Category The First Men on the Moon

The original concept for Apollo 10 called for the spacecraft to enter lunar orbit and for LM-4 to undock, enter a slightly different orbit, return and redock as a test of operating in lunar orbit. In December 1968, however, the mission planning and analysis division of Mission Control successfully argued the case for putting the descent propulsion system through a realistic rehearsal in which the perilune would be lower. This would test the ability of the landing radar to lock onto the surface, with the illumination on the low passes exactly as it would be on the landing mission in order to document the primary site and identify landmarks on the approach route. Howard W. ‘Bill’ Tindall, the assistant division chief, had also suggested that the LM should initiate the powered descent and abort by ‘fire-in-the-hole’ staging, but this was not pursued. After three outstandingly successful manned missions, considera­tion was given to assigning Apollo 10 the landing mission. However, because LM-4 was incapable of landing – the software was not ready for either the simulator or the

vehicle, and in any case LM-4 was too heavy to carry sufficient propellant to lift off again – Apollo 10 commander Tom Stafford argued against waiting for LM-5. “There are too many ‘unknowns’ up there,” he insisted. “We can’t get rid of the risk element for the men who will land on the Moon but we can minimise it; our job is to find out everything we can in order that only a small amount of ‘unknown’ is left.’’ The plans, procedures, mission rules, manoeuvres, thermal regime and communica­tions would provide a high-fidelity rehearsal of the landing mission. On 24 March 1969 it was announced that Apollo 10 would conduct this dress rehearsal, and if it achieved its primary objectives then Apollo 11 would attempt to land.

One aspect of the Apollo 10 mission was to assess the operation, tracking and communications of two spacecraft in lunar orbit. Apollo 8 had confirmed that the mascons significantly perturbed the orbit of a spacecraft. By having Apollo 10 fly the profile planned for the landing mission, it would be possible to assess how the guidance and navigation system of the LM coped with these gravitational effects while making the low passes of the descent orbit. Apollo 10 lifted off on schedule on 18 May, and on the fifth day the LM separated in a circular parking orbit at an altitude of 60 nautical miles, entered an elliptical orbit with a 50,000-foot perilune, made two low passes, discarded the descent stage, and made a perfect rendezvous. The first low pass rehearsed an approach to ALS-2 (site ‘A3’, later 2P-6), and while the aim point itself was acceptable, the western end of the ‘landing ellipse’ was rougher, and Stafford told Armstrong that if he were to find himself coming in ‘long’, his best option might be to abort.

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Preparations

SIMULATION

With Apollo 10 having mitigated the risks, Armstrong and Aldrin were able to focus their training on the powered descent and lunar lift off. However, because Apollo 10 had first call on the simulators until early May, Clifford Charlesworth initiated training in April with the Saturn V launch phase. Two months then remained in which to conduct the specialised training because, with a target launch date of 16 July, the most intensive training using the simulators would be completed about 10 days earlier in order to enable the crew and flight control teams to finish other activities. Simulation explored two basic scenarios: ‘nominal’ and ‘contingency’. The nominal part occupied only a few days, and defined the Go/No-Go decision points, the procedures, and the timings for the interactions between the crew and the flight controllers. The first full set of mission rules for Apollo 11 was issued on 16 May, but was preliminary pending methodical testing by simulation. Because the nominal powered descent was to last only 12 minutes, it was possible to perform many runs and debriefings during a single day’s training. While Apollo 10 was performing its rehearsal in lunar orbit, Armstrong and Aldrin were routinely landing by flying the nominal profile. Contingency training was designed to test how the crew and flight controllers dealt with departures from the nominal profile involving trajectory and systems problems. The Simulation Supervisor (SimSup) for the powered descent was Dick Koos, an early recruit of the Space Task Group to train control teams. As there were then no graduates with computer degrees, NASA had hired engineers with experience, and his background was the computerisation of ground-to-air missiles for the Army Missile Command at Fort Bliss, Texas. Koos and his five support staff occupied a glassed-in partition at the front of the Mission Operations Control Room, and their role was to develop realistic mission scenarios that would assess the mission strategy, rules and procedures, the knowledge and coordination of the individual flight controllers, the ability of the team as a whole to develop real-time solutions to technical difficulties, and generally to probe the psyches of everyone involved. It was considered that a fully trained team of flight controllers ought to be able to function as a single ‘mind’.

The first contingency training was on 10 June. A succession of runs introduced a

An hour after the telecast, Duke asked the crew to participate in an experiment using a laser. ‘‘If you have got Earth through any of your windows, or in the telescope, would you so advise?’’

‘‘I’ve got you in the telescope,’’ Collins replied.

‘‘We have a blue-green laser that is to flash at a frequency of on-for-a-second, off – for-a-second. It’s from the McDonald Observatory near El Paso, Texas, which should be just on the dark side of the terminator. Would you take a look and see if

you can see it.” Collins agreed. “McDonald reports there is a break in the clouds,” Duke announced a few minutes later, “and they’re beaming it through.” Observing nothing through the telescope, Collins switched to the magnifying sextant, with no better result. Armstrong joined him. Aldrin reported, “Neither Neil nor Mike can see it. We did identify the El Paso area, and there did appear to us to be a break in the clouds there.’’ However, at their distance from Earth, the beam would be just a few thousand feet across, and was very likely not illuminating the vehicle.

Half an hour later Duke signed off, “The White Team bids you good night.’’

“You earned your pay today, Charlie,’’ Aldrin said.

As the Black Team began the ‘graveyard’ shift, with Gerry Griffin standing in for Glynn Lunney as flight director, the astronauts finished miscellaneous chores, had supper, and settled down for their second sleep period, this time with Aldrin as the watch-keeper. By this time, Apollo 11 was 137,219 nautical miles from Earth, and travelling at 4,132 feet per second.

Having unstowed the long-handled scoop from the MESA, Armstrong set out to collect the bulk sample from the general vicinity of the SWC, on ground that had been documented as part of that experiment. The television cable was white, but when it became coated with dust it was difficult to see, and because it retained a memory of having been coiled in its dispenser it refused to sit flat on the ground. On seeing that Armstrong’s feet were becoming entangled with the cable, Aldrin called ‘‘Watch it, Neil! Neil, you’re on the cable.’’ Armstrong tried to manoeuvre clear of the cable, but the visor of his helmet limited his downward view and the thickness of the suit prevented him feeling its presence. Aldrin went to help him. ‘‘You’re clear

now.” As Armstrong would have to make many trips to the MESA to collect the bulk sample one scoop at a time, he used his scoop to lift the cable off the ground, Aldrin took it, dragged it aside, gathered the surplus and tossed it beneath the vehicle.

Leaving Armstrong to collect the sample, Aldrin began his first photographic task, which was to document the imprint that his boot made in the surface. After retrieving the Hasselblad from the MESA he went to a patch of ground that they had not yet disturbed and, using the camera hand-held, took a photograph of this. Then he made an impression with his right boot, stepped back and photographed the result. Moving further forward he put his boot on the surface again, and this time took the picture just as he lifted his foot; in so doing he noted that there was so much black material coating his overshoe that its light-blue colour was no longer visible. Moving on to his next task, he took a panorama from a location south of the tip of Eagle’s shadow, covering 360 degrees in 11 frames, one of which captured Armstrong at the MESA. He then went to the southern side of Eagle and took a number of pictures to enable the Grumman engineers to assess the state of the vehicle, in the process capturing a view through the struts of the front gear of Armstrong once again at the MESA. As the next item on his checklist was to take ‘after’ shots of where the bulk sample was collected, he called, ‘‘How’s the bulk sample coming, Neil?’’

‘‘It’s just being sealed,’’ replied Armstrong. Collecting the sample had proved to be more difficult than in training because, in the weak lunar gravity, the material readily spilled from the scoop as he carried it to the MESA, with the result that he lost part of each load. Whatever remained each time, he poured into the bag that Aldrin had prepared. The object of the exercise was to return sufficient material to satisfy the requirements of the many teams of scientists. Over about 15 minutes he drew 23 scoops. Since he did not wish to rely upon having time later to take fully documented samples, he had made an effort to collect a variety of small rocks for this sample. When he was finished, he placed the bag into the first rock box. The lid of the box was a precise fit, and included a razor edge in order to preserve the contents in vacuum once the box was taken into an atmosphere. As there was no lubricant on the hinge, sealing it took longer than expected, in part owing to the fact that in lunar gravity he did not have the same leverage as in training.

On reflection, Aldrin asked if Armstrong would rather take the ‘after’ pictures himself, because he knew precisely where he had sampled. ‘‘Do you want to get some particular photographs of the bulk sample area, Neil?’’

‘‘Okay,’’ Armstrong replied. When Armstrong joined Aldrin, by now back in Eagle’s shadow, Aldrin passed Armstrong the camera, who put it on his bracket even though he was to take just a few pictures. On impulse, he photographed the plaque on the forward strut, and since it was in deep shadow he shot it using a range of exposures. He then went to document the area from which he had collected the bulk sample. Aldrin followed him. Having finished his documentation, Armstrong took an impromptu picture of Aldrin, then returned the camera to the MESA.[40]

“Buzz,” McCandless called. “Have you removed the Close-up Camera from the MESA yet?”

“Negative,” replied Aldrin.

The Apollo Lunar Surface Close-up Camera (ALSCC) was to provide extreme close-up stereoscopic pictures of lunar ‘soil’. It was often referred to as the ‘Gold camera’ because it had been designed by Thomas Gold, an astronomer at Cornell University. As it was a late addition to the mission, the astronauts had very little time to train with it. The plan called for Aldrin to unstow it from the MESA, but Armstrong said he would do it. Aldrin therefore resumed his photographic task. Retrieving the Hasselblad, he took a panorama from a position northeast of Eagle, again covering 360 degrees in 11 frames, and then concluded his documentation of the vehicle.

‘‘Houston, how does our time line appear to be going?’’ Aldrin enquired.

‘‘It looks like you’re about a half hour slow,’’ McCandless replied.

Armstrong set off with the ALSCC. To take a picture (in fact, a stereo pair) he had to rest it on the ground with the Sun illuminating a window at its base, then pull a trigger to expose and advance the film.11 It proved awkward to operate and, although designed to be self-standing, tended to fall over whenever he released it, which was frustrating because he then had to fetch one of the long-handled tools in order to raise its handle off the ground.

‘‘Neil and Buzz, this is Houston,’’ McCandless called, ‘‘Your consumables are in good shape at this time.’’

Deploying the instruments

On finishing his inspection of Eagle, Aldrin was ready to unstow the Early Apollo Surface Experiments Package (EASEP) from the scientific equipment (SEQ) bay, an activity which Armstrong was to document. ‘‘Neil, if you’ll take the camera, I’ll get to work on the SEQ bay.’’

‘‘Okay,’’ agreed Armstrong, taking the Hasselblad from Aldrin.

The compartment on the left-rear quadrant of the descent stage, opposite to the MESA, had two doors – a small door on the left that Aldrin simply hinged open, and a larger one that was hinged horizontally along its upper edge and was to be opened using a lanyard and pulley mechanism. Although the raised door failed to engage its lock, it remained in place. The base of the bay was at chest height. The Passive Seismic Experiment (PSE) was stowed in the left-hand compartment and the Lunar Ranging Retro Reflector (LRRR) on the right. For each, Aldrin had the option of drawing out a boom and using a pulley to lower the instrument onto the ground, but he chose instead to disconnect the hooks and extract them manually, finding this task to be rather easier than in training. Having extracted the PSE he moved off about 10 feet and put it on the ground, then returned to get the LRRR. Meanwhile, having taken the requisite pictures of Aldrin at work, Armstrong put down the

In all, 17 stereo pairs were taken using the ALSCC.

ALSCC and moved to a point about 60 feet southeast of Eagle to shoot a 360-degree panorama in 11 frames. Aldrin closed and locked the doors of the SEQ bay to prevent the sunlight overheating the descent stage. He then asked Armstrong, “Have you got us a good area picked out?”

Although the terrain was pocked by craters, there was a reasonably level spot southwest of Eagle. “I think right on that rise out there is probably as good as any.”

Holding the PSE in his left hand and the LRRR in his right, Aldrin hoisted the load – which in all weighed just 27 pounds in lunar gravity – and headed for the indicated area. After snapping several pictures of Aldrin carrying the instruments, Armstrong retrieved the ALSCC and followed.

“It’s going to be a little difficult to find a good level spot here,” Aldrin warned. “The top of that next little ridge there,’’ Armstrong prompted. “Wouldn’t that be a pretty good place?’’

Aldrin halted about 40 feet from Eagle, “Should I put the LRRR right about here?’’

“All right.’’

Aldrin deposited the LRRR, and moved out 15 feet further out and put down the PSE.

Meanwhile, Armstrong had paused to study some of the larger rocks, “These boulders look like basalt,’’ he ventured, “and they have probably 2 per cent white minerals in them – white crystals. But those things I reported as vesicles before, I now think they’re small craters; they look like tiny impact craters where shot has hit the surface.’’ He was correct. These light patches were where micrometeoroids had exposed clean crystals; they would later be named ‘zap pits’. Armstrong then aligned the LRRR on an east-west axis, levelled it with respect to local vertical by means of an air bubble in fluid that had to be centred (observing that in the weak lunar gravity the bubble took a surprisingly long time to settle) and then tilted the mirror platform to face Earth. It is a common misconception that Earth, seen from the lunar surface, is always at the zenith. In fact, for an equatorial site 23 degrees east of the lunar meridian, Earth is correspondingly situated west of the zenith and revolves upon its axis. In its deployed state, the LRRR came to knee height. Its face incorporated an array of 100 fused silica ‘corner-cube’ mirrors that were to reflect a pulse of laser light straight back to its source. Although a laser directed by a large terrestrial telescope would start out as a narrow collimated beam, by the time the beam reached the Moon it would have dispersed to illuminate an area 2 miles in diameter, and as the instrument would be able to return only a tiny fraction of this the received ‘signal’ would be exceedingly weak. The first laser probe was made by the Lick Observatory near San Jose in California several hours later, but since the precise location of the landing site was not yet identified the first detection was not made
until several days later.[41] As the reflected signal was difficult to discern when the site was in sunlight, the LRRR research was best undertaken during the lunar night.

The deployment of the PSE was rather more complicated. After orienting the instrument with respect to the Sun by ensuring that the shadow cast by a gnomon on the top of the package fell on a predetermined line, Aldrin set out to level it. The design had originally used a ‘bubble’ indicator (like the LRRR) but this had been replaced by a small ball in a cup. Aldrin shuffled the instrument on the uneven surface, pushing the loose material aside, but to his surprise the ball persisted in running around the periphery of the receptacle; on Earth it would have settled immediately. ‘‘That BB likes the outside. ft won’t go on the inside,’’ mused Aldrin. Joining him, Armstrong speculated that the cup might be convex rather than concave. ‘‘Houston,’’ Aldrin called, conscious that time was passing, ‘‘f don’t think there’s any hope for using this levelling device to come up with an accurate level.’’

‘‘Press on,’’ McCandless replied. ‘‘ff you think it looks level by eye-ball, go ahead.’’

The instrument had a pair of З-segment rectangular solar panels mounted on its sides to face east and west. One of the panels deployed automatically, and Aldrin deployed the other manually. As the mechanism unfolded the panels, their bottom corners came into contact with the ground and acquired a coating of dust. With its radio antenna deployed, pointing at Earth, the instrument rose to waist height. The initial transmission from the instrument was received by a ЗО-foot-diameter dish at Carnarvon in Australia. The seismometer was sufficiently sensitive to detect the astronauts walking about.[42]

At this point McCandless had some good news, ‘‘Neil, we’ve been looking at your consumables and you’re in good shape. With your concurrence, we’d like to extend the duration of the EVA 15 minutes beyond nominal. We’ll still give Buzz a hack at 10 minutes for heading in. Your current elapsed time is 2 plus 12.’’

‘‘Okay,’’ Armstrong replied. ‘‘That sounds fine.’’

‘‘Buzz,’’ McCandless prompted. ‘‘ff you’re still in the vicinity of the PSE, could you get a photograph of the ball?’’

‘‘f’ll do that, Buzz,’’ said Armstrong, who had the Hasselblad and had stepped beyond the EASEP to document the instruments with Eagle in the background for context. ‘‘Oh, shoot!’’ he exclaimed upon inspecting the PSE. ‘‘Would you believe

the ball is right in the middle now?” Lunar gravity had finally drawn the ball into the centre of the cup, which clearly was concave.

“Wonderful,” Aldrin replied. “Take a picture before it moves!”

AN EARLY START

Although Armstrong and Aldrin ran some LM simulations on Tuesday, 15 July, they spent the remainder of the day relaxing in the Manned Spacecraft Operations Building. In the evening, Lew Hartzell served a dinner of broiled sirloin steak and buttered asparagus for the crew, their backups, the members of their support crew, and Deke Slayton. The three astronauts then chatted with their wives by telephone, and retired at 10 pm. After clearing away the dinner, Hartzell went to the camper he kept in the nearby parking lot, but as it was too hot to sleep there he slept in a spare bedroom in the crew quarters, awakening at 2.30 am to prepare breakfast.

Guenter F. Wendt’s job title was Pad Leader, but John Glenn had dubbed him der pad fuehrer on account of his Teutonic accent being as thick as the lenses of his spectacles. Although from Germany, he was not one of Wernher von Braun’s rocket team; he had flown night-fighters for the Luftwaffe, as an engineer. After the war he emigrated to the USA, got citizenship, and joined McDonnell Aircraft. When the company won the contract to build the Mercury spacecraft, Wendt was given the task of ensuring that the spacecraft was ready for launch – supervising it from the moment that it arrived at the Cape, to the sealing of its hatch. When the company produced the Gemini spacecraft he continued at the Cape. However, the contract for the Apollo spacecraft was given to North American Aviation, which appointed its own pad crew.[2] After the loss of the Apollo 1 crew in a fire on the pad, Wally Schirra insisted that Wendt be rehired. Before Glenn’s flight Wendt had told his wife Annie that while he could not guarantee her husband’s safe return, he could promise that every effort would be made to ensure that the spacecraft was up to the job. This had remained his objective. Having spent most of 15 July methodically checking and rechecking, he went home at 6 pm, dozed until midnight, then rounded up three of the members of his team: NASA quality inspector ‘Lucky’ Chambers, North

American Rockwell mechanical technician John Grissinger, and backup crew member Fred Haise.

Meanwhile, at 11 pm the chill-down process had begun, preparatory to loading cryogenic propellants into the launch vehicle. During the night, a communications issue on the ground delayed pumping liquid hydrogen into the S-II by 25 minutes, but this time was recovered during the scheduled hold at T-3 hours 30 minutes. A high-pressure cell over the ocean off North Carolina combined with a weak trough over the northeastern Gulf of Mexico to draw light southerly surface winds across the Cape, increasing humidity. The sky was heavily overcast and there was light rain, with occasional flashes of lightning off to the north. Nevertheless, the forecast was optimistic.

A full week before launch, people began to gather at the Cape communities of Titusville, Cocoa Beach, Satellite Beach and Melbourne. With four days to go, the Florida authorities were expecting 35,000 cars, 2,000 private aircraft and a flotilla of boats to converge on the Cape. People were drawn from all around the world to witness the launch and be able to tell their grandchildren that they had been present when men set off to make the first lunar landing. Jay Marks, a Houston car dealer and casual acquaintance of the Armstrong family, had arrived a week early, lived in his camper van, and spent the week fishing. He was not alone. As Marks put it, “Apollo 11 gave a lot of nice people a chance to get acquainted.” By 15 July there was not a vacant room to hire. Hotels and motels allowed late-comers to set up their camp beds in lounges and lobbies, but most people spent the night on the beaches and roadsides, where vehicles were parked nose to tail for a 30-mile radius. Since it was to be a dawn launch, the countdown parties ran through the night. At one of the parties Wernher von Braun and his wife Maria met Hermann Oberth who, at 75 years of age, was the only one of the three pioneers of rocketry still alive to witness the great dream become reality. Konstantin Tsiolkovski had died in 1935 and Robert Goddard in 1945.

“It’s a beautiful morning,” said Slayton as he awakened Armstrong, Aldrin and Collins at 4.15 am local time on Wednesday, 16 July. The weather was clearing, as predicted. Once the astronauts had showered and shaved, they went to the exercise room where Dee O’Hara, wearing a crisp white uniform, short dark hair and vivid lipstick, gave them their final check-up. At 5 am they sat down for breakfast with Slayton and Bill Anders, a member of the backup crew, eating the traditional low – residue fayre of orange juice, toast, scrambled eggs and steak. In fact, Armstrong had earlier confided to his wife, “I’m sick of steak!’’ NASA artist Paul Calle sat in the corner of the room, unobtrusively sketching. After packing their possessions to be sent home, they made their way to the suit room.

Hamilton Standard of Windsor Locks, Connecticut, was prime contractor for the space suit, or pressure garment assembly. Earth’s atmosphere has a sea-level pressure of about 15 psi and a gas mix of roughly 80 per cent nitrogen and 20 per cent oxygen. The International Latex Corporation of Dover, Delaware, was subcontracted to make an airtight bladder to hold pure oxygen at a differential pressure of 3.7 psi. Although contoured to the human shape, the extremely flexible material of the bladder would tend to ‘balloon’ when pressurised. It was therefore restrained by a

complex system of bellows, stiff fabric, inflexible tubes and sliding cables which, while maintaining the shape of the suit, impaired the mobility of the occupant. The design of the knee and elbow joints was simple, since these work in the manner of a hinge, but because the shoulder joint can rotate in several axes this was a greater challenge, so much so that at one point NASA briefly considered reassigning the contract. The bladder incorporated a network of ventilation tubes to cool the occupant and preclude the build-up of moisture. Two versions of the suit were required: one for use inside the spacecraft as protection against loss of cabin pressure, and the other to provide thermal and micrometeoroid protection plus other systems required when operating on the lunar surface.

The space suits varied in certain respects:

• Both suits shared a nomex inner layer, a neoprene-coated nylon pressure bladder, and a nylon restraint layer.

• The outer layers of the intravehicular suit comprised nomex and a double layer of teflon-coated beta cloth.

• The integral thermal and micrometeoroid protection for the extravehicular suit had a double-layer liner of neoprene-coated nylon, a number of layers of beta – kapton laminate and a teflon-coated beta cloth surface.

• The intravehicular suit had one pair of umbilical connectors installed on the chest to circulate oxygen from the cabin system.

• The extravehicular suit had two pairs of such connectors, one pair as on the intravehicular suit, and the other pair for use with the portable life-support system.

• The extravehicular suit also had a coolant water loop.

• Both suits had a connector for electrical power and communications.

The boots were part of the bladder, but the helmet and gloves used aluminium locking rings to maintain the integrity of the bladder. The helmet was a transparent polycarbonate ‘bubble’, with adequate air flow to prevent a build-up of carbon dioxide. The gloves were required to support a natural range of bending and rotating motions of the wrist, with a finger-covering material that was sufficiently thin and flexible to allow the manipulation of switches. Each astronaut had three individually tailored suits – a training suit for use in simulators and the low-gravity KC-135 aircraft, during which it was likely to suffer wear and tear, and two flight suits (one prime, the other backup) which, after integrity tests, were reserved for countdown demonstrations and the actual mission. Each suit had a US flag on the left shoulder, a NASA ‘meatball’ on the right breast and the mission patch on the left breast.[3] As his astronaut specialism, Collins had liaised between the crew systems division and the industrial teams to ensure that the suits were both fit for function and safe to use.

Joseph W. Schmitt led a four-man team. He had supervised the suiting up of every American astronaut since Al Shepard in 1961. After the countdown demonstration test on 3 July, the three primary suits had been stripped, inspected for wear and tear, cleaned and reassembled – a four-day task. On arriving at 3.30 am, Schmitt had supervised the unbagging and inspection of the suits, and the astronauts arrived for simultaneous suiting at 5.30 am. This laborious process started with each man rubbing his posterior with salve prior to donning a diaper that would contain both fecal matter and associated odours. This was a precaution against a loss of pressure in the cabin when retrieving the LM from the final stage of the launch vehicle after translunar injection, in which event the astronauts might require to spend several days in their suits. Next was a prophylactic-style urine collector, with a collection bag worn around the waist. A connector on the thigh of the suit enabled the bag to be emptied while the astronaut was suited. Biosensors were attached to the chest, and linked to a signal-conditioning electronics pack that supplied telemetry through the electrical umbilical. After donning cotton long-johns, which NASA referred to as a constant-wear garment, each man was assisted into his one-piece pressure suit. Armstrong and Aldrin were to wear the 55-pound extravehicular suit, and Collins the lightweight 35-pound model for internal use. In the suiting-up procedure, the astronaut sat on a reclining couch, inserted his legs into the suit’s open rear, inserted his arms, bent forward and eased his head through the rigid metal neck ring. He then had to stand and shuffle until the suit felt comfortable, whereupon a technician would seal the bladder and zipper. The next item was the brown-and-white soft communications carrier, dubbed a ‘Snoopy hat’, with its integrated earphones and microphones. Once the gloves were fastened to the wrist rings and the helmet was in place, the oxygen umbilicals were attached to the sockets on one or other side of the chest and the suit was pumped to above-ambient pressure in order to verify the integrity of the bladder, helmet and gloves. There was a pressure gauge on the right arm of the suit. The Omega watches on the suit wrists were set to Houston time, one hour behind the Cape. They would breathe pure oxygen at sea-level pressure to purge nitrogen from their blood stream, and thereby preclude ‘the bends’ when the pressure was reduced during the ascent to orbit. With the suit sealed, communication was by umbilical intercom.

At 6.20 am, after the astronauts had donned yellow rubber galoshes for the trip to the pad, suit technician Ron C. Woods led the procession from the suit room, with Schmitt bringing up the rear. At Guenter Wendt’s request, Schmitt had put a sign on the corridor wall saying ‘The Key To The Moon Is Located’, the meaning of which was, as yet, obscure. As the astronauts made their way down to ground level, with each man carrying his ventilator like a suitcase, the corridors were lined with old friends and coworkers, but their good wishes were almost inaudible over the hiss of the oxygen circulation. Collins, by arrangement, was handed a brown paper shopping bag containing a surprise for Wendt. On emerging from the Manned Spacecraft Operations Building they waved at the television crews supervised by Charles Buckley, the head of security. Parked by the door were the two white transfer vans – one prime and the other a backup. Slayton checked the astronauts into the van, which had a large mission patch adorning its rear access door, wished

them good luck, and then set off for Firing Room 1 of the Launch Control Center beside the Vehicle Assembly Building, where the 463 members of Rocco A. Petrone’s launch team monitored consoles showing the status of the space vehicle, comprising the launch vehicle and the spacecraft. Schmitt and Woods joined the crew, and the two vans departed in a convoy, driving north to the Vehicle Assembly Building then swinging east over the Banana River causeway to Pad A of Launch Complex 39, a total distance of just over 8 miles. On the way, Armstrong had Schmitt extract a small card from his pocket and push it beneath his watchband. Just before he unplugged from the communications circuit, Schmitt wished the three astronauts “a real good flight’’, to which Aldrin replied, “You take yourself on a good vacation when you get us all off.’’ As they arrived at the pad at 6.37, sunrise was imminent. The elevator of Mobile Launch Platform 1 was waiting. Once on the upper deck, as they crossed to the high-speed elevator of the Launch Umbilical Tower, Collins observed that on previous visits the site had been a hive of activity, but now it was utterly deserted.

On exiting the elevator at the 320-foot level, the astronauts were met by Wendt, wearing a white smock and cap. As they were not yet on intercom, he greeted each man with a pat on the shoulder. Because the White Room that provided access to the command module was so cramped, Aldrin remained on the tower while Wendt led Armstrong, Collins, Schmitt and Woods across Swing Arm 9. Wendt then handed to Armstrong the promised ‘Key To The Moon’. Its shaft was a crescent Moon about 4 feet long made of styrofoam and covered by aluminium foil, with an oval loop on one end and a set of teeth on the other. Armstrong withdrew the card from his watchband and presented it to Wendt.[4] The card read: ‘Space Taxi. Good Between Any Two Planets.’ At 6.53 am Armstrong shed the galoshes that had protected the boots of his suit, stood in front of the hatch, which was set at floor level, grasped with both hands a bar that was located inside the cabin, inserted both of his feet, and slipped onto the centre couch. Haise, who had spent 90 minutes running through a 400-item checklist, setting switches and making checks, was already in the lower equipment bay to assist him to shuffle onto the left couch. For launch, the couch was adjusted to elevate the lower legs, and once in space it would be set flat. Schmitt entered to switch Armstrong’s oxygen from the portable ventilator to the cabin’s system and to plug in the communications umbilical. Armstrong checked in with Clarence ‘Skip’ Chauvin, the Spacecraft Test Conductor in the Firing Room. Jim Lovell, Armstrong’s backup, came on the line. The previous evening Lovell had promised that if Armstrong did not feel up to the flight, he was ready to take his place; Lovell repeated his offer, but Armstrong assured Lovell that he was feeling just fine.

Meanwhile, because Wendt claimed to have caught an implausibly large trout, Collins had purchased the smallest trout available – just 7 inches in length – frozen it, and nailed it onto a wooden plaque with the inscriptions ‘Guenter Wendt’ and ‘Trophy Trout’. It was in the brown paper bag. During the walk out to the van, Collins had dreaded dropping the bag in view of the television cameras, causing the world to wonder why a man bound for the Moon was carrying a dead fish. He presented it to Wendt, then entered the spacecraft.[5] As Aldrin had been CMP when backing up Apollo 8, and was familiar with the centre crewman’s tasks during launch, it had been decided that he should retain this position, which placed Collins on the right.

Alongside the elevator, Aldrin enjoyed 15 minutes of solitude. He admired the view of sunrise and surf to the east, the cars and boats in the distance on the roads and rivers, and the monolith of the Vehicle Assembly Building to the west. Far to the south was ‘Missile Row’, with Pad 5 from which Al Shepard rode a Redstone on a suborbital flight in 1961; Pad 14 from which John Glenn rode an Atlas into orbit in 1962; Pad 19 from which Aldrin and his colleagues rode Titan II missiles on their Gemini missions in 1966; and Pad 34, where the Apollo 1 crew had been consumed by fire in 1967. After Schmitt escorted Aldrin across the access arm, Aldrin presented his fellow Presbyterian with a condensed version of the Bible entitled Good News For Modern Man, inscribed inside: ‘On permanent loan to G. Wendt’.

At 7.22 am, having confirmed that there were no extraneous items in the cabin, Haise departed. As the couches were so closely spaced that the astronauts’ elbows touched, he wriggled under the centre couch to reach the hatch. He could hear the crew on the intercom but could not speak to them to wish them luck, so once he was outside he leaned in and shook each man’s hand. When Chauvin gave the go-ahead to close the hatch, Wendt tapped Aldrin’s helmet and stepped aside; Grissinger then swung the big hatch closed and locked it. Once the hermetic integrity of the seal had been verified, Grissinger added that section of the boost-protective cover. At 7.52 am Wendt’s team descended to ground level and drove to a nearby site in case their services should be required. Meanwhile, Swing Arm 9 with the White Room was rotated 5 feet from the spacecraft, ready to be either restored in an emergency, or swung completely clear just prior to launch.

In the spacecraft, the astronauts verified the switch settings to ensure that none had been disturbed, either by themselves ingressing or by Schmitt or Haise moving around in the capsule. Meanwhile, the cabin was purged. Following the loss of the Apollo 1 crew in a capsule fire, the practice of pressurising the cabin with oxygen for launch had been discontinued. The suited crew remained on pure oxygen, but the atmosphere in the cabin was replaced by 40 per cent nitrogen and 60 per cent oxygen. On being informed that elements of the count were 15 minutes ahead of time, Armstrong pointed out that he wanted them to wait for the launch window to open before starting the engines.

On Tuesday, 15 July, Reverend Ralph Abernathy, successor to the late Martin

Luther King as head of the Southern Christian Leadership Conference, had led a mule-drawn wagon and a small group of protestors to the Kennedy Space Center to decry “this foolish waste of money that could be used to feed the poor”. NASA Administrator Thomas O. Paine had met them. After observing that to cancel the mission would yield no benefit to the poor, Paine had invited a delegation to watch the launch from the official guest area.

Overnight, seeing no one heading away from the Cape, drivers had switched lanes to get closer, generating the worst congestion in Florida’s history. Even the residents of Cocoa Beach, to whom launches were routine, were caught up in the excitement. With the notable exception of alarm clocks, which had been sold out by Tuesday afternoon, local shopkeepers were able to supply the needs of the visitors. As dawn approached on 16 July, it was estimated that 1,000,000 people were on the roads, rivers and beaches, where ‘Good Luck Apollo 11’ had been etched in large letters in the sand. Worldwide, 1,000 times that number were watching the ‘live’ television coverage.

By the time that the countdown entered its final hour, the rain had stopped, the cloud cover was light cumulus topped by patches of cirrostratus, there was a 6-knot southerly breeze, the temperature was already 85°F, and the humidity was 73 per cent: it was going to be a scorcher of a day.

After seeing the astronauts off, Dee O’Hara went to watch the launch with her friend Lola Morrow, who had been hired by NASA in 1962 as a travel clerk and two years later had taken on the daunting challenge of organising the astronauts’ office at the Cape.

Among the thousands of invitees in the VIP stand were Vice President Spiro T. Agnew, four cabinet ministers, 33 senators, 200 congressmen, 19 state governors, 40 city mayors, hundreds of ambassadors,[6] foreign ministers, ministers of science, military attaches, senior NASA employees, and representatives of the companies that built the launch vehicle and spacecraft. Also present were Lyndon B. Johnson and his wife Ladybird, and James E. Webb, NASA’s former administrator. The nearby press enclosure contained 3,500 journalists, 812 of whom were drawn from 54 foreign countries, including 12 from Eastern Europe – but none from either the Soviet Union or the People’s Republic of China. Each of the American television networks had its own team of commentators and consultants. Walter Cronkite, the CBS anchorman popularly regarded as ‘the most-trusted man on television’, was acutely aware that Apollo 11 was different from any previous mission. As he later recalled, ‘‘We knew darned good and well that this was real history in the making.’’ If it succeeded, ‘‘this was the date that was going to be in all the history books’’ and ‘‘everything else that has happened in our time is going to be an asterisk’’. It became evident that there were three milestones in the space program in terms of press

presence at a launch, with the numbers increasing each time: John Glenn’s orbital flight, Apollo 8’s impromptu flight to orbit the Moon, and now, with luck, the accomplishment of John F. Kennedy’s great challenge.

Meanwhile, in Wapakoneta, almost all of the 7,000 population were watching television. Armstrong had advised his parents not to attend the launch, in order to spare them press attention. Although NASA had dispatched Public Affairs Officer Thomas Andrews to fend them off, reporters were camped outside the house and there was an 80-foot-tall transmission tower in the driveway! On the other hand, on hearing that the house had only a black-and-white television, the networks had delivered a large colour set to enable the family to fully appreciate the coverage of the event.

Jan Armstrong had not attended the Gemini 8 launch because her husband had asked her not to, but for Apollo 11 she had insisted. To enable her to escape press attention, North American Rockwell arranged a corporate jet and moored a motor cruiser on the Banana River, several miles south of the pad. On Tuesday evening, Jan, sons Ricky and Mark, friends Pat Spann and Jeanette Chase, Dave Scott, his wife Lurton, and Dora Jane Hamblin representing Life magazine, flew to Patrick Air Force Base and were then driven to a friend’s house on South Atlantic Avenue. At midnight, Jan drove to the Kennedy Space Center to look at the floodlit space vehicle from the astronauts’ viewing area, 3 miles from the pad, then drove back to her hideaway. At 4 am the group boarded the boat. Listening to the commentary on a transistor radio, Jan hoped the launch would be on time because she was exhausted and needed some sleep.

Joan Aldrin set her alarm for 6 am Houston time, but when it sounded she cancelled it and slept for another 50 minutes. “f wish Buzz was a carpenter, a truck driver, a scientist – anything but what he is,’’ she had confided on discovering that he was to make the first lunar landing. Her plan was to keep busy with housework to take her mind off the mission. Her first intended task had been to raise the US flag in the garden, but on seeing the reporters she left this to someone else. Among her guests was Jeannie Bassett, who once occupied the house beyond the backyard fence. After Charles Bassett’s death in 1966, Jeannie had sold the property and taken the children to California, but had returned in order to keep Joan company during what promised to be a nerve-wracking mission. Pat Collins awoke about the same time. ft had been a rough night in Nassau Bay, with a thunderstorm felling a tree on her lawn, and she arranged for its removal. When the television reported that the count was going exceptionally smoothly, she felt sure the launch would be on time.

Clifford Charlesworth’s flight controller team was to handle the launch phase. When Chris Kraft, the Director of Flight Operations seated on Management Row behind the flight director’s console, put a series of needless queries, Charlesworth turned around, smiled, and warned, “Chris, you’re making me nervous!’’

As the scheduled end of the sleep period approached, Cliff Charlesworth, now in charge, decided that since the crew were sleeping soundly and there was nothing on the flight plan requiring urgent attention they should be left in peace. An hour later, telemetry indicated that the astronauts were stirring. Armstrong and Aldrin had slept for 8 hours, and Collins for 9 hours – consistent with the early retirement and late awakening.

‘‘Apollo 11, this is Houston,’’ McCandless called.

‘‘Good morning, Houston,’’ Aldrin replied promptly. ‘‘How do all our systems look?’’

“They’re looking great, and as far as we can tell everything is good from down here.’’

‘‘It looks like the attitude held up really well during PTC last night,’’ observed Aldrin. The spin axis had remained within 10 degrees of the ideal perpendicular to the ecliptic, providing excellent thermal control.

‘‘How’s the Green Team this morning?’’ Collins enquired.

‘‘It was a very quiet night. The Black Team is complaining that they didn’t get a chance to make any transmissions. Ron Evans is getting to be known as the silent CapCom.’’

‘‘That’s the best kind, Bruce,’’ Collins teased.

‘‘Okay,’’ chuckled McCandless. The banter over, he launched straight into the flight plan updates, the most important of which was the cancellation of midcourse correction 3 at 54 hours. ‘‘At 53 hours we have a P52. We’re requesting that you do this while in PTC, and we plan to continue PTC throughout the day.’’ However, one of the first chores of the day – dumping the unwanted water produced by the fuel cells – imparted an impulse that perturbed the roll. ‘‘We’re showing you about 20 degrees out in pitch right now and about 6 degrees in yaw,’’ McCandless called 30 minutes later. ‘‘That’s a little more than twice as much as the deviation you had prior to the waste-water dump. We’ll watch it down here, and let you know if we believe any corrective action is required.’’

“Maybe next time we ought to split that in half,’’ Aldrin suggested. “Put half of it on one side and half on the other, or something like that.’’

“We could do that,’’ McCandless agreed. “We’re actually interested in seeing what the effect on PTC is of this waste-water dump. We don’t recall ever having performed a waste-water dump during PTC on previous missions.’’ In other words, a chore had transformed into an engineering experiment, with the data being filed for future reference. “We’ve been working under the assumption that it would take an hour for a water dump to dissipate to the point where you could reasonably take star sightings for platform alignment, navigation, or something of this sort. If you have a spare minute or two, could you comment on observation conditions, now?’’

“My guess,’’ Collins replied after looking, “would be the telescope’s probably pretty useless, but you can differentiate in the sextant between water droplets and stars by the difference in their motions.’’ But he had not been using the telescope very often. “With the LM attached, the telescope is just about useless because the Sun bounces off its structure. Those star charts that the mission planning and analysis division people provided us, I think, would be most useful if for some reason we had to mark through the telescope – we could use those as a guide for what we’re looking at and say, ‘Well, that bright blob over there must be such and such a star because that’s the position we’re in’. But so far we haven’t been able to pick out any decent star patterns [using the telescope].’’

After two hours of sparse interaction between Apollo 11 and Mission Control, McCandless announced, ‘‘I’ve got the morning news here if you’re interested.’’

‘‘Yes, we sure are,’’ Collins replied.

‘‘Interest in Apollo 11 continues at a high level,’’ McCandless assured, ‘‘but a competing interest in the Houston area is the easing of watering rules. Mayor Louie Welch has promised to lift lawn-watering restrictions if the rains continue. Today is partially cloudy, with a 30-per-cent chance of thunderstorms in the afternoon. In Washington, the Senate Finance Committee has approved extension of the income tax surtax, but a Senate vote on the bill currently seems remote. In Austin, State Representative Ray Lemmon of Houston has been nominated as the National Director of the American Society for Oceanography. Lemmon has proposed a study of the possibility of establishing an institute of oceanography in Texas. This would be the first such institute on the western Gulf of Mexico. In Minneapolis, Minnesota, the weather bureau, after recapping today’s weather showing a high of 88 and a low of 72, has noted ‘snowfall: none’. From St Petersburg, Florida, comes a radio report from the Norwegian explorer, Thor Heyerdahl, which points out that the crew of his papyrus boat, the Ra, will sail into Bridgetown, Barbados, despite damage from heavy seas. The crew, however, are sleeping on their escort vessel. Norman Baker, navigator of the expedition, said the crew was aboard the Ra today repairing damage from storms this week that split the footing of the mast. Part of the broken mast was jettisoned overboard. The vessel is now 725 miles east of the Barbados. ‘It is possible but uncomfortable to sleep aboard the Ra,’ Baker said. ‘But the purpose of our voyage is not a test of strength or human endurance.’ That’s the reason the crew was spending nights on the escort vessel Shenandoah, which rendezvoused with the Ra on Tuesday.’’ In his sports roundup, McCandless related the story of an Irishman, John Coyle, who won the world’s porridge-eating championship by consuming 23 bowls of instant oatmeal in a 10-minute time period from a field of 35 other competitors.

“I’d like to enter Aldrin in the oatmeal eating contest next time,’’ Collins said.

“Is he pretty good at that?’’ McCandless asked.

“He’s doing his share up here,’’ Collins confirmed.

“Let’s see. You all just finished a meal not long ago, too, didn’t you?’’

“I’m still eating,’’ Aldrin pointed out.

“He’s on his 19th bowl!’’ Collins joked.

“Are you having any difficulties with gas in the food bags, like the Apollo 10 crew reported?’’

“That’s intermittently affirmative, Bruce,’’ Collins replied. “We have these two hydrogen gas filters that work fine as long as you don’t actually hook them up to a food bag. But the entry way into the food bag gives enough back pressure to cause the filters to lose efficiency. A couple of times, I have been tempted to go through that drying out procedure, but we found that simply by leaving the filters alone for several hours their efficiency seems to be restored – it ranges anywhere from darn near perfect to terrible, just depending on the individual characteristics of the food bags. Some bags are so crimped near the entry that there is no way to work them loose to prevent back pressure.’’ The gas separator comprised two stainless steel cylinders about 5 inches long and a little over 1 inch in diameter, attached to the water dispenser. These contained two filters, one to attract water and the other to repel it, in the process removing the gas. The design had been modified after the Apollo 10 crew had reported problems, but it evidently required additional work. The ingested hydrogen gave rise to what Collins would later describe as “gross flatulence in the lower bowel, resulting in a not-so-subtle and pervasive aroma’’ reminiscent of “a mixture of wet dog and marsh gas’’. Aldrin would later jest that by the time they were on their way home they were suffering so badly that if the RCS thrusters were to have failed they would have been able to provide manual attitude control!

The first version of the flight plan had envisaged the tunnel remaining sealed until in lunar orbit. Aldrin, however, had successfully argued for an inspection of the LM during the translunar coast, since if the rigours of launch had so damaged that vehicle as to render it unusable it would be best to discover this sooner rather than later. However, as a result of the mass limit imposed on the design of the LM, it could accommodate only six chemical storage batteries, which in turn limited the total electrical power supply, with the result that at this point in the flight it would not be feasible to power it up to transmit telemetry to enable Houston to check its systems. Nevertheless, an early entry would enable Aldrin to make a start on chores such as removing and stowing protective covers.

Six hours into the day, McCandless asked whether they were still intending to take the camera into the LM to televise this inspection.

“If the cord lengths work out all right,’’ Armstrong confirmed.

In view of the growing instability of the roll axis, and the fact that PTC would have to be halted for the telecast, Charlesworth decided that they should go ahead and adopt an attitude in which the high-gain antenna could readily be maintained facing Earth.

“When you work up an attitude for the high-gain, is there any way we could get partial Sun in one of the two LM front windows?” Aldrin asked.

“We’ll have a look at it,” McCandless promised. Several minutes later he relayed, “We recommend stopping PTC at 054:45:00; this should put you at just about the right roll angle to give you Earth in window 1 of the command module, aim the high – gain antenna for television, and put the Sun on the forward hatch of the LM. If you take down the window shades, you should get some sunlight in.’’

While Collins made the manoeuvre, the Green Team handed over to the White Team, and Charlie Duke took over as CapCom.

The telecast was not expected to start until 056:20, or 4.52 pm in Houston, but at 055:10 Apollo 11 began to transmit. “They’re getting television at Goldstone,’’ Duke announced. “We’re not quite configured for it here, but we should be up in a couple of minutes.’’

“This is just for free,’’ Collins explained. “This isn’t what we had in mind.’’

They had decided to enable Houston to watch the tunnel being opened. Aldrin was operating the camera. Collins had just removed the apex hatch and was in the process of stowing it in a bag beneath the left-hand couch. After Armstrong made a preliminary inspection of the probe assembly using a torch, Collins entered the tunnel to release the mechanism by repeatedly cycling its ratchet handle. If it had failed to release, there was a toolkit with which to dismantle it. As the astronauts were not providing running commentary, Duke made occasional observations, but because his remarks ran 12 seconds ‘late’ owing to the time it took to convert the picture this sometimes gave rise to confusion. ‘‘It’s a pretty good show here,’’ he began. ‘‘It looks like you’ve almost got the probe out.’’

‘‘Can you see that?’’ Armstrong asked. ‘‘There isn’t much light up in there, just the tunnel lights.’’

‘‘Roger, Neil. It’s really good.’’

‘‘It’s coming down,’’ Armstrong said, as Collins pulled the bulky mechanism of interconnected rods from the tunnel.

‘‘It looks like it’s a little bit easier than doing that in the chamber,’’ noted Duke. The mechanism was heavy on Earth, and as part of their training they had removed the probe in an altitude chamber.

‘‘You have to take it easy,’’ Collins observed. The probe was weightless, but it still had inertia.

‘‘Mike must have done a smooth job in that docking,’’ Armstrong announced, ‘‘because there isn’t a dent or a mark on the probe.’’ They used elasticated cords to stow the mechanism by the wall at the foot of the couch. The conical drogue was stowed alongside the probe. With the picture lagging so far behind the audio, Duke experienced a sense of deja vu in which he listened to the astronauts describing an action in real-time, and then waited to watch them do it.

Collins re-entered the tunnel and checked an indicator that showed the angular offset between the two docking collars; the fact that this was only two degrees was a tribute to his skill in performing the docking.

“It looks like we’ll be ready to go into the LM early, if that’s okay with y’all down there,” Armstrong said. They were about 40 minutes ahead of the time line.

“Go ahead any time you wish,’’ Duke replied.

Aldrin passed the camera to Armstrong, entered the tunnel, turned the handle on the hatch and hinged it inwards into the LM, activating the cabin lights. For this inspection, the LM would draw power from the CSM. Armstrong returned the camera to Aldrin, who pointed it into the other craft to display items of equipment in stowage on the floor of the cabin ‘above’ him.

“Buzz, are you already in?’’ Duke asked.

‘‘I’m halfway in.’’ Having never seen the LM from this perspective in training, Aldrin was momentarily disoriented. ‘‘I’d better turn around, I guess.’’ By making a half somersault to restore his frame of reference, he immediately felt at home in the cramped cabin. He would later report this to have been the strangest sensation of the mission. Although in the LM, he was on a communications umbilical running back through the tunnel into the command module. Because the mass limit on the LM precluded the use of panelling, the wire bundles and plumbing were largely exposed. The hull interior had been sprayed with a dull-grey fire-resistant coating. The front and sides carried a mass of switches, circuit breakers and instruments. The walls were very thin in places, but were not required to carry structural loads – they were only a pressure shell against the vacuum of space. Although the shades were over the main windows, sunlight diffused through, providing a low level of illumination. Aldrin pointed the camera back down the tunnel to show Armstrong at the far end, with Collins behind him, watching.

‘‘Hey, that’s a great shot,’’ Duke said. ‘‘I guess that’s Neil and Mike – it better be, anyway!’’

Armstrong entered the tunnel to hold the camera, to enable Aldrin to make a start on his inspection. ‘‘I’ll open up the windows to see what the lighting’s going to be like,’’ Aldrin announced. He pulled the shades, first from the right and then the left window, then donned his sunglasses.

‘‘The lighting is superb!’’ Duke exclaimed.

Armstrong made his first contribution. ‘‘Yes, the lighting in the LM is very nice now, just like completely daylight; and everything is visible.’’

‘‘The vehicle is surprisingly free of any debris floating around,’’ said Aldrin. ‘‘It’s very clean.’’ In fact, during his inspection he would discover only one ‘lost’ washer floating adrift. After inspecting the miscellaneous stowed equipment, he tested the LM’s telescope, mounted near the roof in the centre of the front panel, noting that when he looked ‘up’ he could see the shiny surface of the command module. Meanwhile, Armstrong rotated the camera to point down the tunnel to show Collins poking through an oxygen umbilical with which to ventilate the LM’s cabin. Then Aldrin took the camera and pointed it through the narrow overhead window to show one of the forward-looking windows of the command module. ‘‘Charlie, can you see Mike staring out the window?’’ The view was indistinct because there were so many

layers of glass, but when Collins put his head up close to the window his face became apparent.

“We see him staring back at us,” Duke confirmed.

At the scheduled start time for the telecast, the networks picked up the feed. “Your show is going out to the US now,” Duke announced. “We’re about to get the satellite up and then it will go ‘live’ to Japan, western Europe, and much of South America.’’ Aldrin was installing the bracket to the top-right corner of his window on which he was to mount a Maurer camera to document Armstrong’s descent of the ladder at the start of the moonwalk. Next, he installed another bracket midway along a horizontal bar across the window for later photography.

While Aldrin worked, Armstrong zoomed in to show the instrument panel to the estimated audience of 200 million people. ‘‘That’s real good camera work,’’ Duke complimented.

‘‘It’s got to be the most unusual position a cameraman’s ever had, hanging by his toes from a tunnel and taking the picture upside-down,’’ said Aldrin, referring to Armstrong. Aldrin unstowed an assembly designed to fit over a ‘bubble’ helmet for extravehicular activity on the lunar surface, and demonstrated how its twin visors operated.

Armstrong then aimed the camera back down the tunnel. ‘‘Ah, that’s a good view of Mister Collins down there,’’ Duke said. ‘‘We finally see him again!’’

‘‘Hello there, Earthlings,’’ said Collins.

‘‘It’s like old home week, Charlie, to get back in the LM again,’’ Aldrin said to Duke.

‘‘I can imagine,’’ Duke agreed. ‘‘Is Collins going to go in and look around?’’

‘‘We’re willing to let him,’’ Armstrong replied, ‘‘but he hasn’t come up with the price of the ticket yet.’’

‘‘I’d advise him to keep his hands off the switches,’’ Duke warned Armstrong.

‘‘If I can get him to keep his hands off my DSKY,’’ Collins retorted, ‘‘it would be a fair swap.’’

On returning to the command module, Armstrong aimed the camera at Earth, now 177,000 nautical miles away. ‘‘We’re going to turn our television off now for a short bit while we do some other work. Apollo 11 signing off.’’

‘‘That was one of the greatest shows we’ve ever seen,’’ Duke complimented. It had lasted about 1 hour 36 minutes, during which time the spacecraft had travelled over 2,000 nautical miles.

Meanwhile, at home

Joan Aldrin had hosted an afternoon pool party. Pat Collins attended with her sister Ellie Golden. Jan Armstrong brought her sister Carolyn Trude. After the wives had appeared together for the press on the front lawn, they retreated to the swimming pool, joining Jeannie Bassett. The Collins children had been sent to a day camp, but the Armstrong and Aldrin children were present and played in the pool with Kurt Henize, son of Karl and Caroline Henize. Valerie Anders made a brief visit. Audrey Moon prepared snacks and Bob Moon served as a drinks waiter. At 4.30 pm Jan Armstrong and her sister set off for home. When Jan switched on the car radio she was surprised to hear that the telecast was already in progress. On reaching home, they found the house to be even busier, because their mother, Mrs C. G. Shearon of Pasadena, California, and their sister Nan Theissen and her husband Scotty had arrived. Jan watched what remained of the telecast. When Joan switched on her television she was delighted to see Buzz hogging the show. She noted, wryly, that he had gained more air time in this one transmission than she, a trained actress, had managed in her entire career! Pat Collins, who left the Aldrins’ at the same time as Jan Armstrong but did not promptly switch on her television, missed most of the telecast. All three wives were frustrated that their NASA minders had not alerted them to the change in schedule – if they had been told that the crew had started transmitting over an hour earlier than planned, they could have watched from the viewing gallery of the Mission Operations Control Room. Pat Collins successfully eluded the reporters to eat in a favourite restaurant named Rendezvous, but with so many guests Jan Armstrong phoned for a bulk pizza delivery.

On the plan, 30 minutes had been allocated to documented sampling, which was to be a two-man activity. The first task envisaged Aldrin hammering a core tube into the surface. Armstrong was to take pictures prior to sampling, with the tube in the ground, and following its extraction. They were then to collect a number of rocks, each of which was to be photographed in situ, carefully lifted, and inserted into an individual sample bag. Although the lunar material was to be put inside a vacuum – sealed rock box, some material was to be put into a can which, when sealed, would retain any readily volatised constituents that would otherwise be difficult to preserve when the rock box was opened in the laboratory. Finally, if time permitted, they were to collect a second core sample. But when McCandless announced that only 10 minutes was available for this sampling it was decided to forgo the documentation.

While Aldrin prepared a core tube at the MESA, Armstrong disappeared out of sight of the television. Although he had been surprised to discover that, on looking east, he could not see the boulders that surrounded the large crater where Eagle’s computer would have tried to land, Armstrong was able to see the smaller crater over which he had passed just prior to landing. As this was only 200 feet away he decided to inspect it. Saying nothing of his intention, he set off, carrying the ALSCC.14 On reaching the southwestern rim of the crater he shot a sequence of 8 frames across the pit ranging from up-Sun, around the northern horizon and on down-Sun to Eagle. The crater had a raised rim and an interior strewn with rocks. He yearned to enter it to collect a rock as a treat for the scientists, but the pit was 70-80 feet in diameter and 15-20 feet deep and, in any case, he had to rush back. In all, his excursion had lasted just over 3 minutes. He had no difficulty sustaining a ‘loping’ gait, which the timing indicated to have been at 2 miles per hour.

‘‘Buzz,’’ McCandless called while Aldrin was still at the MESA attaching the extension handle to the core tube, ‘‘You’ve got about 10 minutes left now prior to commencing your EVA termination activities.”

“f understand,’’ replied Aldrin. A minute later he took the core tube and went to sample some already documented ground near the SWC. This ‘soil mechanics’ study was to determine soil density, strength and compressibility as functions of depth. ft would also reveal layering, either in terms of the chemical composition of the loose material or its physical characteristics, such as grain size. The plan called for the hollow tube to be driven to a depth of 18 inches. The staffs of the flag and the SWC had indicated that the surface material was consolidated at a depth of several inches, but Aldrin hoped that by hammering on the core tube he would be able to drive it in.

Armstrong would later express surprise that he had lugged Gold’s camera around with him for so long.

The extension handle came up to waist height. At first Aldrin raised the hammer only to chest level, but then he increased this to head level in order to generate the additional force. A complication was that the tube gained little support from the material it penetrated, and he had to maintain a grip on the tool with one hand throughout. As he became more determined, he observed that the hammer was denting the top of the handle. “I hope you’re watching how hard I have to hit this into the ground to the tune of about 5 inches, Houston,’’ he said pointedly. In fact, his hammering drove the tube in only 2 inches beyond the depth to which he had inserted it by hand. Giving up, he withdrew the tube from the ground. The finely grained material coated the section that had penetrated the ground. “It almost looks wet,’’ he noted. To his relief, the material did not dribble out of the open end. On his return, Armstrong snapped pictures of Aldrin at work, then accompanied him to the MESA to help him to cap the tube. A post-mission investigation concluded that the design of the aperture of the tube had inhibited penetration. In the expectation that the surface material would be loose to considerable depth, the core tube had been designed with an internal bevel to compact the material entering the tube as it was hammered into the ground, but because the lunar material at a few inches depth was close to its maximum density, it jammed in the aperture. This discovery made even more ludicrous the idea that the lunar surface was a dust trap that would swallow a spacecraft!

“Neil and Buzz,’’ McCandless called. “We’d like y’all to get two core tubes and the Solar Wind.’’ At Aldrin’s suggestion, Armstrong completed capping the first core tube, and Aldrin took the second sample 15 feet beyond where he had taken the first. “Buzz,’’ McCandless called as Aldrin hammered the second tube, “in approximately 3 minutes you’ll have to commence your EVA termination activities.’’ On realising that he was gaining no greater penetration than before, Aldrin withdrew the tube and returned to the MESA to cap it.

“Neil, after you have got the core tubes and the Solar Wind, anything else that you can throw into the box would be acceptable,’’ McCandless called.

“If you want to pick up some stuff,’’ Aldrin said to Armstrong, “I’ll get the Solar Wind.’’ Aldrin detached the collector sheet from its staff, rolled it up, and stuffed it into a bag. He discarded the staff. He deposited the SWC on the MESA next to the core tubes, ready for Armstrong to stow in the second rock box.

Meanwhile, Armstrong had used a pair of long-handled tongs to collect rocks for the ‘suite’ – a field geologist’s term for a collection of rocks representative of a site, including both the typical and the exotic. This was essentially as planned, but without documentation and with the rocks going into a single large bag rather than into individual bags.

‘‘Buzz,’’ McCandless called. ‘‘It’s time for you to start your EVA close-out.’’

‘‘That’s in progress,’’ Aldrin replied.

As the moonwalkers began to wrap up in silence, Columbia once again flew ‘over the hill’ and out of communication.

‘‘We’d like to remind you of the Close-up Camera magazine before you start up the ladder, Buzz,’’ McCandless called.

‘‘Have you got that over with you, Neil?’’ Aldrin asked.

Armstrong had dispensed with the ALSCC in order to collect samples. “No, the Close-up Camera’s underneath the MESA.” Having made an early report of what appeared to be vesicular rock and then retracted this claim, Armstrong had located some genuine examples, “I’m picking up several pieces of really vesicular rock out here, now.’’

“You didn’t get any environmental samples, did you?’’ Aldrin asked, referring to the material they were to have sealed into cans.

“Not yet,’’ replied Armstrong.

“Well, I don’t think we’ll have time.’’

“Neil and Buzz,’’ McCandless called. “Let’s press on with getting the Close-up Camera magazine and closing out the sample return containers.’’

Aldrin went to the MESA and, supporting himself with one hand, bent down to retrieve the ALSCC. After removing the film, he asked Armstrong to assist in inserting the magazine into his thigh pocket. “Anything more before I head on up, Bruce?’’

“Negative. Head on up the ladder, Buzz.’’

“Remember the film off of that,’’ Aldrin reminded Armstrong, referring to the Hasselblad.

“I will,’’ Armstrong promised.

“I’ll head on in, and get the LEC ready for the first rock box,’’ Aldrin said. As he ascended the ladder he noticed that the dust coating his boots made the rungs seem slippery. Armstrong was to have tried to dust him off, but there was no time.

Armstrong carried the bulk sample box from the MESA out in front of Eagle and hooked it to the LEC, then added the Hasselblad magazine to the same hook. “How are you doing, Buzz?’’

“I’m okay,’’ replied Aldrin, who was now inside the cabin. “Are you ready to send up the LEC?’’

The method for hoisting the box to the hatch required Armstrong to pull on the loop as if drawing washing along a clothes line. Watching, Joan Aldrin laughed, “God bless the rock box. I feel as if I’ve lived with that rock box for the last six months.’’ As the scene played out, she was amazed, “This is like a Walt Disney cartoon, or even a television show – it’s all too much to believe or understand.’’ As the lanyard thrashed in the weak lunar gravity, the film pack detached and fell to the ground by the forward leg. With the leading edge of the box nudging the upper rim of the hatch, Aldrin asked Armstrong to slacken off the tension in the tether in order to lower the box sufficiently to enable it to enter. While Aldrin was stowing the box, Armstrong retrieved the Hasselblad magazine. Because this had fallen beside the foot pad, he decided not to fetch his tongs from the MESA, and instead gripped the ladder with one hand and, bending at the waist, leaned to lift the magazine which, as with everything else that came into contact with the lunar surface, was coated with fine black dust.

“This one’s in. No problem,’’ reported Aldrin, having stowed the first box in its receptacle in the cabin.

At this point McCandless asked Armstrong for an “EMU check’’. Although this was nominally a request that he read out the status of his PLSS systems, the flight surgeon was concerned that in manhandling the rock box and working the LEC, his heart rate had shot up to 160 beats per minute, and the EMU check was a hint that he should take a rest.

“How’s it coming, Neil?” Aldrin asked a minute later.

Having placed the bag of rocks, core tubes and SWC into the second box and sealed it, Armstrong tethered the box and added the recovered magazine. “Boy,” he observed, “that filth from on the LEC is kind of falling all over me while I’m doing this.’’

“All that soot, huh?’’

To give Armstrong a rest, Aldrin suggested they revise the procedure for hauling up the box, “If you can just kind of hold it, I think I can do the pulling.’’

“Stand by a minute. Let me move back,’’ said Armstrong. He backed away to tension the LEC. Once the box was up, Aldrin detached the LEC from the pulley and tossed the cable out through the hatch. The uploading of the boxes had taken rather longer than in training, and repeatedly working against the restraint system built into the shoulder joints of the suit was the greatest exertion of the moonwalk.

“How about that package out of your sleeve, did you get that?’’ Armstrong enquired.

This was a reference to a small canvas bag of mementoes Aldrin had carried in his shoulder pocket with the intention of leaving it on the surface prior to his ingress; he had forgotten. Armstrong proposed that Aldrin pass him the bag once he was on the porch, but Aldrin tossed the bag out through the hatch and it landed at Armstrong’s feet. It contained a gold medallion bearing a representation of the ‘olive branch’ motif – one of four that Aldrin had in his personal preference kit, the others being destined for the astronauts’ wives. There was also an Apollo 1 mission patch in memory of Gus Grissom, Ed White and Roger Chaffee, who died when their capsule caught fire on the pad on 27 January 1967. On returning from his visit to the Soviet Union, Frank Borman handed over two medals that his hosts had requested be left on the Moon. These honoured Yuri Gagarin, the first man to orbit Earth, who died in an aircraft accident on 27 March 1968, and Vladimir Komorov, who died on 24 April 1967 when the parachute of Soyuz 1 failed to open. A more formal memento was a text bearing statements issued by Presidents Eisenhower, Kennedy, Johnson and Nixon, a message from the Pope, and messages of goodwill from the leaders of 73 countries of the United Nations. Some messages were handwritten, others typed, in a variety of languages. It also included a listing of the leadership of the Congress in 1969, a list of members of the committees of the House and Senate responsible for NASA legislation, and the names of NASA management. It was photographed and reduced by a factor of 200, transferred to glass for use as a mask for etching by ultraviolet light onto a 1.5-inch-diameter silicon disk – the same technology as was used to etch integrated circuitry. The disk bore the inscription ‘Goodwill messages from around the world brought to the Moon by the astronauts of Apollo 11’. Around the rim was ‘From Planet Earth’, and ‘July 1969’. Although silicon was chosen for its ability to withstand the temperature extremes of the lunar surface, it was enclosed in an aluminium container to protect the delicate crystal from shock. If it had been intended to mark the placement of these items, the moment had been lost.

Meanwhile, Houston, oblivious to what was going on, was eager to confirm that everything that was to have been loaded was indeed on board. “Neil, did you get the Hasselblad magazine?”

Armstrong had just stepped onto the foot pad. “Yes, I did. And we got about, I’d say, 20 pounds of carefully selected, if not documented, samples.’’

“Well done.’’

Grasping the ladder with both hands for stability, Armstrong adopted a deep knee-bend, then jumped, and his feet landed on the third rung from the bottom of the ladder! It was a shame, he would reflect, that they had not been able to remain out for longer. He had hoped to inspect the boulders off to the north, which, while distance was difficult to judge, appeared to be several feet across.

At T-3 minutes 45 seconds Paul Donnelly, the Launch Operations Manager in the Launch Control Center, wished the Apollo 11 crew, “Good luck, and Godspeed.’’

Ascent 123

By T-2 minutes the ‘boil off of liquid oxygen had ceased, and pressurisation was underway in all three stages of the launch vehicle. With one minute remaining on the clock, Armstrong reported, ‘‘It’s been a real smooth countdown.” Ten seconds later, the launch vehicle went onto full internal power. Because the apparatus was much too complex for the final phase of the preparations to be managed manually, at T-20 seconds an automatic sequencer took over. At T-17 seconds, the guidance system in the Instrument Unit was released. The phased ignition sequence for the five F-1 engines was initiated at T-8.9 seconds, with the vehicle being held down by four clamps. Knowing that no Saturn V had lit its engines and then not lifted off, the astronauts turned their heads in their ‘bubble’ helmets and grinned at each other – they were going to fly! Jack King, the Public Affairs Officer at the Cape, counted down the remaining seconds, ‘‘3, 2, 1,0. All engines running. Liftoff! We have a liftoff at 32 minutes past the hour. Liftoff on Apollo 11.’’

As the clock ran down through its final minute, Joan Aldrin had sat stiffly in a chair, close to tears, fidgeting nervously with a cigarette, twisting a handkerchief, flexing her hands. She watched in silence as the vehicle lifted off. Although in a room full of children, relatives and neighbours, she managed to capture a sense of solitude. In fact, everyone in the room was silent. In contrast, Pat Collins had been very focused, discussing aspects of the flight plan with Barbara Young, who had been through this on Apollo 10. At liftoff, Pat called out delightedly, ‘‘There it goes!’’

As the vehicle began to rise from the pad, a plug drawn from its tail started the master event timer in the spacecraft. NASA specified the timing of mission events in terms of Ground Elapsed Time (GET), as measured from ‘Range Zero’, defined as the last integral second prior to liftoff – in this case 09:32:00 Eastern Daylight Time on 16 July 1969. Armstrong’s heart rate was 110 beats per minute, Collins’s 99 and Aldrin’s only 88, in each case significantly lower than at this point in their Gemini flights. The first 12 seconds of a Saturn V launch were challenging, since the vehicle had to ‘side step’ away from the Launch Umbilical Tower, just in case a gust of wind pushed it towards the tower or one of the swing arms was tardy in rotating clear. As the vehicle gimballed its four outer engines to make this manoeuvre, it swayed this way and that; the effect being most pronounced at the top. As Collins observed later, ‘‘It was, I thought, quite a rough ride in the first 15 seconds or so. I don’t mean the engines were rough, and I don’t mean it was noisy, but it was very busy – that’s the best word for it; it was steering like crazy.’’ Once the vehicle had cleared the 400-foot-tall tower, operational control was handed to Houston. The Instrument Unit of the Saturn V now commanded an axial roll in order to align the vehicle with the flight azimuth. Armstrong was to report key events to Houston, and at an elapsed time of T+ 13 seconds he called, ‘‘We’ve got a roll program.’’ This was acknowledged by Bruce McCandless, a yet-to-fly astronaut serving as the Capsule Communicator (CapCom). Between T+13.2 and T + 31.1 seconds, the vehicle rolled from a pad azimuth of 90°E to a flight azimuth of 72°E. Once aligned, the vehicle started to pitch over in order to arc out over the Atlantic on the desired ground track. ‘‘Roll is complete,’’ called Armstrong, ‘‘and the pitch is programmed.’’

For the crowds, the first indication that a launch was in progress was a light at the base of the vehicle. A jet of flame passed through a hole in the Mobile Launch Platform to a wedge-shaped deflector, which split and vented it horizontally north and south. Water had been pumped onto the pad to diminish the acoustic reflection from the concrete, and the water in the pit was vaporised and blasted out with the flame as a roiling white cloud. The space vehicle weighed 6.5 million pounds, 90 per cent of which was propellant. ft was almost inconceivable that it could be raised off the ground, but the five F-1 engines, drawing propellants at the combined rate of 15 tons per second, yielded a total of 7.5 million pounds of thrust. As the vehicle slowly rose from the pad, exposing the flame, the intensity of the light rivalled the early morning Sun sufficiently to force observers not wearing sunglasses to squint their eyes. fn the press stand, positioned some 3.5 miles from the pad because this was calculated to be as far as an exploding Saturn V could shoot a 100-pound fragment, some of the photographers, their cameras forgotten, simply stood and yelled ‘Go!’ again and again. No launch since John Glenn’s had released such raw emotion in the press. At first it was like watching a silent movie, because the thunderous roar of ignition took 15 seconds to reach the official viewing sites. As the vehicle rose, the roar was overwhelmed by a staccato pop and crackle that was more felt than heard.[7] The ground shook sufficiently to register on remote seismic sensors. To some observers, it was debatable whether the Saturn V was rising, or its great thrust was pushing the Earth aside! Dee O’Hara and Lola Morrow had been joined at the astronauts’ viewing site by Beth Williams, wife of C. C. Williams, an astronaut who had been lost in an aircraft accident in 1967. Tears of joy streamed down their faces. On her boat 5 miles away, Jan Armstrong did not have a very good view, but she preferred reality to a television screen showing the narrow view from a long-range camera.

The main screen in front of the Mission Operations Control Room displayed a plot of the trajectory of the Saturn V, which was exactly as programmed. ff it were to suffer a guidance failure, Armstrong was ready to steer it himself, and was the first commander to have this facility. The vehicle passed through the region of maximum dynamic pressure at an altitude of 4 nautical miles,[8] while travelling at a speed of 2,195 feet per second. The slowly rising thrust from increasingly efficient engines, and the decreasing mass of the vehicle meant increasing acceleration. By design, the centre engine of the F-1 cluster shut down first to limit the acceleration. Once it had consumed some 4.5 million pounds of propellants, the S-fC was shut down. fts sustained thrust had compressed the vehicle lengthwise, and it snapped back to its true length when this force was suddenly removed, throwing the crew against their harnesses; this ‘eye-balls out’ shock being particularly harsh immediately after the peak ‘eye-balls in’ load of 4 g.8 As the 138-foot-long spent stage was released by pyrotechnic charges on its upper rim, small solid rockets in the fairings around its tail fired to retard it. Other such rockets on the exterior of the interstage pushed the remainder of the vehicle clear and gave ullage to settle the S-II’s propellants prior to firing its five J-2 engines. Already on the edge of space, the S-II was to combine continuing to climb with building up horizontal velocity. The spent stage followed a ballistic arc, 357 nautical miles long, into the Atlantic. Although staging occurred at an altitude of 36 nautical miles and 50 nautical miles downrange, it was visible to viewers at the Cape through thin high-level cloud.

The S-II was rather quieter than the first stage, built up its g-load gently, and ran smoothly. The role of the interstage was to prevent the discarded S-IC stage from coming into contact with the engines of the second stage. However, because it represented ‘dead weight’, it was promptly jettisoned. If it had been necessary to abandon the launch vehicle, the launch escape system would have been fired to draw the command module clear. The main solid rocket motor had a thrust of 150,000 pounds, which was fully twice that of the Redstone missile that fired Al Shepard on his suborbital Mercury mission. At an altitude of 60 nautical miles the escape system was jettisoned by firing a secondary solid rocket motor. The tower took with it the conical cover that had protected the command module during the ascent through the atmosphere and, if an abort had been made, would have protected it from the escape rocket’s exhaust. Up to this point, all windows except that in the hatch had been masked. With all five windows uncovered, the cabin brightened markedly.9 As it was above the bulk of the atmosphere, the S-II could manoeuvre without enduring significant aerodynamic stress. It was tasked with correcting any trajectory errors inherited from the first stage. As with the S-IC, the middle engine was shut down first. On fuel depletion, the outer engines cut off. One second later, at an altitude of 101 nautical miles, 875 nautical miles from the Cape and far beyond the range of the television cameras, the S-II was jettisoned to fall into the Atlantic. Joan Aldrin, who had fidgeted throughout, now went into her bedroom to check the abbreviated flight plan that she had pinned on the wall.

On igniting its single J-2 engine, the S-IVB continued to navigate towards the ‘keyhole in the sky’ for orbit. As it pitched over, it presented the astronauts with a view of the curved horizon across the Atlantic; however, being veterans, they had seen it before. At a downrange distance of 1,461 nautical miles, the Instrument Unit of the vehicle noted that it had attained the required combination of altitude and

A load of 1 g corresponds to an acceleration of 32.2 feet per second per second.

9 The cabin had five windows, numbered 1 to 5 running left to right: outboard of the left couch, in front of that couch, in the main hatch by the centre couch, in front of the right couch and outboard of that couch, with the side windows being large and rectangular, the hatch window being circular and the forward-looking windows being small and wedge­shaped.

velocity, and shut down the J-2 engine. At insertion,10 the vehicle was travelling at 25,567.8 feet per second in a ‘parking orbit’ that ranged between a perigee of 98.9 nautical miles and an apogee of 100.4 nautical miles, was inclined at 32.521 degrees to the equator and had a period of 88.18 minutes – which was within 0.6 foot per second and 0.1 nautical mile of the specified velocity and altitudes respectively. Apollo 11 was off to an excellent start.

To communicate with Apollo spacecraft, NASA had established the Manned Space Flight Network (MSFN) using ground stations, ships and aircraft linked to the Goddard Space Flight Center in Greenbelt, Maryland, and then on to Mission Control in Houston. Although some of the stations were simply voice-relays for Mission Control, others had radars to provide the tracking data required to enable the mainframe computers in Houston’s Real-Time Computer Complex to refine the parameters of the spacecraft’s orbit in order to calculate the translunar injection (TLI) manoeuvre.

Once the space vehicle had disappeared from sight, Arthur C. Clarke remarked to the BBC’s veteran space correspondent, Reginald Turnill, ‘‘At liftoff, I cried for the first time in 20 years – and prayed for the first time in 40 years.’’ The protestor, Reverend Ralph Abernathy, having ‘‘succumbed to the awe inspiring launch’’ said, ‘‘I was one of the proudest Americans as I stood on this soil; I think it’s really holy ground.’’

At 061:40, Apollo 11 entered the Moon’s sphere of influence. The strength of a gravitational field is directly proportional to the mass of the gravitating body and inversely proportional to the square of the range from the body. With Earth fully 81 times more massive than the Moon, the ‘neutral point’ was roughly 90 per cent of the way to the Moon; more specifically, 186,437 nautical miles from Earth and 33,822 nautical miles from the Moon. By this milestone, the velocity of the spacecraft had slowed to a relative crawl of 2,990 feet per second with respect to Earth and 3,272 feet per second with respect to the Moon. When Apollo 8 first blazed this trail, the less technically minded members of the press expressed surprise that the crew did not feel a jolt. The origin of this misunderstanding was a comment at a press conference by flight dynamics officer Philip C. Shaffer. After pointing out that Apollo 8 had slowed as it climbed from Earth, and beyond the neutral point accelerated towards the Moon, he added that as the spacecraft crossed the neutral point, the computers in the Real-Time Computer Complex, which constantly calculated its position and velocity, switched from a terrestrial to a lunar frame of reference and the way the numbers were crunched made it appear that the position of the ship had jumped several miles. There was, in fact, no physical manifestation of passing from one gravitational field to the other. Although Apollo 11 entered the Moon’s sphere of influence, it was not committed to it because, being on a free-return trajectory, if it were to do nothing it would pass around the back of the Moon and be deflected back to Earth.

Meanwhile, at home

During the overnight shift, those members of Glynn Lunney’s Black Team who had been asleep during the day and had missed the telecast of the LM inspection, watched a replay.

As soon as Aldrin had guided Armstrong in through the hatch, he reported, “The hatch is closed, latched, and verified secure.’’

The astronauts’ boots, lower legs and gloves were coated with the black lunar dust, and because the LEC had been coated with this material as a result of being trailed across the ground, dust had entered the cabin while hauling up the rock boxes. Some scientists had suggested that iron-rich material on the lunar surface might have been so modified by its long exposure to the charged particles of the solar wind that it would burst into flame on coming into contact with oxygen, and had expressed concern that the last that would be heard from Eagle would be a recital of the checklist leading to cabin repressurisation! Indeed, for several minutes as the cabin pressure built up to 4.8 psi of oxygen, the crew did not respond to calls – but they had not been consumed by flame, they were switching their umbilicals from the PLSS to Eagle’s communications system. On raising their helmets, they noted an odour that Armstrong compared to “wet ashes in a fireplace’’ and Aldrin to “spent gunpowder’’.

As Armstrong and Aldrin ran through their post-ingress checklist, Columbia, reappeared on revolution 19. McCandless brought Collins up to date, “The crew of Tranquility Base is back inside their base, repressurised, and are in the process of doffing the PLSSes. Everything went beautifully.”

“Hallelujah,” replied Collins.

In order to lighten the ascent stage, all items that were no longer needed were to be jettisoned. The extravehicular Hasselblad had been left on the MESA. The version for internal use was to be jettisoned, but first the astronauts used up their film by documenting the views from their windows showing the evidence of their activities. They were amazed at the number of boot prints. To finish up, they shot some interior views, obtaining an excellent picture of Armstrong looking deeply content.

Although the hatch had been open for 2 hours 31 minutes 41 seconds, they had spent longer on the PLSS systems due to having switched to the portable systems prior to opening the hatch, and remained on them for some time after its closure. As the rate at which they would consume coolant water was not accurately predictable

and they had required a margin in case of difficulty in reverting to the cabin’s life – support system, the nominal duration of the surface excursion had been set much shorter than the potential total duration of the backpack. To evaluate the cooling system of the PLSS, the water remaining in their tanks was poured out and weighed. It had been thought that Armstrong (by being outside for longer) would use some 5.4 pounds of coolant and Aldrin 5.1 pounds. In fact, Armstrong used a mere 2.9 pounds; Aldrin, however, used 4.4, this being due to his preference for intermediate cooling. As he reflected later, “I had cooler levels set on the (feed water) diverter valve because it just seemed to be pleasant that way. In retrospect, it appears that this leads towards a higher consumption of water. I wasn’t fully aware that when I was on a higher flow I would be pumping more water overboard. It wasn’t clear to me pre-flight that it would have such an effect on my water consumption. I certainly could have operated at lower levels without overheating.” Nevertheless, both men consumed significantly less water than expected, and could have remained outside for a longer period.

As they tidied up, Aldrin discovered that the button had snapped off a circuit breaker on the panel on his side of the cabin, and that of an adjacent breaker had been pushed in; evidently, while wearing his PLSS he had nudged the panel. The breakers were of the standard push-pull configuration used in aircraft. When the button was pulled to open the circuit it exposed a white band, and when pushed to close the circuit it hid the band as a visual cue. Although it would be possible to close the circuit by inserting the tip of a pen to set the latch, there would be no way to open it again. As the damaged breaker would be used to feed power to the ascent engine, the priority was to determine its current state. Houston said the telemetry indicated that it was open. It was decided to wait until the circuit was required, then use a pen to push it in; if it were to fail to latch, the designers had a manual workaround to feed power to the engine.

As the astronauts finished the post-moonwalk meal of cocktail sausages and fruit punch, Deke Slayton called to offer his congratulations, “I want to let you guys know that since you’re an hour and a half over your time line and we’re all taking a day off tomorrow, we’re going to leave you. See you later.’’

“I don’t blame you a bit,’’ replied Armstrong.

“That was a great day, guys. I really enjoyed it,’’ said Slayton.

“Thank you,’’ Armstrong said. “You couldn’t have enjoyed it as much as we did.’’

“It was great,’’ Aldrin added.

“We sure wish you’d hurry up and get that trash out of there, though,’’ Slayton urged.

“We’re just about to do it,’’ Armstrong assured him.

To depressurise the cabin they put their helmets and gloves back on and verified their umbilicals to the cabin’s life-support system. In view of the time it had taken to vent the cabin the first time, it was suggested that this time they should also open the valve in the overhead hatch. This reduced the depressurisation time to a mere 90 seconds. There were no communications while the hatch was open. Armstrong shoved out first one PLSS and then the other with sufficient force to clear the far end of the porch. The overshoes and helmet augmentation followed, together with the cabin arm rests, the body of the Hasselblad, a saturated lithium hydroxide carbon dioxide filter from the cabin system, urine bags and food packaging. The OPS were retained in case an external transfer to Columbia proved necessary.

Meanwhile, Columbia reappeared once again and McCandless called, “I guess we’ll bid you a good night and let you get some sleep, Mike.”

“Sounds fine,’’ agreed Collins.

Having flown a very ‘busy’ Gemini 10, Collins relished the day that he would have alone in Columbia. ‘‘I really looked forward to a chance to relax and look out the window – to get some assessment of what it’s all about.’’ He enjoyed the 48 minutes per orbit during which he was on the far side of the Moon. He would later write, in the style of a diary, ‘‘I’m alone now, truly alone, and absolutely isolated from any known life. I’m it. If a count were taken, the score would be three billion plus two over on the other side of the Moon, and one plus God-knows-what on this side. I feel this powerfully – not out of fear, or loneliness – but as awareness, anticipation, satisfaction, confidence, almost exultation. I like the feeling.’’

‘‘Repress complete,’’ Armstrong announced, ending Eagle’s period of silence.

‘‘We observed your equipment jettison on the TV,’’ said McCandless, ‘‘and the passive seismic experiment recorded the shocks when each PLSS hit the surface.’’

‘‘You can’t get away with anything anymore, can you?’’ laughed Armstrong in respect of their littering.

‘‘No, indeed,’’ McCandless agreed.

Several minutes later, McCandless was back, ‘‘We’d like to say, from all of us down here in Houston – and really from all of us in all the countries in the entire world – we think that you’ve done a magnificent job up there today.’’

‘‘Thank you, very much,’’ Armstrong replied.

‘‘It’s been a long day,’’ Aldrin noted.

‘‘Indeed,’’ McCandless agreed. ‘‘Get some rest there and have at it tomorrow.’’

‘‘Have you had enough TV for today?’’ Aldrin asked.

‘‘Yes, it’s been a mighty fine presentation.’’

‘‘Okay. Signing off. See you again tomorrow.’’ Aldrin pulled the circuit breaker to end the television transmission. The time in Houston was almost 3 am, and most people had already retired.

As McCandless went off-shift, he handed over to Owen Garriott of the Maroon Team, who posed a number of questions on various aspects of the surface phase of the mission. After accepting a deferment of a detailed description of the geology of the area, Garriott wrapped up with a question designed to assist in identifying their location, ‘‘You commented, Neil, that on your approach to the landing spot you passed over a football-field-sized crater containing blocks of rock 10 to 15 feet in size. Can you estimate its distance from your present position?’’

‘‘I thought we’d be close enough so that when we got outside we’d be able to see its rim back there, but I couldn’t. But I don’t think that we’re more than a half mile beyond it – that is, a half mile west of it,’’ Armstrong explained.

‘‘So you would estimate your position as less than half a mile, approximately, west of this large crater,’’ Garriott asked.

‘‘That’s correct,’’ Armstrong agreed.

With that, Garriott wished the crew of Eagle good night.

Armstrong and Aldrin had a 7-hour rest period scheduled prior to initiating preparations to liftoff. As a safety precaution against airborne dust they donned their helmets and gloves. Aldrin settled on the floor across the cabin, with his legs bent since the cabin was not wide enough to stretch flat. Armstrong reclined on the circular cover of the ascent engine, leaning against the aft wall and with his feet suspended above Aldrin in a sling improvised by hanging one of the waist tethers from the fixture installed for the LEC. With the windows shaded and the vehicle powered down, the temperature dropped. “The thing that really kept us awake, was the temperature,” recalled Aldrin. “It was very chilly in there. After about 3 hours it became unbearable. We had the liquid cooling system in operation in our suits, of course, and we tried to get comfortable by turning the water circulation down to minimum; it didn’t help much. We turned the temperature of our oxygen system to maximum; that didn’t help much either. We could have raised the window shades and let the light in to warm us but, of course, to do that would have destroyed any remaining possibility of sleeping.’’ The telemetry system allowed monitoring just one set of biomedical sensors. This indicated that although Armstrong was unable to fall into deep sleep, the period of inactivity permitted him to ‘wind down’ after the most momentous of days.

Meanwhile in the Sea of Crises

As Armstrong and Aldrin were attempting to sleep, the Soviet Union’s unmanned spacecraft Luna 15 tried to land and crashed. Sir Bernard Lovell, having tracked it using the 250-foot-diameter radio telescope at Jodrell Bank, estimated that it fell onto the Sea of Crises about 500 miles east of Tranquility Base. The Soviet news agency TASS reported, ‘‘The program of research in space near the Moon, and of checking the new systems of the automated station Luna 15, has been completed. At 6.47 pm Moscow time on 21 July, a retrorocket was switched on and the station left orbit and achieved the Moon’s surface in the preselected area.’’ If Luna 15 had managed to land and scoop up some material, it would, by virtue of not pausing in lunar orbit, have been able to return to Earth a day or so ahead of Apollo 11. Gerry Carr pointed out that the presence of the human pilot had undoubtedly saved Eagle from similar disaster. ‘‘Its computer was heading for a blocky crater, and Neil just intervened and moved it over a bit.’’ Although Soviet television had not shown the moonwalk ‘live’, a short clip was included in the news the next day. The People’s Republic of China, however, made no mention of the mission.

The USNS Vanguard had relayed communications as Apollo 11 entered orbit, then there was a hiatus until the spacecraft came within range of the tracking station on the island of Grand Canary, off northwest Africa. A valve in the command module had opened during the ascent through the atmosphere, and while its regulator had slowly allowed the cabin pressure to fall to 5 psi the environmental system started to increase the oxygen ratio and slowly purge the nitrogen that had been present to reduce the risk of a fire at sea-level pressure. Simultaneously, the pressure in the suits had also been reduced. For several hours prior to launch, the astronauts had been breathing oxygen at sea-level pressure to cleanse their bloodstreams of nitrogen, and on completing the post-insertion checklist they were able to doff their helmets and gloves, which were stowed in canvas bags. Despite the pre-breathing, Collins found that his left knee ached, as it had during his Gemini 10 mission, but in view of that experience he expected the discomfort to fade in a few hours.

‘‘Apollo 11,’’ McCandless called, ‘‘this is Houston through Canary.’’

‘‘Post-insertion checklist is complete, and we have no abnormalities,’’ reported Armstrong.

Insertion occurred at T + 709.33 seconds; this being S-IVB cutoff plus 10 seconds to allow for engine tail-off and other transient effects.

As they left Canary behind, Collins unstrapped himself from his couch and went to the lower equipment bay to unstow the equipment that they would require. In a gravitational field the vestibular system of the inner ear facilitates a sense of balance, but in weightlessness the fluid that yields these cues sloshes about freely. Despite having performed aerobatics a few days previously to ‘condition’ himself, he avoided sudden head movements that might induce disorientation.

‘‘Hey, Buzz?’’ Collins called.

‘‘Yes?’’

‘‘How would you like the camera?’’

‘‘Okay.’’

‘‘Here’s a Hasselblad for you.’’ The Hasselblad for internal use was fitted with an 80-millimetre lens.

‘‘Just a second!’’

‘‘I’ll just let go of it, Buzz; it’ll be hanging over here in the air – it’s occupying my couch.’’

A minute later, Collins asked, ‘‘Buzz, did you ever get that camera?’’

‘‘Yes.’’

‘‘Are you ready for 16-millimetre?’’

‘‘Yes. How about a bracket?’’

‘‘Neil will give you the bracket.’’

Collins unstowed the 16-millimetre Maurer ‘sequence camera’, also known as a Data Acquisition Camera, and gave it to Aldrin, who mounted it on a bracket in the right-hand forward-facing window ready to film the retrieval of the LM following TLI. It could run at 1, 6 and 12 frames per second on automatic, and 24 frames on semi-automatic, with shutter speeds of 1/60th, 1/125th, 1/500th and 1/1000th of a second.

‘‘I’m having a hell of a time maintaining my body position down here,’’ Collins complained, ‘‘I keep floating up.’’

After briefly checking in with Houston through the relay site at Tananarive on the island of Madagascar in the Indian Ocean, they crossed the evening terminator. As the ‘platform’ of an inertial measurement unit tends to drift out of alignment, it requires frequent resetting. While they were in Earth’s shadow, Collins was to run computer program 52 (referred to as ‘P52’) and take star sightings with the sextant in the wall of the lower equipment bay to realign the platform. At orbital insertion, the long axis of the vehicle was aligned with the velocity vector, with the sextant aimed towards space, and the S-IVB had established a pitch rate designed to maintain this ‘orbital rate’ attitude.

The platform used a nest of three gyroscopes and associated accelerometers to measure the spacecraft’s attitude and velocity with respect to the orthogonal axes of a coordinate system in a specified frame of reference. Different frames were to be used at different times during the mission, each specified by a ‘reference to the stable member matrix’ (REFSMMAT). As the spacecraft rotated, the platform tended to remain fixed in inertial space and the gimbals rotated to compensate. The platform, aligned to a REFSMMAT – the ‘stable member’ against which the gimbals tracked the attitude of the spacecraft – was the one reference that remained in the same position relative to the stars irrespective of what the spacecraft did. For the start of the journey, the REFSMMAT was defined (in part) with respect to the line from the centre of the Earth through the launch site at the time of liftoff and also with respect to the flight azimuth. This frame would be retained through to TLI. The optical system had a telescope and a sextant. The telescope gave a 60-degree field of view, without magnification, and was intended to be used to identify a constellation and aim the coaxial sextant in the direction of a given star. The sextant’s 1.8-degree field of view was magnified 28 times in order to make precise sightings. If the platform lost its sense of direction – which would occur if a pair of its three gimbals became co-aligned, locking them together (a condition appropriately known as ‘gimbal lock’) – Collins would run through this procedure to realign the platform from scratch. But when he merely wished to find out whether the system really knew its attitude, he would simply ask the computer to aim the sextant at a particular star, and check to see how far it was from the centre of the field of view, then mark its true position. With sightings on two stars, the computer could refine the alignment of the platform. As confirmation, he would then ask the computer to aim the sextant at a third star, which should then appear precisely centred in the field of view. With knowledge of its attitude and the ‘state vector’ specifying the spacecraft’s position and velocity, the computer could, at least in principle, calculate all the manoeuvres necessary to conduct the mission independently of ground support.

Explorers have been navigating on Earth by telescope and sextant for centuries. The computer served essentially the same function as the chronometer. The inertial system not only acted as a compass, but also measured acceleration, which was not a quantity needed on the surface. The digital computer was the technological marvel – a decade earlier, navigating in space would have been a considerably more manual process. Indeed, it could be argued that a lunar landing mission would not have been very practicable prior to the 1960s. The display and keyboard (DSKY, pronounced ‘disky’) of the computer was supplied by the Raytheon Company. It had a power supply, decoder relay matrix, status and caution circuits, a 21-character display unit, and a 16-button key pad with the digits ‘0’ through ‘9’, ‘VERB’, ‘NOUN’, ‘CLEAR’, ‘ENTER’, ‘PROCEED’ and ‘KEY RELEASE’. The executives, developed by the Instrumentation Laboratory of the Massachusetts Institute of Technology, were named ‘Colossus IIA’ for Columbia and ‘Luminary’ for Eagle, and used ‘programs’, ‘nouns’ and ‘verbs’. Verbs were the instructions to do something in the context of a program, while nouns represented the structures that were to be operated upon. For example, if Verb 06 Noun 62 was entered, the verb meant ‘‘display in decimal’’ and the noun indicated what was to be displayed (in this case three numbers of the spacecraft’s inertial velocity, vertical speed and altitude). Some programs had many verb and noun pairings. Numerical data took the form of five-digit quantities, scaled to fit and incorporating an implied decimal point. When a key was depressed, the appropriate item illuminated on the display. A verb would be flashed if the computer wished to attract attention when awaiting crew input. There were two DSKYs in Columbia – one on the main control panel, and the other in the lower equipment bay by the navigational instruments – and one in Eagle.

Star sightings were impractical while the spacecraft was in daylight because the particulates that the vehicle shed, and which floated alongside it, reflected sunlight and made it difficult to see the stars. But this material became invisible in Earth’s shadow. After jettisoning the external cover of the optical system and inserting the eyepieces into the sextant and telescope, Collins peered though the telescope. The view was not encouraging. “f think f am seeing the horizon, but I’m far from being dark-adapted; it’s hard to tell.’’ He installed the handles that were to enable him to hold his weightless body in position to use the instruments. Finally, to cover his left eye while viewing with his right, Collins donned a small plastic patch attached to an elasticated string. The computer knew the celestial coordinates of 37 naked-eye stars that were widely distributed across the sky, each identified by an octal (i. e. base 8) number.

With the vehicle maintaining a fixed attitude with respect to Earth while they remained in low parking orbit, there were only a few reference stars available for this initial P52 check, and the mission planners had decided which ones he should use. Collins told the computer to aim the optics towards star 30, Menkent in the constellation of Centaurus. As the view through the telescope was poor, he went straight to the sextant. The star was slightly ‘off. He centred the cross hairs of the sextant on the star and instructed the computer to record its true alignment. Then he asked for star 37, Nunki, in Sagittarius, checked it, and marked it. The Apollo sextant was more practicable than the hand-held version he had tested on the first orbit of Gemini 10, when John Young, his commander, had dubbed him ‘Magellan’ after the captain of the first ship to circumnavigate the world. Having marked two stars and told the computer to update the platform, Collins instructed it to find star 34 as a final check. ‘‘Atria is there in the sextant, but it’s not dab-smack in the middle.’’ He asked the computer to display the alignment discrepancy as a fraction of a degree. ‘‘0.01, Goddammit! Now that’s enough to piss a body off.’’ Glenn Parker, an instructor at the Cape, had bet him he would not achieve an accuracy better than 0.02 degree, and Collins had been sure he could attain a perfect 0.00 alignment. Finished with the optical instruments, he removed and restowed the eyepieces.

Carnarvon on the southwestern coast of Australia was operating three tracking systems to ensure that the parameters of the orbit were accurately measured, to enable Dave Reed, the flight dynamics officer in Houston, to calculate the TLI burn. After McCandless confirmed that there were no issues involving the S-IVB that might threaten the continuation of the mission, Collins, judging his bet to have been a tie, asked McCandless to pass on a message, ‘‘Tell Glenn Parker at the Cape that he lucked out – he doesn’t owe me a cup of coffee.’’

A black-and-white Westinghouse television camera with scan rate of 10 frames per second and 320 lines of resolution was carried on Apollo 7 and Apollo 8 with good results. A camera using the sequential colour technique was tested by Apollo 10, and issued to Apollo 11. Passing over Australia, Collins unstowed the camera and its ancillary apparatus and plugged in the power and signal cables. The camera was a rectangular box with a lens protruding from the front end. The monitor to enable them to see the field of view in order to verify the focus and lighting was the same width, about half the length, and slightly thicker, and had a small display

screen on one end. The flight plan called for a test of the system by sending to the Goldstone station of the Manned Space Flight Network, situated on a dry lake in the Mojave Desert near the town of Barstow in California. Having had no in-flight anomalies, they set off across the Pacific Ocean with 20 minutes of free time.

“How does zero-g feel?” Armstrong enquired of Collins, who was the only one to have left his couch.

“I don’t know,” Collins mused. “It just feels like we’re going around upside down.”

Indeed, they were, because the S-IVB was maintaining them in a ‘heads down’ attitude, but Collins was referring to the sensation of ‘full headedness’ that arises from the accumulation of blood in the head with the onset of weightlessness.

Passing south of Hawaii, the eastern horizon began to glow.

‘‘Stand by for sunrise,’’ announced Collins.

‘‘Neil hasn’t seen many of those,’’ pointed out Aldrin. Gemini 8 had performed an emergency return after only a few orbits, during which Armstrong had been too preoccupied to appreciate sunrise.

‘‘We haven’t got too many of them on this flight, so you might as well enjoy it while you can,’’ Armstrong advised.

By now the view ahead was a spectacular arc of colour.

‘‘Jesus Christ, look at that horizon!’’ Collins exclaimed.

‘‘Isn’t that something?’’ Armstrong agreed. ‘‘Get a picture of that!’’

‘‘Has anybody seen a Hasselblad floating by?’’ Collins asked. ‘‘It couldn’t have gone far, a big son of a gun like that.’’ He scrambled around looking for it. ‘‘Well, that pisses me off.’’ As he searched, he spotted a ball-point pen that should not have been floating freely. ‘‘I’ve looked everywhere over here for that Hasselblad, and I just don’t see it.’’

‘‘It’s too late for sunrise, anyway,’’ Armstrong lamented.

‘‘You want to get it before TLI,’’ Aldrin noted, referring to the camera. Objects floating freely would have to be collected and stowed prior to the manoeuvre, to prevent them slamming into something else and causing damage.

‘‘I know,’’ agreed Collins. As he continued his search, he endeavoured to avoid making movements that might induce ‘space sickness’. ‘‘Ah! Here it is, floating in the aft bulkhead.’’ He belatedly snapped a few pictures of sunrise.

‘‘How are we doing checklist-wise?’’ Armstrong prompted, several minutes later. ‘‘Let’s make sure we don’t screw up and forget something.’’

‘‘After I extend the docking probe,’’ Collins replied, ‘‘I have got to copy down a bunch of data, and you’ve got the RCS hot-fire.’’

As they approached Baja California, McCandless called via the relay station at Guaymas in Mexico to remind them that they were coming up on Goldstone, but the vehicle barely rose above Goldstone’s horizon and the station received less than 1 minute’s worth of the FM carrier signal without any image modulation. While this proved that the transmitter worked, it had yet to be demonstrated that the camera functioned. One point of progress, however, was that Collins decided that having the monitor float beside the camera was awkward, and that in future it should be taped on top of the camera.

Houston monitored the spacecraft’s telemetry to verify that the docking probe extended properly, and that the RCS thrusters in the quads positioned at 90-degree intervals around the service module imparted pitch, yaw and roll impulses – using only small ‘blips’ in order not to disturb the S-IVB. The Instrument Unit was then updated by direct uplink with the parameters of its orbit and the time and duration of the TLI manoeuvre. This data, plus information on options for an abort if that burn did not go to plan, was also read up to Collins, who wrote it on the flight plan and read it back for confirmation. It had once been intended that there should be a teleprinter to simplify the provision of such information, but this had been deleted in an effort to control the mass of the spacecraft. Because Goldstone had not been able to verify the television camera, as they passed over Florida they transmitted to the Merritt Island Launch Area where, although there was no longer any apparatus to process an image, it was possible to confirm that the carrier signal was modulated. McCandless reported via Canary Island on revolution 2 that the telemetry from the hot-firing indicated that one of the RCS quads was cold. On checking, Armstrong reported that the switch for the heater in that unit had been set incorrectly. ‘‘It was Off; it’s On now. Thank you.’’ With the heater operating, the unit rapidly warmed

up.

As Apollo 11 approached Earth’s shadow for the second time, Collins resumed his couch and they put their helmets and gloves back on in preparation for the TLI burn. McCandless attempted to call through Tananarive but received no response; it transpired that the remote station was not uplinking. Unconcerned, the astronauts worked on through the checklist.