by Gene Kranz
The future of our space program after Apollo was a small Earth-orbiting space station dubbed Skylab. Its mission included astronomy, life sciences, Earth studies, and a grab bag of other experiments. The Skylab space station would use the leftover hardware from the canceled Apollo missions.
During the period after the Apollo 13 mission, a small team of controllers continued to follow the redesign of the oxygen system, while others were reassigned to the developing Skylab program. John Llewellyn was one of the controllers reassigned. I believed his trajectory skills could be put to good use in the Skylab Earth studies. John initially was not happy with the reassignment, but I was convinced that he would eventually come around.
With two programs, the computing services (not to mention our budget) were tight, and all computer runs were prioritized based on need and schedule. One afternoon I got a call from a computer operator asking if I had authorized some runs by Llewellyn. My response was short. “Not that I know of, but it is possible they are for his Earth resources project.” The operator said, “Gene, you better look at these. They are for a lunar trajectory that lands on the back side of the Moon.”
“There aren’t any sites on the back side,” I said, “and I don’t know what in the hell John is doing. Send the computer run requests up to the office.”
In short order, John was standing at attention in front of my desk. He was never one who stammered or tried to mince words. He came right at you, and you better be ready for every emotion except regret. John never apologized. He believed that offense was the best defense. I found it hard to keep a straight face as my judo partner proceeded to explain why he was studying landings on the back side of the Moon. As he talked he paced the room, gesturing wildly in patriotic fervor. “We think the program is pretty well fucked up. This cancellation of the rest of the Apollo missions is a bunch of shit, and we’re trying to do something about it.”
John both challenged me and piqued my curiosity. We stood nose-to-nose. “John, just who the hell is ‘we’?”
He ignored my question and continued, “Gene, can’t you see what the hell is going on? The pogues”—John’s favorite word for bureaucrats—“ are taking over and pretty damned soon there won’t be anything left of the space program. I know you had to put someone in this crappy job you gave me, but you better be aware that I am A RETRO first, and the section chief for Earth resources second!” John then stormed out. My office echoed from his shouting, and I still did not know what had set him off and what he was thinking.
An hour later, I received a visit from our geologist-astronaut, Jack Schmitt. He knocked on the door, politely walking into the office. “I understand you just had a talk with Llewellyn,” he said. Now I was really confused, but I was starting to suspect that I had uncovered something that Schmitt probably had started. My suspicion was confirmed when he said, “I’ve got a small study group going on alternate lunar missions. We meet after work in my apartment. I provide the refreshments.”
Jack Schmitt was the astronaut most like a member of the flight control team. He was a geologist, and the son of a geologist, who had explored Indian reservations in his native New Mexico as a boy. Jack had assembled some of the early composite lunar photographs while he was working in Flagstaff, Arizona. Accepted as a scientist-astronaut in 1965, he finished second in his class of fifty in Air Force flight school. At NASA, Jack helped develop the scoops, shovels, and other tools that were used to dig samples from the lunar crust.
Jack was unique, an intellectual with degrees from the California Institute of Technology and Harvard but with the soul of an adventurer. He was at every flight control party, celebrating each victory, big or small. A favorite of the controllers, he was one of the few astronauts who really put a few away at our parties—the others nursed their drinks. He was loud, effervescent, brash, not quite my image of the typical scientist. Schmitt seemed to have no limit to his interests, no end to his enthusiasms. He was an instigator who dropped a few well-chosen words in receptive ears and then let events roll on to what he knew would be a stormy, noisy, and wild conclusion. Currently without a mission assignment, Jack wanted to make sure that he got to the Moon, and the more missions on the schedule, the better his chances.
I went to Jack’s next study session and was not surprised at finding Llewellyn and a handful of my flight controllers and flight designers. As I watched them work, I had the impression they were a bunch of Boy Scouts setting up tents and starting campfires. It was the same impression I had had of a similar bunch when I joined the Space Task Group. It was crowded in the apartment and the cross-talk was lively. One moment they were busily sketching out mission options, and then debating the pros and cons of missions to the back side of the Moon for the final Apollo flights. The team believed that if we could pull off something spectacular, something that had never been done before, we might recapture the interest of the American public and get the canceled missions back in the program. After all, the space hardware was already bought and paid for, and the team did not want to let the Saturn boosters and capsules end up as displays in museums.
The risks involved in a back-side landing might well create compelling drama. The risks would again put the lunar program on the front pages of the newspapers, and for a few days we would capture the public’s interest. During a back-side landing, Mission Control could not give the crew any help. The crew would be on their own in a virtually uncharted world and, like the early explorers, living by courage and ingenuity alone.
We would not even know whether they landed or crashed until the CSM relayed the status a half hour later. These would be explorers like Byrd, Scott, Peary, and Cook. Schmitt’s team continued its work; Llewellyn got his computer time, and when I had a chance, I joined the discussions. I wondered if meetings like this had happened before the master mariner Christopher Columbus decided to find the Indies by sailing west.
The plan never had a chance, never got to the attention of NASA management, but Llewellyn, Schmitt, and their team members believed it was better to go down fighting than to meekly accept defeat. Schmitt wasn’t going to let the Apollo program come to an end without making sure that a real geologist set foot on the Moon. Mission Control, and the small group that worked in his apartment, cheered Schmitt the day he got his assignment to Apollo 17, the mission that would close the era of lunar exploration.
January 31, 1971, Apollo 14
Mission Control was a world bounded by math and physics, a world of statistics and probabilities. We were not superstitious, but we knew that every time we flew we were rolling the dice. We had beaten the odds on the last three missions. Probability said that someday we would run out of luck—as we almost did with Apollo 13. So we treated every mission as if it were our very first one.
I was out of the flight director rotation again. Frank, Griffin, Lunney, and Windler led the Apollo 14 teams. With a nod to the Wright brothers, the crew of Apollo 14 had named the spaceship the Kitty Hawk. Apollo 14 lifted off on the last day in January, headed for the Apollo 13 landing site, Fra Mauro. Alan Shepard, the first American in space, was the mission commander. Shepard had been scheduled to lead one of the first Gemini missions, but had been grounded by a rare inner ear disorder that caused severe vertigo. Like Slayton, he had been looking out for the interests of the astronaut corps. Then, in the summer of 1968, when he was partially deaf, he took a chance on experimental ear surgery to correct the vertigo and, against the odds, it worked.
There wasn’t enough time to get sentimental, but all of us shared the pleasure of Shepard’s comeback. Ten years earlier, while the nation watched and prayed and wondered, he soared into space in a capsule called Freedom 7. In just fifteen minutes the ride was over, but we had opened the door to space just that much wider.
Now forty-seven, Alan’s appearance had changed little. He still resembled the actor Steve McQueen, and had a direct, no-nonsense, I-am-what-I-am kind of air about him. He always looked you right in the eye, and you felt he was looking right
through you. (He would go on to become an admiral, one of the few who attained that rank without ever commanding a major ship. The list was small but distinguished, and two of the other names on it were the explorer Richard Byrd and Hyman Rickover, the pioneer of the nuclear submarine program.)
Shepard’s compatriot in Apollo 14’s lunar module, the Antares, was Ed Mitchell, a naval aviator flying his first mission and a virtual unknown to most of the controllers. Mitchell dabbled in psychic phenomena and for once I was sorry that I had moved Llewellyn out of the RETRO job. I would have liked to see if they could pull off a retrofire data exchange via mental telepathy. Stu Roosa, the command module pilot, had been my CapCom on Apollo 9 and had won the “most valuable player” award. At mission completion, when we light up the cigars, an eighteen-inch replica of the crew’s mission patch is hung on the wall of the control room. The flight directors, by consensus, select the single controller considered most valuable to hang the patch. Like many of my controllers, Roosa came from Oklahoma, bringing with him the cheerful exuberance of a farm boy. You might say we had a mixed bag of characters playing in this one.
Roosa faced the first challenge when the docking system malfunctioned. In spite of Roosa’s precise maneuvering, three docking attempts in two hours failed to dock the CSM with the LM. Even the tiniest debris lodged in the mechanism would account for the latches failing to engage. Running out of time, fuel, and options, MCC decided to advise him to come in fast and dock with a bang. Roosa would ram the lunar module, in effect, doing a ring-to-ring docking. Shepard turned to Roosa and said, “Stu, just forget about trying to conserve fuel. This time, juice it.” While Roosa thrusted against the docking ring, Shepard manually fired the latches. The technique worked, and after some hair-raising moments, the mission was back on track.
Spaceflight rarely gives you a second chance, but Apollo 14 was the exception. Crisis management textbooks use the term “prodrome” to define a warning or intimation of an impending crisis. I define it as the signal that causes the hair on the back of your neck to rise. With luck, someone picks up the signal, recognizes something is wrong, and starts an action that short-circuits the crisis.
The mission had gone well, and Shepard and Mitchell were in the LM, setting up the switches and computer for the descent to Fra Mauro. The timeline had been followed almost perfectly, the crew and ground were in sync. It was the way we like it when we are getting ready to land on the Moon.
Bordered with black and yellow tape and centered in the LM control panel was a round, red push-button switch. The white letters ABORT on the in button distinguished this switch as the one that started an irreversible process to terminate a mission. It was used only when there was no other alternative. The switch had electrical contacts to issue signals to the LM engines, computer, and abort electronics. When the abort switch for Apollo 14’s LM had been manufactured, a small piece of metal had been left in the switch. Now, in zero gravity, and with both crew and ground oblivious, this piece of metal was floating among the contacts of the switch, randomly making intermittent connections.
Dick Thorson was the LM control engineer for the descent and landing. Using his console television display, he was tracking the crew’s progress through the checklist. The CSM had undocked and separated from the LM. Shepard and Mitchell in the LM were passing on the front side of the Moon on the final orbit, one hour before starting the lunar descent. All was looking good in both spacecraft and in the MCC.
After Apollo 13, the controllers’ console warning light logic had been reversed to aid the controller in rapidly recognizing a changing status in critical systems. Of the hundreds of event lights on Thorson’s panel, only a few were now illuminated. The earlier problems with the docking system were long forgotten; the focus now was keeping to the precise timing for the landing trajectory.
Out of the corner of his eye, Dick noted a change in his status panel. He glanced up quickly to see a red light at his console that indicated the crew had pushed the LM abort switch. This did not make sense. Thinking there might be a telemetry patching error to the light panel at his console, he selected a TV display that let him look into the guts of the computer. Rapidly scanning down the list he saw that Computer Channel 30, Bit 1 (Abort) had been set on. He kept his cool and called the back room to get a reading directly from the data stream. The technician confirmed, “Channel 30, Bit 1 is set.” There was no doubt now, this was a valid indication. If the LM engine had been running, the abort bit would have signaled the computer to change operating modes from the landing mode to the ascent/rendezvous mode. When this occurred, the descent engine would automatically throttle up. If the LM was close to the lunar surface and near fuel exhaustion, the computer would command a fire-in-the-hole staging. This staging sequence would shut down the descent engine, fire the explosive bolts to separate the ascent and descent stages, and ignite the ascent engine, while simultaneously changing computer programs and switching electrical power and control to the ascent stage. When you started the ascent engine, which was buried in a cavity inside the descent stage, under these conditions, you had a fire-in-the-hole situation. All events occurred in fractions of a second. The sequence had to work perfectly.
If the crew was near the surface and the abort bit set, it would, at best, eliminate the possibility of landing. Coupled with other malfunctions, it could lead to a lunar crash. The abort bit now illuminated on Thorson’s console quickly got his full attention.
In the SPAN room, two of Thorson’s counterparts, Hal Loden and Bob Carlton, also noticed that the abort bit had been set. Without hesitation Carlton, the Silver Fox, leaned over Loden’s shoulder. In a laconic drawl he said, “We should get the crew to knock on the panel.”
Great controllers seem to have a prodigious memory and the gift of excellent recall. Carlton remembered a NASA ALERT bulletin, that cited problems with internal switch contamination. Loden concurred with Carlton’s rather unusual troubleshooting and told Thorson on the intercom, “Dick, have the crew knock on the panel by the switch and let’s see if the abort indication goes away. We may have a contaminated switch.” Thorson momentarily wondered if this wasn’t a crazy idea, but he didn’t have any alternative to offer. He stood up, stretching his headset cord, and walked to the side of flight director Gerry Griffin’s console. In the high-tech age of Apollo, he was embarrassed to resort to shade-tree mechanic fixes in front of the whole world.
Leaning toward Griffin, Dick puffed on his cigarette and hoarsely muttered, “Gerry, I’m seeing an abort indication in the lunar module. Have the crew verify that the button is not depressed.” Thorson now had Griffin’s attention as he continued, “If they say negative, have them knock on the panel while we watch it.”
The CapCom, Fred Haise, passed the instruction to the crew. The crew, unaware of the potential gravity of the situation, acknowledged the call. Mitchell reached over and tapped on the switch with a flashlight.
At Thorson’s console the light and TV indication disappeared. Thorson called out, “Gerry, I’m NoGo. I’ve got some problems here and it is going to take some time to work them out.” Griffin waved off the landing attempt, and Apollo 14 had dodged a bullet. The crew and control team received another chance. The crisis was real, but with advance warning the team could develop options to save the mission. The critical element once again was time. We had precious few hours to work on the problem. Thorson’s dilemma was a thorny one: to land, we needed to bypass the switch, but if we had problems during landing, we needed the switch to abort. It was a hell of a risk-gain trade.
While developing the mission rules, the LM controllers studied every switch and circuit breaker in the spacecraft, assessing the failure potential of each and options to work around a switch failure. This included the case where a failed switch would set the abort bit in the computer. Thorson’s team had developed a set of instructions to tell the computer to ignore the abort switch. Thorson now reached into his bag of tricks, addressing Griffin: “Flight, I’ve got a software p
atch for the LM computer that will disable Channel 30, Bit 1, in the computer. It will lock out the abort switch for the landing.”
Griffin listened intently, then frowned as Thorson concluded by saying, “There is only one problem. If the crew has to abort, they will have to use the backup system or the computer keyboard to manually enter the abort program for the primary system.” Griffin was willing to buy the extra risk, and he knew without asking that Shepard would, too. “Dick, dig out the patch,” he instructed, “and run it through SPAN and get with the simulator people. If it works, I’m going to give it a Go.” Astronauts were soon clambering into the simulators, with the results to be relayed instantly to CapCom Haise.
Satisfied with the ongoing action, Griffin called his team to attention, resetting the timeline for the landing. The answers were needed in less than two hours.
In the Flight Dynamics staff room, Jack Garman listened to the conversation. Garman was the computer expert who had helped Steve Bales out of his hole on Apollo 11. Now he had to come up with the answer to a different problem. Jack was normally excitable and when there was an option to use “his” software to save a mission, he leaped into action. Garman talked with every part of his body, eyes and hands constantly in motion. Within seconds, he was on the voice loop to the software team at MIT. Like Griffin, he was worried about the time it would take the crew to make the computer entries if they had to abort. Garman felt that the crew needed a software patch to protect against the switch failure that would still give them the ability to use the abort button. He didn’t know whether such a patch could be developed, but he sure as hell was going to give it a try.