by Dan Parry
In preparing the spacecraft for launch, Buzz had to find an alternative way to close the engine arm circuit breaker, which had been damaged the previous day by his PLSS. Looking for a suitable object that could be inserted into the hole, he found that a felt-tipped pen fitted perfectly, and he successfully pushed the circuit breaker into the correct position. Electrical power could now reach the engine when a switch was pushed by Neil. If they hadn't been able to close the circuit, they would have had to resort to more complicated ways to get round the problem. After preparing the 16mm camera in Buzz's window, they put their gloves and pressure helmets back on and waited for the countdown to end. Once again, timing was essential. They had to launch at precisely the right moment if they were to catch up with Collins before running out of electrical power.
When Michael approached the Sea of Tranquility on his twenty-fifth orbit, Houston asked him to look for Eagle one final time. The LM had been on the surface for a little over 21 hours, but Collins had not been able to spot it once. Mission Control had refined the search, and with less than 30 minutes to go before lift-off Collins was given a new location that later proved to be only 220 metres away from Eagle. By that point, feeling 'like a nervous bride',4 Michael wanted to focus only on the launch. 'My secret terror for the last six months,' he wrote, 'has been leaving them on the Moon and returning to Earth alone.'5 In Houston, Janet Armstrong believed that as long as Eagle lifted off from the surface, 'Mike will come and get them, wherever they are'.6 Collins, however, knew that if Neil and Buzz failed to reach 50,000 feet, the lowest height he could descend to, there was little he could do to help them. 'One little hiccup and they are dead men,' he wrote.7
Mission Control: 'Tranquility Base, Houston.'
Aldrin: 'Roger. Go ahead.'
Mission Control: 'Roger. Our guidance recommendation is PGNS, and you're cleared for take-off.'
Aldrin: 'Roger. Understand. We're number one on the runway.'
While pressurising the two fuel tanks Buzz discovered that one failed to respond, which for him was 'the worst thing we could have seen'.8 The problem began to resolve itself, however, and the flight controllers were not especially worried – but they were slow to reassure the crew.
At 12.54pm – 21 hours and 37 minutes after landing – the launch countdown reached zero. Neil pushed switches that ignited four explosive nuts and bolts and severed the electrical cable connecting the two stages of the spacecraft. After Armstrong pushed the engine arm switch, Aldrin then punched the computer's 'proceed' button, allowing the software to ignite the engine. A second went by and nothing happened. Then, in a sudden jerk of movement, the engine fired, and as the ascent stage smoothly rose vertically from the surface its exhaust plume knocked over the flag and shredded the foil on the descent stage. A swarm of sparkling ribbons of Kapton scattered sunlight in its wake.9
As they accelerated towards orbit, Neil and Buzz noticed that in the time they had been on the ground the terminator had crept back, revealing features they had not previously seen. Gravity gradually fell away as they raced towards the escape velocity of 3,400mph, and some of the lunar dust in the cabin began to float about. Although the ascent engine was relatively small, the ascent stage was by far the lightest spacecraft in the Apollo system, and compared to the pick-up truck characteristics of Columbia it handled like a sports car. 'It's a very light, dancing vehicle,' Armstrong later said.10 Aldrin felt that 'each time you hit the thrust controller, the vehicle behaved as if somebody hit it with a sledge hammer, and you just moved'.11
After seven minutes the engine shut down, and at an altitude of ten miles above the Moon they entered orbit. Coasting at nearly 3,800mph towards their highest orbital point, 47 miles above the surface, the men removed their gloves and helmets as the spacecraft raced through shadow. Once they switched on the rendezvous radar, Armstrong and Aldrin began to play catch-up with the command module. Eagle would perform the rendezvous procedures while Columbia, coasting at an altitude of 60 miles, remained the passive partner. Mission Control took a back seat as Neil and Buzz pursued the command module around the Moon, progressively raising their orbital altitude over three hours, as perfected during the Gemini missions.12
With Eagle chasing him from below, Collins worked flat out to make sure he was holding a stable position. Operating on his own, during the course of the day he would have more than 850 key strokes to make on the computer. As the LM drew closer, Michael kept his eye glued to the sextant and was taken aback when he spotted Eagle coming up towards him. 'For the first time, I had the feeling that that son of a gun was really going to get there in one piece,' he wrote.13 Relief was starting to replace his long-harboured anxiety. Having slowed to match Columbia's speed, Eagle took up a position less than 100 feet from the command module. The two spacecraft were behind the Moon, and for the moment the crew were unable to tell Houston that everything was going to plan. As soon as they came back into radio contact Mission Control was anxious to know how things were developing.
Mission Control: 'Eagle and Columbia, Houston. Standing by.'
Armstrong: 'Roger. We're station-keeping.'
It was the news the controllers had been waiting for, and relieved applause filled the Mission Operations Control Room.14
With the two spacecraft flying in formation, the three astronauts were ready to begin their docking manoeuvres. Neil was preparing to adjust Eagle's position when he realised he was about to look directly into the Sun. In swiftly taking alternative action, he inadvertently jammed the LM's guidance system, triggering warning lights and freezing the autopilot. Just a few feet short of the command module, Armstrong and Aldrin were forced to switch to the backup computer. But they managed to hold their course, and at 4.35pm the combined command and service modules successfully docked with the lightweight ascent stage. Working on the probe and drogue assembly inside the tunnel, once again Michael smelt the odour of burnt material that he had noticed on the first day of the flight.15
As they prepared to enter the clean cabin of the command module, Neil and Buzz knew they risked carrying with them a quantity of lunar dust. To keep this to a minimum, they unstowed the LM's small vacuum cleaner and tried to collect as much dirt as possible. It wasn't only cleanliness they were concerned about. Before the mission, fears of so-called 'moon-bugs' had prompted NASA to adopt an extensive set of precautions. Virtually none of the 127 teams of scientists awaiting samples of moon rocks believed there was any point in testing the material for forms of life. Nevertheless, Congress was persuaded to hurriedly authorise the construction of a special quarantine facility in Houston, as part of the elaborate plan to isolate potential bugs. The plan also included protective rubber suits, the vacuum cleaner for Eagle and a period of quarantine for the crew – beginning the moment Neil and Buzz left the surface.16
Aboard Columbia, Michael raised the level of the cabin's oxygen supply. Once the hatches were open the increased pressure would flow into the LM, rather than the other way round.17 As Armstrong and Aldrin returned through the tunnel he was ready to kiss his crew-mates, but settled for firm handshakes instead. Smiling and giggling like schoolboys, Neil, Buzz and Michael warmly congratulated each other and joked about the difficulties that had caused so much anxiety and which had now been successfully completed.18 Later, Buzz returned to Eagle, and telling Mike to 'get ready for those million-dollar boxes' he passed the two sample containers through the tunnel. These were then zipped up in white cloth bags before being stored in the lower equipment bay. Since they had been sealed in the vacuum of space Michael was unable to open them, but Neil showed him the contingency sample so that he could see the dark powder for himself. 'Sort of like wet sand,' was his first impression.19
As part of their preparations to leave lunar orbit, the crew collected rubbish, urine bags and items they no longer needed and dumped everything inside the LM. Eagle was to be jettisoned and left to freely coast around the Moon. Its decaying orbit would eventually bring it crashing down to the surface. Once Neil and
Buzz had taken a last look at the cabin of their spacecraft, the hatches were replaced and Collins fired pyrotechnics to separate the two vehicles. 'There she goes,' said Armstrong, 'it was a good one.'20 At 6.41pm, Collins flew Columbia away from the LM, and as they began to leave it behind they saw its thrusters fire as Eagle loyally held its position.21
Two hours later, Columbia was passing the near side on the twenty-ninth orbit when Charlie Duke offered to read them some news.
Starting off: Congratulatory messages on the Apollo 11 mission have been pouring into the White House from world leaders in a steady stream all day. Among the latest are telegrams from Prime Minister Harold Wilson of Great Britain and the King of Belgium. The world's press has been dominated by news of Apollo 11. Some newsmen estimate that more than 60 per cent of the news used in papers across the country today concerned your mission. The New York Times which, as we mentioned before, has had such a demand for its edition of the paper today – even though it ran 950,000 copies – said it will reprint the whole thing on Thursday as a souvenir edition. And Premier Alexei Kosygin has sent congratulations to you and President Nixon through former Vice President Humphrey who is visiting Russia. The cosmonauts have also issued a statement of congratulations. Humphrey quoted Kosygin as saying, 'I want you to tell the President and the American people that the Soviet Union desires to work with the United States in the cause of peace.
Duke then moved on to news from home.
You're probably interested in the comments your wives have made. Neil, Jan said about yesterday's activities, 'The evening was unbelievably perfect. It is an honour and a privilege to share with my husband, the crew, the Manned Spacecraft Center, the American public, and all mankind, the magnificent experience of the beginning of lunar exploration.' She was then asked if she considered the Moon landing the greatest moment in her life. She said, 'No, that was the day we were married.' And Mike, Pat said simply, 'It was fantastically marvellous.' Buzz, Joan said – apparently couldn't quite believe the EVA on the Moon. She said, 'It was hard to think it was real until the men actually moved. After the Moon touchdown, I wept because I was so happy.' But she added, 'The best part of the mission will be the splashdown.'
After one more orbit, Michael was ready to make the final significant burn of the mission, the trans-Earth injection manoeuvre, which would launch them out of lunar orbit and send them on their journey home. At 11.55pm they ignited the engine, and for two minutes and 30 seconds a stream of flame accelerated them from less than 3,700mph to 5,900mph, enough to free them from the grip of the Moon. Coasting back to Earth, once again they maintained the passive thermal control roll – slowly turning the spacecraft in order to distribute evenly the impact of the Sun's heat. As on the outward journey, platform alignments, fuel cell purges and waste dumps needed to be regularly tended to, but other than their routine chores there was little to do beyond watching the Moon get smaller. 'What did we do with our free time?' Collins asked himself later. 'We mostly just waited. We had plenty of time to eat, had plenty of time to get rested up.'22
At last they had time to complete some minor tasks. It had been hoped that before Eagle parted from Columbia, prior to the descent to the surface, the crew would have time to frank a first-day cover commemorating a new 10-cent stamp showing an astronaut on the Moon. The idea was that the envelope would bear proof that it had been handled by the crew only hours before the landing. They had been given ink and a rubber stamp marked with the date 20 July, but they did not have a chance to use them until 22 July, the seventh day of the mission.23
That night, as they aimed their camera out the window during their TV broadcast, Charlie Duke identified what he could see.
Mission Control: 'We see the Earth in the centre of the screen ... and see some land-masses in the centre, at least I guess that's what it is. It's very hazy at this time on our Eidephor [screen]. Over.'
Collins: 'Believe that's where we just came from.'
Mission Control: 'It is, huh? Well, I'm really looking at a bad screen here. Stand by one. Hey, you're right.'
Collins: 'It's not bad enough not finding the right landing spot, but when you haven't even got the right planet!'
Mission Control: 'I'll never live that one down.'
Collins: 'We're making it get smaller and smaller here to make sure that it really is the one we're leaving.'
Mission Control: 'All right. That's enough you guys.'
On the following day, Wednesday 23 July, Houston informed the men that Nixon was planning to meet them on their return. The president was about to embark on a trip to seven nations and would begin his travels with a visit to the USS Hornet, the aircraft carrier that was waiting to recover the crew. As well as international updates there were also domestic headlines: 'A little closer to home here, back in Memphis, Tennessee, a young lady who is presently tipping the scales at eight pounds, two ounces, was named "Module" by her parents, Mr and Mrs Eddie Lee McGhee. "It wasn't my idea," said Mrs McGhee, "it was my husband's." She said she had baulked at the name Lunar Module McGhee, because it didn't sound too good, but apparently they have compromised on just Module. Over.' The crew were also told that the residents of Seattle, Portland, Vancouver and San Francisco were planning to make their cities visible by switching on all their available lights.
That evening Janet Armstrong and Pat Collins took their children to Mission Control to watch the crew's final TV broadcast. With the mission drawing to a close, each of the men had prepared a personal statement. After Neil delivered a brief introduction, he handed over to Michael. Collins was conscious that while TV audiences around the world knew of the three astronauts, Apollo 11 represented the work of thousands of people who did not receive the same recognition. Paying tribute to those who had put together the hardware on which their lives depended, he thanked the 'American workmen' who had built the spacecraft, the technicians who had assembled and tested everything and everyone who had worked on the mission at the Manned Spacecraft Center. 'This operation,' said Collins, 'is somewhat like the periscope of a submarine. All you see is the three of us, but beneath the surface are thousands and thousands of others, and to all those, I would like to say, thank you very much.'
Buzz took a different tack, and suggested that the mission was representative of something more than the will of one nation. To him, Apollo 11 stood 'as a symbol of the insatiable curiosity of all mankind to explore the unknown'. He added, 'Neil's statement the other day upon first setting foot on the surface of the Moon, "This is a small step for a man, but a great leap for mankind," I believe sums up these feelings very nicely.' Buzz then finished with a verse from Psalms before handing back to Armstrong, who ended the broadcast with a farewell to everyone listening in: 'We would like to give a special thanks to all those Americans who built the spacecraft, who did the construction, design, the tests, and put their hearts and all their abilities into those crafts. To those people, tonight, we give a special thank you, and to all the other people that are listening and watching tonight, God bless you. Goodnight from Apollo 11.'
After the broadcast, looking down at the lights shining on the west coast of North America, the crew prepared for the final night of the mission.
By the morning of Thursday 24 July the crescent-shaped Earth was growing rapidly larger in the windows. Gravity was pulling the spacecraft towards the planet with ever-increasing speed. By the time the crew hit the atmosphere they would be travelling at nearly 25,000 miles per hour, 40 per cent faster than a Mercury capsule.24 At this velocity, if they came in at too steep an angle they would burn up; if their approach were too shallow they risked bouncing off the atmosphere on a trajectory that would take them back into space. The acceptable gap between the two was just 40 miles wide. If the Earth were the size of a football, this re-entry corridor would be little thicker than the edge of a sheet of paper.
After securing loose items in the cabin, the men took seasickness pills while working their way through the re-entry checklist.25 Sitting in the l
eft-hand commander's seat, Michael kept an eye on their progress by monitoring the angle of the horizon, assisted by Neil in the middle couch who was reading from the DSKY. The computer would guide them down, but Collins had to be prepared to take over should anything unexpected develop. 'As our journey draws to a close,' he later wrote, 'the consequence of a screw-up looms as large as life, literally.'26
Columbia's shape was designed to produce a small amount of lift, like an aircraft wing. The angle at which the spacecraft fell could be altered by thrusters embedded in its hull, allowing some control over its path through the atmosphere. Collins had been expecting to fly just over a thousand miles during re-entry, but fearing turbulent weather in the landing zone Houston advised him to increase the ground-track to 1,500 miles. The Hornet had already moved to the new position, which was 800 miles southwest of Hawaii. By using the thrusters to change the angle of lift, the command module's flight-path could be extended. But the new landing point was at the far end of its range and Michael was concerned that should he need to take over from the computer he would be 'hard-pressed to come anywhere near the ship'.27