by Jay Barbree
“Hey, gang.” Heads turned. Kranz smiled. “We’re really going to land on the moon today. No bullshit. We’re really gonna do it.” It was July 20, 1969.
Smiles and thumbs-up met his words. He took his seat and switched his microphone so that the tense, nail-biting visitors in the viewing rooms could again hear him speak. These visiting dignitaries, including congressional officials and members of the NASA family, marveled at the sight of the man with the crisp clothes and dazzling good-luck vest of white brocade and silver thread that Kranz wore with professional calm.
The calm was a front. The flight director’s stomach was knotted, his heart thumped hard in his chest, and when he lifted his right hand from the cover of the moon landing flight plan, he left behind a wet, perfect image of his perspiration-soaked palm.
Close by flight director Kranz, Alan Shepard and Deke Slayton studied the “situation monitors.”
Shepard and Slayton could have been those astronauts in the Eagle had it not been for the medics. Instead they were watching Armstrong, Aldrin, and Collins as if they were mother hens assuring the safety of their brood.
The fateful words were relayed across space.
Eagle was GO to ignite its descent engine. Armstrong and Aldrin locked their eyes to the glowing numbers displayed before them. They were almost at an invisible junction of height, speed, range, and time when everything would join together for commitment. When the instruments told them that they were 192 miles from their projected landing site, and were precisely 50,174 radar-measured feet above the long shadows of the moon, they would unleash decelerating thrust and begin slowing their speed for the touchdown.
Bright green digits changed constantly, the numbers flashing by in a breathless blur.
This was it. PDI. Powered Descent Initiate.
On earth, radio listeners and television viewers held their breath. People prayed. Fingernails dug into palms.
Armstrong and Aldrin braced themselves for the shock of ignition as volatile propellants rushed through lines, sprayed into the ignition chamber of the powerful descent engine, and lit off. They waited for the punishing deceleration, a full body blow that would buckle their knees and vibrate through their ship.
They were met with silence and calm.
Had the descent engine fired? Where was the gripping tug of deceleration, the onset of force?
At 10 percent power there was no sudden hard smash of energy as Eagle’s descent rocket was brought to life with a caress. Gently the ship descended through the black sky.
The Eagle’s electronic brain monitored the deceleration, measured the loss of velocity, judged height, and confirmed the angle of descent. The invisible hand of the computer then began to add power.
Throttle up. Full power!
Flame gushed beneath them. Glowing, gleaming plasma in a shock wave buoying them in vacuum. The Eagle rocked from side to side and pitched violently. The computer—sensitive, alert, instantly responsive—fired control thrusters to hold the craft steady. Hollow thuds, distant subdued bangs, could be heard within the four-legged landing craft as small thrusters performed the ultimate balancing act.
Gravity pulled at Eagle with a vengeance as it decelerated. Inside the lunar lander Armstrong and Aldrin, who had been weightless, free from the weight of the heavy pressure suits and helmets and boots and backpacks, were once again in a gravity field. Their arms sagged. Legs settled within their suits. Their feet pressed downward in their boots as they yielded to their down-rushing speed.
Neil Armstrong smiled. His eyes were tired but warm with anticipation, immersed in the reality of their incredible adventure. He saw Buzz Aldrin grinning like a kid.
Good Lord, they were going to land on the moon!
Fuel pumped through the lines under full throttle. Flame spewed far ahead and beneath them. The Eagle was in full fury now, blasting away her weight and mass, slowing, slowing.
Headsets crackled. Charlie Duke in the control center was incredibly calm and professional as he called out: “Eagle, Houston. You are GO. Take it all at four minutes. You are GO to continue powered descent.”
But all was not well.
Back on earth, Mission Control was thick with tension.
The highly trained flight controllers were focused on the monitors before them, tracking the curving line of the Eagle’s landing descent. They were waiting for the vertical metal probe that extended from the landing legs of the ship to touch the moon’s surface and signal a successful landing.
Those manning the front row of consoles were in what was known as the “trench.” This was where final decisions were made, where ultimate responsibility lurked unseen but inescapable, where Deke Slayton concentrated his attention.
Deke had confidence in all those who worked in the supercharged atmosphere of the trench, but he was especially keen about a twenty-six-year-old computer hotshot named Steve Bales. Like many in the control center, he was young, but he was a seasoned veteran.
No one called him by his name. With a mission underway, he became GUIDO, the acronym for guidance officer. To the old-timers in the space flight business, Bales was pure genius. They referred to him sometimes as “The Whiz Kid.”
Today Bales had been early for his shift, excited, filled with anticipation and wonder at what was coming. This was the most important, demanding, and exciting day of his life, and that sobering thought stayed with him as he took his seat at the guidance officer’s console and nervously began twisting a lock of his hair along the back of his head.
Bales made a mental run through the list of possible signals that could sound danger alarms at any point in the epochal descent of the Eagle. And he knew that twenty-four-year-old Jack Garman, in the back room, was running through the same mental check list. Both were experts on the lunar lander’s computers, and they shared the same knowledge and concerns.
Deep within the bowels of the Eagle were computers essential to measuring all the electronic and mechanical forces and factors that would determine the success of the lunar landing. A landing soft enough to safeguard the health of the two astronauts and maintain the structural integrity of the bug-eyed lander demanded a complex monitoring system. Changes in speed; rates of deceleration; shifting centers of gravity, weight, and balance; and engine thrust were all factors that were too sophisticated for the human mind to process without the aid of computers, the electronic brains designed to perform superfast computations and to ride shotgun on everything that happened aboard Eagle.
Every man in the tiers of Mission Control knew the computers aboard the Eagle also contained sensitive electronic watchdogs. Alarm systems to detect imbalance, misalignment, deviation from the exquisitely created flight plan. Only Bales and Garman were familiar with each of those alarms and what it meant. They were the only two people in that vast control system equipped to interpret any alarm emergencies aboard Eagle.
Everything they monitored aboard the landing craft was green and go. The tension was there, but everyone was feeling pretty good about the descent.
Suddenly Eagle’s computers shrilled madly.
Alarm!
Emergency signals flashed within Eagle and one and a half seconds later on consoles in Houston. No one expected a cry of danger. Not now.
Eagle’s descent engine had blazed at partial throttle for twenty-six seconds. Everything fit within the flight plan. But at six thousand feet above the moon a yellow light flashed at the two astronauts. Buzz’s voice responded immediately as he called out the numbers flashing on his flight panel and on the console before Steve Bales.
“Program alarm,” Buzz snapped crisply. “It’s a twelve-oh-two.”
Twelve-oh-two. A warning that the ship’s main computer was overloaded. So much was happening; so many performance signals were being generated that the computer could not absorb them all. It was a cry for help.
There was no panic in Mission Control. But everyone sensed an abort. A hellish maneuver that would explosively separate the upper ascent stage of t
he Eagle from the landing stage and squeeze every ounce of thrust from the ascent rocket to make it climb back to an altitude of sixty miles for docking with the command ship Columbia.
The flight controllers crossed their fingers, prayed, and clenched their teeth. They swallowed hard, as if their hearts had surged into their throats.
All eyes were on Steve Bales.
He stared at his console. Coded numbers told him instantly what was going wrong. Immediately he was in contact with the back room, where Jack Garman had heard the call, had checked his computers, had made his own analysis. Garman spoke carefully, articulating his words to Bales. “It’s executive overflow. If it does not occur again, we’re fine.”
Bales understood instantly. The computer within Eagle was being overtaxed with data. Bales knew that force-feeding a computer could lead to overload. But he also knew this computer. He understood what it was doing.
It was doing just what it was supposed to do. Eagle’s computer operated on a fixed cycle of one second. He saw it was recycling on schedule and knew the hardware was probably still in good condition. Every second, the computer needed to navigate, guide, trim engine thrust, update all earlier data, and display multifaceted data to the crew. It also was performing the calculations necessary for the Eagle to abort the landing.
If the computer failed to do all these things in the allotted one second, it would flash the 12-0-2-overload alarm.
To hell with that, Bales judged. He and Garman had programmed the Eagle’s computer so all the key functions were performed in the time allotted. His computer was working, and that’s what mattered.
But Neil Armstrong’s voice demanded a response. “Give usthe reading on that twelve-oh-two program alarm.”
“GUIDO?” Gene Kranz shouted the question into the loop of Mission Control. Everyone hung on the edge of the cliff.
Bales wanted more time.
Kranz didn’t have time. Armstrong and Aldrin didn’t have a single second to spare as they plunged downward. Kranz stared at Bales. The flight director slammed a clenched fist against his console.
Bales jerked in his seat. No time to judge, weigh, consider.
“GO!” he shouted. He closed his mike, staring at his console. “Go, damn it,” he said in a hoarse whisper only to himself.
Charlie Duke showed surprise. He didn’t have time to wait, either. His words came forth immediately. “We’ve got, uh, we’re GO on that alarm, Eagle.”
The beat speeded up. The closer Eagle came to lunar soil, the greater the need for instant judgment and reaction.
The astronauts were four thousand feet above moon dust. Kranz keyed his mike. “All flight controllers. Coming up on GO-NO GO for landing.”
He called every flight controller in the big room. Everyone responded with “GO,” until Kranz again came to Steve Bales. His guidance officer hesitated.
Kranz had no time for hesitation. Not with a ship and two men blazing onto another world a-quarter-of-a-million-miles away.
“GUIDO, you happy?” Kranz snapped.
Bales was not pleased. Program alarms still were leaping onto the monitoring screens. Bales had to judge whether Neil and Buzz would have a good computer working for them not just now but tomorrow as well, when they were scheduled to blast off from the moon. In a flash of memory and instinct, he reviewed all the practice and simulator runs they’d made. Just weeks earlier, similar alarms had sounded in the simulator, and he and Garman had studied them, calculated the system was working all right. But that was a practice. This was it. He had a gut feeling and an absolute conviction the hardware was working properly, that he wasn’t jeopardizing the lives of two men so far away. Yet, there were those alarms. . . .
“GO,” he said firmly.
Charlie Duke called it out. “Eagle, you’re GO for landing.”
Three thousand feet up another alarm sounded. A 12-0-1. They made an immediate judgment call in Mission Control. Another “executive overflow.”
“You’re GO,” said Charlie Duke.
Two thousand feet high, craters widening rapidly below, Neil called it out again.
“Twelve alarm. Twelve-oh-one alarm.”
Kranz shouted to Bales. “GUIDO? What about it?”
Deke Slayton locked eyes with Steve Bales. The young man read confidence in that look. It was Steve’s call. Whatever he said would . . .
“GO!” Bales snapped. “Just GO!”
Charlie Duke looked at Slayton. Deke grinned, turned his right thumb upward with a quick, firm, stabbing motion. Instinctively Deke scanned the room for Alan Shepard. He spotted him in the rear of the room. Their eyes met. Both winked, flashed the thumbs-up sign.
Charlie keyed his mike. He swallowed hard. “We’re GO, Eagle. Hang tight, we’re GO. . . . ”
Thirteen hundred feet above the moon’s surface, Eagle began its final descent. Flames gushed downward as the craft slowed. Neil Armstrong had flown his mission right along the edge of the razor. He and Buzz functioned as one mind. Now they were doing more than falling moonward. They were so close Neil had to fly this ship. He punched proceed into his keyboard. The computer would handle the immediate descent tasks. Buzz would back up both man and electronic brain so Neil could adapt to flying in vacuum.
Both men looked through the triangular windows to study the surface of the moon. They’d made simulated runs so many times they knew their intended landing site as well as they did familiar airfields back home. Almost immediately they noticed that they weren’t where they were supposed to be.
Damn!
Eagle had overshot the landing zone, Home Plate, by four miles. A slight navigational error and a faster than intended descent speed accounted for the Eagle missing its planned touchdown on a selected smooth spot on the moon’s Sea of Tranquility.
Neil studied the surface rising toward them. Boulders surrounded a yawning crater wider than a football field, and Eagle was running out of fuel and headed straight for it. No time to waste.
In the lunar void there was no gliding to conserve fuel. Eagle was only dead weight in vacuum. There also was no opportunity to orbit again for another try at landing. Their only chance to succeed was to land.
Neil Armstrong gripped the hand controller in his fist, firm and strong, with a touch honed by years of flight in jets and rockets. He knew the “thin edge” well, both in atmosphere and in hurtling through orbit. Now he had to fly as he’d never flown before. Knowledge, experience, the touch—the skill, the Gemini 8 emergency, the X-15 rockets skimming over Edwards’ hard sands, ejecting from his crippled jet fighter over Korea when he was 21, dammit even ejecting from the lunar lander trainer before it crashed—all of it, everything came to this one moment.
The Ohio farm boy, Neil Armstrong came from the same soil as Orville and Wilbur. This was his Kitty Hawk and he needed to hand-fly man’s first landing on the moon the rest of the way.
His fingers alternately tightened and eased his grip on the controls. Eagle was sailing down at twenty feet per second. Neil nudged the power, slowing to nine feet per second.
He attuned his senses to the rocking motions, the nudges, and the skidding motions of the sixteen small positioning thrusters that kept the Eagle aligned throughout its descent. A level touchdown was their ticket to safety, survival, and the return home.
Mission Control listened, mesmerized and awed, to the voices closing in on the lunar surface. Neil flew Eagle. Buzz watched the landing radar, called out numbers that represented split-second judgment and maneuvering.
“Five hundred forty feet [height above the surface], down at thirty [feet per second] . . . down at fifteen . . . four hundred feet, down at nine . . . forward . . . three hundred fifty feet, down at four . . . . three hundred feet, down three and a half . . . forty-seven forward . . . one and a half down . . . thirteen forward . . . eleven forward, coming down nicely . . . two hundred feet, four and a half down . . . . ”
Despite the confidence of the astronauts voices, there was a looking problem: There
was no place to land. Rocks, huge boulders, and deadly craters were strewn everywhere.
Mission Control was dead silent.
Neil fired the Eagle’s right bank of maneuvering jets. The Eagle scooted across rubble billions of years old. Finally, beyond a field of boulders, a smooth, flat area.
“Five and a half down . . . 5 percent . . . seventy-five feet . . . six forward . . . ninety seconds,” Buzz chanted. “Ninety seconds.”
Ninety seconds of fuel left in their tanks for the descent. The Eagle needed to land in ninety seconds or—
No one wanted to think about it. If the engine gulped its last fuel before Eagle touched down, they would crash, falling to the surface without power.
Eagle was now top-heavy. The ascent stage still crammed with fuel but the tanks of the descent stage were perilously close to empty. And the module had to land on an even keel, otherwise, Eagle could hit the surface tilted, out of position to re-launch itself for its rendezvous with the command ship Columbia.
Slayton, Shepard, and everyone else in the control center were gritting their teeth. Anxious and concerned, all they could do was watch. The fate of the mission was in the hands of the two astronauts.
Charlie Duke sounded the warning. “Sixty seconds.”
There was one minute of fuel left. In sixty short seconds the rocket power flaming beneath Eagle would burn out. The tanks would be empty. An abort would need to be initiated seconds before that happened if Eagle was not to crash.
Neil Armstrong calmly aimed for his new landing site. The Eagle’s commander kept one thought uppermost in his mind.
Fly.
Eagle swayed gently from side to side as the thrusters responded to Neil’s experienced hand.
Far away, down through the atmosphere and the clouds, enclosed within Mission Control, the flight controllers were almost frantic with their inability to do anything more to aid Neil and Buzz.
Deke Slayton knew they had to leave it to the pilots on the final approach. As Eagle skittered over boulders and across craters, only Neil Armstrong’s judgment counted. He was there. He was flying. The clock was ticking away precious fuel. Charlie Duke looked at Deke and held up both hands, palms out. He didn’t need to voice the question. Gene Kranz did it for him on the internal communications loop. Everyone heard his words.