Moonshot: The Inside Story of Mankind's Greatest Adventure

by Dan Parry

  In seeking to build transmitters at sites across three continents, Kraft and his colleagues suddenly found themselves embroiled in international politics. Dealing with the Brits was one thing, but installing tracking stations with space age telemetry facilities in remote corners of Africa was something else. Seven sites involved the State Department in 'serious diplomatic discussion', as Kraft put it, while two others were in the middle of oceans, and for these NASA needed help from the navy.41 Some of the locations were so remote Kraft felt that 'the word primitive was the accurate description'.42 According to Gene Kranz, late one night in 1962 flight controller Charles 'Skinny' Lewis was driving the two members of his team back to their quarters on Zanzibar when he saw a roadblock made of burning oil drums 'manned by natives not in uniform'43. Lewis, a former tank commander who before joining NASA had never left America, accelerated towards the barrier and escaped by smashing his way through the blazing obstacles.

  By the late 1960s, the tracking stations had been substantially developed and brought within the control of NASA's Manned Space Flight Network. The MSFN permitted a permanent link between Houston and Apollo 11 through a worldwide chain of 17 ground stations, supported by four specially adapted ships and up to eight aircraft. Eight of the ground stations were equipped with 30-foot antennas, capable of tracking the spacecraft in Earth orbit and for some distance beyond. Once the crew had reached an altitude of 10,000 miles, communications would be provided by the more powerful 85-foot antennas installed at Madrid, Canberra in Australia and Goldstone in California. These used a system known as S-band, a single signal capable of simultaneously carrying tracking data, telemetry, voice and television. The spacecraft responded by bouncing the signal back, which helped the ground keep track of its position. As the Earth spun on its axis, at least one of the three powerful antennas would be in sight of the Moon throughout the mission, with each station handing control to the next to maintain a continuous connection.

  Voice signals, tracking data and telemetry were passed to Houston via NASA's Communications Network, which linked the ground stations and other facilities through two million miles of landlines and undersea cables. Relying on six intermediate switching centres around the world, and two communications satellites, the network included redundant signal routes to increase reliability. Some remote switching points were triggered automatically whenever the CapCom began to speak. Each time he pressed his microphone button, it emitted a short beep known as a Quindar tone. This prompted the remote site to begin operating, and gave a distinctive sound to transmissions from Mission Control.

  All communications were routed through NASA's Goddard Space Flight Center in Maryland. From there, radio signals were relayed to and from Mission Control, where secure rooms on the ground floor housed the Real Time Computer Complex. Houston's powerful computers monitored launch operations as well as the continuous supply of tracking and telemetry data. The data was recorded, processed and sent upstairs to the Mission Operations Control Room (MOCR), where it was displayed on the controllers' consoles. The flight surgeon might look at Neil's heart-rate while the CapCom talked to Buzz, at the same time a flight controller could follow the spacecraft's position displayed on a wall-sized map, while the man next to him monitored the performance of Columbia's thrusters. Once the LM separated from Columbia at the start of the descent, the MSFN would have to supply this information for two spacecraft simultaneously. Reliability was critical since mission rules could lead to an abort if the signal from space failed at key moments during the landing.

  Although redundancy and reliability were built into the communication systems, Apollo 10 had still encountered many problems. Course corrections and PTC manoeuvres frequently left the spacecraft's antennas in a position where they were either pointing away from Earth or trying to send a signal through the body of the vehicle. Sometimes John Young in the command module had to ask Houston what the astronauts in the lunar module were trying to tell him. Prior to Apollo 11, these issues were addressed by better co-ordination of both the manoeuvres and the communications demands. To maintain the strongest signal, the crew were trained when and how to swiftly switch antennas.

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  Armstrong: 'The view of the Moon that we've been having recently is really spectacular. It fills about three-quarters of the hatch window, and of course, we can see the entire circumference, even though part of it is in complete shadow and part of it's in Earthshine. It's a view worth the price of the trip.'

  Mission Control: 'Well, there are a lot of us down here that would be willing to come along.'

  Collins: 'I hope you get your turn, and soon.'

  Armstrong: 'One of these days, we'll be able to bring the whole MOCR along, I hope. Save a lot of antenna switching.'

  Mission Control: 'That's jolly.'

  Drifting closer to an alien world that was itself moving towards them at more than 2,200mph, the crew were now caught up in a galactic game of chicken. Instead of hopping over the tracks in front of a speeding train, they had to put themselves in a position where the 'train' – here, the size of a small planet – effectively picked them up and carried them along with it. Getting into lunar orbit was fraught with danger. If they did nothing, they would be pulled around the far side and flung back into space towards the Earth on a free flight home, without having to use the big engine at the back of the service module. By burning the engine for precisely six minutes and two seconds they hoped to slow down enough to enter lunar orbit. If the engine failed to ignite, their 'free-return' trajectory gave them a hope of coming back. However, if the braking manoeuvre lasted longer than planned, it might cause the spacecraft to slow so much it would crash into the surface. If the engine stopped early, the crew would be sent off into space at an angle that could be impossible to recover from. Apollo 8 had reduced the risk by breaking the lunar orbit insertion (LOI) manoeuvre into two separate burns. Apollo 11 would do the same.

  To successfully perform LOI-1 Michael would have to fire the engine at precisely 75 hours, 49 minutes and 49 seconds into the mission – while they were behind the far side. Radio signals could be sent to and from the spinning spherical Earth via the elaborate network of radio stations, but the spinning spherical Moon didn't have much beyond dust. Radio communications would be unable to curve round to reach the far side, so LOI-1 would have to be done without the support of Mission Control. If it were unsuccessful, Collins would need to urgently establish whether they would be able to get home, and if so how – something he had practised many times in the simulator.

  Three hours before ignition, at 9.22am on the morning of Saturday 19 July, a long list of numbers was read up to the spacecraft, giving Michael navigation instructions and details on roll, pitch and yaw. The radio link would break at 12.13pm. A few minutes before losing contact flight director Cliff Charlesworth asked each of his controllers for a go/no go decision on LOI. The spacecraft was now 9,000 miles away from the Moon. With the two fast approaching each other, the distance between them would be covered in less than 12 minutes.

  Mission Control: 'Apollo 11, this is Houston. Over.'

  Aldrin: 'Roger. Go ahead Houston, Apollo 11.'

  Mission Control: '11, this is Houston. You are go for LOI. Over.'

  Aldrin: 'Roger. Go for LOI.'

  Mission Control: 'Apollo 11, this is Houston. All your systems are looking good going around the corner, and we'll see you on the other side. Over.'

  After a flight of nearly 240,000 miles, during which they had made just one course correction (a three-second burn on day two), Armstrong, Aldrin and Collins dodged the leading edge of the Moon by just 309 miles. Having halted PTC, the main engine faced the direction of travel as the spacecraft silently coasted through the darkness at 5,200mph. The crew were now less than eight minutes from LOI. Above them, the stars were beginning to fade as the first rays of sunshine reached over the curved horizon, stretching towards the approaching spacecraft. With two minutes to go they slipped from the gloom into glaring sunlight, and
for the first time they could clearly see the heavily cratered landscape, more than 2,000 miles wide.

  Collins: 'Yes, the Moon is there, boy – in all its splendour.'

  Armstrong: 'Man, it's a—'

  Collins: 'Plaster of Paris grey to me.'

  Aldrin: 'Man, look at it.'

  Armstrong: 'Don't look at it. Here we come up to ignition.'

  Aldrin: '8 seconds.'

  Collins: 'Stand by for ignition.'

  Armstrong: 'Burning.'

  Chapter 10

  PUSHED TO THE LIMIT

  The final say on whether Apollo 11 would launch on schedule was down to the crew as much as anyone, and determined to make the deadline they pushed themselves through their training regime. For six months, Armstrong, Collins and Aldrin regularly spent 14 hours a day, six days a week, preparing to fly to the Moon.1 With evenings and weekends often devoted to studying, this was the most demanding period of their lives. While Michael got to grips with the computer and the rendezvous procedures, Neil and Buzz worked in the lunar module simulators, particularly Grumman's elaborate replica at the Cape. Like its command module counterpart, the cabin of the LM simulator mirrored the real thing. Hooked up to external computers, the instruments indicated apparent changes in the flight-path as the crew perfected engine burns and other manoeuvres. Initially the practice flights were straightforward and free of problems – 'nominal' in NASA-speak. But like Michael, as their skills developed, Neil and Buzz began to be tested by their instructors.

  Shortly after the mission rules were issued on 16 May, the flight controllers were due to begin their own training for the descent to the surface. In a spacecraft, as in an aeroplane, the commander has the final say and the controllers knew that in certain situations Neil might overrule them. To discuss this possibility, Gene Kranz held a meeting with the crew.2 They were joined by Charlie Duke, an astronaut who had been selected in 1966. Duke, who had yet to fly in space, had served as a CapCom on Apollo 10, doing the job with such a degree of reliability and easy confidence that Armstrong requested he serve as CapCom for the descent. An air force pilot from North Carolina, Duke successfully supported both the flight controllers and the astronauts. To the controllers he represented the accessible side of an overstretched and rapidly tiring crew, who spent much of their time at the Cape. At the same time, he defended the crew's opinions among a tight team of people who had little personal experience of the demands facing the astronauts. Sometimes occupying a precarious position, Duke did a smooth job in extending understanding on both sides.3

  In his meeting with the crew, Kranz said that if difficulties developed early in the descent Houston would halt the mission and start the rendezvous procedure. Such problems were potentially easier to deal with than emergencies that might occur during the middle of the flight. If the mission needed to be aborted, the descent stage could be jettisoned and an attempt made to return to orbit. But the lunar module had been tested in just two manned missions and both had ditched the descent stage under calm conditions at high altitude. Armstrong considered aborts to be 'not very well understood'. The theory called for the descent engine to be closed, pyrotechnic bolts to be ignited, the descent stage to be jettisoned and the ascent engine to be fired. 'Doing all of that in close proximity to the lunar surface was not something in which I had a great deal of confidence,' he later said.4 For Kranz, a late abort was like a parachute – only to be used as a last resort after all other options had been tried.5 Both he and Armstrong believed that if a problem should strike just as the LM was about to land, actually settling down on the surface would be better than attempting a last-minute abort. At least this would provide a full set of technical data that could improve the chances of the next mission.

  In the last few hundred feet of the descent, only the crew would know whether it was safe to land. But just how far would they push their luck? Kranz knew that on this issue Armstrong had his own thoughts, 'I just wanted to know what they were'.6 Neil kept his opinions to himself, and since he was less than forthcoming, Kranz was left to guess what he might do if it were possible but risky to reach the surface. He suspected Armstrong would press on, 'accepting any risk as long as there was even a remote chance to land'.7 Neil later admitted that he would have been willing to use what he called his 'commander's prerogative' to disregard a mission rule, if he felt that was 'the safest route'.8 He said that while he would not have continued if there were only a 'remote chance' of landing, he would have pushed on if there were a 'good chance' of settling down safely.9 Unsure what Armstrong might do in the event of difficulty, Kranz decided he would let the descent continue as long as there was a chance of success.

  Such gaps in communication were to be addressed during a formal series of joint simulations involving Neil, Buzz and the flight controllers. These sessions, focusing on the landing, could not begin until late May because of delays in developing software for the LM simulators.10 Since the final phase of the descent would last just 12 minutes, a number of training 'runs' could be carried out in a single day, under the supervision of the Mission Control Center's Simulation Branch. A handful of simulation supervisors (shortened to 'Sim Supe') took responsibility for various phases of the mission, and between them they trained the prime and backup crews for Apollo 11, as well as four teams of flight controllers. To accommodate everyone, the simulators were run 16 hours a day. With the computers stretched to the limit they frequently broke down – leading to varying degrees of abuse being directed at the technicians.

  The Sim Supe for the descent phase was Dick Koos, who – according to Kranz – 'was a thin guy, wore wire-rimmed glasses, expressed himself in incomplete sentences, and seemed unsure of what he was trying to say'.11 Beyond his understated demeanour lay a talent for dragging astronauts and flight controllers through sweat-drenched training sessions that Kranz said took him and his team to a 'place beyond exhaustion'.12 Frank Borman later remembered that while his crew were preparing for Apollo 8, 'we were killed more times in simulation than you can shake a stick at'.13 Armstrong believed 'these were the most extensive simulations I had ever encountered'.14

  The first few formal sessions were designed primarily to develop everyone's understanding of the landing sequence. At the same time, they also identified points of no-return. At these moments, each controller was required to give a curt 'go' or 'no go' depending on whether he felt confident in letting the mission continue. These early exercises also helped prepare everyone for the fact that the distance between the Moon and the Earth would delay communications. Travelling at the speed of light, radio messages from the Moon take 1.5 seconds to reach Earth, adding at least a three-second delay to any response urgently required from the ground.

  As the training progressed, the procedures improved, and new mission rules were agreed before the next round of simulations began. Focusing on aborts, these threatened to take everyone on a steep learning curve. In each simulation, Armstrong and Aldrin worked closely with the controllers on the latest challenge Koos had thrown at everyone. Nobody beyond Koos and his team knew what the next problem would be. In some cases the crew would act quickly without advice from the ground, at other times they urgently needed support. Working in this way the two flight teams became familiar with each other, and all the while Koos continually tried to expose the fault lines between them. Sometimes Collins would be involved, for example when the LM crew and the ground controllers practised the rendezvous procedure. Everybody knew what was at stake. The simulations consequently became as realistic and as demanding as possible, with Koos raising the tension in every successive session. Trajectory problems, electrical failures, emergency launches, master alarms and data dropouts – anything was possible. 'Nothing is sacred; no quarter is given and none asked,' Kranz later wrote.15

  After each round of simulations, Neil and Buzz spent time on their own, refining their procedures and leaving the flight controllers to do the same. The mission rules would then be updated, and the next series of exercises would b
egin. Once again Koos would scatter catastrophes about, daring the crew and controllers to take on his mischievous team of instructors. After particularly difficult sessions, the flight controllers would conduct a soul-searching inquisition into what had gone wrong. Especially challenging was the 'dead-man's box', the region between the surface and a few hundred feet above. At this height, the complex relationship between speed, altitude and time made a safe abort impossible.16 This wasn't lost on Armstrong. With Kranz and his team sitting on a planet far removed from them, Neil knew the final decisions would be down to him. Chris Kraft, the director of flight operations who saw his flight directors as 'God', wondered whether Armstrong would be prepared to accept a higher degree of risk than he was ready to allow.17

  In mid-June, Kraft brought Neil into Mission Control to go over the rules that had been agreed so far. As far as Kraft was concerned, Houston was running the show and an independent decision by the crew 'wasn't something we encouraged'.18 Yet Armstrong made no secret of the fact that he would be the man on the spot. Neil, who was first and foremost a test pilot, knew that instruments could sometimes give faulty readings, needlessly causing concern. Unless the spacecraft was actually out of control, what was there to worry about? But inaccurate telemetry sent from space could prompt a controller to mistakenly order a safe flight to be aborted. Neil's opinion on the issue 'led to some heated discussions', Kraft wrote. '"I'm going to be in a better position to know what's happening than the people back in Houston," he said over and over,' Kraft later remembered. 'And I'm not going to tolerate any unnecessary risks,' Kraft retorted, 'that's why we have mission rules.' In the final weeks before the launch, Kraft suspected Armstrong still privately harboured doubts about some of the rules. 'I wondered then if he'd overrule all of us in lunar orbit,' he said.19