First Man

by James R. Hansen

  In the beginning God created the heavens and the Earth. And the Earth was without form and void. And darkness was on the face of the deep. Somefive billion years ago, whirling and condensing in that darkness, was a cloud of interstellar hydrogen, four hundred degrees below zero, eight million miles from end to end. This was our solar system waiting to be born.

  A hundred million years passed. And God said, “Let there be light.” And there was light at the center of that whirling cloud as a protostar began to form, its gravitational pull attracting larger and larger mass—rotating faster and faster. And in that condensation and heat the Sun was born—in fire out of cold—ever smaller and ever more brilliant, ringed with those satellites that were to be its planets. Two protoplanets—the Earth and the Moon—now separate gaseous eddies mutually trapped in their gravitational pull, moving in tandem orbit around the Sun and growing more dense. Through space and time the increasing gravitation of the system drew in more and more debris, the heavier elements converging in those burning clouds to form molten cores at their centers.

  And more millions of years passed. The Earth and the Moon drew slowly apart, their rotation about each other gradually decreasing in the expanding universe. By now, most of the dust in the solar system had disappeared, either swept up by the planets, or condensed into solid particles of varying size—meteoroids that roamed in eccentric orbits through the vastness of space. Millions of these wandering objects showered onto these new planets, disappearing into their molten surfaces, leaving no trace of their impact.

  And time passed. The Moon, being smaller than the Earth, began to coolfirst and its outer crust to harden. But this hardening was interrupted by gigantic asteroids colliding with the Moon and breaking through the crust, opening fissures that released seas of molten lava from within, flooding vast areas of the lunar landscape. As the molten seas flowed outward and over the torn surface they formed the plains or mares. Impact debris projecting above the flows became the mountains of the Moon.

  And, with time, the crust would cool again and, as it cooled, fissures opened, wrinkles and ridges formed. And volcanic pressures under that surface raised great domes that would later collapse leaving craterlike formations when the eruptions subsided. Most of the lunar craters though were probably being formed by bombardments that had been going on from theMoon’s earliest beginnings: a continuous shower of meteoroids upon the lunar surface, some of the larger ones breaking through the crust and releasing lava from below.

  Millennium upon millennium, this cosmic rain persisted. Through billions of years, meteorite debris has been collecting upon the surface of theMoon. Even the level areas caused by the lava flows are now deeply buried.Nearly every square foot of this outer layer is pitted with impact craters of its own. Seven hundred thousand years ago came perhaps the most recent large alteration of the lunar surface. A gigantic meteoroid struck the southern mountainous region, creating the Crater Tycho with an explosive force that scattered material in a radiating pattern nearly halfway around the Moon.Some of this material was driven out into space and into the Earth’s gravitational pull, penetrating our atmosphere and falling to Earth among the life on our planet at the time.

  As we look back through space and time at the origin of the Moon, we may be in part contemplating our own beginnings. Were it not for the Moon and its effects on the creation of the Earth, man might not be on this planet at all, gazing into that luminescent face on countless nights, or be reaching out for it on this day.

  Switching from Kuralt’s taped segment to the CBS anchor desk live in New York City, the venerable Cronkite—personally equipped with ten separate notebooks full of pertinent facts about Apollo 11 and the U.S. space program—referred to the upcoming Moon landing as “a giant step,” not realizing, of course, that, in less than twelve hours, similar words uttered by the First Man would be heard and forever remembered by a worldwide multitude.

  Armstrong and Aldrin had been together inside Eagle for less than thirty minutes by the time CBS began its comprehensive coverage at 11:00 A.M. Nervous anticipation of what was to come had made it difficult for the astronauts to perform even mundane tasks that morning. Buzz remembers: “The activity of three men in space must, of necessity, be a cooperative venture. By now we had worked out various routines for living together, but in our excitement this particular morning the system came unglued.” The rhythm that had been devised for eating, with one man pulling a food packet out, another snipping the packet, and the third liquefying his food with the water gun, got a little out of whack. Attaching new fecal-containment garments, urine catheters, and collection bags prior to suiting up proved especially unpleasant. Nerves frayed as the three men took turns dressing inside the CSM’s navigation bay, a space large enough for only one man to change clothes, requiring another man to stand by to help with buttons, clasps, and zippers. Besides Armstrong and Aldrin, Collins also had to suit up in case something went wrong with the undocking.

  Suiting up for spaceflight was always done meticulously, but never more so than on the morning of the landing. Neil and Buzz would need to be in their pressure suits for over thirty hours. The first garment they had carefully squeezed into was liquid-cooled underwear. Resembling long johns, the mesh garments held hundreds of small transparent plastic tubes. On the Moon, cooling water pumped from the astronauts’ backpacks would circulate through the tubes, but until the mission progressed to that point the tight undergarments only added to the general discomfort and claustrophobia of being outfitted for space. Aldrin, with only his underwear on, was first into the LM because he wanted to make some initial checks. A half hour later a fully suited Armstrong crawled his way into the module. With Neil inside, Buzz returned to the CSM navigation bay to finish suiting up, then immediately reentered the LM. He and Neil sealed their side of the hatch, with Mike doing the same on the other side.

  Inside Eagle, Neil and Buzz powered up several more systems preliminary to deploying the LM’s spiderlike landing gear. Successful extension of the gear came just before noon EDT. Because a number of communication and equipment checks still had to be made, it took another hour and forty-six minutes before the LM was ready to be detached by a firing of Columbia’s engine. Characteristically, Collins and Aldrin did most of the talking over the radio. “How’s the czar over there?” Mike asked from the command module. “He’s so quiet.” “Just hanging on—and punching,” came Neil’s answer, referring to inputs he was making on the LM’s primary computer in readiness for separation. “You cats take it easy on the lunar surface,” Collins told them shortly before he threw the switch to release them. “If I hear you huffing and puffing, I’m going to start bitching at you.”

  His nose pressed against a window, Collins watched them drift away and waited for word from Neil about the efficacy of the two spacecrafts’ relative motion. It was a good idea not to drift too far apart until Mike gave the LM a very close visual going-over; it was critical to make sure that all four legs of the landing gear were down and in place. To help Mike with the inspection, Neil performed a little pirouette, turning the vehicle around a full rotation. A few months before launch, Mike had made a special trip to the Grumman factory on Long Island just to see what the LM looked like with its gear properly deployed. In particular, it was important for Collins to take a close look at the six-foot-long touchdown sensor prongs that extended from the LM’s left, right, and rear footpads. He also needed to confirm that the footpad on the front gear, the only one without a sensor, was in the correct position. That leg held the ladder down which the astronauts would climb to the lunar surface. Originally that leg, too, had a landing sensor, but it was removed after Armstrong and Aldrin indicated that there was some chance they might trip over it when climbing down. “It was another piece of metal that was there around the ladder where you were coming down,” Neil explains, “and we asked, ‘Why do we need that there? We have three others.’”

  It was a bird unlike any that had ever flown, and the teasing Collins coul
d not stop himself from poking fun at the LM’s appearance: “I think you have a fine-looking flying machine there, Eagle, despite the fact that you are upside down.”

  “Someone’s upside down,” Neil joked back.

  Inside the LM, now flying less than sixty-three nautical miles above the Moon, Neil and Buzz were not seated; they stood upright. Grumman’s chief engineer, Thomas J. Kelly, reflects back on why getting rid of the seats was such an advantage: “Without the bulky seats, the usable volume of the LM cabin became much greater. Seats were not required because the LM’s mission was relatively brief and the astronauts were at zero gravity while flying or at Moon gravity [one-sixth Earth’s] while on the surface. Even LM rocket firings did not exceed one-third g.” Some form of astronaut restraint was needed, so Grumman anchored foot restraints into the deck of the cabin and devised a spring-loaded cable and pulley arrangement that clipped onto the astronaut’s belt. If they needed to brace themselves further, Neil and Buzz could grab handholds and armrests located at mid-body nearby. Best of all, the astronauts standing erect meant that the windows of the LM could be smaller (triangularly shaped) and more lightweight while at the same time giving the astronauts an excellent vantage point from which to peer down out of the spacecraft to the landing zone.

  Before Eagle could begin its landing approach, Neil and Buzz needed to lower its orbit down to the vicinity of 50,000 feet. Flying feet first and facedown relative to the lunar surface, they accomplished this by igniting the LM descent engine, its first firing of the mission. This burn, known as Descent Orbit Insertion, occurred fifty-six minutes after separation from Columbia, at 3:08 EDT. DOI took place while both spacecraft were on the back side of the Moon and out of contact with Earth. Lasting 28.5 seconds, the burn dropped Eagle into a coasting path that took it down on the front side of the Moon where the landing would be made.* As the descent proceeded, Neil and Buzz checked their range rate so they could return to Columbia via the LM’s abort guidance system should the craft’s primary navigation system fail or something else major go wrong.

  With the DOI burn accomplished, Eagle was now considerably lower than Columbia and thus orbiting at a faster speed. This put the LM out in front of Columbia’s orbit by about one minute. As Columbia was in a higher orbit and at an angle that brought it in direct line with the Earth, Columbia’s carrier signal arrived first in Houston, about three minutes earlier than Eagle’s. In both cases, less than a minute after acquisition of signal came the return of voice contact.

  A minute and a half later, Aldrin’s voice was heard in Houston:

  Aldrin reported that DOI had come off extremely well, and that it had put Eagle into almost the exact, predetermined perilune from which it was to start its final, powered descent. If all went well from this point, in less than thirty minutes, the lunar module would touch down.

  Prior to initiating final descent, it was important for Armstrong and Aldrin to check out their onboard guidance and navigation systems. The LM possessed two unique and independent systems. The first was the Primary Navigation, Guidance, and Control System (PNGS), or “pings” for short. This small digital computer, located in the panel in front of and between the astronauts, processed data from a built-in inertial platform—one that was held in a constant position by the action of gyroscopes that sensed movement and kept the platform from tipping in any direction. Finely tuned to the position of distant stars, PNGS flashed yellow-green numbers on a digital display that indicated the LM’s position.

  The second system was the Abort Guidance System (AGS). Rather than basing its navigation on an inertial platform, the spacecraft itself, however it was flying, served as AGS’s measuring table, with body-mounted accelerometers providing the flight data. Both PNGS and AGS integrated accelerations that estimated the spacecraft’s velocities, with PNGS generally producing considerably more accurate data. Ideally, the mathematics inherent to the two systems—both involving the measurement of angles changing over time—produced the same answers as to where the spacecraft was and where it was heading, but inevitably errors crept into the measurements. If tiny errors were allowed to compound, gross errors in computing the LM’s course and location could result.

  After DOI and prior to initiating powered descent (PDI), Neil and Buzz ran a number of cross-checks between the two systems. Close agreement was essential to prevent PNGS from initiating an undesired path. The primary cause of error in PNGS was platform drift, a constant concern for any inertial system. Drift needed to be corrected by realignment of the platform via computer-aided celestial navigation, followed by mechanical reorientation by the motors and gears connected to the gyroscope.

  During their outbound flight, Apollo 11 performed a number of platform alignments, but these took time and required the spacecraft to be kept relatively still. In the half-orbit prior to DOI when they were busy doing other things, Neil and Buzz made a gross check on the accuracy of their previous alignment. “The way we did that,” Armstrong explains, “was by telling the spacecraft to get in an attitude so our sextant was looking directly at the Sun. If our crosshairs were in the center of the Sun, we knew the platform had not drifted. If the crosshairs were an eighth or a quarter out of the Sun’s center, we knew the alignment was still okay.” Neil performed the Sun check shortly before PDI. Though it had been a few hours since the last alignment, he found that the platform was still aligned satisfactorily, with only a fraction of a degree of drift. “I figured for the next thirty to forty-five minutes, the time it would take us to land, it was probably okay.”

  Platform drift was not the only worry relevant to LM navigation. Both PNGS and AGS had to be “on” during the descent, and this could prove to be a problem if the astronauts did not keep everything about the operation of the two systems straight. While only PNGS could help the astronauts make a successful descent to the lunar surface, AGS had to be waiting and ready to navigate an emergency return to the command module; in the final seconds before touchdown, AGS also could take over from PNGS if it failed. According to Armstrong, “We couldn’t land on AGS unless we got right down close to the surface, because you couldn’t navigate the trajectory with it.” Yet both systems needed to be energized and running, because the crew might have to switch instantaneously from PNGS to AGS. “That doesn’t mean that the two systems were both driving the spacecraft simultaneously,” Neil explains. “Both were operating as independent systems, and only one was selected to actually be controlling the spacecraft. We also had information coming out of both that was important to compare.”

  In Apollo 10, as Armstrong well knew, Tom Stafford and Gene Cernan experienced some wild gyrations in their LM, nicknamed Snoopy, when AGS and PNGS got crossed up. In the midst of simulating an abort, the astronauts, while some 47,000 feet above the lunar surface and on their way back up to the command module, switched their navigational control from PNGS to AGS. In doing so, however, Stafford did not realize that Cernan had already flipped the AGS switch from AUTO to HOLD ALTITUDE and flipped the switch himself. This put it back in AUTO and caused the lunar module to go “bouncing, diving, and spinning all over the place.” Set in the automatic mode, the abort computer was only doing what it was designed to do: in the mind of AGS, Snoopy was heading in the wrong direction and had to be immediately turned around so that it could power its way up to a rendezvous with its command module (Charlie Brown, with John Young aboard). Fortunately, Stafford and Cernan managed to switch back to manual and regain control without damaging their spacecraft, but it was the sort of systems mixup that Armstrong and Aldrin knew they had to avoid at all cost.

  Another major concern involved the fuel supply. Recognizing exactly when it was they were to reach the point where powered descent should begin was extremely important from the point of view of fuel consumption: if Neil and Buzz started down from too high out, Eagle would run out of fuel before it was in a position to make a safe landing. “I don’t remember exactly what the altitude limits were,” Neil comments, “but they must have been
in the range of plus or minus four thousand feet.”

  Calculating that altitude was almost as much art as science. A standard altimeter could not tell the astronauts when they reached their perilune because an altimeter was an instrument that determined altitude based on changes in atmospheric pressure and the Moon has no atmosphere. The LM did have a radar altimeter, but from the cockpit perspective that instrument pointed down and forward. Early in the descent when the LM’s vertical axis was nearly horizontal—meaning that the pilots were facing downward—the radar altimeter pointed up and away from the lunar surface and could not provide any landing data. (It would have produced very poor radar data from that height anyway, as landing radar was not reliable above about 30,000 feet.) Guesstimating their PDI point from the height of the lunar mountains protruding below them was impossible, because, while Neil and Buzz could roughly figure out the heights of the mountains at the edges of the lunar sphere, they could not judge them in its middle.