Apollo 16

This is Apollo Control. We've now had Loss of Signal with Apollo 16. We'll be reacquiring the spacecraft in about 45 minutes. With a good maneuver we would expect that acquisition time to be 79 hours, 10 minutes, 25 seconds. Without the burn we would be reacquiring about three and a half minutes prior to that, or at 79 hours, 6 minutes, 46 seconds. As Apollo 16 went around the corner of the Moon, everything looked good for the maneuver. The spacecraft was in an orbit of 169.4 by 58.1 nautical miles [313.7 by 107.6 km] and the last velocity reading we got was 5,368 feet per second [1,636 m/s]. We're now about nine minutes, 17 seconds away from the scheduled time that the crew will be performing Descent Orbit Insertion. At 78 hours, 25 minutes; this is Apollo Control, Houston.

This is Apollo Control at 79 hours, 6 minutes. We're about four and a half minutes away from the expected time of reacquiring Apollo 16 on its third revolution of the Moon, at which time they should have lowered their orbit to about 10 by 58 nautical miles [19 by 107 km]. If, however, for some reason they did not perform that maneuver we would be reacquiring in about 30 seconds. The Service Propulsion System engine on this particular spacecraft is consuming about 66 pounds of propellant per second of burn; based on that, when next we see Apollo 16 they should be about 1,600 pounds [726 kilogrammes] lighter and traveling about 136 miles an hour slower. The Descent Orbit Insertion maneuver, which was targeted to occur at the Ground Elapsed Time of 78 hours, 33 minutes, 44 seconds, was to have been a 24.2-second burn of the Service Propulsion System engine, and this would produce a total velocity change of 210.3 feet per second [64.1 m/s], most of which would be retrograde, giving us the desired orbit of 58.5 by 10.3 nautical miles [108.3 by 19.1 km]. And we've passed the time of acquisition had they not performed the burn. All continues to be quiet. We're now three minutes away from the expected time of acquisition with a good Descent Orbit Insertion maneuver.

This is Apollo Control. We should be coming up on Acquisition Of Signal now. And network reports that we have AOS.

That last comment was from John Young. Earlier we heard from Charlie Duke reporting a nearly perfect Descent Orbit Insertion maneuver. Young reported that they're onboard readings show that they had an apolune of - rather a perilune of 10.9 nautical miles. The targeted was 10.3, but again that's an onboard reading and we'll be tracking and getting a reading here on the ground.

John Young's question is in reference to Stay/No-Stay - that we'll be passing up from the Control Center here in the event that tracking data - we've got about two minutes of it on which the Flight Dynamics Officer will make his calculations. In the event tracking data showed that we did not get the desired orbit and we're in an unsafe orbit, the crew has a maneuver on board that they would perform to raise their orbit to a satisfactory level. This is a so-called bailout burn which would be performed at 79 hours, 22 minutes, 8 seconds or about six minutes from now. All indications, preliminary, are that everything is good.

Assuming that maneuver went as planned, and the orbit is as we would expect, Apollo 16 should be at an altitude of about 19 nautical miles [35 km] above the lunar surface, accounting for Charlie Duke's earlier comment that it appeared to be right down among the tree tops.

This is Apollo Control. The landmark tracking Ken Mattingly is referring to is a procedure used on board the spacecraft to determine their orbit. It's also a procedure that'll be used by Mattingly from lunar orbit to track the spacecraft on the surface of the Moon, hopefully, and allow scientists on the ground to compute a precise location for the landing site for the touchdown part of the Lunar Module. We now show Apollo 16 at an altitude of 13.8 nautical miles [25.6 km], continuing to drop down towards pericynthion. And the preliminary tracking data the Flight Dynamics Officer reported, shows an orbit of 59 by 10.7 [nautical miles, 109 by 19.8 km]. We expect that that orbit will be refined somewhat as we get additional tracking that's based on the first look at the tracking data, but is - is very close to the desired orbit of 58.5 by 10.3 nautical miles [108.3 by 19.1 km].

Gator crater is about 700 yards [640 metres] across, one of the craters at the Descartes landing site. Ken Mattingly obviously taking a landmark sightings on that crater at the present time as Apollo 16 passes directly over the landing site.

This is Apollo Control at 80 hours, 12 minutes. The Guidance and Control Officer reports that from looking at the replay of data from that Descent Orbit Insertion maneuver performed at the end of the second revolution, he reports that the engine appeared to perform normally in every respect and we're currently showing Apollo 16 in an orbit 58.6 nautical miles by 9.9 [108.5 by 18.3 km] and we expect that that will continue to be refined somewhat. Ken Mattingly has completed a series of exercises that deploy certain of the experiments in the Service Module Scientific Instrument Module Bay, the SIM bay experiments, the Gamma Ray and Gamma Ray Spectrometer and Mass Spectrometer on 25 foot [7.6 metre] and 24 foot [7.3 metre] booms respectively were extended to their full out positions and then retracted, to check the operation. Mattingly then extended the Mass Spectrometer to about a third of it's length and turned it on. It's about 8.4 feet [2.6 metres] out from the side of the Service Module now on it's retractable boom. And also turned on the Laser Altimeter. The Mass Spectrometer is designed to gather information on the nature and composition of the lunar atmosphere; also to detect contaminants in that atmosphere. Such things as the volatile products...

The Mass Spectrometer detects such things as the volatile products given off by volcanoes, should any of those happen to be active around this time. Would also detect water vapor should that exist in the lunar atmosphere. The other experiment activated by Mattingly was the Laser Altimeter. You heard him ask how that was performing. A report from the Orbital Science Officer here was that it appeared to be functioning normally. This device measures the spacecraft altitude above the lunar surface and is correlated with Panoramic Camera photographs obtained of the lunar surface. Putting these two bits of information together - the photo and the laser altimeter data - it's possible to determine within about 6 feet [1.8 metres] the elevation of lunar surface features. We're now about 45 seconds from losing radio contact with Apollo 16 as the spacecraft passes behind the Moon on its third revolution. We'll be reacquiring - reestablishing radio contact at the beginning of the fourth revolution in about 45 minutes.

This is Apollo Control at 81 hours, 4 minutes. We're standing by now to regain radio contact with Apollo 16, now in it's fourth revolution of the Moon. This will be the last frontside pass prior to the time the crew begins their scheduled nine-hour rest period. And should be a relatively quiet period. And the Flight Dynamics Officer has just reported that their latest tracking shows the spacecraft to be in an orbit of 58.6 by 10.6 nautical miles [108.5 by 19.6 km] as a result of that Descent Orbit Insertion maneuver. We're about ten seconds now from regaining radio contact.

We've had Acquisition Of Signal.

This is Apollo Control at 81 hours, 30 minutes...

This is Apollo Control. We've lost radio contact now with the spacecraft as it passes behind the Moon on the fourth revolution. The crew is scheduled to begin a nine-hour rest period while on the backside of the Moon, and we would expect to hear no further word from them until the end of that rest period. During this frontside pass on the fourth revolution, there were three major items covered. I'll try to run through those three, and summarize what to us appeared to be the major points. On first reacquiring contact, John Young reported that they had seen two Main Bus B undervolt conditions - as he described it these were transitory events with the Main Bus B voltage dropping briefly to the point to where it triggered a Master Caution and Warning alarm. Normally, Main Bus B, which is one of two Main Buses supplying electrical power to the equipment aboard the Command and Service Module, operates at about 27 to 28 volts under load. The Master Caution and Warning is set to trigger at about 26.25 volts, if the voltage drops to that level. And in replaying the data tapes, we saw the voltage drop to about 26.14 volts. The data tape replay, however, showed no indication of a problem with any of the electrical equipment. One sometimes suspects momentary current overloads - a heavy drain of current which would then drag the voltage down, but there was no indication that any of the equipment was malfunctioning. The one thing that the crew described that appeared to be coincident with the voltage drop, was the operation of the Pan Camera. However, simultaneous data on this camera, when it was operating, showed that the camera was functioning normally. At this point after looking at all of the data, and considering the loads on both Main Bus A and Main Bus B, one supposition is that we had a coincident series of events, which momentarily overloaded Main Bus B. Such things as heaters coming on simultaneously at the same time we had a heavy current drain for the SIM bay activities. If this is, in fact, the case, it can easily be remedied by transferring some of the load to Main Bus A - a simple re-configuration. And that appears to be the most likely cause of the Main Bus undervoltages, in which case we would have no - no particular problem. One other thing that was discussed, was the suit problem. Going back to the beginning of this one - Charlie Duke reported last night on entering the Lunar Module suited, getting suited up and getting into the Lunar Module, that John Young had had some difficulty getting the [Charlie's] suit zipped. The restraint zipper closed across the back of the suit. This zipper does not maintain the pressure of the suit, but is a load carrying zipper that holds all the layers together on the outside of the pressure - pressure layers. And Duke mentioned that in order to minimize the problem of getting the suit zipped tomorrow, he would like to leave off the Fecal Containment System. In zipping the suit up the first time both the Fecal Containment System and the Liquid Cool[ed] Garment were not worn. Duke's feeling was that once these additional items were added underneath the suit it would increase the problem of closing that zipper. And we gave him a go ahead to leave the fecal containment system off, and recommend that he make an attempt to get the suit zipped using the normal procedures. John Young suggested the possibility of using a pair of pliers that they carry on board to assist in it, a recommendation at this time is that not be done. Dave Scott, who was by earlier in the evening, discussed with the flight controllers a similar problem that they encountered, although apparently not quite so severe, on Apollo 15. And Dave's analysis of that situation was that in zero G it's more difficult to arch one's back without gravity to help. Arching the back is a method that is used to reduce the strain across the zipper so that it's easier to get it closed, and it was suggested to Charlie that he make every effort to brace himself and get the back arched in order to make the job a little easier of getting that zipper closed. And we do have a backup procedure that'll be discussed with the crew to assist in closing that zipper if the problem arises tomorrow when they're preparing to get into the Lunar Module and suiting up. Also CapCom Henry Hartsfield discussed a procedure with Ken Mattingly for checking out the docking latches. One of the 12 docking latches has apparently not latched down firmly onto the LM tunnel docking ring. This causes no particular concern, but there is some interest in determining why the latch did not close. Mattingly, last night, was asked to cycle a device that is connected with the latch. This gave the flight controllers an indication that the latch, which is cocked prior to docking, was not fully cocked, and therefore, did not latch fully. There is also the possibility that the latch is broken. In order to determine which of these is the case, he was - Mattingly was given a series of procedures to follow, of which we hope will provide some information and shed some light on whether the latch simply was not fully cocked, or whether it is broken or has malfunctioned in some other way. This is primarily of concern for future flights. It doesn't have a direct bearing on this flight. It's felt that the latch will in no way effect undocking and since only three of the 12 latches are required for a firm hard docking, there's no particular concern that it will in any way effect the docking either. As mentioned previously, we expect to see the crew asleep when next we reacquire the spacecraft. That'll be about 40 minutes. And as Apollo 16 went around the corner on the fourth revolution, we showed it in an orbit of 58.7 by 10.4 nautical miles [108.7 by 19.3 km]. At 82 hours, 19 minutes into the flight of Apollo 16, this is Apollo Control, Houston.

This is Apollo Control at 82 hours, 58 minutes. We're about one minute away from regaining radio contact with Apollo 16, the spacecraft now in it's fifth revolution of the Moon. And we expect the crew is in their sleep period at this time. They're scheduled to have a nine-hour rest period, beginning about 30 minutes ago, while they were on the backside of the Moon. However we will have the circuits up live in case they haven't begun their sleep period and have any last minute items to discuss with Mission Control before beginning the rest period.

And network has just called out AOS, Acquisition of Signal, and we see all of the data now suddenly come alive on the television displays here, the telemetry data from the spacecraft. We won't plan to put in a call to the crew, however we will be standing by should we get a call from them.

And the communications engineer says that the spacecraft appears to be configured for sleep. The High Gain Antenna is in the proper position, the voice subcarrier is turned off, so we'll presume that the crew has begun its rest period.

This is Apollo Control at 83 hours, 35 minutes. We now have a little under thirty minutes of acquisition time remaining before Apollo 16 goes around the corner on the fifth revolution of the Moon and we lose radio contact. And it has remained quiet, and no calls from the crew, and relatively little activity here in the Control Center - primarily monitoring systems and preparing for tomorrow's activities. We're continuing to watch the spacecraft orbit change gradually. We're now showing an apogee of 58.8 nautical miles [108.9 km], and a perigee, or pericynthion more correctly, of 10.5 nautical miles [19.4 km]. This crew rest period is scheduled to last for about nine hours. And the crew is - is to be awakened at about 91 hours, 30 minutes or about eight hours from now.

This is Apollo Control at 84 hours, 3 minutes now into the flight of Apollo 16. And nearing the end of the fifth revolution around the Moon. We have about one minute, 45 seconds before we lose radio contact with the spacecraft. We've heard nothing from the crew. They're in their rest period. And all spacecraft systems appear to be functioning properly at the present time. We show Apollo 16 in an orbit 10.4 nautical miles by 58.8 [19.3 by 108.9 km]. And at this time in Mission Control we're in a midst of a shift handover. Flight Director Gene Kranz and his team of flight controllers coming on to replace the Pete Frank team. Spacecraft communicator on the upcoming shift will be astronaut Donald Peterson. And we do plan to have a change of shift briefing. We expect that that will start in about 15 minutes. The briefing will be in the MSC News Center Briefing Room. At 84 hours, 4 minutes; this is Apollo Control, Houston.

This is Apollo Control, Houston at 84 hours, 52 minutes into the mission. We're a little more than 20 seconds away from scheduled time of acquisition of Apollo 16, now on its sixth revolution around the Moon. We presently show an orbit of 58.8 nautical miles [108.9 km] by 10.6 nautical miles [19.6 km]. Meanwhile in the Mission Control Center, we have had a shift changeover of flight control teams. The White Team of flight controllers headed by Flight Director Gene Kranz is now aboard. Surgeon reports that he has two of the crew members on his biomed. He reported that Lunar Module Pilot Charlie Duke went to sleep rather rapidly, whereas Command Module Pilot Ken Mattingly was still awake at Loss of Signal. The crew of Apollo 16 is now in their rest period, however, we'll leave the line up on this frontside pass in the event we do have conversation with the crew of Apollo 16. Our CapCom on this shift is astronaut Don Peterson. We have acquired data from Apollo 16 and we'll continue to monitor. This is Apollo Control, Houston at 84 hours, 54 minutes Ground Elapsed Time.

This is Apollo Control, Houston at 85 hours, 19 minutes Ground Elapsed Time. We have some 40 minutes remaining on this front-side pass for Apollo 16. Now on its sixth revolution around the Moon. We've had no communication with the crew, presently in their rest period, however, we will continue to leave the line up during this front side pass. We show Apollo 16 traveling at a velocity of 5,546 feet per second [1,690 m/s]. Current altitude, 11 nautical miles [20.3 km]. The spacecraft is presently in an orbit of 58.8 nautical miles [108.9 km] by 10.5 nautical miles [19.4 km]. Spacecraft weight in orbit at this time, 76,109 pounds [34,522 kilogrammes]. At 85 hours, 20 minutes, continuing to monitor; this is Apollo Control, Houston.

This is Apollo Control, Houston at 85 hours, 59 minutes Ground Elapsed Time. At this time we've had Loss of Signal with the Apollo 16 spacecraft as it passes above the back side of the Moon. We will take down our line at this time. And at 85 hours, 59 minutes; this is Apollo Control, Houston.

This is Apollo Control, Houston at 86 hours, 46 minutes into the mission. We're coming up now on acquisition with Apollo 16 now on its seventh revolution around the Moon. Apollo 16 is presently in an orbit of 58.9 nautical miles [109.1 km] by 10.6 nautical miles [19.6 km]. We expect no conversation with the crew on this front side pass. Young, Duke, Mattingly now well into their rest period. We will leave the line down on this front side pass but we'll bring it up should any conversation developed. We do now have acquisition with Apollo 16 and are receiving data. At 86 hours, 47 minutes Ground Elapsed [Time]; this is Apollo Control, Houston.

This is Apollo Control, Houston at 87 hours, 52 minutes Ground Elapsed Time. Apollo 16 has now passed out of acquisition range. We had Loss of Signal with Apollo 16 as it passes above the backside of the Moon on it's 7th revolution. We show orbital parameters of 58.8 nautical miles [108.9 km] and 10.4 nautical miles [19.3 km]. We had no conversation with the crew of Apollo 16 during this frontside pass. The crew is presently in a rest period. We're at 87 hours, 53 minutes and this is Apollo Control, Houston.

This is Apollo Control, Houston at 88 hours, 40 minutes into the mission. We're standing by now awaiting acquisition with the Apollo 16 spacecraft on its eighth revolution around the Moon. We presently show an orbit of 58.9 nautical miles [109.1 km] by 10.6 nautical miles [19.6 km]. The flight surgeon here in Mission Control reports that Command Module Pilot Ken Mattingly and Lunar Module Pilot Charles Duke were sleeping very well when he looked at their data through the last pass. We are now receiving data from Apollo 16. The spacecraft has been reacquired. We're at 88 hours, 41 minutes into the mission and this is Apollo Control, Houston.

This is Apollo Control, Houston at 89 hours, 46 minutes into the flight. We now show Apollo 16 with an orbit of 58.8 nautical miles [108.9 km] by 10.4 nautical miles [19.3 km]. The Apollo 16 spacecraft has passed out of range on its eighth revolution around the Moon. On this past frontside pass, we had no conversation with the crew, still in their rest period. Our wake-up clock here in Mission Control shows that the crew has one hour and 43 minutes of sleep time remaining before the wake-up call. We're at 89 hours and 47 minutes, and this is Apollo Control, Houston.

This is Apollo Control, Houston; at 90 hours, 34 minutes into the mission. We now show Apollo 16 in an orbit of 58.9 nautical miles [109.1 km] by 10.5 nautical miles [19.4 km]. We're coming up on acquisition of the spacecraft on this the ninth revolution. Because we will wake up the crew at some point on this frontside pass, we will leave the line up live. And at 90 hours, 35 minutes; this is Apollo Control, Houston. We're acquiring data now.