make a blue sky. Some substances also polarise light passing through, allowing filters to be produced with this property. If you pass an unpolarised light beam through two polarising filters, both of which are aligned to polarise in the same direction, the beam will emerge only slightly dimmed. Rotate one filter by 90° and the beam will be cut off entirely. Photographers find polarising filters very useful because they can be rotated to exclude light from polarised sources. Therefore the sky can be made to look a deeper shade of blue; or, by removing the specular reflection from each blade of grass, a lawn can appear a much richer shade of green; or the reflection of the sky on the surface of a pond or river can be nearly eliminated, allowing the objects beneath to become much more visible.
To get the best use of the polarising filter on the TV camera, Bill would need to rotate the filter, looking for changes in the image of Earth as a result of varying the angle of polarisation. As he does not have a monitor with which to view the output of the camera, this is essentially impossible.
055:17:12 Anders: Okay. The polarizing filter is in front. [Pause.]
055:17:24 Anders: How is it now, Mike?
055:17:28 Collins: It's still looking good. That didn't make much of a change one way or another, but in general, considering how far away, it's looking excellent. [Pause.]
055:17:51 Anders: Well, I hope that everyone enjoys the picture that we are taking of themselves. [Pause.] How far away from Earth now, Jim, about?
055:18:03 Collins: We have you about 180,000 [nautical miles].
055:18:11 Anders: You are looking at yourselves at 180,000 miles out in space. [Pause.]
055:18:22 Lovell: Mike, what I keep imagining is, if I'm a - some lonely traveler from another planet, what I think about the Earth at this altitude, whether I think it'd be inhabited or not.
055:18:31 Collins: Don't see anybody waving; is that what you are saying?
055:18:36 Lovell: I was just kind of curious whether I would land on the blue or the brown part of the Earth.
055:18:44 Anders: You better hope that we land on the blue part.
The Flight Director calls out to Mike Collins, "Tell them so do we!"
055:18:48 Collins: So do we, babe.
055:18:49 Anders: Jim is always for land landings.
Jim Lovell is one of those astronauts (Dave Scott is another) who bought into the romance of space travel. His love of flying in space began in his youth when, with friends, he built and flew rockets. He knew about the work of pioneers like Hermann Oberth, Wherner von Braun and Robert Goddard, and made conscious career decisions to work towards rocket science.
Lovell, from 2003 correspondence: "My interest in space flight began in grade school when I became fascinated with astronomy. There were the space comics of Flash Gordon and Buck Rogers to peak my interest. Of course actual space flight by me never crossed my mind. This was something that would occur long after my time.
Lovell (continued): "My interest in rockets began in early high school. I read about Robert Goddard's work with liquid fuel rockets and the subject completely fascinated me. I read Willy Ley's book on the German Rocket Society' rocket experiments. I researched the V-2 program when information came out at the end of World War 2. Rockets to me were like dinosaurs to most kids. Toward the end of high school I wanted to become a rocket engineer. I wrote to the American Rocket Society for advice on the best educational path to follow. As I mentioned in my book ['Apollo 13', formerly 'Lost Moon' by Jim Lovell and Jeffrey Kluger], I didn't have the money to follow my first desire.
Lovell (continued): "My second choice was the navy. My uncle was an early naval aviator and I wanted to follow his footsteps. In my rocket research I also knew that the navy was developing rocket technology. I became a naval aviator, a test pilot and that led into our space program. Strange how fate works out.
Lovell (continued): "I always looked at my space flights as an adventure. I knew I was going to plow new ground especially on the Apollo 8 flight. I wanted to express to the world what we did and what we saw. I didn't view my flights as strictly a technical exercise but a once in a lifetime romantic adventure. I guess it is the explorer in me."
Bill Anders has a super sharp, pithy wit and picks up quickly on the humour in Jim's imaginings, as well as Jim's background as a naval aviator.
055:18:55 Collins: Roger. This picture is drifting off center again. If you could make another correction to bring it back. I couldn't tell you which direction, but that - you're going the right way, you're going the right way. A little bit more; a little bit more. Ah, whoa, stop right there. That's the best centering we have had, Apollo 8. If you could just hold that, that's perfect.
055:19:25 Lovell: To give you some idea, Mike, of what we can see: We can - I can pick out the southwest coastline of the Gulf and where Houston should be, and also the mouth of the Mississippi; I can see Baja California and that particular area. I'm using a monocular which we have aboard.
055:19:50 Collins: Rog. Understand.
055:19:55 Lovell: This is an 8-power instrument I have.
055:19:58 Collins: Right. Well, we are seeing the entire Earth now including the terminator. Course we can't see anything past the terminator at all. Are you able with your binoculars to see the dark horizon? Anything past the terminator?
055:20:13 Lovell: Negative. Mike. We can't see anything past the terminator with the binoculars or without them. This Earth is just too bright, and it cuts down the night adaptation to see anything on the dark side.
055:20:31 Collins: Rog. Understand.
055:20:33 Anders: Since this is winter - since this is winter time in the northern hemisphere, we can see all of the South Pole and the southern ice cap, and not too much of the North Pole.
055:20:48 Borman: Hey, you and Jim better get together. Jim just said he saw the North Pole.
055:20:54 Collins: He is looking out a different window.
055:20:57 Borman: That's what makes it different.
055:20:59 Collins: Do you still have the...
055:21:01 Lovell: [Garble] the monocular upside down.
055:21:03 Collins: Do you still have the polarizing filter in front of the camera?
055:21:08 Anders: Negative.
055:21:09 Collins: Okay.
055:21:12 Collins: Try putting it back in front of the camera one more time.
055:21:18 Anders: [Garbled.] Okay?
055:21:25 Collins: And once again, we need a small attitude correction. Our Earth is disappearing up and to the right. Our Earth and your Earth. The wrong way, wrong way. A little bit more. [Pause.] Okay. That's fine if you can hold it right there. Oops! No, it's slipping back off again. [Pause.] Okay. Keep coming a little bit more, a little bit more. Okay. Ninety degrees to that direction; that's the wrong 90, the other way. There we go. A little bit more. Nope, no, wrong way, wrong way; I'm sorry. Keep coming in that direction. [Pause.] No, it is gone up at our 12 o'clock, to that last - There we go, it is coming back down, it's coming back down. Bring it down more. Okay. Stop. Now we need 90 degrees to that direction again.
055:22:54 Anders: I hope that the next camera has a sight on it.
055:22:58 Collins: Rog. [Long pause.]
With no monitor, viewfinder or simple sight, the narrow 9° field of view of the telephoto lens makes it very difficult to line up on a target. Mike Collins' efforts at talking Bill onto his quarry, and getting to see the result, are hampered by the two-second or more delay inherent in communications at distances of one light-second.
The suggestion comes up in Mission Control that they try looking at the Moon.
055:23:11 Anders: How's that?
055:23:13 Collins: Well, that has disappeared, just practically. We were wondering if there was any chance of your looking out one of the other windows and seeing the Moon? Hey, it's coming back in now, Bill. Okay. Hold it right there. That - that - that's fine for the Earth right where you are. That - that's extremely good on the Earth if you can just hold that.
055:23:35 Borman: I don't think we have - It has the polarizing filter in front of it now, Mike.
055:23:43 Collins: Roger. Thank you, and it's centered very well. We get a very slight improvement with this, but in general, it is very good considering the distance.
Our present distance from Earth is 175,803 [nautical miles, 325,587 km] - 175,803.
055:23:57 Collins: How about the Moon, Frank? Is it visible through one of your other windows? Could you get it visible with a small maneuver?
055:24:05 Borman: Negative. I think we will have to save the Moon for another time.
055:24:08 Collins: Roger. I understand.
Perhaps Frank wants to maintain his sanity by not going through another aiming exercise.
055:24:26 Collins: You're still very well centered with your picture. We noticed a couple of jumps in the apparent intensity. Did you make some filter changes?
055:24:37 Borman: Roger. We tried to put that other red filter in front of it, but it didn't seem to fit.
055:24:43 Collins: Roger. [Pause.]
Since the Earth is mostly blue and white, with a little brown, using a red filter in front of a black and white camera should darken the blue of the sea while retaining the lightness of the land, so it should improve the contrast between the two. However, the low quality of the TV image makes it difficult to spot
055:24:49 Collins: We'd - On a final test when you get down to the end of your allotted time here, we would like you to remove all filters and let us see how it looks with all filters removed, and then we would like to get several spotmeter readings at the very end after the test.
055:25:13 Borman: Okay. We will be removing the red filter now.
055:25:15 Collins: Roger. [Long pause.]
055:25:50 Borman: Do you still have us, Mike? The lens [means filter] is off now.
055:25:53 Collins: Roger. We have it, and if you could maneuver it toward the terminator slightly, we - you would again center our picture. [Long pause.]
The spacecraft is almost directly over dead center South America. This picture is being received simultaneously through our antenna at Madrid and at Goldstone, California.
055:26:11 Borman: Okay. Stand by. [Pause.] How's that? Is that the right direction?
055:26:21 Collins: That's the right direction. Keep coming. [Long pause.] Now that's the wrong direction, Frank. Did you...
055:26:44 Borman: How is it now, Houston?
055:26:46 Collins: Well, negative. I need another maneuver toward the terminator. [Pause.] It's drifting off the screen to our 11 o'clock. We appear to need a maneuver toward the terminator, Frank.
055:27:08 Borman: Thank you. [Pause.]
055:27:17 Collins: No, that is apparently the wrong way, Frank. We are starting to lose the picture. There you go. That's the correct way. [Pause.]
055:27:35 Borman: Okay, Houston. How's that for today?
055:27:39 Collins: That's just fine, Frank. That's great. We would like to, at the conclusion here, take three spotmeter readings. You can do that at any time at your convenience. We'd just like to get some after-the-fact readings on the Earth's intensity.
055:27:55 Borman: Roger. Jim has got the spotmeter on now.
055:27:57 Collins: Thank you.
055:27:58 Borman: Is it centered now, Houston?
055:28:00 Collins: Not quite, Frank. [Pause.]
055:28:08 Collins: That's good right there. Hold that right there. That's good. That's perfect. [Pause.]
055:28:24 Borman: Okay, Earth. This is Apollo 8 signing off for today.
055:28:29 Collins: Good show, Apollo 8. We appreciate it. See you mañana.
055:28:34 Borman: Roger. [Long pause.]
055:28:55 Collins: We have Haney down here following your trajectory, so all is well. He says you're 10 minutes from the Moon's sphere of influence.
At this point, the second TV transmission from Apollo 8 comes to an end. Paul Haney is the announcer at the Public Affairs Office console.
055:29:04 Borman: Okay. Good.
Long comm break.
This is Apollo Control, Houston. We think that wraps up our television viewing for the day. The picture started - I have to go back and get a hack on it - I would estimate about 5 minutes off 2 [o'clock]. Stand by and we will get an exact start time. We had not anticipated the starting of the pass until about 5 or 6 minutes after the hour. The crew moved in on us a little early as they did yesterday. I guess we should have anticipated it, when we began receiving a signal through Goldstone. Stand by one. We have had word from our station on Goldstone that they suspect that their reception may be even sharper than what we were receiving back here in Houston. We are going to get an early relay on that. We are still awaiting here a start time. Our assistant is trying to get it for us. Well, we go with the estimate of 1:58 pm CST and the signal went off at approximately 2:20 pm CST. Both of them are - The spacecraft now 176,000 [nautical] miles [326,000 km] from Earth. Its velocity, in relation to the Earth, is 3,265 feet per second [995 m/s]. This is Apollo Control, Houston.
It appears that three shots of Earth are taken at around this time; AS08-16-2607, 2608 and 2609. All three images show the same cloud pattern and point of rotation of the planet so all were taken within a few minutes of each other. The first, however, is taken using the 80-mm lens while the other two were shot using the 250-mm telephoto. Analysis of the size of Earth's image on the last two photographs yields an approximate distance of 326,000 km and comparison with the solar system simulator Celestia suggests a very rough time of exposure of 55 hours, 50 minutes GET.
AS08-16-2607 - Earth
AS08-16-2607 - Earth at approximately 326,000 km (based on photo analysis) taken using the 80-mm lens. South is to the right and South America is dominant. North America is to the left.
AS08-16-2608 - Earth
AS08-16-2608 - Earth at approximately 326,000 km (based on photo analysis) taken using the 250-mm lens. South is to the right and South America is dominant. North America is to the left.
AS08-16-2609 - Earth
AS08-16-2609 - Earth at approximately 326,000 km (based on photo analysis) taken using the 250-mm lens. South is to the right and South America is dominant. North America is to the left.
055:33:28 Borman: Houston, Apollo 8. Returning to the PTC mode.
055:33:34 Collins: Apollo 8, Houston. Understand; returning to PTC. Thank you.
055:33:41 Borman: Roger. [Long pause.]
055:33:54 Collins: You can tell Jim he is getting pretty ham-handed with that P21; he got a perilune altitude three-tenths of a mile off what we are predicting down here.
055:34:08 Borman: Is that right?
055:34:09 Collins: Roger. Apparently, he got 69.7 [nautical miles], and the RTCC [Real Time Computer Complex] says 70.
055:34:18 Borman: Are we going to leave it at that, or are we going to correct it to make it lower?
055:34:24 Collins: We are talking about it, Frank. [Long pause.]
There are two separate determinations of their trajectory, Jim's and Mission Control's, and they are becoming very close to agreeing on what altitude the spacecraft will make its closest approach to the Moon. The current figure of 70 nautical miles (130 km) is about 10 nautical miles higher than planned so thought is being given to how it should be adjusted. Of course, Collins is teasing Jim about the accuracy in his navigation sightings. 0.3 miles (a little more than 1500 feet or 500 metres) is simply stunning.
It is worth considering for a while what they have achieved here. After a journey of over 300,000 kilometres across empty space with no marked out roads to guide them, both the onboard computer and the RTCC agree within maybe 500 metres! Let's put this into perspective. That's less than two long New York City blocks! On the first trip to the Moon! And even if it diverges to a kilometre or two, that still represents navigation of exquisite accuracy. Jim's achievement goes a long way to preparing the path to the Moon with the knowledge that crews can safely navigate there and back.
055:34:50 Borman: We have got a lumen reading [of the Earth] of about between 1 and 1.25 thousand - 1.25 K.
055:35:01 Collins: Roger. Understand; between 1 and 1.25 K. Thank you. [Long pause.]
055:35:31 Lovell: Houston, Apollo 8.
055:35:35 Collins: Apollo 8, Houston.
055:35:40 Lovell: Roger. If you put your CM TLM to Accept, we will send you our state vector.
055:35:47 Collins: Touché.
Long comm break.
It is the state vector, a set of seven numbers in the computer (three position vectors, three velocity vectors and the time [and there are those who argue that time is really not part of it]), that defines their current trajectory. Jim's humour reverses the normal situation whereby Mission Control would send up their state vector to the spacecraft on the basis that it is usually considered to be the more accurate. But since the vector that Jim determined is very close to Mission Control's, it is difficult to define which is better. Jim acts the role of the CapCom and suggests sending his vector to spaceship Earth.
This is Apollo Control, Houston at 55 hours, 38 minutes into the flight and we have been asked for a reaction here in the Control Center during that television passage. I think the remark from Lovell that got the most reaction was in his description of the blue and brown Earth and not being sure of whether he would land on it. This triggered a tremendous spike of laughter, the likes of which I can't recall, which immediately settled down to business. And in general, the room the - there was just zero talking going on in the room at the time, except for what we all heard from Mike Collins. In an exchange which the crew - And as we have been talking, the Apollo 8 has passed the - into the Moon's Sphere of Influence; and quite literally this is a historic landmark in space flight because, for the first time, a crew is literally out of this world. They are under the influence of another celestial body, the Moon, from which the Earth - 33,820 straight line nautical miles. We indicated earlier our space digital chart, at some point - not yet completely clear - will switch over and start giving us Moon-related values. That switch just took place and we immediately have configured. Velocity is now 3,989 feet per second in relation to the Moon and the last value, in relation to the Earth, was 3,261 feet per second in relation to the Earth. We'll see this number go down off the Moon related figure over the coming period. ...Apollo 8 ... now presently 33,681 [nautical] miles [62,377 km] from the Moon and moving in a Moon related velocity [of] 3,989 feet per second [1,216 m/s]. At 55 hours, 42 minutes into the mission, this is Apollo Control, Houston.
Not only does the velocity display change, their apparent position in space, as calculated by the computers in the RTCC, shifts slightly as an altered state vector is used, based on the new reference body. CapCom Mike Collins, in his super autobiography Carrying the Fire, related the confusion that FIDO Phil Shaffer, encountered when he mentioned to journalists about the apparent jump in the spacecraft's position when crossing into the Moon's Sphere of Influence.
Mike Collins, from his autobiography 'Carrying the Fire', p308: "Never has the gulf between the non-technical journalist and the non-journalistic technician been more apparent. The harder Phil tried to dispel the notion, the more he convinced some of the reporters that the spacecraft actually would jiggle or jump as it passed into the lunar sphere. Big as a professional football player, red-faced and sweating, Phil delicately re-examined his tidy equations and patiently explained their logic. No sale. Wouldn't the crew feel a bump as they passed the barrier and become alarmed? How could the spacecraft instantaneously go from one point in the sky to another without the crew feeling it? The rest of us smirked and tittered as poor Phil puffed and labored, and thereafter we tried to discuss the lunar sphere of influence with Phil as often as we could, especially when outsiders were present."
Collins' book indicates that Shaffer was on the Green Team but a document supplied by Gene Kranz places Shaffer in Windler's Maroon Team.
055:45:03 Borman: Houston, Apollo 8.
055:45:06 Collins: Apollo 8, Houston.
055:45:10 Borman: How does everything look, Mike, all our systems and everything? See any switches out of place?
055:45:16 Collins: Negative. I'll take a check around here, but it is looking good. Just a second.
055:45:23 Borman: We are over in the cabin, Mike, like monkeys, and I wanted to make sure we didn't hit anything. [Long pause.]
055:45:51 Collins: Apollo 8, Houston. Everything is looking good down here. All switches and systems are Go.
055:46:00 Borman: Thank you.
Long comm break.
055:50:25 Borman: Houston, Apollo 8. How are you reading on Omni D?
055:50:28 Collins: We are reading you loud and clear, Frank.
055:50:32 Borman: Okay. We are reading you like that, also. Thank you.
055:50:38 Collins: We are having a playback of your TV shows and are all enjoying it down here. It was better than yesterday because it didn't preempt the football game.
055:50:57 Borman: Thank you. Don't tell me they cut off a football game; didn't they learn from Heidi?
055:51:10 Collins: Well, you and Heidi are running neck and neck in the telephone call department.
Very long comm break.
Apollo Control, Houston here. 56 hours, 3 minutes into the flight and in the last 15 to 20 minutes, we have had a most interesting discussion with the crew. Like getting Frank Borman's reactions primarily to the television pass. He was advised by Mike Collins that fortunately today, those spectacular views of the Earth had no competition - had no football games to compete with and Borman allows as how he hopes a football game wasn't stopped to see the view from space. That pretty well sums up Frank Borman's extraordinary interest in the game of football. ...
On November 17, 1968, the New York Jets and Oakland Raiders were in the middle of what has been often called "One of the best football games ever played". Some truly outstanding plays were executed, and with 1:05 left to play, New York was ahead 32-29. The problem was, it was running late. The heavily promoted network premier of Heidi, the tale of the little Swiss girl, was scheduled to air at 7:00 Eastern, and network executives were getting very nervous about what to do. Finally, at the appointed hour, NBC went to a commercial, and Heidi began. In the 65 seconds of play that was pre-empted, a most incredible change of luck occurred (good or bad - it depends on loyalties). Through a series of events - all bad for the New York Jets, the Oakland Raiders scored two touchdowns within nine seconds of each other. In the end, Oakland won the game, 43-32.
There has never before, or ever since, been such an outcry from fans. Calls came pouring in, to the point that the phone switches crashed. Network execs couldn't communicate with their producers at the game, who realized their mistake. A banner was displayed during Heidi with the final score, but as it occurred during the most tearful moment of the movie, it only further enraged viewers, this time upset with having a mournful scene ruined.
The next day, the debacle was front page news in the New York Times (above the fold), and during NBC's prime-time news program, a public apology was issued. From this event, the policy of never, ever interrupting a football game was instituted; if it ran late, that was too bad - the entire program schedule was shifted. Even if, for example, the first live pictures of Earth were being broadcast from space. Finally, networks required that a phone be routed through a separate telephone switching center to connect headquarters and the game producers. It's name? The "Heidi phone".
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