The Eagle Has Landed: The Story of Apollo 11

by Jeffrey Smith

  “I think you’ve got a fine looking machine there, Eagle, despite the fact that you’re upside down,” Collins reported.

  “Somebody’s upside down,” Armstrong quipped.

  Now that the Eagle appeared structurally sound, Armstrong was given the okay to proceed with lunar descent.

  “Okay, Eagle. You guys take it easy on the lunar surface,” Collins radioed his crewmates. For the next 24 hours, Michael Collins would orbit the Moon, hoping and praying that his crewmates would return safely.

  Because of features unique to the Moon, the flight of the lunar module could never be exactly duplicated in the flight simulator. Lunar gravitational pull was not evenly distributed due to heavier subterranean rocks called mascons, which exerted magnetic forces strong enough to alter the LM’s altitude and direction. In many respects, Armstrong and Aldrin’s lunar descent was perilous on-the-job training.

  Outwardly calm, Neil Armstrong later recalled his anxiety about the lunar landing: “The most difficult part, from my perspective, and the one that gave me most pause, was the final descent to landing. That was far and away the most complex part of the flight. The systems were heavily loaded at the time. The unknowns were rampant. The systems, in this mode, had only been tested on Earth, and never in the real environment. There were just a thousand things to worry about in the final descent… Walking around on the surface (of the Moon), on a one to ten scale, I deemed a one. The lunar descent, on that scale, was probably a thirteen.”

  To complicate matters, the Grumman-built LM had been plagued by multiple system test failures during the construction process. The first lunar module had not been ready for test flight until March of 1969, less than four months before the Apollo 11 launch.

  The Eagle, 23-feet-tall and weighing over 36,000 pounds, was divided into two parts. The lower section housed the descent engine, fuel tanks, storage areas, and the landing gear, while the upper part was home to the ascent engine, fuel tanks, and cockpit. To minimize weight, the lunar module was encased in a thin aluminum shell; the walls were only 5/100th of an inch thick. The spacecraft’s outer skin was so thin, a pencil could be poked through it, leading astronaut Jim McDivitt to describe the LM as a “tissue paper spacecraft.” The lunar module’s sparsely decorated interior was sprayed with a dull blue-gray fire-resistant coating. To further reduce weight, the interior plumbing and wire bundles were fully exposed.

  “The LM flight deck was about as charming as the cab of a diesel locomotive,” Aldrin joked.

  To conserve space and lessen weight, the Eagle had no seats, forcing Armstrong and Aldrin to stand during flight, held in place by elastic cords. During the early stages of the lunar descent, the LM was flown in a sideways position, with its two triangular-shaped cockpit windows facing the Moon’s cratered surface. When the spacecraft reached the designated area, Armstrong would reposition the LM into the legs-down mode.

  After making a full lunar orbit, Armstrong and Aldrin received instructions from Mission Control: “Eagle, Houston. You are a go for DOI (descent orbit insertion).”

  Armstrong then initiated a 30-second DOI engine burn, lowering the LM’s orbit to eight miles above the Moon’s craggy surface.

  “Eagle, Houston. If you read, you’re go for a powered descent,” Cap Com, Charlie Duke, radioed.

  The combination of static and a three-second radio delay made it difficult for Armstrong and Aldrin to hear the instructions from Mission Control. Collins, orbiting 50 miles above his crewmates, alertly relayed the message: “Eagle, this is Columbia. They just gave you a go for powered descent.”

  Armstrong responded by firing the power descent engine, positioning the lunar module for landing. At the same time, Aldrin activated a 16-millimeter movie camera, located in his cockpit window, to record the historic approach.

  Mare Tranquilitatis (the Sea of Tranquility) was the Eagle’s predetermined landing spot. One degree above the Moon’s equator and 23 degrees east of an arbitrary line running from the North to the South Pole, the Sea of Tranquility was thought to be free of large boulders and level enough for a smooth landing.

  Approaching the landing zone, 33,500 feet above the lunar surface, the Eagle’s computer systems overloaded, sounding a 1202 alarm. While the LM’s computer was state of the art for the year 1969, with a 64K memory and 36,864 fixed-word memory, the sheer volume of incoming data suddenly overwhelmed its capabilities. The computer experts at Mission Control, led by 26-year-old Steve Bales, the ranking expert on the LM’s guidance systems, concluded that the alarm was not indicative of any serious problem. Flight Control soon advised Armstrong and Aldrin to disregard the warning, classifying it as an acceptable risk.

  The Eagle continued its descent at a rate of 30 feet per second. When the LM was 1,000 feet above its designated landing point, Armstrong realized the area was uneven and filled with lunar rocks. With his fuel supply dwindling, the Apollo 11 commander had little time to find a smoother landing place.

  “We could have tried to land there, and we might have gotten away with it. It was a fairly steep slope, and it was covered with very big rocks, and it just wasn’t a very good place to go. You know, if I’d run out of fuel, why I would have put down right there, but if I had any choice of a more promising spot, I was going to take it. There were some attractive areas, far more level, far less occupied by boulders, about a half-mile ahead or so, so that’s where I went,” Armstrong later remembered.

  The landing spot Armstrong ultimately selected was 20,800 feet west and approximately 4,500 feet south of the original destination. Carefully monitoring computer flight data, Aldrin called out relevant numbers to his partner, as the lunar module neared the surface. Much to his relief, Armstrong found the LM easy to maneuver: “It settled down like a helicopter.”

  As the Eagle’s fuel supply was rapidly disappearing, the stoic Armstrong seemed unfazed. In spite of his outward calm, the flight surgeons in Houston noted that Armstrong’s heart rate had increased to 156 beats per minute during the final lunar descent. When the LM was 50 feet above the lunar surface, Mission Control radioed the bingo fuel call, meaning the Eagle had but 20 seconds to land.

  With its fuel supply precariously low, the LM’s landing sensors finally contacted the surface.

  “Contact light,” Aldrin relayed to Armstrong.

  “Shutdown,” Armstrong announced.

  At 3:17:40 p.m., the lunar module touched down on the surface of the Moon.

  “Houston, Tranquility Base here. The Eagle has landed,” Armstrong announced to Mission Control and a worldwide television audience.

  Aldrin later recalled his exact thoughts: “We had less than 20 seconds of fuel remaining, but we were on the Moon.”

  At Mission Control, the flight controllers and engineers in the Trench erupted in applause.

  “Roger Tranquility, we copy you on the ground. You’ve got a bunch of guys about to turn blue. We’re breathing again,” Cap Com replied.

  Armstrong and Aldrin shook hands and clapped one another on the back.

  “There are lots of smiling faces in this room, and all over the world,” Cap Com announced.

  “There are two of them up here,” Armstrong replied.

  “And, don’t forget the one in the command module,” Michael Collins chimed in, orbiting high above the lunar surface.

  “Whew, boy! Man on the Moon!” Walter Cronkite announced to CBS television viewers.

  Far away from Tranquility Base, at Arlington National Cemetery, an anonymous visitor placed a small bouquet on the grave of John F. Kennedy, whose ambitious proposal, eight years earlier, heralded the Apollo program. A simple message was penned on the card attached to flowers: “Mr. President, the Eagle has landed.”

  CHAPTER 12

  One small step

  During space exploration, danger was a constant companion. Immediately after the Eagle landed on the Moon, Mission Control observed that the temperature in the descent engine fuel line had climbed to a dangerous level. NASA and Grumman
engineers concluded that a “solid slug” of frozen fuel had trapped a small amount of overheated liquid in the line. If the temperature continued to rise, a catastrophic explosion was quite possible.

  Two options were considered—aborting the mission, whereby the astronauts would immediately take off and leave the descent engine behind, or “burping” the engine, by quickly opening and closing the fuel line valve to relieve the mounting pressure. Neither choice was particularly appealing. Aborting the mission before the scheduled lunar excursion would be a major setback for the Apollo program. However, if the Eagle was not firmly planted on the lunar surface, the “burping” process could generate enough force to topple it over, stranding the astronauts on the Moon.

  NASA officials faced a difficult choice, balancing mission goals with the safety of the flight crew. Suddenly, the pressure inside the fuel line began to drop, when the frozen fuel slug began melting. Fate had once again smiled on Apollo 11.

  Soon after landing on the Moon, Buzz Aldrin conducted a preplanned ritual of thanksgiving. A Communion kit had been prepared by Dean Woodruff, Pastor of Aldrin’s Webster Presbyterian Church in Texas, allowing the astronaut to celebrate his blessings with bread and wine: “This is the LM pilot. I’d like to take this opportunity to ask every person listening in, whoever and wherever they may be, to pause for a moment and contemplate the events of the past few hours and to give thanks in his or her own way.”

  Aldrin’s actions were not without controversy. Certain non-believers had vehemently protested the recitation of verses from the book of Genesis by the Apollo 8 crew the previous Christmas Eve. Renowned atheist, Madalyn Murray, subsequently filed suit against NASA. The clergy and members of Webster Presbyterian Church, however, were honored—the church has since used Aldrin’s chalice to celebrate an annual Lunar Communion, on the Sunday closest to July 20th.

  Neil Armstrong, whose religious beliefs were a private matter, remained detached from his crewmate’s ceremony: “He told me he planned a little celebratory Communion, and he asked if I had any problems with that, and I said, ‘No, go right ahead.’ I had plenty of things to keep busy with. I just let him do his own thing.”

  The Apollo 11 astronauts were originally scheduled for a four-hour rest period prior to walking on the Moon. Far too excited to sleep, Armstrong and Aldrin received permission from Mission Control to move forward with the lunar excursion.

  “Telling us to try to sleep before the EVA (extra vehicular activity) was like telling kids on Christmas morning they had to stay in bed until noon,” Aldrin explained.

  It took over four hours for the astronauts to complete their pre-EVA checklists. Conditions inside the lunar module were cramped, as Aldrin later recalled: “We felt like two fullbacks trying to change positions inside a Cub Scout pup tent.”

  Armstrong and Aldrin were already dressed in spandex and nylon lunar underwear equipped with 300 feet of plastic tubing to circulate water and maintain proper body temperature control. Their external spacesuits, also known as extravehicular mobility units (EMU), constructed by ILC Dover, were designed to withstand the extreme lunar temperature fluctuations (+ 260 degrees to – 273 degrees Fahrenheit) and to protect against the impact of rock specks called micrometeoroids. At the same time, the spacesuit was designed to afford the astronauts with mobility while walking on the lunar surface. The seamstresses at ILC Dover had stitched, glued, and cemented together 22 layers of Nomex, Neoprene-coated nylon, Beta cloth (a fiberglass type material, coated with Teflon), and Mylar to create durable and functional spacesuits, costing $100,000.00 each.

  After donning their bulky spacesuits, Armstrong and Aldrin disconnected themselves from Eagle’s life support systems, becoming totally dependent on their portable life support system (PLSS) backpacks. The bulky units, developed by Hamilton Standard Company, provided the astronauts with a temperate atmosphere during their lunar excursion. The PLSS supplied oxygen, maintained appropriate body pressure, supplied water to keep the astronauts’ bodies climate controlled, and housed communication equipment. A separate, smaller pack, worn on their chests, contained a pump for the water-cooling system, a fan for oxygen circulation, a communications switch, and in Armstrong’s case, a camera mount.

  The astronauts’ helmets were equipped with tinted visors to ward off the Sun’s ultraviolet rays; a necessity, since the Moon has no protective atmospheric layer of its own. Armstrong and Aldrin wore special boots to promote traction on the yet unknown texture of the lunar surface. The combined weight of the spacesuit and PLSS was 180 pounds, but with lunar gravitational forces less than 1/6th of the Earth’s, the extra load was equivalent to only 30 pounds.

  Before stepping foot on the lunar surface, the astronauts vented oxygen from the LM’s cabin. Once the cabin was depressurized and the hatch opened, seven hours after landing, Commander Neil Armstrong was ready to make history.

  Aldrin helped his crewmate, who was encumbered by his bulky space suit and PLSS, negotiate passage through the narrow hatch. On his hands and knees, Armstrong backed his way out the hatch onto the porch, a small platform at the top of the descent ladder.

  As he began to step backwards down the ladder, Armstrong pulled a lanyard, releasing the modularized equipment stowage assembly (MESA)—a workbench and storage area at the base of the lunar module. The MESA housed a black and white television camera aimed at the foot of the ladder, which was programed to record Armstrong’s historic first steps. At the bottom of the ladder, Armstrong jumped three feet down to the footpad, located just inches above the lunar surface.

  “I’m at the foot of the ladder. The LM footpads are depressed in the surface about one or two inches,” Armstrong reported, “The surface appears to be very, very fine grained, as you get close to it. It’s almost like powder.”

  As 500,000,000 people, 1/15th of the world’s population, watched on television, Armstrong was poised to make history: “I’m going to step off the LM now…”

  At 9:56:20 p.m., Neil Armstrong stepped onto the surface of the Moon, announcing to the world: “That’s one small step for man, one giant leap for mankind.”

  Armstrong, who had not shared his planned statement in advance, later recalled the sentence did not come out exactly as he had hoped. In the excitement of the moment, he had left out one word, having planned to say: “That’s one small step for a man, one giant leap for mankind.” Armstrong, alone, was aware of the omission, and his prosaic description of the historic moment seemed most fitting.

  “Armstrong is on the Moon. Neil Armstrong, 38-year-old American, standing on the surface of the Moon!” Walter Cronkite exclaimed to CBS viewers, as the camera mounted on the MESA delivered a clear image of the monumental first steps.

  “Isn’t this something? 240,000 miles out there, and we’re seeing this!” Cronkite excitedly reported.

  Armstrong’s boots lightly penetrated the lunar soil: “The surface is fine and powdery…I can see the footprints of my boots.”

  Armstrong immediately inspected the area at the base of lunar module: “The descent engine did not leave a crater of any size. It has about one-foot clearance on the ground. We’re essentially on a very level place, here,” he reported.

  Before exploring his new environment, Armstrong used his contingency sampler to scoop up a small amount of lunar soil, which he placed in a Teflon bag and then stored in the pocket on one leg of his space suit. The hastily gathered contingency sample would be available if the Apollo 11 mission was suddenly aborted, before the crew could gather more soil and rocks.

  Armstrong began to walk away from the lunar module, adjusting his gait to match the reduced gravity and accommodate the bulkiness of his spacesuit. With its diameter smaller than Earth’s, the Moon’s planetoid curve was more visible, and Armstrong had to watch where he was walking, keeping his eyes several steps ahead, to keep from falling. After establishing his “lunar legs,” the mission commander ventured as far as 60 yards away from the lunar module, while examining the neighboring East Crater.


  Armstrong described the lunar topography: “It has a stark beauty of its own. It’s much like the high desert of the United States.”

  Buzz Aldrin waited patiently inside the lunar module, biding his time and taking repeated photographs of the lunar surface. Nineteen minutes after Armstrong’s descent, it was Aldrin’s turn.

  “Okay. Are you ready for me to come out?” Aldrin radioed his crewmate.

  “All set. Okay. You saw what difficulties I was having (clearing the hatch). I’ll try to watch your PLSS from underneath here,” Armstrong replied.

  Standing near the base of the lunar module, Armstrong carefully photographed his crewmate’s painstaking descent. Once he was on the porch, Aldrin paused: “Okay. Now, I want to go back up and partially close the hatch, making sure not to lock it on my way out.”

  “A pretty good thought,” Armstrong chuckled.

  “That’s our home for the next couple of hours, and we want to take care of it,” Aldrin emphasized; an important point, as outside of the hatch did not have a handle, and if the door had sealed shut, the astronauts would have been stranded on the lunar surface.

  Armstrong watched Aldrin gradually back down the ladder: “You’ve got three more steps and then a long one.”

  After Buzz Aldrin’s feet touched the lunar surface, he shared his observations with the world: “Beautiful view.”

  “Isn’t that something? Magnificent sight out here,” Armstrong replied.

  “Magnificent desolation,” Aldrin spontaneously exclaimed.

  Armstrong placed his gloved hand on Aldrin’s shoulder: “Isn’t it fun?”

  Aldrin carefully surveyed the barren terrain: “I felt buoyant and full of goose pimples when I stepped down on the surface. I immediately looked down at my feet, and became intrigued with the peculiar properties of lunar dust. If one kicks sand on a beach, it scatters in numerous directions, with some grains traveling farther than others. On the Moon, dust travels exactly and precisely as it goes in various directions, and every grain of it lands nearly the same distance away.”