Failure Is Not an Option

by Gene Kranz

  We were ten hours into the crisis when Lunney handed over to Griffin. I joined them at the console, reviewing the maneuver options in preparation for Kraft’s meeting in the viewing room on the second floor, where the shift change briefings for management were held. By now Glynn and I had settled on the maneuver option that got us back to a landing in the Pacific at 142 hours MET. This was a middle-of-the-road option, cutting only twelve hours off the return journey. Because we had doubts about our ability to check the LM navigation with crew fixes on stars, we chose this approach, which gave us a greater margin for error in maneuvers and reserved some propellant for correction maneuvers on the return. The road to safety would prove to be long and cold and dark.

  19

  COMING HOME

  April 14, 1970

  As I arrived with the White Team at 3:00 p.m. Houston time for the get-home maneuver I glanced up at the viewing room and chuckled. Two members of the press (one print and one TV) and their public affairs escort were now firmly compressed in a small glass booth about the size of a large desk at the far corner of a viewing room. The reporters, their noses pressed to the glass, were listening to our communications. Headsets, reference data, pencils and paper, and all kinds of the tools of their trade were visible on the desktop. Jack Riley was the PAO chaperoning this duo in the viewing room. I had no doubt he would have preferred to be on the floor. I just hoped they were pumping air into the room or we might have another emergency to deal with. From now on we were living in a fishbowl. Everything we said and did was going directly into the homes of America and the world.

  Griffin had set us up well for the maneuver and, after a brief handover, the White Team was back on console. As the spacecraft passed the Moon, the lunar gravity pulled it in an arc toward a rendezvous point with Earth. Our job was to hasten the rendezvous. We briefed the crew on the maneuver procedures, mission rules, consumables, and the return strategy on the remote chance we would lose communications during the return. Throughout the briefings I continually stressed to the controllers and to the crew that the burn start time was not critical. We were already on a return path and if anything did not look right we could NoGo the burn until everyone was confident about proceeding with it. I had a high degree of confidence in this maneuver, since it was a variation of an LM engine burn we had executed on Apollo 9.

  There was an air of expectancy in the room as the maneuver time approached. The viewing and control rooms were filled to the brim. The maneuver was a turning point in the struggle to get our guys home, anchoring the return time and placing many tough decisions behind us. Two hours after Apollo 13 passed behind the Moon, the crew ignited the small descent engine designed for the Moon landing, burning for four and a half minutes and increasing the return velocity by almost 1,000 feet per second. The execution by the crew was perfect, fixing the landing time for 142 hours and moving the landing point from the Indian Ocean to the Pacific near Samoa. The aircraft carrier Iwo Jima was dispatched to the landing point to recover the crew and spacecraft.

  Getting back on the console with my team felt good. By the process of elimination, we were whittling down the work yet to be done and improving the crew’s chance of survival. I had one more thing to do before finishing the shift. The systems controllers had been watching the temperatures at various locations on the LM (and by inference the CSM) since we had started using the LM as a lifeboat. We initially believed that a random drift would keep the temperatures in limits, and conserve power, water, and propellant. The designers disagreed. Prior to the return maneuver I spent some time in the spacecraft analysis room reviewing their data. I left the meeting convinced that we had to execute a passive thermal control (PTC) maneuver before we powered down and sent the crew to sleep.

  The PTC is a kind of rotisserie maneuver that slowly spins the spacecraft on its long axis so the sun can heat all sides. The maneuver is used routinely to ensure equal heating of all surfaces and the systems under the skin of the spacecraft. Setting up this roll maneuver is not easy. After getting properly oriented the spacecraft must become perfectly motionless, then the small control jets are briefly fired, setting up the spin. If the procedure is not done perfectly, the spin will rapidly turn into a wobble and diverge from the sun line. This procedure had never been done in a docked configuration using the LM jets, which were not favorably located for this procedure.

  As I was discussing the procedure with the White Team, Slayton and Kraft approached the console. When Slayton growled a hoarse “Gene,” it was obvious they had something on their minds, so I stood and turned to talk to them. Slayton didn’t waste a second. Jabbing me with his finger, he said, “I want you to get my crew to sleep. They are too damn tired, they are going to make a mistake.”

  I, too, was tired as I looked into Slayton’s grizzled face; his heavy black beard stubble was starting to show. We glowered for a few seconds, but before I could respond, Kraft started in. “I want you to get the spacecraft powered down. You’re calling it too damn close on the batteries!” My team was approaching our thirty-fourth hour; we also were running out of gas. I turned to Slayton and snapped, “Crew sleep and power-down are gonna have to wait. We won’t get them home if we let everything freeze up. I’m gonna do the PTC.” Slayton and Kraft were not used to being shouted at. Before they could respond further, I motioned them away and returned to my seat at the console. “CapCom, read the crew the PTC procedures,” I ordered.

  Slowly, Kraft and Slayton retreated to a position at the console above me. Max Faget, the chief of engineering, sat down next to Kraft. I think spacecraft analysis had sent him out to lobby on behalf of our plan if the argument got too heated. Faget’s earnest Cajun voice carried. “Chris, that’s the right thing to do,” he said. “There is no use getting the spacecraft back if the systems don’t work when we reenter.” I envisioned Max patting Kraft on the hand, telling him to settle down.

  Every second of delay stole time, power, and badly needed sleep for the crew. The spin-up maneuver had to be perfectly set up, very deliberate. Doing it using the LM jets was like trying to thread a needle with bad eyesight. After about forty minutes the crew fired the thruster to start the roll. We watched the resultant motion, and within minutes it started wobbling. To head off a repeat visit from Kraft and Slayton, I roared, “Okay, CapCom, tell the crew we’re gonna have to do it again!” I could hear Kraft and Slayton grumbling on the console above me, probably muttering in my direction, “We told you the crew was too damn tired!” This was a good test of the flight director’s mandate. I respected both Kraft and Slayton for not second-guessing me and letting me get on with my job.

  The second spin-up attempt worked, and we initiated the complete power-down of the spacecraft. It was now twenty-six hours after the explosion. The crew and my team could finally get to sleep. I tried not to think about how cold it was going to get for the crew, but I knew we had decided on the right option, staying powered up until we went around the Moon.

  With the shift over, I called a brief meeting of the White Team in Room 210. Aaron’s battle plan had the crew powering down to a twelve amp load (about a quarter of the power consumed by a household vacuum cleaner) for the return journey. It would be an ordeal for the crew. It would get cold, damned cold, but there was nothing we could do. Crew comfort was our last priority; they would have to tough it out. The power numbers had improved as a result of the work of Peters and Aaron, but we were still too tight on water. When we ran out of LM water we planned to use waste water and urine for cooling, if needed.

  Engineering gave a status report indicating that they were close to a solution on another problem. The crew’s breathing was slowly poisoning the cabin atmosphere with carbon dioxide. We had run out of the cylindrical air scrubbers used in the lunar module, and engineering was testing an adapter for the square command module canister that was being fabricated from cardboard, a plastic bag, a sock, and a hose from one of the crew’s pressure suits. You have to picture a plasticized flight plan cover, to f
unnel air flow, curved over the top of a lithium hydroxide air scrubber (for removing CO2) and a hose attached to the scrubber’s bottom, which in turn ran down to a small fan, which pulled air through the scrubber and sent it through the sock, which served as a filter. The device was all held together by duct tape, a commodity which, fortunately, was always carried in the spacecraft.

  By the time we arrived at this rather bizarre but functional contraption, we had been awake for a day and a half, so I told the White Team to get six hours’ sleep. Then we would start working out the final set of procedures for the reentry phase. I had developed a habit on previous missions of resting in the viewing room when we had problems. The room was as cold as a meat locker, quiet except for the crew and flight director voice loops, and with few occupants except during major events. I staked out the upper corner of the viewing room as my home base when I wanted to rest, and after a thirty-to forty-five-minute catnap generally got back on track quickly. Since there were a lot of people in the third-floor room, I went down to the second-floor viewing room. It was also close to the action if someone needed me.

  The final phase of the struggle to return the crew now began. Flight Control had fought a delaying action. We had stabilized the situation and protected the options. We had a pretty good idea of the resources available in both spacecraft. The show now belonged to Aldrich, Peters, and Aaron. Their job was to manage the resources, trade off the options, build margins wherever possible, and finalize the detailed procedures for the final entry phase of the mission. If ever there was a trio prepared for battle it was this one.

  The ebb and flow among the design, test, and operations communities provided answers to the questions we had yet to ask, problems we had yet to identify. Aaron Cohen and Owen Morris, the NASA spacecraft program chiefs, rolled up their sleeves and joined with their counterparts Dale Myers from North American and Tom Kelly from Grumman. Together they directed a superb effort to solve a complex technical problem in a very tight time frame. These four engineers were the highly respected generals who commanded the engineers in the factories, laboratories, and test facilities. I believed that this team could move mountains. The flight directors had worked with all of them during the spacecraft redesign after the Apollo fire and subsequently in preparation for the missions. The trust among program manager, designer, and mission control was absolute.

  Added to this respected group were two other great engineers, Don Arabian and Scott Simpkinson, whose pedigrees traced back to the early days in Mercury Control. They were well versed in real-time troubleshooting and were fully aware of the high-stakes poker we were playing. Above all, they knew that you had to have answers before the clock ran out.

  This task force worked in the SPAN (spacecraft analysis) room, focusing on only one thing—how to get the crew home. They provided the missing pieces we needed. The handovers between engineering and operations were smoother than on an Olympic relay team and we did it repeatedly for almost four days. There were a lot of heroes but the SPAN team never got the gold medal and the recognition it deserved.

  Aldrich was the scribe, watching the clock, assembling the pieces, listening to the debates, then deciding when enough was enough and it was time to put the plans on paper. Aaron was the accountant, keeping a meticulous balance sheet on the precious resources. Aaron became critical for power, Peters critical for water. Aaron checked every procedure entry, exercising his sole and absolute power of veto, often sending the controllers back to square one, telling them, “Your input was not good enough. Give it another shot and be back to me in an hour with your bottom line.” Aaron, with his veto authority, soon became the dominant player in the return planning. The LM water available for cooling dictated an extremely low power level during the return journey. As a result it soon became clear that we could make it home with the LM battery power.

  When Aaron recognized we would now have some power to spare he wanted to recharge the command module batteries. The three CM batteries would be the sole power source for the final hours of reentry. Since the batteries had provided the CSM power in the minutes after the explosion, they were no longer fully charged. Aaron wanted to find a way to charge them to maximum capacity.

  When the two spacecraft were designed, it was never envisioned that we would need to charge the command module batteries from the LM. But now the controllers started looking at ways to use the LM heater cable in the reverse direction to charge the batteries for the final entry phase. Aaron and Aldrich now started bartering with Peters for the excess power in the LM batteries. The controllers were intensely debating the risks to both systems, trading off options but keeping an eye on the clock. Aaron finally resolved the issue: “We’re going to charge the CSM batteries. I can’t see leaving any power in the LM when we jettison it. I want a test rig set up to verify the procedures and to measure the power loss during charging.” With the decision made, he turned to the SPAN team to set up a test rig to prove the procedure.

  While we labored in Mission Control, SPAN continued to dig out the answers and give us their best judgments about tough, critical questions that would lead to irrevocable decisions. “How cold can the thrusters get and still fire?” “How many amp hours are really in the battery beyond the spec values?” “We don’t want to chance skipping off the Earth’s atmosphere because our trajectory is too shallow—how critical is the reentry angle?” These questions triggered other questions; discussions of alternatives abounded; engineers wanted priorities. The engineers needed to know how their piece of data fit in to that of other engineers working on related problems.

  A 100 percent correct answer, too late to be of use, was worthless. The White Team needed answers quickly to develop the procedures, integrate them in the simulators, and voice them up to the crew. Personally, I wanted a few hours to sit and think before the White Team and crew started the final eight hours of entry.

  I don’t think Aaron got any sleep in the last forty-eight hours. He had delegated well, but he knew where the buck stopped. His intuition was incredible. He kept turning up at the place where the logjams were building. With a few words he cleared the jam, then moved to another room, another debate. His prescience was almost mystical.

  Throughout this period, astronauts in simulators tested the entry procedures, looking for traps that could endanger a near-freezing, deadly tired, and dehydrated crew. We all knew that cold and dehydration impair cognitive and motor responses—and it was now damn cold in the spacecraft.

  In the final thirty-six hours the White Team came together at four-hour intervals with Aldrich, Aaron, and Peters to review the progress. Buck Willoughby, my GNC officer, was concerned about his thrusters. The LM would provide attitude control until jettisoned, then control would switch to the CM. Without heat since the explosion, the CM thrusters were dangerously cold, the propellant valves sluggish. Willoughby wanted a “hot fire” test to make sure they were all working before separating from the LM. The Trench joined in supporting the request. Slayton lobbied to power up early, using excess power to warm the spacecraft and his crew.

  I vetoed most departures from the agreed procedures, stating that we had to keep them simple, and I wanted to be able to function in case of an LM battery failure. I intended keeping everything possible in reserve until I knew we had it made. Then and only then would I consider other options. The flight planners started a shopping list to be used when power became available. The hot-fire and early power-up were put at the top.

  Since the White Team would handle the final shift for reentry, my deadline to Aaron and Aldrich to complete the procedures was landing minus twenty-four hours. As the deadline approached, the crews in the simulators wanted more time to check out the “final-final” set of procedures, which were in the tenth revision. Thirty-nine pages in length and containing more than 400 entries, they were the ticket home for our crew. The astronauts in the simulator were bothered by the continual changes and the frequent updates. They wanted a run-through with the final set of procedure
s. I froze further changes to the procedures and agreed to give the simulator crews six more hours to give me their okay.

  With this delay, Lovell finally showed his exasperation with the entire process. The crew had been living in an icebox that was hurtling toward the Earth. Other than a brief overview of the intended sequence of the final eight hours, Mission Control had given them nothing but the reassurances that “the procedures are coming along.” Lovell wanted specifics, not vague reassurances.

  Aldrich kept the master copy of the procedures in his personal possession, identifying each update by a revision number. He guarded them as if they were the tablets Moses brought down from Mount Sinai. Others may have had mark-ups, but his procedures were the ones that would be executed. His great fear was that he would misplace them as he moved between the meeting areas. At the time of Lovell’s prodding, Aldrich was working on the third revision for Thursday, April 16. We were less than twenty-four hours from entry.

  In the final hours the flight planners, John O’Neill and Tommy Holloway, became the last link in the chain to get the crew back to Earth. They established a loop between the crews in the simulators, the controllers, and the work being done by Aldrich and Aaron. They tracked the instructions voiced by the CapCom to the crew. Their checks and balances virtually guaranteed that in the rush to brief the crews nothing would be overlooked. They were the guardian angels, always hovering near and making sure that we gave the crew the right information at the right time.