by Gene Kranz
MIT was listening to the astronaut voice loops and had heard the discussion about the software patch to bypass the abort switch. They had already cranked into action. (MIT’s Draper Laboratory developed the guidance and navigation systems for Apollo. To assist in rapid troubleshooting during a mission, the MCC was in direct communications with the lab.) Within an hour the Draper Lab came up with a procedure that gave us an option to bypass the abort switch at engine start and then reenable the switch. The procedure was complex and time-critical. Sight unseen, Griffin elected to give the new procedure a shot.
Communications were a mess during the final front-side pass. Static crackled and punctuated Haise’s instructions to Mitchell. The procedure required the crew to start the engine at a low power, using the acceleration to move the contaminating piece of metal away from the switch contacts. Once the engine was started, Mitchell would insert a string of sixteen computer commands to enable guidance and provide steering.
When this was completed, another string of sixteen commands would disable the abort program, and another fourteen commands would lock into the landing radar and the descent software. This entire sequence would occur as the crew was descending to the Moon. The mission now rested on an emergency patch to the flight software that was less than two hours old, had been simulated only once, and was being performed by a crew that had never practiced it. Every step had to be executed precisely on time and in sequence.
Sitting on the step behind Griffin, I looked into the viewing room. I could see the spectators buzzing. Our words and procedures were gibberish to them. In the mission operations control room, it was just another day, another final exam, as the controllers calmly chipped away at the final procedures and counted the seconds until engine start. The controllers’ ability to focus at times like this was nothing short of a miracle, a miracle of ingenuity, discipline, and training.
Shepard sounded just as he had all those years ago when he first went into space. Marvelously calm, his voice was flat and emotionless as Mitchell read the checklist, verified the switches, and entered data to the computer. With split-second teamwork, we started down to the Moon. Mitchell announced, “Engine start.” Thorson, staring at the abort switch display, added, “Ten percent thrust . . . throttle up. I see no abort indications.”
Mitchell quickly entered the first string of commands to bypass the abort bit. With the successful entry of the data, you could hear the relief in Shepard’s voice: “Thank you, Houston, nice job down there.”
Just another day at Mission Control.
Thorson’s eyeballs, which had been locked on to the abort bit, now swung over to his engine systems. “Gerry, I’m Go,” he confirmed. “All of the data is in correctly. The abort program is bypassed.” Fred Haise, the Apollo 13 LM pilot, then talked Mitchell through the rest of the workaround procedure.
With a lyrical comment from Alan Shepard—“It’s a beautiful day to land at Fra Mauro”—the LM Antares was on its way to the Moon. We had skated across thin ice and reached the other side.
But the battle was not over. The team would be challenged once more.
Prior to starting the descent the guidance officer provided the navigation and target data to the lunar module computer for landing. The computer then developed the guidance commands to reach the target during descent. In the final phase of the landing, the LM computer needed more accurate data than that provided by Mission Control. There might be an error of several thousand feet between the altitude data provided by the MCC and the true altitude provided by the LM radar. Mission rules required an abort if the radar data was not obtained before descending to 10,000 feet. Landing without a good hack at the altitude would be worse than landing on a carrier on the ocean on a dark night; there was no good way to judge height. LM landing fuel was tight, so that a “grope and feel” approach would deplete fuel prior to touchdown, leaving the crew in a low-down fire-in-the-hole abort. Not a good situation.
Passing through 32,000 feet, Mitchell started looking for the landing radar data. In Mission Control, guidance officer Will Presley cued up his displays. He had about ninety seconds to make a judgment to accept the data or, if it was not in limits, abort the mission. The radar data did not show up when expected, and Presley in the MCC and Shepard in the LM both had to be thinking, “Where the hell is the radar?”
In a voice lacking conviction, Presley gave Griffin a Go to continue descent at five minutes, knowing that in the next sixty seconds he would have to call an abort if he didn’t get radar. I knew his stomach had to be churning. The LM radar was Thorson’s responsibility. He and Griffin were also watching for the indications that the radar was tracking the surface.
Griffin was the first to move. “Dick, you got anything you want to try?”
Thorson reached into his bag for the only thing that could be done in a few seconds: “Flight, have them cycle the circuit breaker.”
Quickly, Shepard acknowledged, “Cycled.”
Seconds later, a jubilant Will Presley shouted, “Flight, we got radar lockup!” Every controller had been holding his breath. For a few seconds the voice comm was noisy as all exhaled, some even whistled. Presley’s next words were virtually shouted, tripping over each other as he blurted, “Altitude data is Go, accept the radar.” From there on, the landing was a piece of cake.
Of course, Alan Shepard walked on the Moon and left behind two souvenirs for some future explorers to find. Somewhere in the craters of the Moon are two golf balls, the first ever hit in outer space. He attached the head of a Spaulding 6-iron to a tool used to scoop up lunar soil. This was done for the highly scientific purpose of seeing how far a golf ball would travel in gravity that was one sixth the Earth’s. Actually, he duffed his first shot. “It got more dirt than ball,” he confessed to our controllers.
“That looked like a slice to me, Al,” came the reply.
His second shot traveled, by his estimate, “miles and miles.” The experiment did not appear on anyone’s manifest, but Shepard had cleared it with Deke Slayton. The agreement was that he would do it only if the landing had gone well, and it had. Years later, Al would reflect, “I’m probably a lot more famous for being the guy who hit the golf ball on the Moon, than I am for being the first American in space.”
After the post-mission debriefing, Mitchell invited Thorson and several members of the Trench to dinner. Mitchell, the astronaut who be lieved in psychic phenomena, said that he knew moments before the call that Thorson was going to have the crew cycle the landing radar circuit breaker. Griffin and Thorson were never sure whether Ed was kidding them or not. They were just happy it all worked out.
After the debriefing, Shepard took Griffin aside and confided, “I had come too far to abandon the Moon. I would have continued the approach even without the radar.” On Apollo 14 the error in the LM computers’ knowledge of the actual altitude was almost 4,000 feet before the landing radar data update. With an error this great in the computer, Griffin and the Trench were convinced Shepard would have run out of fuel before landing. But everyone who knew Al never doubted he would have given it a shot. We also never doubted he would have had to abort. The fuel budget was just too tight.
In the three Moon landings, the crews and controllers had become masters of improvisation. With three lunar missions to go, we were pretty cocky, feeling that there was no emergency we could not handle and nothing that would defeat us.
21
WHAT DO YOU DO AFTER THE MOON?
Spring 1971
One morning in the spring of 1971 Gerry Griffin walked into my office. Briskly, he said, “The 15 crew thinks it would be good for you to take a break and get out of this stuffy cell. How would you like to go on the next field geology trip with the crew and myself?”
I felt my pulse speed up a bit. This was something new, something different, something pure fun. I knew nothing of field geology, but since we had won the race to the Moon, the shift to lunar science dominated much of our effort. This trip might provide an o
pportunity to get smart on a new aspect of the business. Lately, I had spent much of my time with the lunar scientists and, although they were much older than my controllers, they had a similar kind of enthusiasm, energy, and commitment to the future of manned spaceflight. Knowing how important the data collected in the Apollo missions would be to our understanding of unknowns like the formation of the solar system, I made sure that my controllers served them well in the planning and execution of their experiments. So when they asked me to work with and learn from them, I jumped at the chance.
The field geology trips provided the practical training ground to complement the astronauts’ classroom training. By their nature, astronauts were curious, and many became dedicated to studying the space sciences. Scott, Griffin, and I made for a colorful trio, to put it mildly. All three of us had flown jet fighters. Scott could have served as a poster for astronaut recruitment. He and Griffin shared a cheery exuberance, a perpetual optimism, and a zest for their work.
The field sites were the laboratories for the astronauts preparing to explore the lunar surface. No terrestrial site could replicate the lunar surface, but there were locations where the rugged terrain could provide conditions similar to those found on the Moon. While training the astronauts, the geology instructors used sites that covered the globe, from the volcanic areas of Iceland to the Grand Canyon, from the mountains of New Mexico to the craters of Hawaii. This training would be vital in selecting the materials to be returned to Earth from the Moon and in answering such questions as the Moon’s age and composition.
I had first met the lunar surface science teams in the conferences to set up their operating structure. I got to know more of them when my Flight Control Division inherited the operation of the Experiment Packages placed on the Moon during each lunar mission.
Our scientists didn’t pay much attention to bureaucratic structure. They wanted to work directly with the crews and controllers to establish a mutual understanding and supportiveness that would make their work on the Moon much more productive.
No one among them impressed me more than Lee Silver. He stood out as we were setting up the surface science rooms, and again during the skull sessions at the apartment of Jack Schmitt. Silver had taught Schmitt as a student at CalTech, and it was obvious they shared the same passions. Silver’s academic credentials were formidable, but the man was even more impressive. You can tell great teachers by their demeanor, how they talk, how they always seem effortlessly in control. Silver appeared born to roam the deserts and mountains, reading the land.
William Muehlberger, from the University of Texas, had the same characteristics. Each geologist approached his work passionately; you felt this passion when you were around them. Schmitt, Silver, and Muehlberger inspired and motivated others much in the same way as my other great teachers like Harry Carroll at McDonnell in St. Louis, Jack Coleman in flight training, Ralph Saylor at Holloman, and Chris Kraft in the MCC, all supremely confident and capable leaders and teachers.
Since I had trained in fighters at Nellis Air Force Base in Nevada, I was familiar with the general terrain as our helicopter lifted off at dawn for the flight to the north end of Frenchman’s Flat, ninety miles northwest of Las Vegas. I had flown over this area en route to the gunnery and bombing ranges but I had never really looked closely at the surface. From the helicopter, I was amazed at the results of the nuclear tests that had pockmarked the desert as far as the eye could see, the craters a myriad of desert colors, the rocks and boulders arrayed from the blast point. Flying low over the area, I imagined this was what the surface of the Moon might have looked like, except for the colors, as Armstrong and Aldrin described it during and after the landing.
The bond between teacher and student astronaut was clearly evident on the way to the site as Silver and his students engaged in a lively Q&A session. There was not a wasted moment from the time we crossed the snowy mountains and descended to the test site.
The Apollo 15 crew, Scott and Irwin, attacked their role as surface geologists with the intensity and enthusiasm they demonstrated in learning to fly a new spacecraft. To them, the surface experiments were just another form of flight test. They were exploring a new world full of riches for the scientists, and were in competition with their predecessors and themselves.
Griffin and I were really just along for the ride, but we found out quickly that Silver had other ideas. After a brief summary of the training objectives, Lee gave me a quick course in field geology 101, then sent me off to find as many different materials as possible within walking distance of our landing site. I had no clue where to start, but I felt obligated to give it my best shot. Griffin tagged along with the crew, listening as Silver laid out their project for the morning. I learned to use my eyes to detect subtle changes in hue, composition, and texture of the land . . . to see the parts and assemble the whole, then to work it in reverse, striving always for the big picture, looking for cause and effect. After Silver’s brief training, I could visualize the great collisions as the meteors showered the Moon, instantly forming the craters and hurtling the rocks and boulders enormous distances in the low gravity of that airless sphere.
On the final Apollo missions, a Jeep-like vehicle called the Lunar Rover extended the range of operations on the surface. The Rover had a television camera mounted on it, one that Ed Fendell and his team would control from 240,000 miles away to bring history into the homes and offices of the world. The first priority was to use that camera for studying the lunar surface. We could now see what the astronauts saw, close up and in real time. It was like being able to look over the shoulders of Lewis and Clark as they trekked into the great unknown of their era. Scott and Irwin would be the first humans to walk the vast and incredibly lonely Hadley-Apennine region. At the atomic test site, I could visualize what they would see, touch, and do.
Back at MCC, the challenge of the final three missions was emotional as much as technical. My controllers, average age now twenty-seven, were asking themselves, “What do you do after you have been to the Moon?” They had come to us at the beginning of Apollo, in their early twenties. Now, with NASA limiting the program to only three more missions, they were taking it the hardest. Mission Control was their portal to the stars; they believed we had taken only that first “giant step for mankind” and could not understand why we were not taking the next leap forward. I knew how they felt. When I won my wings, I believed I would fly fighters forever. When my dream ended, my world folded. So I had to pick myself up and get on with life, and find a new vision. In the process, I took a lucky fork in the road that got me first into flight testing and then into the space program. It was that one-in-a-million chance you take in life that pays off.
In 1971 a big part of my job was convincing my young controllers that there was a damned interesting and challenging world after Apollo. Together we would take the next fork in the road and blaze a path into the next era of space. I am a dreamer, believing that the mark of a champion is the ability to thrive in tough times. I was convinced that Mission Control would evolve, adapt, and exploit every opportunity. We can make the future ours if we believe and fight to make it happen.
Change was again in the wind. The high visibility of my controllers provided them with opportunities for top-level leadership roles. In 1970 Glynn Lunney had traveled with Robert Gilruth to Moscow to determine the degree of Russia’s interest in a joint space mission and the resources the Russians would make available for it. Now after Apollo 15, Lunney joined Hodge and Charlesworth in top management. While I lost extremely capable leaders, I had the opportunity to bring along another new generation of young leaders in the Mission Control “leadership lab.” Every young man or woman coming in at the bottom could take a shot at a flight director, division, or branch slot in the first ten years of their career.
• • •
In the final days of Apollo I was fortunate to be knee-deep in mission-ready leaders, most veterans of twenty or more space missions, including those of Gemini and
Apollo. My only fear, with the constant juggling of priorities and people, was the loss of focus on the final three missions. I also knew that any major mission glitch would give those who were nervous about the risk an opportunity to argue that since the Moon had been reached there was no need for the remaining missions. I was glad the final flights would be led in Mission Control by three former aviators, who understood how to live with and manage risk. Maybe it was our fighter aircraft mentality, or maybe it was our confidence in the human factor, but flight directors Gerry Griffin, Pete Frank, and I believed the nation had sacrificed too much to surrender to the increasingly conservative national leadership. As we opened the era of extended lunar operations, we felt fully capable of meeting every challenge that we and our crews would face during the final missions.
To extend the range of the lunar expeditions, modifications had been made in the LM to provide stowage for the battery-powered, Jeep-like Rover. We shaved our mission rule margins and, with extra oxygen and batteries, we extended the surface duration to almost three days. Extravehicular activity was planned for each day the crew spent on the lunar surface.