Apollo 11’s countdown proceeded smoothly, so Kyle made his way up to the top row of the bleachers; he wanted to stand above everyone else, with his back against the railing so he could have a good view of the launch and be able to hold his camera steady.
The launch of Apollo 11. Credit: Earle Kyle.
Excitement was in the air, but the majority in attendance had never witnessed the kind of power they were about to experience. Everyone watched the clock count down. At T minus nine seconds, the ignition sequence began, and with about six seconds to go the first flames snorted out of the F-1 engines. As the thrust built up, huge clamps held the rocket in place, but when the countdown clock hit zero, the clamps were released—and the 6.5-million-pound rocket began to climb, slowly, almost defiantly.
At the viewing site 2.8 miles (4.5 km) away, the light and heat arrived instantly; to Kyle, it felt like a blowtorch, but it was silent. He heard himself say, “Hey, I don’t hear anything.” But as the rocket slowly rose, the sound started to arrive, taking 14.7 seconds after ignition to travel across the water. The sound wave was almost visible, rolling across the lagoon, scattering the birds. And then the full sound hit, the rumble and the deafening roar, and it was like Mohammad Ali punching all the spectators in the gut, those five gigantic engines vibrating and banging like five cannons firing at the rate of a machine gun. It was all Kyle could do to hold the camera steady, but he got his pictures.
It took fifteen seconds after liftoff for the Saturn V to clear the tower, but the sound kept raining down on the crowd, giving them a long, loud show as the rocket picked up speed, rising faster on its journey. Kyle found that after the sound hit, the emotions hit. He started to cry, and hollered, “Hey, wait for me!” He knew he could never fly on a mission to the Moon, but he was honored that some of the equipment he had built and refined was on its way there.
Apollo 11 launch on July 16, 1969. Credit: NASA.
Inside the Spacecraft Analysis Room, called SPAN, at the Mission Control Center at MSC, during the Apollo 11 Mission. Credit: NASA.
As a vibration and acoustic expert, Bob Wren thought he knew what the Saturn V launch would be like. He knew that the sound wave from the F-1 engines is a frequency that couples with the natural resonate frequency of the human body. “Your whole body is coupling with that sound wave,” he said, “and that’s the reason why your whole abdomen and chest cavity starts shaking like crazy. It’s not the sound coming through your ears, but the entire body just vibrating.”
To Wren, the Saturn V appeared to just lumber its way off the pad, “You think, Oh my God, is it ever going to clear the tower?“ he exclaimed. “It seemed like a week later it cleared the tower. But oh, what a sight, what a sight! To see something the size of a thirty-five-story building lifting off the pad … just amazing, just amazing. I’ll never, ever forget it!”
DURING A BUSY TWO HOURS AND FORTY-four minutes after launch, the crew checked out all systems on the spacecraft, and after one and a half orbits around the Earth, the S-IVB stage reignited for a burn of nearly six minutes. Neil Armstrong, Buzz Aldrin and Mike Collins were on their way to the Moon. Collins detached the Command and Service Modules (CSM), Columbia, from the rocket stage. The Lunar Module (LM), Eagle, had ridden behind them, so Collins—in a nine-minute procedure—turned Columbia around and docked the spacecraft’s nose to the docking port on the top of Eagle.
On board, Collins said Columbia “flies like a spacecraft instead of a simulator. Hope that’s good.”
About an hour later, after checking out the LM’s systems, Collins “backed up,” extracting Eagle from its holding spot in the spacecraft LM adapter, all while traveling at just under 25,000 miles per hour.
The crew finally had a moment to look out the window and saw Earth receding. “And Houston, you might be interested that out my left-hand window right now,” reported Armstrong, “I can observe the entire continent of North America, Alaska, over the Pole, down to the Yucatan Peninsula, Cuba, northern part of South America, and then I run out of window.”
Fourteen hours after lift-off, it was 10:30 p.m. back in Houston. A new shift across Mission Control and the support rooms now monitored all the systems. The three astronauts covered Columbia‘s windows and went to sleep.
The next two days of the translunar flight were uneventful although no one felt flying to the Moon was at all routine. The crew sent live color TV transmissions to Earth: “Apollo 11 calling in from about 130,000 miles out,” Armstrong said while showing views of Earth from space. He would later note that in his recollection of science fiction—from notable writers like Jules Verne and H. G. Wells—no writer had ever imagined that lunar explorers would be in constant communication with people back on Earth or, even more surprisingly, that transmissions and images would be shared in real time. Armstrong understood the importance of sharing their voyage, and his comprehensive descriptions of the views and their activities reflected that.
The rest of the flight to the Moon focused on keeping the spaceship operating smoothly. Mission Control was in constant contact with the crew, to assist them in tasks like making a midcourse correction, monitoring the fuel cells and making sure all the temperature and pressure readings stayed in the proper ranges. All the engineers in the MER observed and plotted their telemetry readings, feeling very much in touch with the systems, even across the ever-growing distances.
And the Moon grew larger out Columbia‘s windows. On July 19, after traveling 240,000 miles in seventy-six hours, Apollo 11 flew behind the Moon out of contact with Earth for the first time since launch.
On the lunar far side, the crew fired the service propulsion system engine for exactly 357.5 seconds, slipping the spacecraft into orbit. They viewed the heavily cratered backside of the Moon with awe and argued over its color:
The Apollo 11 astronauts’ view of the lunar farside, looking at a crater which is about 30 statute miles in diameter. Credit: NASA.
Collins: “Look at those craters in a row … Something really peppered that one. There’s a lot less variation in color than I would have thought, you know, looking down?”
Aldrin: “Yes, but when you look down, you say it’s brownish color?”
Collins: “Sure.” [Earlier, Collins had insisted the color was “plaster of Paris gray” but the Moon’s color seemed to change with various sun angles.]
Aldrin: “Oh, golly, let me have that camera back. There’s a huge, magnificent crater over here. I wish we had the other lens on, but God, that’s a big beauty. You want to look at that guy, Neil?”
Armstrong: “Yes, I see him … What a spectacular view!”
Collins: “God, look at that Moon! … [That crater] is enormous! It’s so big I can’t even get it in the window. That’s the biggest one you ever seen in your life. Neil? God, look at this central mountain peak.”
Spacecraft communicators are pictured as they keep in contact with the Apollo 11 astronauts during their lunar landing mission on July 20, 1969. From left to right are astronauts Charles M. Duke Jr., James A. Lovell Jr. and Fred W. Haise Jr. Credit: NASA.
The view of the Lunar Module Eagle, as seen by Mike Collins in Columbia. Credit: NASA.
When the spacecraft came around the Moon, the telemetry signal arrived on Earth right on schedule, and everyone in Houston knew the burn had been successful. After a few initial exchanges on the status of the spacecraft, Armstrong reported the view of the Moon looked very much like the pictures taken by the crews of Apollo 8 and Apollo 10, “but like the difference between watching a real football game and one on TV, there’s no substitute for actually being here.”
All was well in lunar orbit.
On July 20, everyone in Mission Control and all the support rooms felt the same tension and electricity as on launch day but magnified. Today, they would attempt to land on the Moon. The Mission Rules for Apollo 11 covered 218 pages, many of them detailing what actions were required for every contingency during the LM’s lunar descent.
The seats in Missio
n Control were filled for this critical moment, with several astronauts joining Charlie Duke at the Capcom console or sitting where they could. More astronauts and nearly every high-ranking NASA official filed into the viewing room. The MER and SSRs swelled with people—everyone wanted to be on hand, even if they weren’t scheduled to be on shift.
During the crew’s eleventh orbit around the Moon, Armstrong and Aldrin moved to the LM to check out all the systems, confirming voice communications and telemetry links. Gene Kranz led his team of flight controllers in Mission Control, listening in on all the communication loops between the crew, the Capcom and all the backroom teams. Everyone told themselves this day should feel no different than the hundreds of hours spent in simulations and previous missions. But the difference was undeniable.
Ahead of the timeline, Armstrong and Aldrin continued their checkouts. On the twelfth orbit, at one hundred hours into the flight, Eagle undocked and separated from Columbia, with Collins performing a visual inspection, telling Armstrong and Aldrin they had a “fine-looking flying machine.” Behind the Moon on the mission’s thirteenth orbit, the LM descent engine fired for thirty seconds, providing the thrust necessary for slowing down for the first descent to the Moon’s surface. Both Columbia and Eagle reappeared on the telemetry back to Earth as they came around from behind the Moon, and with another burn, Armstrong and Aldrin made their descent.
Unexpectedly, however, communication problems began: Radio communications drifted in and out from the LM; sometimes static filled the loop. Aldrin repositioned Eagle‘s steerable high-gain antenna and communications returned but then dropped again as the spacecraft turned in flight. Kranz needed to make a decision: Keep going or abort? Telemetry showed all the spacecraft systems working well, however, and Kranz concluded they could press on, knowing in the back of his mind that his decision might need to change if communication problems persisted. Duke radioed up to Collins in Columbia to have him relay that Eagle was go for the powered descent initiative. They were truly going to land on the Moon.
Finally, communications seemed to stabilize as Eagle came closer to the Moon. Armstrong and Aldrin would be arriving at their landing site in about twelve minutes. All eyes in the Mission Control Center were on the consoles, keeping a close watch on the numbers, looking for any anomaly that could force an abort.
The Guidance and Navigation Computer on the LM was doing its job, and to this point, it ran in two-second cycles, reading all the parameters and performing calculations to pump out the next two seconds’ worth of commands. Jack Garman described this type of navigation and flight control as if someone walking down the street opened their eyes once every two seconds to see their location and then decided how to proceed. “You see the hallway around you, and then you shut your eyes and then decide where to put your feet,” he said. “If there are no obstacles ahead of you and you haven’t reached the destination yet, take three steps before you open your eyes again, interpolate and figure out how many steps to take; and open your eyes, look around, shut your eyes, and go.”
The Apollo Guidance computer on the Lunar Module. Credit: NASA.
But the closer the LM got to the lunar surface, the more precise the navigation needed to be. The computer would switch to one-second cycles, with a program called P63 running the computations for this phase of flight. The program held one of the busiest loads for the computer, certainly reaching—or perhaps exceeding—the 85 percent capacity requirements. But if nothing went wrong, the computer’s executive should maintain its prioritized list of tasks.
Meanwhile, the spacecraft turned to make its final approach. A video camera positioned to look out Aldrin’s side window allowed everyone back on Earth to see later what it looked like as Eagle came closer and closer to the lunar surface. Then Armstrong radioed to Houston that, based on their instruments and their view, they were going be “long,” that they would overshoot their intended landing site. Suddenly, an alarm from the Caution and Warning System sounded.
“Program alarm,” Armstrong called out with concern. He checked the display. “It’s a 1202.”
Steve Bales, the Guidance Officer in Mission Control, heard the call and saw it on his console. The alarm number sounded familiar. He quickly scanned the crib sheet of notes he and Garman had made after the simulation a few weeks earlier where he called the abort on the computer alarm. Before he could find it, however, Garman found it on his list and called Bales. The 1202 was an executive overflow, similar to the sim; the computer was overloaded, but it was designed to compensate. “As long as it doesn’t reoccur, it’s fine,” Garman told Bales.
In the meantime, eighteen seconds had passed, and Armstrong urgently called for a reading for the 1202. Bales called, “We’re go, Flight.” In another twenty seconds, the alarm sounded again—another 1202. Aldrin called down, “Same alarm,” noting that the alarm seemed to happen when they called up radar data to display the range to the landing site, along with the LM’s velocity. As it turned out, this wasn’t the cause of the alarms, but it was just more data for the computer to process. Aldrin asked Houston to call up the ranging data over the radio instead of the crew having to retrieve it from the computer.
But despite the alarms, the computer continued to handle the load of the landing program, and both Aldrin and Armstrong jubilantly called out when a critical scheduled throttle-down (a computer-driven reduction in speed from the thrusters) took place. “Wow, throttle down!” said Aldrin. “Better than the simulator!”
“Throttle down on time,” Armstrong said decisively, now feeling confident in the computer again.
“You’re looking great,” Duke replied.
When the computer switched to the next phase, the landing approach program called P64, another alarm sounded, this time a 1201. “Same type!” Garman yelled to Bales. Then Garman heard the same call up the line, Bales to Duke, Duke to the crew: “Same type!” When the alarm sounded again, Garman yelled, “Go, go, go,” leaving no doubt on the question of continuing.
But then Armstrong noticed another problem. The landing program appeared to be sending Eagle toward a large crater, littered with enormous boulders. He entered the program named P66 on the computer, which gave him manual control of the LM. He pitched the craft forward to maintain enough speed to fly past the hazards, and after thirty more seconds, Armstrong eyed a suitable landing area and reduced Eagle‘s speed to begin the final descent.
And that’s when the low-fuel light came on. Only ninety seconds of fuel remained. It would now be a race against the clock.
Armstrong told Aldrin he found a good spot to land, while Aldrin continued to call out the landing parameters: “Still looks good. One hundred twenty feet. One hundred feet, 3½ down, 9 forward … Okay, 75 feet. And it’s looking good; down a half. Six forward.”
Just sixty seconds of fuel remained. Aldrin continued his call: “Forward, forward, 40 feet, down 2½. Picking up some dust.”
At that moment, even amid the air of tension, everyone at the consoles in the Mission Control Center knew this landing was the real thing. In all the simulations and all the practice runs of landing on the Moon, they had never heard the words picking up some dust.
“Faint shadow, 4 forward. 4 forward. Drifting to the right a little. 20 feet, down a half,” Aldrin reported.
Duke let the crew know they had just thirty seconds of fuel left.
About twelve seconds later, Aldrin called out, “Contact light,” as the 3-foot (1-m) long probes on the end of the LM’s landing footpad touched the lunar surface. “Okay. Engine stop … Descent engine command override, off. Engine arm, off.”
After a few seconds of silence, Armstrong’s steady, confident voice called up, “Houston, Tranquility Base here. The Eagle has landed.”
Again, nothing in the simulations could have prepared everyone in Houston for that moment. Cheering erupted, but Kranz quickly brought all the teams under control, because several LM shutdown activities need to be performed and a series of “stay–no stay�
� decisions needed to be made within forty seconds. The astronauts and everyone in Mission Control needed to determine if there were any reasons the astronauts might need to make an emergency lift-off from the Moon. It would take time to arm the ascent engine, and there was only a four-minute window where they could lift off, catch and rendezvous with Collins in Columbia.
One of the first decisions was an “upright” call. Ken Young, Dave Alexander and Jerry Bell sat at the console in the vehicle systems Staff Support Room, supporting Flight Dynamics Officer Jay Greene, listening to Aldrin send down the initial readouts on the LM systems. When they heard the vertical alignment reading, Young, Alexander and Bell needed to determine if there was any danger of the LM tipping over, or if the angle could cause problems for lift-off (in case one of the landing pads had come down inside a small crater or depression or the lunar surface really was “fluffy” as one scientist had predicted).
“The tip angle we could tolerate was 15 degrees,” said Young, “and in the backroom, when we got Buzz’s callout, the angle was only about 2 degrees. It wasn’t even close, but we checked our charts to make sure. It was a tense first few seconds until we got the call because we knew we only had about twenty seconds to make our decision.”
The view of Tranquility Base out the window of the Eagle. Credit: NASA.
Eight Years to the Moon Page 30
