Gene Kranz - Failure Is Not an Option

There is no such thing as a first team in mission control. All teams must be balanced, equally competent, equally capable of sustaining the effort. Over the next four days the flight control teams would routinely shift every eight hours, with Lunney, Griffin, and Windler steering the return course. But at this moment the battle for the return of Apollo 13 shifted to the back rooms and factories where the components were assembled and tested. We needed their data and we needed it fast. We needed tests in the laboratories and crews in the simulators to prove the procedures we were writing. Engineers hastily recalled from sleep and still rubbing their eyes were given the challenge to get the tests running, dig out the data, bring up the simulators.

My immediate job now centered on developing the procedures for the get-home maneuver using the engine designed for the lunar landing. The maneuver would have to take place two hours after the CSM and LM passed the lowest point of the orbit around the Moon (pericynthion). My next set of decisions involved determining how aggressively to pursue a rapid return to Earth. The most aggressive option would cut twenty-four hours off the return journey and require jettisoning the damaged service module and using all of the LM descent propellants. Several other options were available and there were advocates of each option. Glynn and I kept our powder dry, abstaining from the debate, knowing Kraft would ultimately turn to us for the final decision. Griffin strongly pushed for any option that would get the splashdown point moved from the Indian Ocean to the Pacific, where we had full recovery capability. We vetoed two faster return options as too time-critical, leaving no downstream options. Some folks lobbied to jettison the service module, but since we had not worked out jettison techniques, that was a moot point.

Almost since the instant of the explosion Glynn and I were pretty much in agreement on not using the main engine. We seemed to be running with some intuitive link that surprised our team members. When we needed to synchronize our thinking we would pass messages via runners or a brief phone call or meeting. Kraft was running interference for the flight directors and we agreed to let the NASA managers play with the options and alternatives. During a crisis every boss wants to get in on the act. Letting them think like flight directors for a few hours kept them out of our hair, and prepared them for when we laid the real plan on the table. The flight directors would get together privately, generally in the second-floor viewing room over a cup of coffee, and discuss our positions before we went to management meetings. The last thing we wanted to do was let the brass think there was any real disagreement in our group or uncertainty about our recommendations.

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.

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.”