9

“We’ve Got More Than a Problem”

Apollo 8 showed that human beings could journey to the moon and back.

Apollo 11 and Apollo 12 showed that astronauts could land and walk on its surface.

Apollo 13 proved mission control could bring those space voyagers back home again when their lives were on the line.

There was no lunar landing during the flight of Apollo 13, no momentous words to be spoken from the surface, no rocks to be returned to Earth. What the mission did instead was unleash heroics of a different sort. “It was almost as if the whole reason we were there was culminated in that moment,” John Aaron began. “The ground controllers worked so well as a team, we were able to successfully salvage that mission and get the crew home safely. Apollo 8 is a highlight in terms of what a country can do and what makes us feel good. Apollo 13 was the final proof of just what flight controllers could do.”

Aaron was on to something. The miraculous recovery of the Apollo 13 crew of Jim Lovell, Fred Haise, and Jack Swigert was perhaps the finest example of teamwork in NASA’s history. No one person was most responsible for their safe return—not Aaron, nor Arnie Aldrich, nor Bill Peters, each of whom oversaw crucial procedures and checklists in the days after the accident.

Nor was Milt Windler, the mission’s lead flight director. Nor Glynn Lunney, whose calm, measured leadership style impressed more than one of his charges that week. Nor Sy Liebergot, the EECOM on duty at the time of the mishap.

Gerry Griffin, Jerry Bostick, Dave Reed, Jack Knight, Chuck Deiterich, Merlin Merritt, Bill Stoval, Bill Boone, and Bob Heselmeyer all made significant contributions. The SPAN rooms, MER, and contractors across the country ran around the clock. Gene Kranz could not have done it on his own. Instead, each of these men and many, many more people banded together to bring Lovell, Haise, and Swigert home safe and relatively sound.

The Trench’s trajectory calculations would not have meant a thing had the systems guys up on the second row not been able to stretch their consumables. The same was true in reverse. It would not have mattered in the least how much water and oxygen remained if the trajectory of the Command Module Odyssey caused it to either bounce off the earth’s atmosphere or burn up during reentry.

American astronauts were some of the most famous people on the planet, and they were viewed by millions around the world as virtual superheroes. It was indeed the lives of the Apollo 13 crew that were on the line. They were the ones who felt the shudder of the explosion, who saw oxygen bleeding from their spacecraft, who endured miserable freezing temperatures, and who were in danger of carbon dioxide poisoning. All the while, they had to somehow remain coherent enough to manage midcourse corrections, power-up procedures, and reentry checklists.

But first, somebody back on the ground had to figure out how to do it all. If ever there was an all-for-one-and-one-for-all moment in the history of the MOCR, this was it.

The high-activity phases of a flight—launch, lunar descent, and lunar ascent and rendezvous—were like a feather in the cap of a NASA flight controller. The assignments were not handed out to stroke somebody’s ego or because the line looked good on a resume. Instead, standing vigil at those times was recognition that they could do their jobs and do them very well under pressure. Of the nine FIDOs who worked in the front room during the Apollo era, only two worked a lunar descent; three handled all of the lunar ascents and rendezvous; and four took care of the launches.

Before the manning lists for the flight of Apollo 13 came out, Bill Boone and Bill Stoval felt sure they might land one of those coveted spots. Stoval was pumped, thinking he might have a shot at launch, while Boone would have been happy with launch . . . lunar descent . . . blastoff from the moon and rendezvous between the LM and CSM . . . whatever might come his way. The two men came away disappointed—Stoval was on Gene Kranz’s White Team and Boone on Glynn Lunney’s Black, and both groups were slated to handle the much-less dynamic coasts to and from the moon.

Stoval was a freshman at the University of Wyoming at the same time as Dave Reed was a senior, and it was Reed who hooked Stoval up with his job at NASA. Although Jerry Bostick penciled Stoval in as FIDO for the launch of Apollo 13, Reed felt that his younger counterpart was not yet quite ready. “That really sort of pissed me off,” admitted Stoval, who arrived in Houston to start work at NASA on the Fourth of July weekend in 1967. “It hurt my feelings, and created sort of a rift between me and Dave for a while.” Stoval, though, had the ability to get past the episode and see it for what it was. “In the grand scheme of things, he might have been right,” Stoval continued. “He probably was right.” When Stoval was inducted into the University of Wyoming Engineering Hall of Fame in 2007, Reed and Bostick both wrote letters of recommendation for him.

Boone, on the other hand, had already been a witness to history long before he started work at NASA. After growing up in Leland, Mississippi, Boone became a page for U.S. senator John C. Stennis and helped escort dignitaries like Herbert C. Hoover, Lyndon B. Johnson, and Richard M. Nixon to their seats on the rostrum prior to John F. Kennedy’s presidential inauguration. When the man who would soon send the country on its way to the moon gave his famous “ask not what your country can do for you, ask what you can do for your country” inaugural address, Bill Boone was standing maybe twenty yards away.

While a student at Mississippi State University, he was not an engineering but a math major. That made Boone “a different cat” in the MOCR, and it took him a long time to feel comfortable there. By Apollo 13, he felt he was up to speed and wanted nothing more than to be on duty for a high-activity phase. When he did not get one, he was as spun out as Stoval had been. “We all wanted the activity phases, because that was where the fun was,” Boone said. “I was really torqued off. I remember going up to Bostick and having a heated discussion with him. I basically just threw my badge on the table and said, ‘I’m out of here. I’m not going to do the sleep shift. That’s not what I came here to do.’” Boone was coaxed back into the fold, and Apollo 13 turned out to be what he called his “fifteen minutes of fame.”

Boone and Stoval were not the only ones disappointed as launch approached, but Ken Mattingly had a far different reason for being down in the dumps. Before joining the astronaut office in 1966, Mattingly had launched and landed jet fighters on the decks of the USS Saratoga and the USS Franklin D. Roosevelt. He forged bonds with his fellow naval aviators, and he left it behind only for the possibility of one day venturing into space. Being named as an astronaut was obviously a fine achievement, but actually flying on an Apollo crew? That was the question. He and his eighteen 1966 classmates took to calling themselves the “Excess Nineteen,” not knowing when, or even if, any of them would ever journey to the moon. The wait was difficult, especially for a hotshot jet jockey like Mattingly.

The friends he had known in the navy were starting to get shot down in the skies over Vietnam, and some were dying. In what he felt was a stark contrast, Mattingly was leading what he called “The Life of Riley” while his buddies were at war. Such a contrast was stark. The conflict in Vietnam was the flashpoint around which much of the turmoil of the 1960s was centered, although it tore at Mattingly for a far different reason. Protesters wanted to know why the country was in Vietnam, and Mattingly wondered why he was not. It was the letters from wives of some of his friends who had not made it that truly bothered him. “I had very serious reservations,” Mattingly remembered. “I got to the point where I thought, ‘I can’t sit here and do this while they’re getting taken to the cleaners.’”

Mattingly went to Alan Shepard, his boss in the astronaut office, and told him that he wanted to leave the astronaut corps and start flying again in the navy. Surely, “Big Al” would understand as a fellow naval aviator. Rather than accept the resignation then and there, however, Shepard asked Mattingly to wait a week and think about his decision. After that, if he still wanted to leave NASA, Shepard would help make it happen.

Within that very same week, on 6 August 1969, it was announced that Mattingly would join the crew of Apollo 13 and fly with Lovell and Haise as the mission’s CMP. “Al just looked at me, smiled, and never said another word,” Mattingly said. Shepard had good reason to grin, for it was the very same press release that told of his assignment as the commander of Apollo 14.

Charlie Duke came down with a case of rubella—better known as German measles. Duke was on the backup crew, and that meant that Lovell, Haise, and Mattingly had all been exposed. Tests determined that Lovell and Haise were most likely immune, but their CMP probably was not. Swigert started getting time in the simulators, and with just a handful of days remaining before launch, Mattingly turned his car radio on to hear the news that he had officially been replaced. He obviously knew getting bumped was a possibility, but to get the news like that must have seemed unspeakably cruel.

It was an understandably dejected Mattingly who took a T-33 from the Cape back to Ellington Field in Houston, and the very next day, he found himself in the MOCR for liftoff. He had no assignment, no real reason to be there. The viewing room was packed, so he simply took a seat on the aisle steps near capcom Joseph P. Kerwin’s console. “Let me put it to you this way. I think Gary Sinise is a good actor, but when it comes to feeling sorry for yourself, he’s a pure amateur,” deadpanned Mattingly, referring to the actor who portrayed him in Ron Howard’s 1995 film. “There are no words that can describe it. I told myself, ‘There will be something Joe doesn’t know that I know, and I’ll have to help him. Well, it didn’t take very long to find out that wasn’t true.”

The Saturn V rumbled off KSC’s Pad 39A at 2:13 p.m. Eastern on Saturday, 11 April 1970. It was an hour behind in Houston—or, in military time, 13:13. The first-stage S-IC engines pushed the 6.5-million-pound vehicle skyward by producing 7.6 million pounds of thrust and consuming 4.8 million pounds of kerosene and liquid oxygen propellant in a little more than two minutes and forty-three seconds.

At eighty-one feet, seven inches tall, the S-II second stage took over at that point. The flight’s first anomaly was just ahead, when the center of the S-II’s five clustered engines shut down five and a half minutes into the flight due to substantial oscillations. The issue was no big deal according to Frank Van Rensselaer, the Marshall Space Flight Center employee on duty at the booster console down on the far left of the Trench. “The second stage had to burn longer to get to where it needed to go, since it was only four engines burning instead of five,” Van Rennselaer explained. “We had practiced that, and we knew how much longer it was going to take as a function of when the engine went out.”

Apollo 13 was Milt Windler’s first mission as lead flight director. He tossed Van Rensselaer a quick query to see if they had a real problem on their hands, and Van Rensselaer said there was not.

Negative, not right now, Flight. All the other engines are go.

Forty seconds after the shutdown, Lovell was on the air-to-ground loop asking about the issue. Kerwin calmly responded.

Jim, Houston. We don’t have the story on why the inboard out was early, but the other engines are go and you are go.

If there was a tendency to downplay the center-engine cutoff in light of what was to come, Windler hinted that it should not have been the case. “I got assigned to be the lead flight director on 13, which nobody remembers very much,” he quipped, tongue firmly in cheek. “It lost an engine [during the launch phase], which was probably the most dangerous part of the flight, but nobody knows that.” This was Windler’s concern. If the engine continued to vibrate the way it had been, “it would’ve blown up, probably. A few more oscillations, which wouldn’t have taken very many seconds, and it would’ve probably been a catastrophic failure. But, presumably, we would’ve aborted the spacecraft and we would’ve survived that. It wouldn’t have been like Challenger.”

Before Windler had the chance to consider an abort, the engine shut down on its own. Down in the Trench, lead FIDO Dave Reed was very carefully watching the events unfold. When the center engine went out, the launch vehicle’s altitude was 10.7 nautical miles lower and its velocity was 5,685.3 feet per second slower than expected. The S-II finally shut down, then separated from the S-IVB third stage. Second-stage shutdown and third-stage ignition both took place thirty-four seconds late, in order to keep boosting uphill. After a forty-four-second delay in shutting down the third stage, the vehicle was just 1.9 feet per second slower and 0.2 nautical miles lower in altitude than planned when it at last reached orbit.

“I would have had to wait until the loss of the engine affected the trajectory to the point of violating a limit line,” Reed recalled. “We’d seen early engine out before and nominally what happens as a result is that the trajectory depresses as the other four engines burn longer—thrust drops from 1 million to 800,000 pounds—and then the S-IVB has to make up any shortfall. Any depression of the flight path would have to have been quite severe before I would have invoked action.”

The sadness that enveloped Mattingly was almost palpable in the control center. His place on the steps put him just behind and just a few feet or so from Reed. After Apollo 13 was inserted into its orbit, Reed spun around in his chair to confirm for Mattingly that all was well. And when Reed was sure that he saw tears in the grounded astronaut’s eyes, he spun right back around without saying a word.

16. Ken Mattingly had nowhere else to go after being bumped from the crew of Apollo 13, so he headed into the MOCR during the flight’s launch. FIDO Dave Reed would later say he saw tears in Mattingly’s eyes as the flight got under way. Courtesy NASA.

The gloomy black rain cloud hanging over Mattingly was nothing compared to the brutal force of an F5 tornado that was about to hit the MOCR.

Gerry Griffin’s Gold Team was on duty during the translunar coast, and he would joke years later that the spacecraft was in perfect shape before he turned it over to Kranz on Monday, 13 April 1970. Every flight director on every shift during every flight dealt with glitches, and Kranz had already seen two after taking over for Griffin that day. The High Gain Antenna on Odyssey seemed to have a mind of its own, not working in its automatic modes and then shutting off and coming back on again unexpectedly. Heading into a sleep period, there was not enough time to work the issue with the crew, so Kranz left it as an open action item. Then, forty-six hours and forty seconds into the flight, a short circuit in its quantity gauge caused Oxygen Tank 2 to cycle high and low four separate times before finally landing at off-scale high. Sy Liebergot was working the issue when a planned television transmission from the linked spacecraft—The Jim, Freddo, and Jack Show—began fifty-five hours, fourteen minutes after launch at approximately 8:26 p.m. in Houston.

17. The last calm moments the MOCR team would have during the flight of Apollo 13 took place during a television broadcast on the night of Monday, 13 April 1970. Courtesy NASA.

None of the networks were carrying the feed. It was the irony of all ironies that going to the moon had become what the general public considered to be routine.

Sy Liebergot might have been headed back home, or maybe out to get a beer after the shift ended. That was Ken Mattingly’s plan, to grab a brew or maybe even something a little stiffer after a chance encounter in the VIP room with George W. S. Abbey, who was at the time a technical assistant to MSC director Robert R. “Bob” Gilruth. Abbey told Mattingly he looked like he needed a drink, and suggested that the two of them make their way to the Singin’ Wheel. That sounded good enough to the still-blue Mattingly, so Abbey left to get his briefcase.

Mattingly and Abbey never made it to the bar, because it was at that point when all hell broke loose in the control room.

Still keeping watch over the off-scale-high issue on Oxygen Tank 2, Liebergot asked Kranz to have the two liquid oxygen and the two liquid hydrogen tanks stirred shortly after the end of the television transmission. Kranz described the cryogenic mixture of the tanks as a “thick soupy vapor,” while Liebergot said it was a “very dense fog.” Whatever the case might have been, it tended to stratify in zero gravity and it needed to be stirred in order to get a good read on its quantity levels.

No one knew that a line of dominoes dating back nearly two years was about to be set into disastrous motion. The tank had been dropped a mere two inches back in October 1968, but just enough to jar loose a fill and drain tube. Then, during a countdown demonstration test three weeks before launch, the tank failed to drain properly. The solution was basically to boil off the remaining oxygen using internal tank heaters. Rather than staying at a design limit of no more than 85 degrees, however, the tank heater element and wiring baked for eight hours at temperatures reaching a peak of 1,000 degrees due to a failed safety switch. Teflon wiring on the heater circuit was left charred and frayed.

All that was left in the recipe for disaster was a spark to ignite the whole thing. After telling Liebergot to allow the crew some time to settle down after closing out the broadcast, Kranz gave capcom Jack R. Lousma the go-ahead to have the tanks stirred.

Thirteen, we’ve got one more item for you, when you get a chance. We’d like you to stir up your cryo tanks.

Swigert’s reply drifted down from the spacecraft.

Okay. Stand by.

Nothing more, nothing less. The flight was about to dominate world headlines and the attention of the MOCR for the rest of the week, and the start of it all was as simple as that.

The accident did not take place at the instant Swigert threw the four switches on Odyssey’s control panel, although that was certainly the trigger point from which there was no turning back. Three of the stirs worked perfectly. One did not. Ninety-five seconds later, telemetry between the ground and the spacecraft was lost for 1.8 seconds. It was during that brief down time that a master caution and warning was triggered in the Command Module. Lovell was in the lower equipment bay, stowing the television camera; Haise was in the docking tunnel between Odyssey and Aquarius; and Swigert was in the left-hand couch. An explosion of the basketball-shaped Oxygen Tank 2 estimated to have a force of seven pounds of dynamite rocked the spacecraft, completely ripping off the panel covering Bay 4 on the side of the Service Module.

Just before the loss of telemetry, the pressure in Oxygen Tank 2 reached 995.7 pounds per square inch. And that was down from a high of 1,008.3 psi just a few seconds before. The vacuum of space almost immediately contained the explosion, which might very well have saved the spacecraft from being torn to shreds then and there.

Liebergot and his SSR staff of Dick Brown, his electrical power system officer; George Bliss; and Larry Sheaks on environmental control systems were still watching the other oxygen tank after the stir. Their attention elsewhere, it caused them to miss the flickering data that signaled the ruptured tank.

It was 9:08 p.m. in Houston, and Swigert’s voice sent a jolt through the MOCR.

Okay, Houston. We’ve had a problem here.

At almost the same instant, guidance officer Will Fenner became the first controller to report an accident-related issue to Kranz over the flight director’s loop. Fenner, who passed away in March 2000, was remembered by Jerry Bostick as sort of a “Fox Jr.” because, like Charley Parker, he was always so calm and collected. The only accolades he ever wanted—forget the fact that he was the first to tell Kranz something out of the ordinary had just taken place—was to be recognized by his peers as a trustworthy guy. “He was a slow talker but had a brain as fast as anyone I’ve ever known,” Bostick said. Fenner never seemed to get excited, and his slow Texas drawl did not betray any panic over the flight director’s loop to Kranz.

We’ve had a hardware restart. I don’t know what it was.

It was at that point that Liebergot’s comm loop came alive with activity.

What’s the matter with the data, EECOM?

We’ve got more than a problem.

Liebergot reached out to his back room.

Okay, listen, you guys. We’ve lost Fuel Cell 1 and 2 pressure.

Lousma had been turned around in his chair, talking to Kranz offline when Swigert turned the world upside down. He heard one of the crew say something but was not quite certain who it had been or what they had said.

This is Houston. Say again, please.

This time, it was Lovell who called down from Odyssey.

Houston, we’ve had a problem. We’ve had a Main Bus B undervolt.

Liebergot looked at his screens and everything appeared to have gone haywire. His data showed that Oxygen Tank 2’s pressure had just disappeared. At the same time, he saw that Oxygen Tank 1’s pressure was dropping like a rock and that Fuel Cells 1 and 3 both indicated the presence of an unrecoverable shutdown. That rendered them useless for the remainder of the mission.

The situation was getting worse by the second. Without a power source, Main Bus B went down. That silenced all electrical equipment connected to that power distribution point. With pressure still dropping in Oxygen Tank 1, Fuel Cell 2 would soon be toast as well due to the loss of oxygen supply it needed to generate electrical power.

Liebergot wondered if what he was seeing was real. If so, Odyssey would soon be dark and quiet because its remaining systems would simply shut down and experience a total blackout. It would be a first for a manned spacecraft, but certainly not the good kind of first NASA and the nation celebrated. The fuel cell systems were the main source of power and drinking water for Odyssey, and the oxygen tanks were the sole supply of breathable oxygen for the crew. There was no other way to put it. The situation at hand was bleak and getting bleaker.

Such massive simultaneous failures were not supposed to happen. Was this just an illusion caused by a failure of the telemetry data system? Liebergot fell back on countless hours of simulations training that emphasized getting a jump on the problem by checking known potential single-point failures in the telemetry system. Instrumentation failure could often be the real source of the numerous anomalous and seemingly unrelated readouts he was seeing—but not this time. To continue troubleshooting required maintaining power to the systems, and even though it would mean consuming stored power reserved for Odyssey’s earth entry and post-landing phase, Liebergot made the decision to connect one of the reserve batteries to the main bus.

Veteran telmu Bill Peters had been sitting with Bob Heselmeyer, the new kid on the block who was working just the second or third shift of his very first flight at the console. Peters unplugged his headset to leave for the night—after all, there was not much to do since the LM was not yet scheduled to be powered up—and took just a couple of steps before he caught something out of the corner of his eye.

Liebergot’s status lights were lit up like a Fourth of July fireworks display, and the EECOM had what Peters called a two-handed death grip on the handles framing both sides of his monitor. Although Peters was this close to leaving for the night, he could not recall years later when he actually made it home. He tried sleeping in the dorm, but he found it to be small and uncomfortable, and besides that, the other guys who sacked out there snored too much.

This is what the next few days were to be like for those who worked the flight of Apollo 13. “Rest is defined as when you can’t stay awake any longer no matter how hard you try,” Peters said. “At some time or another, I laid down on the floor under the console and went to sleep with my headset on.” Incredible.

Heselmeyer quickly called Peters back. “From where I was sitting, right there next to Sy’s console, I looked over and saw his console just abuzz with light,” Heselmeyer recalled. “Essentially, my first thought was, ‘If that’s not an instrumentation problem, then something really serious is happening.’ Shazam, there it all was. My second thought was that Sy had a problem, because it all happened so fast, there wasn’t a starting place to troubleshoot.”

Just six seconds after Lovell’s soon-to-be-famous pronouncement, Kranz asked Liebergot if he was seeing the undervolt on Main Bus B. The issues were piling up, and Liebergot told his flight director that he did not. When Kranz replied that the crew had reported it, the EECOM tried to staunch the flow.

Okay, Flight. We’ve got some instrumentation funnies. Let me add ’em up.

Kranz’s reply was crisp.

Rog.

Liebergot went through a litany of issues with Dick Brown back in the SSR. “To me, I thought it was an instrumentation problem, because I was hoping and praying that it was going to be Apollo 12, where just a switch would make it all come back,” said Liebergot, referring to the preceding flight’s lightning strike during launch. “It wasn’t my luck. I tried to put Gene Kranz off for a couple minutes.” As Liebergot and Brown went through their paces, Haise dropped another bombshell from more than 200,000 miles away.

We had a pretty large bang associated with the caution and warning there.

Eighty seconds had passed since the tank ruptured, and this was the first hint received by the MOCR that this was not just an event taking place on some instrument panel. The crew felt the explosion, because their ship felt it. Sudden accelerometer activity on the roll, pitch, and yaw axes gyros was detected. Instrumentation issues do not generally cause large bangs or thumps, as described by the crew in post-mission debriefs. Two minutes after Haise’s observation, Kranz sounded like he was still holding out some hope.

EECOM, you seeing any AC problems? It looks like we might have a lot of instrumentation problems.

Liebergot confirmed that the power distribution point was, in fact, still in trouble. Kranz’s response was quick.

Well, let’s get some recommendations here, Sy, if you’ve got any better ideas.

Kranz waited for a few moments, then pressed again.

Sy, what do you want to do? Hold your own?

Another brief pause, then another query.

Sy, have you got a sick sensor-type problem there or what?

Fuel Cell 1 and Fuel Cell 3 were offline, and Liebergot wanted the crew to attempt to reconnect them to the buses. Once more, Kranz asked if there were instrumentation problems and Liebergot said that AC Bus 2 was reading just four volts. That meant, in effect, that it was dead. Although Kranz was either actively or passively monitoring seventeen different comm loops at the time of the accident, he was soon listening to only two—his own flight director loop and the air-to-ground transmissions. “The training process really allows you to remain focused on one or two loops, and you’re listening for key words,” Kranz said. “The training process alerts you to the tone of the crew’s voices and the tone of the controllers’ voices. In addition to that, you’ve got key words that you’ve used throughout the training process that will get additional attention. This is unique to every controller in the room. They have a way of phrasing things that immediately alerts you to listen up.”

Lousma continued his conversations with the crew and he knew they needed some answers pronto. Lousma had already asked once when he came on the loop to Kranz with similar, if not somewhat more insistent, questions.

Is there any kind of leads we can give them? Are we looking at instrumentation? We got real problems or what?

That was just the problem. No one knew for sure exactly what had happened. If it was indeed instrumentation, nothing of any real significance had actually taken place. There had been a big bang, yes, but nothing was tagging up. What could Lousma tell the crew? Nothing at this point. “My job was not to protect the control center, but to act as if I were on board the spacecraft and get the information to them,” Lousma said. “Whatever frustration I might have had would’ve been from that point of view. One of the difficulties, of course, was that much of the telemetry was blown out, so a lot of the information that we would’ve used to understand the health of the spacecraft came up missing. So the frustration was rampant within the control center, I think. We went down a few dark alleys, realizing all the time this was something different than we’d ever seen before.”

A former air force jet fighter pilot, Kranz had no qualms whatsoever with describing his own sense of vexation.

It took a while to catch on. During that period of time, it was very frustrating because the crew was trying to solve a lot of these problems on their own and they kept changing configurations. About the time we were ready to give some recommendations, the crew would’ve changed configurations. So we had to regroup and come up with another set of directions for them. During those initial few minutes, there was an awful lot of confusion and a lot of communication, air-to-ground wise. We were behind the power curve, and the crew was trying to solve the problem on their own because we weren’t providing them as much assistance as we needed. Jack Lousma was my capcom, and basically he kept saying, “Is there anything we can do to help them? Anything we can do to help them?” But by that time, the crew would’ve changed configurations, so then we were back to square one.

Arnie Aldrich, the chief of the CSM Systems branch, was in the SPAN room when the accident took place. There were no answers, and the folks in the MOCR seemed to be “all over the place” as to what the problem might have been. Aldrich also understood that John Aaron was the best EECOM he had. “I just knew we needed to have John,” Aldrich said. “I knew John would get the answer immediately, and he did.” Aldrich called Aaron, who was at home shaving, and told him as best he could what was taking place. They were in this thing deep and needed to start getting things straightened out now. The memory of Aldrich’s phone call remained vivid in Aaron’s mind more than four decades later.

“I was standing in front of the mirror, shaving,” Aaron began. “My wife handed me the telephone and she said, ‘It’s Arnie.’ He said, ‘John, I want to tell you we’ve got a problem out here, and the guys are chasing it like it’s an instrumentation problem.’” Incredibly, Aaron had all but memorized all the circuits that were common in instrumentation systems and the way they worked to provide information back to the ground. If a circuit or junction failed, he knew which parameters it would affect.

Aaron had Aldrich go to the consoles and read him off some numbers here and there. “He did that a couple of times on two or three aggregation points within the electronics,” Aaron said. “That’s when I said, ‘Arnie, I don’t know what the problem is. The kinds of things you’re telling me are not single-point failures. They’re some combination of lots of failures. I will be right there, but in the meantime, you tell those guys to treat this as a real problem. It’s not an instrumentation problem.’”

There were problems aplenty in the MOCR, not just at the EECOM console. INCO Gary Scott was working problems with the High Gain Antenna, which had been struck and damaged by the blown-off panel. Seated to Liebergot’s immediate right, GNC Buck Willoughby dealt with random thruster firings. Will Fenner saw that the linked spacecraft was moving around unexpectedly. The reason why was about to become painfully clear.

A little more than fourteen minutes after the mishap, Lovell’s voice again got the attention of the MOCR. This time, it was even more chilling.

It looks to me, looking out the hatch, that we are venting something.

The instant Lovell finished speaking, Kranz repeated the report, drawing out the last syllable almost as if he was speaking to himself.

The crew thinks they’re venting something . . .

Liebergot chimed in.

I heard that, Flight.

Lousma was concerned by the news of the venting, but he was also a good marine, and good marines do not fly off the handle at the first sign of trouble. “I never felt threatened or rattled or confused or excited,” he said. “This was not the first emergency I’d ever been in. I’d also learned through some flying experiences that to get rattled is not the thing to do. You solve the problem as it comes along.”

By this time, Glynn Lunney had made his way into the control room. Others were on their way. Gerry Griffin and Ed Fendell had played softball that night and were having a postgame beer when they learned of the accident. Griffin eventually showed up, still in his sweats. He stayed for maybe half an hour, listened for a while, knowing that a landing was off, and then went home to try to get some sleep. Fendell made it to the space center only to find the parking lot full, so what the heck? He found the first available space, jumped out, and promptly locked his keys in the car. It sat there for five days—in a space reserved for none other than director of Flight Operations Sigurd A. “Sig” Sjoberg.

Ken Mattingly was there, too, his drink with George Abbey now forgotten. “Sy said something to Gene about, ‘We’re still trying to see where we can have this instrumentation flaw,’” Mattingly remembered. “Gene looked at him and said, ‘Sy, when was the last time instrumentation blew gas out the side?’ And Sy’s face just went . . . clunk. Everybody was in that scramble mode, being that there were totally unintelligible signatures, trying to make sense of it and at the same time recognizing that whatever is going on, that spacecraft is coming apart.”

Less than a minute after it became clear that the spacecraft was bleeding, Liebergot was scanning his monitors to see if he could somehow figure out where it was coming from. The flight director was seated almost directly behind the EECOM console, and he knew that Liebergot would need all the help he could get.

I assume you’ve called in your backup EECOMs.

There was no reply.

EECOM?

Flight, say again.

Have you called in your backup EECOMs now? See if we can get some more brainpower on this thing.

Most if not all of Lunney’s Black Team was also in the room, trying to help work the issues. Each console had four plug-ins for headset jacks, and almost every single one was in use. Lousma, too, had plenty of company from his fellow astronauts at the capcom console. “They had access to the control center, and they wanted to see for their own eyes exactly what was going on,” Lousma said. “You wouldn’t get that from the room in back, nor would they get it from sitting by their televisions. The way to do it was to come down to the control center, and they basically felt they had access to my console, because that’s where they would’ve sat if they were in there doing my job.” Although they were there watching over his shoulder, Lousma insisted that they were never a distraction.

That might not have been the case for others in the room at the time. Listen closely to the comm loops from that night, and a marked increase in background buzz is clearly evident when someone is speaking. At one point, Kranz recalled standing up and yelling over the consoles, “Okay, all flight controllers, cut the chatter. I want every member of the White Team to settle down and get back on the voice loops. The rest of you shut up!” Kranz then took to his own flight director’s loop, and this time, he was rallying the troops and at the same time getting across the seriousness of the situation.

Okay, now, let’s everybody keep cool. We’ve got a LM still attached. The LM spacecraft’s good, so if we need to get back home, we’ve got a LM to do a good portion of it with.

That was the first time Aquarius had been mentioned by Kranz over the loop as a potential solution to the problem. It would certainly not be the last.

Okay, let’s make sure we don’t do anything that’s going to blow our CSM electrical power with the batteries or that will cause us to lose . . . Fuel Cell Number 2. We want to keep the O2 on that kind of stuff working. We’d like to have RCS, but we’ve got the Command Module system, so we’re in good shape if we need to get home.

It is likely that Kranz meant to say Lunar Module in that last sentence. He concluded the message with a line that would become one of the flight’s most well known, if for no other reason than his distinct emphasis on the last word.

Let’s solve the problem, but let’s not make it any worse by guessin’.

Kranz had gone from thinking this was just another relatively quick-fix glitch to Buck Willoughby’s report that several of the thruster jet valves had closed. This was a whole new phase of his thought process, which he years later described as, “Tread lightly, lest ye step in crap.” It was the venting that brought Kranz around to the full seriousness of what was happening with his spacecraft.

It was at that point, Kranz said, that the situation entered survival mode in his mind. “Over about a ten- to twelve-minute period of time, I went through three stages,” Kranz explained. “I called them downmoding. It’s the same thing you do when you have an aircraft that’s got a problem. Basically, you now get totally focused upon this one problem we got, which is one of survival.”

Despite the back-and-forth conversations he was having with Kranz and his back room, or maybe because of them, Liebergot felt a deepening sense of isolation as the crisis continued to unfold. This was his problem to handle, and he had his hands full getting it squared away. John Aaron had known what to do during the launch of Apollo 12 just like that, but that was not happening for Liebergot. “It was an incredibly tense time,” Liebergot wrote in his book, Apollo EECOM: Journey of a Lifetime. “A monster CSM failure had occurred and I had no quick answers. As EECOM, I felt very much on the spot. I could feel the chill of panic begin to well up. There was no one to whom I could turn, and I will admit that a fleeting thought of getting up and going home did cross my mind. Of course, that was not an option! I firmed my grip on the security handles of my console, and brought my emotions under control.”

Lovell’s observation about the venting was, for lack of a better way to put it, the “oh, shit” moment for Jerry Bostick. He was not actually on the manning list for that shift, but he was there. Kranz remembered Bostick almost always being in the MOCR, almost like part of the decor. Less than five minutes after “Houston, we’ve had a problem,” Bobby T. Spencer rechecked his numbers for a direct-return abort at the retro console. That would have amounted to stopping a speeding bullet in midflight and redirecting its course in the exact opposite direction.

Such an intention was noble enough—get home now, or at the very least, as soon as possible. A direct abort could have been done at that point in theory, but it would have required a huge burn of some six thousand feet per second from the SPS. That would have wrung out almost the very last drop of fuel and then what? Lovell, Haise, and Swigert would have been up a creek without an SPS. There was more. The SPS was the big engine at the back of the Service Module, and nobody knew if it had been damaged in the explosion. Moreover, a powered maneuver by the SPS would have required maybe 50 amp-hours of power out of the CSM entry batteries, and there was not enough to spare.

Dave Reed, like many others, had all kinds of reservations over the extent of the damage that had been done to the spacecraft. “Chuck Deiterich and I made our case for why we did not want to do a direct abort, and we strongly recommended that we go around,” Reed added. “I gave them lots of arguments. One of the ones I remember giving them was, ‘Guys, theoretically, you blew a hole in the side of that thing, but do you know what it looks like? You really don’t know, do you?’ Chuck and I were pretty adamant that the way to go was around the moon.”

Within just twenty minutes of the accident, members of the Trench decided among themselves that the best course of action was to perform a burn using the LM’s Descent Propulsion System (DPS, pronounced “dips”) to get on a free-return trajectory. Apollo 13 would continue its outbound journey and then use the moon’s gravitational force to slingshot the spacecraft back to Earth. The SSR started work on the burn, and IBM was helping put together software to do it down in the RTCC. It was not exactly the way he had planned it, but FIDO Bill Stoval had gotten his high-activity phase. He began to compute the minimum delta-v—the force needed to move a spacecraft from one trajectory to another—that would be needed for the free return.

Also weighing in on free return’s favor was the fact that the Trench had at least a couple of options for which they had already simmed. Once on a free-return trajectory, the nonstop fly-by maneuver without going into lunar orbit was one of them. Another was known as a pericynthion (PC)–plus 2 burn, in which the DPS engine would be ignited two hours after the point at which the spacecraft came closest to the moon’s surface in order to speed up the return. A midcourse correction here and there would be tossed in for good measure to stay in the reentry corridor. “It was a no-brainer, frankly,” Lunney said. “When the guys went through the analysis, it was not like you’ve got to make a real big judgment call. It was like, ‘This is what the math tells you and it’s unmistakably clear what you have to do.’ Once that got explained out loud, everybody was okay with that.”

Free return was the way to go, but would there be enough life-sustaining juice left in the spacecraft? Nearly twenty minutes after the accident, Liebergot cleared his throat and told Kranz that the best option at that point was to start a 10-amp power-down. After a brief exchange over how far to go on their emergency checklist, Kranz added an emphatic note to the proceedings.

Let’s make sure we don’t blow the whole mission.

The whole mission, as it existed in the official flight plan, had already been blown. Five minutes later, the full extent of the problem seemed to bore down on Liebergot like a sledge hammer.

Flight, I’ve got a feeling we’ve lost two fuel cells. I hate to put it that way, but I don’t know why we’ve lost them. It doesn’t all tag up, and it’s not an instrumentation problem.

When John Aaron made it to the MOCR about forty minutes after the accident, he did not bother to put on a headset but instead spent another fifteen minutes or so walking behind the systems consoles on the second row of the MOCR and looking over the data that was streaming down from Odyssey. Aaron approached Liebergot. “I said, ‘Sy, this is fruitless. You have brought the emergency batteries on to power the spacecraft while you troubleshoot this problem. We’re not going to be able to fix it, so you need to turn the Command and Service Module off,’” Aaron remembered. “That had never been done before. I said, ‘You’ve got to turn it off. You’ve got to save the batteries. I don’t know what’s happened, but you save those batteries and you turn it off.’”

What Aaron was suggesting—make that insisting—was the most traumatic thing anyone in the room had ever done in support of a spaceflight. There had never been an emergency like this, in which the CSM mother ship had to be completely shut down three-fourths of the way to the moon. Such a notion was so inconceivable, there were no procedures whatsoever in place to turn the whole thing back on. It would not be long before working on those procedures became Aaron’s life.

Liebergot, in turn, requested a still more stringent power-down and this time told Kranz that he should start thinking about getting into the LM and using its systems. Kranz ordered Heselmeyer to have his back room start figuring out the minimum power in the LM to sustain life. Going into the flight, Heselmeyer was sure he had been placed on Kranz’s team so the veteran could keep an eye on the new guy. This was his baptism by fire. It was everybody’s baptism by fire, for that matter. “All the chatter was trying to figure out what was going on,” Heselmeyer said. “It was becoming more and more obvious that it was likely that the LM was going to be where they were going to need to get to.” Still, Aquarius would not be powered up and fully used as a lifeboat until after Lunney’s team came on shift about twenty minutes later.

Nearly an hour had passed since the end of the television transmission. Swigert reported that the number of particles surrounding the spacecraft had decreased greatly, and that whatever it was that was venting had almost stopped. That might have been a good thing under ordinary circumstances, but this was not just another hum-drum night on console, and Liebergot knew it. Finally, he reported to Kranz that Oxygen Tank 1 would hit 100 psi—the point at which there would be too little oxygen to be forced into the pickups—in one hour, fifty-four minutes. He added an ominous postscript.

That’s the end right there.

Kranz’s attention was focused on the LM, and he told FIDO Bill Stoval that unless the MOCR got a heck of a lot smarter, they were wasting their time planning to use the SPS. From there on out, he added, planning should involve the use of the LM DPS and RCS systems, and only as a third option, Odyssey’s RCS. Stoval responded, asking if Kranz wanted to get back to Earth as soon as possible. Absolutely. At the very same time as Kranz and Stoval were having that conversation, Liebergot and his back room were finally coming to grips with the source of all that ailed the spacecraft—and the MOCR by proxy.

Scott H. Simpkinson started work for the National Advisory Committee for Aeronautics—NASA’s forerunner—in 1943. He was on duty in the SPAN room during the Apollo 13 crisis, and he thought that the thing to do might be to close the reactant valves on the two balky fuel cells. Might that be where the leaks were located? Liebergot once again touched base with Dick Brown in the SSR.

Brown did not seem to care for the idea of shutting the oxygen source down, at least initially. Closing the reactant valves meant that the fuel cells were lost, and Brown added that he was not sure if the problem was not somewhere in the tank itself. The more they talked, the more the fog seemed to clear.

It would have to be in the cryo tanks for them both to go.

Yes. That was it, Liebergot figured at last. Something had happened that impacted both oxygen tanks, and whatever took place had also hampered the manifold connection to the three fuel cells. That it was not a single or double failure, but what Liebergot later called a quadruple failure, seemed unfathomable. If anything like it had ever been thrown at the MOCR during a simulation, the guilty party in the curtained room to the front right of the control room almost certainly would have drawn more than a few angry stares. Stuff like that just did not happen—but it had this time.

Less than fifteen minutes later, Kranz was telling his team to get ready for the handover to the Black Team. A fresh team would be thinking clearer, and the White Team could continue to work in support. It was 10:17 p.m. in Houston, barely an hour after the accident.

Never before had a shift change taken place with a spacecraft in quite so dire a predicament. The issues facing Lunney were numerous, and he listed at least some of them in a paper he wrote for NASA’s Oral History project.

A loud bang had been reported, and the crew was seeing particles of some variety venting out of the spacecraft.

The pressure on Oxygen Tank 2 was reading zero, and Sy Liebergot had predicted that Oxygen Tank 1 would last less than a couple of hours.

Fuel Cells 1 and 3 were not supplying power, and the reactant valve had already been closed on Fuel Cell 3. Because both fed off Fuel Cell 3, Main Bus B and AC Bus 2 were also at zilch.

Considerable reconfiguration had been performed to get enough thrusters powered by Main Bus A. The still-outbound LM and CSM stack was not yet on a free-return trajectory. That burn would take place on Lunney’s watch, and so would an emergency power-up of the LM so that it could be used as a lifeboat. Last, but certainly not least, was the fact that the crippled Command Module had to be shut down.

Other than that Everest-sized mountain of responsibilities, it was going to be a nice, quiet evening for Lunney and the Black Team. “There were a number of things that had to be done fairly quickly,” Lunney conceded. In the back of his mind the whole time was the cardinal rule, “We don’t want to do anything to screw it up more than it’s already screwed up.” Ken Mattingly was truly impressed by Lunney’s show of leadership over the next few hours. “Glynn went around the room and methodically went to every console and gave them a specific question to get an answer to,” Mattingly remembered. “They were things he knew he would need to know in the next thirty minutes, which gave everybody an assignment.” There was more, Mattingly said.

If there was a hero, Glynn Lunney was, by himself, a hero, because when he walked in the room, I guarantee you, nobody knew what the hell was going on. Glynn walked in, took over this mess, and he just brought calm to the situation. I’ve never seen such an extraordinary example of leadership in my entire career. Absolutely magnificent. No general or admiral in wartime could ever be more magnificent than Glynn was that night. He and he alone brought all of the scared people together. And you’ve got to remember that the flight controllers in those days were—they were kids in their thirties. They were good, but very few of them had ever run into these kinds of choices in life, and they weren’t used to that. All of a sudden, their confidence had been shaken. They were faced with things that they didn’t understand, and Glynn walked in there, and he just kind of took charge.

While Lunney took charge in the control room, Kranz presided over a meeting one floor down from the MOCR in Room 210 that began at about 10:30 p.m. in Houston. Aaron joined the meeting late, having stayed in the MOCR to oversee the orderly turn-off of the CSM. Aaron would vividly remember an exchange that took place near the end of that process, when it came time to pull one of the last circuit breakers that removed power from the heater that kept the IMU platform within temperature limits. GNC Gary Coen pleaded his case to Aaron.

John, it only takes less than half an amp of current. Without it, the platform may never work again.

Aaron responded the only way he could, with reason. Half an amp times the estimated 100 hours it would take to get back to Earth was 50 amp-hours. That was more energy than what remained in one of the batteries that Odyssey had left. Coen, realizing the magnitude of the power crunch, responded simply.

Okay, John.

Aaron remembered, “It’s amazing that we were struggling with an item that was the power drain equivalent of a twelve-watt light bulb, but managing to such small levels meant the difference between success and failure relative to having a shot at a successful reentry.”

That was the kind of agonizing number-crunching Kranz and his team would work on from that point forward, while the teams led by Lunney, Milt Windler, and Gerry Griffin sat the consoles in the front room. Before taking over for reentry, the White Team worked just one more shift in the front room the rest of the week—Kranz’s crew was in place for the all-important “PC–plus 2 burn” Tuesday night.

Aaron hopped out of the frying pan and into the fire by going to Kranz’s meeting. For the rest of the flight, he would oversee the power-up checklist for the CSM; Bill Peters would be in charge of the LM’s systems; and Arnie Aldrich held on to a procedures checklist for reentry. “I had worked with all of these guys,” Kranz said. “I knew them intimately. John Aaron was one guy I used, from a standpoint of resources. Arnie Aldrich was Aaron’s boss as the branch chief, and he did the reentry checklist work. Bill Peters basically looked over everybody’s shoulders to see if there was anything we were missing on the LM.”

The flight director had started the meeting with what Aaron called a “pep talk”—the situation was stabilized, the LM was in control, and the spacecraft would soon be on a free-return trajectory around the moon and headed back to Earth. Then, once back in the vicinity of Earth, the CSM would go through a normal power-up procedure. Aaron was not sure how the CSM would be powered up, or even if it could be once it had been shut down so definitively. That’s when Aaron stood up.

Gene, you can’t do that.

Why’s that, John?

Because you don’t have enough power.

It was at that point when Kranz made one of the quickest decisions of his life.

Okay, EECOM. You’re in charge of power. Anyone needing power, talk to Aaron.

Just that fast, Aaron was put in charge of everything that needed electrical power for the rest of the mission.

Even then, Aaron had a sinking feeling in the pit of his stomach. “Me, initially, I had doubts that we could do it,” he admitted. “After the meeting in Room 210, I thought it looked nearly impossible. Realizing my state, I remember I forced myself to look at the problem from a different perspective. Rather than focusing on thinking that it was impossible, I forced myself to start working with the mindset of ‘What will it take to make this possible?’ Such a switch in thinking got me on the road to a workable solution.”

If anybody needed power for the rest of the week, they talked to Aaron. They pleaded with Aaron. They argued with Aaron.

Really, they were up against the formidable duo of Aaron and his SSR back-room counterpart Jim Kelly, whom Aaron called “absolutely instrumental” in putting the power profile together. There was already a deep trust between them when Apollo 13 flew, but Kelly was not in place just because he was Aaron’s buddy. He knew his stuff, and he was the sort who had already contemplated what might happen if two fuel cells were lost on the way to the moon. “We had access directly back to the Rockwell and North American plant,” Kelly said. “If NASA needed something, they didn’t have to go through all this damn formality. We just hopped on an airplane if necessary, put a Rockwell badge on, walked in the plant, and started asking questions.” Prior to Apollo 11, one of the questions Kelly asked was how many watts each circuit breaker on the spacecraft drew and if there were any backdoors to that circuit breaker. When he met some initial resistance, he went to the Rockwell boss and got the information he wanted.

Aaron and Kelly had their hands full. “People were howling and screaming—not really howling and screaming—they were trying to figure out what was going on and trying to voice a solution,” Kelly continued. “John and I kind of looked at each other, and John knew I had some ideas. He just asked everybody to leave the room and come back later. When they came back, we had a rough sketch on the board of a power-up sequence. We had no idea at that point what we even had to work with.”

What Kelly initially described as howling and screaming, Aaron called “a tussle between those who wanted power and the guy who didn’t have it.” Aaron knew systems throughout the spacecraft, and knew how they interacted with each other. What he also accepted was the fact that there was sometimes a huge difference between the power a controller wanted and what was actually needed. “I got up to the blackboard and started sketching out when we could turn on what, and of course that started people saying, ‘Oh, no, no, EECOM. I’ve gotta have this on and not only that, I’ve gotta have it on longer than you want it on.’ We weren’t getting anywhere right away. I did that for about ten minutes and I said, ‘Hold on. Why don’t you guys go get some coffee and come back here in forty-five minutes, and we’ll have something that’s more refined for you.’”

Peters and Aldrich were also busy getting up to speed. Using the LM to ferry the crew back home was doable, Peters thought, but he was not quite sure. The LM had been designed to support two people—Lovell and Haise—for up to forty-five hours. Not only was Swigert a third person to consider, but the return could take anywhere from seventy-seven to one hundred hours depending on the burns to come.

The math was not working out, and the uncertainty weighed on Peters in a huge way. “To be honest, for the next three days, I had butterflies in my stomach,” he admitted. “It was that sickening feeling that, ‘Oh, crap. I can’t do anything about this.’” It was not until later, after the stack had swung around the moon, performed the PC–plus 2 maneuver, and the LM itself was powered down, that Peters’s case of the nerves finally eased. “It was a very tense time in my life,” he added.

Arnie Aldrich’s job put him in contact with the MOCR, the SPAN room, and the MER. Once he was put in charge of the reentry checklist, his task was not only to put it together, but also to get it blessed by North American—and if not blessed, then at the very least to make the makers of the CSM aware of what was going to take place. Every day, he tagged up with Aaron and Kelly, to see where they were with the power-up procedures. He reviewed what was going on in the simulators. Analyses were conducted on equipment, to see if it could withstand the kind of cold to which it was going to be subjected in an unpowered CSM. The sequencing was crucial.

To avoid any confusion over which version might contain the latest updates, there was one copy of the reentry checklist and one copy only. Aldrich guarded it with his life. “The changes to be made over the three days were all penciled in and initialed,” Aldrich said. “In the end, I had to go and meet with Kranz and Rocco (A.) Petrone (the Apollo program director) and tell them what I’d done. I said, ‘This is the checklist. Here it is.’ Then I turned it back to John, and he executed it. He and Jim Kelly had done the bulk of the analysis and the work on the pieces that kept feeding into this thing until it got put all together.”

Many would later claim that they never doubted the crew’s survival. “There was a feeling of faith,” telmu officer Merlin Merritt remembered. “There was a feeling of, ‘I don’t know how it’s going to happen. There was certainly a question of not knowing. You can only do so much. You pray, you do what you can do, which is what we did, and leave the rest up to God. I sort of felt all along that they would get back, that God would work it out. I never had a feeling of hopelessness or depression.”

Kranz also believed that the crew would make it back alive, and he said he moved from belief to certainty after the PC–plus 2 “get home fast” burn. Dave Reed insisted he had not the first worry about Lovell, Haise, and Swigert making it back. Gerry Griffin had been trained to never give up hope. Bill Stoval, however, was not among the optimists. “Once we lost the landing, then clearly all emphasis shifted to saving the crew,” Stoval said. “That wasn’t clear. When I got home that night, I told my wife, Ruth, I thought they were dead. I thought we were going to run out of consumables. It wasn’t a trajectory problem. It was going to be an air or electricity problem.”

Less than forty minutes had passed since Sy Liebergot announced that the quantity in Oxygen Tank 1 would last only another two hours or so, but the news from his counterpart EECOM Clint Burton got progressively worse almost from the very beginning of the Black Team’s shift. Just forty minutes remained. Four minutes after that call, eighteen remained. Fifteen. “It hurts to be the bearer of bad news time after time after time,” said Burton, who died on 17 September 2006. “Nonetheless, it fell my duty to be that bearer of bad news time after time after time.”

Lunney and the controllers under him that night must have felt like an embattled company of soldiers, hunkered down in their foxhole and facing one bombardment after another. No sooner had Lunney dealt with one critical issue than another was needing his immediate attention.

Gary Renick, working the guidance slot in the Trench, wondered if the IMU would survive the cold of a complete power-down of Odyssey. He was not the only one. Extraordinary measures had always been taken to limit the temperature range on the vital instrument back on the ground. The problem was that no official data existed on what might happen if and when it was subjected to subfreezing temperatures—which was exactly what was about to happen following the power-down of the Command Module.

No official data existed, but legend holds that a technician heard the worried discussion about whether or not an IMU would survive in the cold. Turns out, the guy once had one in the backseat of his car when he was sent home due to an ice storm. The expensive and delicate piece of space equipment was left in the car overnight and then taken back to work, nobody any the wiser. It evidently worked perfectly afterward. “We said, ‘That’s good enough for us,’” Ken Mattingly admitted.

Astronaut Tom Stafford helped Lunney understand the importance of transferring the Command Module’s inertial guidance alignment to the Lunar Module. “Tom said, ‘Keep the platform up if you at all can,’” Lunney said. “He wasn’t on duty for the flight. He wasn’t on the manning list, but he was there. We all knew each other. We had been through all this stuff together in simulations. It was a comforting kind of thing.” Lunney opted to take the time and utilize electrical power from both vehicles to make the transfer.

A little more than thirty minutes into the Black Team’s shift, Renick wanted to run a P52 automatic star pointing program. It was one in which the IMU required realignment from a known orientation, but it was doubtful any of the three Apollo 13 crewmen could align the sextant on any two actual stars, for the very same reason Stafford was so insistent on maintaining alignment in the LM for as long as possible. With so many particles of debris and venting still surrounding the spacecraft, they all looked like stars.

For the first time, Lunney sounded just short of perturbed. He shot back.

That’s what I’m asking you. Do you have one now? We don’t have much time. Do you have a good one now, as far as you know?

Renick answered Lunney’s question with a question of his own.

A good alignment?

Lunney spoke again, still sounding somewhat aggrieved.

Yeah, that’s what I’m asking you. Do you have a good alignment? I’m not worried about tenths of a degree, either.

It ought to be that good, Flight.

Yeah, okay.

Information was flying at the flight director. During the lightning-quick exchange between Lunney and Renick, both GNC Jack Kamman and then Burton attempted to break in. Burton won out.

Okay, we need to open up the surge tank. The manifold pressure’s dropping.

There was a pause, as if Lunney was trying to decide what to do next. The surge tank contained a small amount of reserve oxygen, and Burton was telling him that it was all that was left. Forget power. The astronauts needed to breathe. It was the very last line of defense in Odyssey, and Lunney knew it.

Uhhhhhh . . .

Lunney then let out a short breath, audible on the flight director’s loop, before he continued.

Okay, wouldn’t you rather power it up from the LM. . . or pump that up in the LM?

Burton momentarily stammered.

Well . . . we . . . we . . . w . . .

He got it out.

We got to get into the LM first, Flight.

Other orders in NASA’s history might have been given as quickly as the one Lunney was about to issue to Lousma, who was still on duty, but none were ever quicker or more decisive.

Capcom, get ’em going in the LM. We’ve gotta get the oxygen on the LM.

Lovell and Haise were already there.

If the exchange with Renick had Lunney on the verge of frustration, Burton had just kicked him where the sun did not shine. Control officer Hal Loden and telmu Merlin Merritt raced to shorten LM power-up procedures that in normal circumstances took at least two hours to complete. They needed to get the job done fast, because Lunney intended to keep power trickling in the CSM only for as long as it took to get its guidance platform transferred to the LM. Loden’s gut feeling had shifted from one of disappointment at not making the lunar landing to, once it became apparent just how serious a turn that mission had taken, one of uncertainty. The crew, he had to admit to himself, was in “deep yogurt.”

“Their whole survival was going to depend on whatever we could do to help them on the ground,” Loden said. In simulations, situations had been imagined in which the LM would be used as a lifeboat. The procedures that came about, however, met with mixed results. That was the kindest way Loden could describe it. “We had some thoughts down on paper about what we needed to do, but it wasn’t nearly to the extent of what we wound up having to do,” he added. “So, yeah, I was concerned. Everybody in the control room had to be concerned. If they weren’t, they probably didn’t understand the situation.”

Swigert was getting Odyssey powered down at the same time Lovell and Haise were in Aquarius, getting it powered up. As quickly as they were trying to get things done, something was almost bound to get lost in the shuffle. More than an hour into the Black Team’s turn on console, Lousma had to remind the astronauts not to speak at once. Then, the CSM’s thrusters wound up disabled before the LM’s were brought on line. Lunney nor Lousma could hardly believe it. Lunney began.

I want to be sure we got control somewhere. I’m not satisfied we do yet.

The disbelief in Lousma’s voice was thick.

Okay. We haven’t got ourselves in a position here where we have no attitude control in either vehicle, have we?

I’m . . . I’m waiting to see when we get attitude control in the LM. Would they . . . would you ask them to call us when they have attitude control in the LM? And then we’ll power the inverters et cetera down in the CSM.

Loden broke in and said that once control was established in the LM, some cleanup work needed to be done in the power-up procedures. As Loden and Lunney talked, Lousma got word from Haise in the LM that he and Lovell were still working on pressurizing the Attitude Control System. In other words—no joy. Lousma got back on the loop to Lunney, and for a brief moment, stumbled over his words.

Hey, Flight. They don’t have attitude control and we don’t have it in the CM. . . CMS. . . CM. . .

Okay. Well, we’re trying to get it up, right?

Lousma’s reply was matter of fact.

Yeah, they are.

Lunney was not pleased with the slip-up. “It turned out to be not a real problem, but I was really pissed at myself because it was—well, it was kind of the only mistake we made that night,” Lunney admitted. Lousma, on the other hand, would not remember the episode. It had not caused any sort of real, pressing issue—there were plenty of those to go around already—so why sweat it? “Frankly, I don’t recall this lapse in the transfer of attitude control, probably because the time period of no control was so short that it had not yet caused a problem,” Lousma said. “With so many identified problems already presenting themselves in need of immediate attention, a no-control configuration not yet causing a noticeable problem would be easy to overlook until some no-control behavior was noticed. It appears Glynn directed transfer of attitude control before the symptoms of no control showed up, thus making the situation a non-event.”

One hour, thirty-five minutes after the start of the Black Team’s shift, Odyssey was finally powered down. About 20 amp-hours of the entry battery’s power—as much as 15 percent—had been used before the CSM was finally put to sleep. As the steps to do so wound down, Lunney experienced the sensation of the bottom falling out from under him for the first and only time in his ten-year career on consoles during flights and training.

We were abandoning ship in the middle of the North Atlantic, at night, in the storm, and we were in this little life raft. It really struck home, like a big, hollow feeling in my stomach. It was something like, “Holy shit. I can’t believe this is really happening.” It was a sinking feeling, but it didn’t last very long, probably measured in a few seconds. It was pronounced on me, because of the sense of a black hole abyss just sucking us all into it. The training took over. There’s no Superman tale about this, because probably everybody in one way or another at some kind of moment were approaching the dead-serious realization of how much trouble we were really in. If you didn’t get the feeling of looking into the abyss, you weren’t paying attention.

Odyssey was now lifeless, but critical work remained. An attempt to come up with a passive thermal control barbeque mode was made, to keep the stack from burning to a crisp on one side and freezing on the other. Someone realized that there were not enough carbon-dioxide scrubbers in the LM. It was not a problem at the moment, but it was going to be in the not-too-distant future. There was more than enough oxygen in the LM for the crew’s return, but water was another matter. The astronauts themselves needed water to survive, of course, but water was also used as coolant for equipment inside the spacecraft. Some early estimates figured that the supply would run out at ninety-four hours into the mission, and that was going to be more than two full days short. However, that was based on the assumption that the LM would run on about 35 amps for the rest of the flight.

Merlin Merritt wanted that number down, and he wanted it down as soon as possible. If that meant turning the LM’s guidance system off in the process, then so be it. He told Lunney so in as forceful a manner as MOCR decorum would allow. “I finally just unplugged my headset, which was kind of a no-no, and went up to him on his row there, and sort of got in his face,” Merritt said. “I said, ‘Glynn, if we don’t power down this thing, we’re not going to make it.’ He said, ‘Okay, well, let me see your data.’” Lunney remembered the exchange well. “That was really the closest thing to a difference of opinion, but it really never even manifested itself as such,” Lunney said with a laugh. “Occasionally, they would remind me that they would like to get powered down as soon as possible. I was in the position of saying, ‘Yes, I know. I agree with you. I agree with you. But . . . our real job is to get them back home, not to save power.’”

What Merritt got was a compromise of sorts. A few items here and there were turned off in the LM, dropping its power usage from 32 to 25 amps after the free-return maneuver and before the PC–plus 2 burn. The guidance system remained online until after the “get home fast” maneuver, at which time virtually everything was shut down. Kranz was adamant that the platform remain on until then. “There was never any question in my mind,” Kranz said. “I would’ve fought to the death to prevent anyone from trying to turn that platform down. That was as essential to survival as water and air and electrical power.”

While Merritt concerned himself with power usage in the LM, FIDO Bill Boone worried about urine dumps. Venting from the damaged spacecraft was moving its trajectory “all over the map,” according to Boone. On previous flights, it had been possible to actually see overboard urine dumps cause a small change in trajectory. “There were so many things that were happening,” Boone said. “We were trying to minimize any effect it had on the Doppler, so we could figure out where we were. That’s when I made the call.” Boone asked Lunney to halt the urine dumps, and Lousma passed the word up to the crew less than half an hour after the free-return burn.

Two words were not added to the request when it was passed up to the crew.

For now.

Boone was unable to remember if it had been his intention to call a permanent or just a temporary halt to the dumps, but the fact was, there were no more during the flight of Apollo 13. For the remainder of the mission, Boone’s call forced the crew to search the two cabins for any possible storage containers. “If somebody would’ve asked later, I probably would’ve said, ‘Let’s don’t,’” Boone said. “We really did not have a good handle on the trajectory until we got close to reentry. Fred Haise still gives me a ration about that.”

A little more than five and a half hours after the accident, at about 2:43 a.m. on Tuesday, 14 April in Houston, the LM’s descent engine burned for 34.23 seconds to get the docked vehicles on a free-return trajectory. The burn was projected to drop Odyssey into the Indian Ocean early on Saturday, 18 April. “When we did that midcourse and the Lunar Module engine and the Lunar Module guidance system all worked the way we planned it, that was another boost in the fact that we were now back on a free-return trajectory,” Lunney said. “It was a psychological boost for people. The crew never said much about it, but I suspect it put them in a better frame of mind than they might otherwise have been.”

The Black Team left their consoles four and a half hours after the burn, and when Lunney gave way to Gerry Griffin, he felt that his consumables projections were “solid.” The power-down of both vehicles dramatically decreased water usage, easing that particular crisis. “For me, I felt that the Black Team shift immediately after the explosion and for the next fourteen hours was the best piece of operations work I ever did or could hope to do,” Lunney said. “It posed a continuous demand for the best decisions often without hard data and mostly on the basis of judgment, in the face of the most severe in-flight emergency faced thus far in manned spaceflight. There might have been a better solution, but it still is not apparent what it would be. Perhaps we could have been a little quicker at times, but we were consciously deliberate.” In short, Lunney concluded that he and his team had delivered their best when it counted the most.

For almost exactly nine hours, Merlin Merritt had been at the center of the most prolonged in-flight emergency NASA had ever faced at that point. After the busiest shift he and most everyone else had ever experienced at NASA, Merritt and an acquaintance found an empty room and prayed. “We didn’t want to make any mistakes, and asked that the Lord would guide us,” Merritt recalled.

Despite all that had happened, the spacecraft still would not disappear behind the far side of the moon for another eleven hours.

After Gerry Griffin’s Gold Team took over in the MOCR, the big items up for debate were how big a PC–plus 2 burn to make and figuring out how to ensure its alignment with the LM’s Alignment Optical Telescope (AOT). The normal process was to fix the AOT on a particular star, but with so many particles and debris still hovering about the spacecraft, there was no way to tell which was which.

Guidance officer Ken Russell came up with an alternative. Why not use the biggest star around—the sun—for the check? There were all kinds of problems with Russell’s suggestion. With a target as big as the sun, the alignment would not be as precise as one performed on a much-further-distant star. The AOT was fixed in the LM, so it could not be swiveled to get the star in its sights. Instead, Lovell would have to maneuver Aquarius into just the right position. Still, there was no better option.

When Griffin’s Trench team—Russell, Dave Reed, and Chuck Deiterich—approached Griffin at his console, they had his attention. They explained the AOT sun check and told him it was their best if not only option, and Griffin had it passed on to John Young and Charlie Duke in the simulators to see if it was feasible.

Lovell had his doubts while discussing it with Haise onboard the spacecraft.

I don’t have all the confidence in the world in this Earth-Sun P52. You know how many times I screwed up on my arithmetic.

Yes. Don’t count your chickens before they hatch.

Listen, I’m not.

The sun check did not work as well as a star sighting would have, but it worked well enough. That was the best anybody could have hoped for.

There had been some talk of doing a burn while the spacecraft was behind the moon, but the Trench pushed to wait for another couple of hours. The morning after the accident, Deiterich and Reed represented the Trench and presented five different options during a meeting in the VIP room overlooking the MOCR. It was a gathering of Who’s Who in Spaceflight, because it included executive management from NASA headquarters and centers around the country; major NASA and contractor executives at MSC; and the head of the Department of Defense’s recovery forces. Glynn Lunney, Gerry Griffin, Jerry Bostick, Deke Slayton, Chris Kraft, and Bob Gilruth were there, and so was Thomas O. Paine, the NASA administrator.

Option 1 required doing nothing and staying on the present course charted by the free-return burn.

Option 2 was a burn of 850 feet per second, with landing in the mid-Pacific at 143 hours into the flight. This was Deiterich and Reed’s preferred method. Deiterich had computed many different configurations for a PC–plus 2 burn, and Reed reviewed each and checked them all in his processors. “Had we done a bigger PC–plus 2 burn and lost an engine, we could’ve been pretty far out of the corridor,” he remembered. “If we lost an engine any time during the smaller burn, we were never far from the corridor. It wouldn’t take much RCS to take us back in the corridor. We wouldn’t necessarily have made it to the Pacific Ocean for splashdown, but we would’ve been on a reasonable trajectory. We would’ve been in water somewhere.” Lunney was on board as well and noted in his Apollo 13 paper, “Option #2 was conservative on fuel, leaving a large reserve for midcourses, best recovery posture, solid plan for consumables.”

Option 3 would have brought a burn of 2,000 feet per second and landing in the South Atlantic Ocean at 133 hours into the flight.

Options 4 and 5 were similar, in that both would have required a huge burn of nearly 4,800 feet per second and landing at 118 hours. However, the damaged Service Module would have been jettisoned in option 4 and in 5, it would have remained. “We could have gotten back a day earlier by jetting the SM, but early shutdowns of this burn had a significant problem with the entry conditions,” Deiterich noted. “We also did not like the exposure of the heat shield for a long time. As it turns out, we—the whole MCC—needed the extra day to get our act together for the entry day procedures.”

The case boiled down to this.

This is the data. This is what we recommend. We do not want to jettison the Service Module. We think we can get back to the Pacific Ocean at 142 hours, and we will not get on any sort of trajectory that would present a problem later.

“They bought it,” Deiterich concluded.

Lunney would never forget the response from the rest of the room. “Gerry [Griffin] and I were still bracing for a prolonged discussion,” Lunney wrote. “The senior NASA official was Dr. Thomas Paine, the NASA administrator. He did not know us, but of course George Low, his deputy, did. After one question from Deke Slayton, Dr. Paine took over and thanked me for the discussion and the clarity of the situation report and then he said, ‘I only have one question. What can we do to help you men?’ WOW.” It was, to Lunney, a sign of how NASA worked in those days. Low, he was sure, must have sold Paine on the MOCR team on the flight to Houston. He called it a “delegation of trust” that prevented what could have been a much testier meeting.

Beginning at 8:40 p.m. on Tuesday in Houston, the PC–plus 2 burn of the LM’s descent engine lasted for 263.82 seconds and speeded the stack up by 860.5 feet per second. Seventeen precious hours were cut from the projected landing time—seventeen hours that would not have to be accounted for when it came to consumables—with expected splashdown now targeted for the Pacific rather than Indian Ocean. “The Gold Team worked on the details of all the options for the PC–plus 2 burn,” said Griffin, who handed the flight director console back over to Gene Kranz a few hours before the maneuver. “Lunney and I both favored the choice of getting back to the Pacific, where we had recovery forces at 143 hours with some reserve in propellant. A faster return would mean the systems wouldn’t have to perform as long, and there was some concern expressed about the CM thrusters staying dormant so long. But at the end of the day, the consensus favored the 143-hour elapsed time landing in the Pacific and senior NASA management concurred. So, like most decisions made in the MOCR, everyone endorsed the outcome and set out to make it happen.”

The next two and a half days were similar in a lot of ways to a normal flight to the moon. “Any time you’re in a coast phase, whether you’re going to the moon or coming back, you don’t have a lot of dynamic stuff going on,” Griffin admitted. The difference was a constant talk of consumables. How much power was being used? How much water? How long would it be before carbon dioxide poisoning became an issue? “That’s what made it different,” Griffin continued. “It wasn’t hectic. There wasn’t something that had to be done in an hour. We never got to a shortage of something, where if we didn’t do something quick, we were going to lose them. It was constantly trying to figure out how to squeeze a little more out of this or squeeze a little more out of that.”

After the PC–plus 2 burn, the three astronauts closed up shop in Aquarius as well as Odyssey. Ordinarily, the LM operated on about 55 amps of power. Now, however, that number was down to 15 to 18 amps. That was not belt tightening. It was noose strangling, and it left guys like Bob Heselmeyer, Merlin Merritt, and Jack Knight at the telmu console without a lot to monitor. “There wasn’t that much powered up, but what was powered up, I can guarantee you was watched very closely,” Heselmeyer said with a chuckle.

That did not mean that they could kick back and relax. There was not a single person who worked in and around mission control that week who was not fully aware of exactly what was on the line. Heselmeyer was on duty at the time of the accident, and after attending Kranz’s meeting down in Room 210, had wearily trudged into the dorm to try to get some sleep. He woke up at some point, the clothes he had worn into work the day before completely soaked in sweat. Stress had hit him with full force. The next morning, he was back on duty, this time on Griffin’s Gold Team.

Heselmeyer was still in his same sweat-soaked clothes. “[I] had to go back down and sit on the console for another whole shift, not having changed or washed or anything,” Heselmeyer remembered. “I was probably not the most popular guy. But I have a distinct memory of having tried to get myself cleaned up and then going back and sitting on the console, and watching those now very critical LM systems and making sure that vehicle was still doing its job.”

In fact, the rookie flight controller was not alone. INCO Ed Fendell remembered the “human” aspect of the crisis, and it had nothing to do with crunching consumables or keeping track of trajectory. “Think about it a second . . . no, I mean it,” Fendell began. “People were sitting in the control center and this thing occurred, right? With that, everybody called all their people in, right? Do you think everybody was ready to go to work? Some guys had been working in the garage. Some guys had just finished playing softball and were drinking beer, okay? And off you went to the control center and you stayed there for three days. You ate and you drank there. You spilled coffee. You spilled pizza. You spilled hamburger. You never bathed. What do you think it smelled like? We all smoked about three packs a day.”

Within hours of the accident, it became apparent that the LM’s two primary and three secondary carbon dioxide scrubbers would not be enough to handle the poison that the three astronauts would be exhaling with every breath. Other issues took priority early on—like powering down Odyssey and Aquarius, as well as the free-return and PC–plus 2 burns. Yet as time wore on—and the carbon dioxide got thicker in the LM—the issue of fitting the CM’s square cartridges into the LM’s round hole became more pressing.

“There was enough water and enough oxygen. That was not a problem,” said Jack Knight, the telmu officer on the Maroon Team led by Milt Windler. “But the ability to take out carbon dioxide was, in my mind and for my systems, the immediate problem—or it was going to be a problem.”

Over in Building 45, R. Edward “Ed” Smylie presided over an impromptu meeting of MSC’s Crew Systems Division that began at about 1 a.m. on Tuesday. Maybe, just maybe, the crew could gather up a Liquid Cooling Garment stowage bag, an outlet suit hose, and gray duct tape and rig up a solution. Toss in a cardboard arch—say a trimmed EVA cue card from the flight plan, to prevent the bag from collapsing—and voilà. The problem was on the way to being solved.

By 2:30 a.m., a mockup was being shown to Ken Mattingly over in the Mission Control Center. A plane was commandeered to bring test canisters in from the Cape. Astronaut Anthony W. “Tony” England helped with extensive testing. At 7:22 a.m. on Wednesday, capcom Joe Kerwin began reading up instructions for construction of the device.

I think the equipment you’ll need will be two Command Module lithium hydroxide canisters, a roll of the gray tape, the two LCGs, because we’re going to use the bags from the LCGs, and one . . . one LM cue card. One of those cardboard cue cards which you will cut off about an inch and a half out from the ring. Now, I think that’s all we’ll need.

While the crew collected the items, Kerwin took the time to ease Swigert’s fears about something he had mentioned before the accident.

Okay, Jack. Did anybody tell you that you got a sixty-day extension on your income tax?

Forty-five minutes later, the contraption was finished. When it was put into place, the LM cabin’s carbon dioxide reading stood at about 7.5 mm Hg. Thirty minutes later, it was reading just 0.3 mm Hg. The fix had worked. An identical boxy scrubber was put together, and when each was depleted, an additional canister could be taped to it to continue working unimpeded. Smylie had been the point person, but nearly a hundred people had a hand in the solution in some way or another. “It was pretty straightforward, even though we got a lot of publicity for it and Nixon even mentioned our names,” Smylie said. “I always argued that was because that was one you could understand. Nobody really understood the hard things they were doing. Everybody could understand a filter. I said a mechanical engineering sophomore in college could have come up with it. It was pretty straightforward, but it was important.”

The Apollo 13 rescue was personal in many ways for many people, and Smylie was certainly no different. He lived just three doors down from Fred Haise and his family, and their sons were good friends. To avoid the press that was camped out at the astronaut’s home, Fred Haise Jr. made his way through some woods behind the home and stayed for the next three days with the Smylies.

There were more scares to come. At 2:26 p.m. on Wednesday, an LM battery failed to the tune of another thump felt in the spacecraft and the venting of what appeared to the crew as “snowflakes.” This time, however, it was not a substantial issue. “The LM battery that exploded continued to supply electrical power and did not prove an issue to battery amp-hour management or current load sharing by all the batteries,” Bill Peters explained. “I had maintained enough reserve electrical power to cover instrumentation errors in each of the other batteries to cover a contingency, so even if the battery had completely failed, there was enough power to complete the mission.”

Each of the two LM batteries was sealed in a metal box, and tests after the flight showed that a similar “explosion” in the container resulted only in a very slight lifting of its lid. That pushed out the sealing O-ring just enough to allow electrolytes to escape, which was more than likely the “snowflakes” reported by the crew.

A fourth midcourse correction was performed at 10:31 p.m. on Wednesday, and while it was a short fourteen-second burst of Aquarius’s descent engine at 7.8 feet per second, planning for it had cost FIDO Bill Stoval almost an entire eight-hour shift of back-and-forth conversations with those who handled the LM propulsion systems. The LM’s guidance system was now turned off, so Lovell and Haise would have to fly it by the seat of their pants, with Swigert hovering on the engine-bell cover timing the burn with a stopwatch. How would the engine perform? Would the Abort Guidance System be an acceptable monitoring device for the burn? Stoval did not know if the thrust profile in the RTCC would match the thrust profile when the engine started, because he did not know if the ullage burn would be enough to push propellant into the pump.

It resulted in what he called the most frustrating day of his life in mission control. “I basically had to do the entire maneuver by myself,” said Stoval, who moved over to Gerry Griffin’s Gold Team after the accident. “I couldn’t get the guys on the AGS to tell me if the AGS would work. I couldn’t get the guys on the engine to tell me how the engine was going to work in terms of propulsion. It was just unbelievable how little help I could get, because they were in worlds they’d never been before.”

The next-to-last midcourse correction of the flight went off perfectly.

In the meantime, Odyssey had all but depleted one of its three entry batteries. While there was a system on board that could recharge the entry batteries off the fuel cells, that was obviously not an option because they were dead. It was Dick Brown who remembered the heater circuitry that Bill Peters had modified back in 1967.

That was the year that Peters had been assigned to meet with Grumman officials for an LM engineering design review in a large hangar in Bethpage, New York. Several folding tables were arranged in a horseshoe, and there were microphones at each spot so everyone could hear. The meeting was chaired by U.S. Air Force brigadier general Carroll H. Bolender, who had commanded more than a hundred World War II combat missions in southern France and Italy. Bolender’s nickname was “Rip,” and rumor was, it was very easy to find out why if and when anyone crossed him.

Peters nervously began his presentation. His team had noticed two sets of heater wiring between the Lunar and Command Modules while preparing for the meeting, and came up with a procedure in which they could be rerouted so that the CM could be used to maintain heat in the unpowered LM and its essential equipment during the trans-lunar coast. One set of wiring would be considered primary, and the other as a backup. This was no small task, with two incredibly complicated spacecraft being built by two different contractors on opposite sides of the country.

Bolender accepted the changes Peters had suggested and directed that they be implemented by Grumman and North American. Brown remembered the exchange, and eventually, the team came to the conclusion that the circuits could be used in reverse so that the CM’s entry batteries could be charged by the LM. It was not the most efficient way of transferring electrical power, but it worked well enough. Odyssey’s reentry batteries were topped off with an extra 15 percent or so Wednesday and Thursday.

Peters figured that it was just another in a long line of game changers that week. “This demonstrates that the preparation our leadership required of us provided the team with the capabilities to successfully solve one of the most complex engineering challenges of our time,” Peters said. “Our analysis for years prior to the mission enabled us to understand the systems better than the designers did. We wrote procedures to use those systems in ways that the designers never anticipated. We developed troubleshooting procedures in advance of any problems that actually occurred, and we fine-tuned the capability to work together as a team through extensive simulations.”

John Aaron had a deadline that he could not miss. As the earth continued to get bigger in the windows of the spacecraft, Lovell got more and more insistent concerning the power-up procedures on which Aaron and Jim Kelly were so diligently working. When the pressing deadline was mentioned to Aaron, he laughed and called it his “hour of destiny.” What was once a collection of conceptual ideas had become more refined, more detailed in terms of what circuit breakers and switches to actually cycle. Controllers and contractors came back with all their tweaks, all of which had to be resolved. The ground was happy, but could the crew actually handle each and every item on the lengthy document in a short amount of time? The checklist was farmed out to astronauts in the simulators. “They would come out of there and say, ‘No, no, EECOM. You’ve got to give me a little more time here.’ Well, that meant more power,” Aaron said. “I’d have to go find something else to turn off.”

Finally, late Thursday afternoon, Arnie Aldrich escorted Aaron into the control room. In Aaron’s hands was a single, marked copy of the power-up checklist. At some thirty-nine pages and more than four hundred entries, it was something to behold. Capcom Vance D. Brand told Lovell that he was ready to start reading up the first installment, and Lovell responded by getting Swigert on the line. Even then, Brand’s first message to Swigert was to hold on for a minute and after that, for a little bit longer. Copies of the checklist needed to be made.

Okay, Jack. Going to hold up one. All the hordes of people that devised this procedure are going to be coming into the room in a minute, and they’d like to hold up until everybody can listen in.

Swigert sounded somewhat less than thrilled with the delay.

Okay, Vance. We’re ready to go.

Temperatures had dropped to a low of around thirty-eight degrees in the cabin. That, along with a body- and mind-numbing array of other factors, combined to give Fred Haise a urinary tract infection. The crew was, to put it mildly, exhausted. “They never complained,” said Gerry Griffin, the Gold Team flight director on duty when the procedures were read up. “A lot of that, we didn’t even hear about until they got home. They never said, ‘We’re freezing to death,’ or anything like that.” While an old-school copier furiously cranked out duplicates, Deke Slayton brought to bear every ounce of his calm and collected persona when he began to chat with Swigert.

How’s the temperature up there, Jack? You guys chopping wood to keep warm?

It was not unprecedented for someone other than the capcom to be speaking directly with an in-flight crew, but it was something very close to it. Swigert responded.

Deke, it’s about fifty-one, I think, or fifty in the LM and it’s about—I don’t know—forty-five or a little bit less in the Command Module.

Oh, it’s a nice fall day, huh?

Yes, I tell you, we don’t have to worry about chilldown.

Some fifteen minutes passed before Brand was finally able to begin the lengthy process of reading the power-up procedures to Swigert. It lasted so long, Mattingly took over the capcom console midstream. The process took maybe two hours, followed by another hour of LM procedures.

“The first question they asked me was, ‘Where’s my copy?’” Aaron said. “These were the days when we didn’t have high-speed Xerox machines. It was pretty slow to copy things. It was a pretty thick little package, so the flight director said, ‘Standby. You go run thirty copies of this and come back.’” Aaron called the delay, at least for him if not for the crew, a blessing in disguise. “All the other console operators and then everybody in that building had access to a copy, and so they were able to follow each step as it was read up to the flight crew. Everybody got a common understanding of it at once.”

Getting Odyssey’s power-up checklist read up to the crew was a major hurdle, but there were still plenty more to clear. The LM power margins were good to go, which allowed for an early power-up late Thursday night. It afterward operated on a fairly healthy 42 amps for the final nine hours of its lifespan. “In retrospect, the LM power was managed conservatively and that was understandable,” Lunney said. “But we had not been sufficiently sensitive to the crew condition in the cold, cramped spacecraft and the difficult sleeping environment. A fully informed assessment would likely have led us to release more LM power earlier to ease the checklist planning bind and to warm the cabin. We could have provided some improvement on both those counts. Even so, the crew never complained and performed heroically.”

The trajectory continued to shallow, and a fifth midcourse correction was performed at 6:52 a.m. on Friday, a little less than five hours before reentry. Gene Kranz’s team returned to the MOCR, taking their places alongside the one led by Gerry Griffin. Like Bill Stoval on the one before it, the flight’s last trajectory adjustment caused FIDO Dave Reed and retro officer Chuck Deiterich all kinds of headaches. They were fat—they had lots of thrust, lots of fuel, and lots of options to use either the LM’s ascent or its descent engine. They could not use any power to set up the platform in the LM, but they worked around that problem by orienting the stack at the horns of the earth. To the crew, the terminator of their home planet made it look like a crescent moon and the object was to place the crosshairs of the AOT on one of its “horns” for the check.

Dave Reed insisted on running one last simulation in the RTCC before the crucial burn of the LM’s RCS, and it was a good thing they did. The wrong attitude had been entered into the computer, using Aquarius’s orientation instead of Odyssey’s. “Now you’re getting down to the short strokes where Chuck and I realized it’s all on our backs,” Reed said. “We would’ve killed them right then and there if we hadn’t found that. Now, what possessed me to do that one last sim beats the crap out of me.” Reed would later call his friend and Trenchmate Deiterich one of three heroes in the flight, along with John Aaron and Glynn Lunney. “The numbers were all scrambled. They didn’t make any sense at all,” Deiterich added. “So what we did was put in a Command Module maneuver in the mission plan table of zero delta-v, and when we did that and then computed the entry attitude, it came up correctly. I don’t know if it was luck or being thorough, but had we not done that, we would’ve really been confused the next day when we got to the real entry time. We sorted that one out. It was an easy workaround.”

Twenty-one minutes after the burn, it was time to cast off the damaged Service Module. At 7:14 a.m. on Friday in Houston, Jim Lovell’s description sent yet another chill through the control room.

And there’s one whole side of that spacecraft missing.

Joe Kerwin responded, similarly amazed.

Is that right?

Right by the . . . look out there, will you? Right by the High Gain Antenna, the whole panel is blown out, almost from the base to the engine.

The base? The base of the Service Module was very near the heat shield, and if it was damaged, that meant game over. The last three and a half days had been for naught. “We were still trying to figure out exactly what had happened,” Gerry Griffin said. “We didn’t know how bad the damage was. We were playing a little bit of ‘what if’ games. What if it got the chutes? That was not so likely, but what if it got the heat shield, which was where the Service Module was plugged in back there? We figured there had been damage of some kind, but we didn’t know how extensive. But there wasn’t a lot we could do about it.”

Press on. That was all anyone could do from that point forward. While preparations to cast off the LM were underway, Glynn Lunney came to Jerry Bostick with yet another problem. The Atomic Energy Commission was bent out of shape over the Radioisotope Thermoelectric Generator (RTG) on board the LM, which would have been used to power experiments on the lunar surface. The powers that be wanted to make doubly sure that since the nuclear device was not going to be left behind on the moon, it must be safely deposited somewhere in the ocean. Bostick’s response was quick—you’ve got to be kidding, right? “Glynn said, ‘I know, but just double check and give me something I can tell them to make them happy,’” Bostick said. Reluctantly, Bostick told Chuck Deiterich and Dave Reed about the request and their response was pretty much the same as his had been. The two men checked and made a tiny adjustment to the LM’s separation attitude to ensure that the remains of the LM that did not burn up during reentry—the RTG included—would impact the Tonga Trench and one of the deepest spots in the south Pacific.

At 9:10 a.m. in Houston, the Command Module’s comm system was activated. Aaron quickly checked every possible piece of status and configuration information. “I was relieved and delighted to find the CM systems functioning properly and that the power-up procedure had worked as envisioned—and just as impressive, Jack had executed the procedures perfectly,” Aaron concluded.

The CM platform was course aligned based on the LM’S alignment, using the same technique used much earlier to transfer alignments from the CSM to the LM. Swigert had some difficulty with sunlight reflecting off the LM, but he was finally able to refine the alignment using star sightings.

Next came the attitude change for jettison of Aquarius.

Setting it up required Lovell to yaw the docked vehicles to an out-of-plane attitude, in order to minimize the possibility of making contact. Miraculously, everything had gone according to plan, when suddenly guidance officers Ken Russell and Will Presley noticed the CM’s platform was headed toward gimbal lock.

The crew was quickly alerted of the problem. Lovell was using the LM platform reference to effect the attitude change, and due to the two platforms being aligned in different physical orientations, he was not aware of the impending gimbal lock. “We all held our breath,” Aaron remembered. “We watched and waited as Jack, in the CM, coordinated with Jim in the LM to avoid gimbal lock. We all breathed a sigh of relief when the attitude maneuver was successfully finished.”

The new procedure had not been checked for this condition prior to sending it to the crew. It had very nearly been a costly oversight, because a gimbal lock would have destroyed the alignment with very little time remaining to recover. Aaron remembered thinking that all that work and planning for reentry was almost for naught. It was just one more near-disaster on a flight that already had a long, long list of them.

Aquarius was sent on its way at 10:43 a.m. Friday. It was a spacecraft that could never have flown in the earth’s atmosphere, yet it had just done its part to save the lives of three astronauts. “I think our whole telmu team was on shift for the jettison,” said Merlin Merritt. “It was sort of an excited, happy time—a time of elation as we felt our telmu team had done our part to save the mission as well as the lives of the astronauts. However, as with life itself, we were excited and ready to move on to the next stage to see if the Command Module could withstand the stress of reentry. It was sort of a feeling of mission well done, but we couldn’t celebrate yet.”

With just a handful of minutes to go, there was not much left to say between the astronauts in the spacecraft and the controllers in the MOCR. What Kerwin and Swigert did have time for was a bit of good-natured chit-chat. Swigert began.

You have a good bedside manner.

Kerwin laughed.

That’s the nicest thing anybody’s ever said! How about that?

Next, it was Swigert’s turn to perk up the ears of those in the Trench.

Sure wish I could go to the FIDO party tonight.

That prompted more laughter from Kerwin, who got in a dig on the bachelor Swigert’s reputation as a ladies’ man.

Yes, it’s going to be a wild one. Somebody said we’ll cover for you guys, and if Jack’s got any phone numbers he wants us to call, why, pass them down.

Moments later, static. At last, 142 hours, 40 minutes, and 45.7 seconds into the flight, at 1:53 p.m. on Friday, 17 April 1970, Odyssey began digging back into the earth’s atmosphere over Australia. Communications were lost due to the ionization of the atmosphere around the spacecraft—a period known in the MOCR as blackout—some fifteen to twenty seconds later. A hush fell over the room, quite unlike anything it had ever experienced. All eyes were on the clocks, and at the moment blackout was expected to end—nothing. Only more silence. A minute passed. Still no word from the spacecraft. Kranz asked Deiterich a question, hoping there had been some sort of mistake.

Chuck, were the clocks good?

It was almost in a whisper that the veteran retro officer answered.

They’re good, Flight.

The delay meant different things to different people in the room. “They were probably the longest moments of the entire mission,” Kranz said. “There’s a very graphic photograph of all the flight directors standing at the console, and basically, you can just see the guys staring at the clocks. That picture was taken just about the time we were expecting acquisition of signal and we didn’t get a response from the crew. The expression on the faces was looking and wondering what in the hell went wrong.” Griffin was standing next to Kranz, and he was wondering the very same thing. “We couldn’t raise them and we couldn’t get voice comm with them,” Griffin added. “Nobody said anything. We didn’t even look at each other. We were all kind of looking straight ahead. I know I thought, ‘Good God. We’ve come all this way and got them all the way back here and that dang heat shield had been damaged and they didn’t make it back in.’”

An outright despair was closing in on the Trench. “In the back of our minds, Chuck and I knew we had kept having a problem with the spacecraft drifting and altering the reentry angle,” Reed concluded. “It obviously was coming in shallow and instead of being three minutes like it was supposed to be, we didn’t hear from them. Whose head does this fall on? Chuck and Dave. That’s it. Nobody else involved. We were the ones who had to pick the vectors. We were the ones who computed the midcourses. We were the ones who decided to tweak that midcourse. My God, think about it. A minute goes by, and you still don’t hear them? I’m sure there was enough gravity around me, I probably crushed the floor.”

Jerry Bostick, the branch chief, went through one of the biggest mood swings of his career, if not his life. “Before we went into blackout, it was a great feeling of relief and accomplishment,” he said. “We have done the impossible here. We’re going to get these guys back. Then we went into blackout and it lasted about a minute longer than we were expecting. We’d never had that before. Everybody was thinking, ‘There was some damage to the heat shield and we’ve lost them.’ Personally, I went to one of the biggest letdowns I’ve ever had. That last minute of blackout was not a good time.”

An agonizing one minute, twenty-eight seconds passed between the expected end of blackout and S-band contact finally being established with recovery aircraft. A minute later, helicopters in the area had Odyssey in sight. Finally, voice contact came at 2:03 p.m.

Kerwin tried to establish the connection to Houston.

Odyssey, Houston standing by. Over.

Five more seconds passed before Swigert’s voice was heard.

Okay, Joe!

Minutes later, the drogue parachutes were out, followed by three large, billowing orange-and-white parachutes. The control room erupted in a frenzy of unabashed relief.

Odyssey, Houston. We show you on the mains. It really looks great. Got you on television, babe.

When the crew was on the deck of the USS Iwo Jima, the celebration was on in full force. They had accomplished the near impossible. Kranz described the moment in Apollo 13: To the Edge and Back, a 1995 documentary on the flight. “About the time that you see chutes, you’ll see the cheering and the American flags come out,” he said. “And then it’s again tradition that you wait until the crew gets on the carrier deck.” It was at that point that emotion welled up within Kranz. “At which time cigars and the world map lights up and . . .” This time, Kranz stopped. “Ah, shit,” he added, looking away from the camera for a second in an attempt to collect himself. “It was neat.”

18. It had been a close call, but Glynn Lunney (foreground), Gene Kranz, and the rest of the MOCR are able to celebrate moments after the Apollo 13 Command Module Odyssey splashed down. Courtesy NASA.

It had been close, but Jim, Freddo, and Jack were home. “We knew what was at stake, and we knew how deep the hole was that we were in,” said Lunney, who along with Kranz, Griffin, Windler, and Sjoberg accepted the Presidential Medal of Freedom on behalf of the entire Flight Operations team during a ceremony at MSC the day after the landing. “Seeing the spacecraft on three chutes, short of landing, was a big indication that we got it figured out and figured out right.” There was satisfaction and accomplishment, and no small amount of humility to boot. “If things had gone just a little bit differently, we would not have been able to get them back,” Lunney continued. “Things could have happened in different sequence, different order, different place in the mission and it could’ve been impossible to recover them. Watching the parachutes, I don’t know how much of that went through my head, but we were well aware of how close we came to losing this crew.”

The splashdown party was indeed a good one that night, if not rather subdued. Most had not slept much in the last few days, so it did not quite go into the wee hours of the morning as it usually did. “Jack Swigert and Jack Schmitt were regular attendees, so Swigert knew what he was talking about,” said Jerry Bostick, referring to Swigert’s crack about the party. “We usually spent most of the time at the parties cutting each other down for mistakes we had made, but this one was tame in that respect. We spent most of the time congratulating each other on a job well done.”

Sy Liebergot went home that day, yet he was not overly exultant. He had the nagging feeling that he had not performed like some sort of “super EECOM.” He wound up with nightmares in which he relived in great detail the experience of being on console as the accident unfolded. Awakened every morning for two full weeks, Liebergot doubted himself and his performance. During yet another dream one night, he was finally able to come up with perfect answers for every problem caused by the explosion. Still, Liebergot’s calls made no difference to the final outcome of the flight. Relieved, he never had another nightmarish, nighttime vision.

His subconscious, he joked, had let him off the hook.