Apollo: The Race to the Moon (46 page)

The humor and the breeziness of the Tindallgrams were window dressing for a serious endeavor. From the first Mission Techniques meeting in October 1967 through the first lunar landing in July 1969, Tindall’s collected works comprised eight thick loose-leaf volumes of highly technical memoranda. These were backed by stacks of compilations of specific techniques broken down by mission phase. During Apollo 11, these are the volumes that Guido Gran Paules carried with him to his console in just his “Descent” binder alone:

“Apollo Mission Techniques, Mission G, Lunar Orbit Activities”

“Apollo Mission Techniques, Mission G, Lunar Descent, Revision A”

“Mission G, Abort from Lunar Powered Descent and Subsequent

Rendezvous Techniques Description”

“A User’s Guide to the LUMINARY Lunar Landing Programs”

“Ground Monitoring of Guidance Velocity Residuals during Powered

Descent”

“Topography Profiles of Potential Apollo Lunar Landing Sites”

Inserted into these volumes were another hundred pages of dense technical updates and revisions.

It was impossible that anyone should sit down, absorb this Torah of flight control, then go out and be a controller on a mission. Nor could anyone expect to learn it all through actual mission experience. As Apollo was gearing up for its first flight in 1968, there had been no manned flights since November 1966. What the flight control team needed above all else was practice, and it was to this end that the simulation people plied their trade.

The Simulation Control Area (S.C.A.) was a room to the right of the MOCR proper, down on ground level with the Trench. A long picture window opened onto the MOCR to let the simulation controllers in the S.C.A. watch what was happening to their victims. Inside the room were two U-shaped work areas of consoles that looked just like those in the control room. This was where the simulations—sims—were played out, making the mission rules and the mission techniques come to life. The Simulation Supervisor, called SimSup (“Sup” rhymes with “loop”), was for the controllers what the flight instructor is for the novice pilot.

The simulations had four distinct functions. First, they were a way of keeping in shape, the equivalent of five-finger exercises for a pianist. Second, they gave everyone a chance to see whether the mission rules and techniques that worked on paper also worked when put to a test. Third, they gave the controllers experience in how to deal with the particular set of emergencies portrayed in a particular sim. And fourth, they made the controllers familiar with fear, putting them through such hair-raising, gut-wrenching adventures that nothing they encountered in an actual flight could seem more terrifying or hopeless.

The one point emphasized by everyone who was in the Apollo MOCR is that simulations never felt like games, or even practice runs. Their verisimilitude, and the seriousness with which they were taken, reproduced even the emotions of the real thing—controllers swore that, with momentary exceptions, they felt no more anxiety during missions than they had during the sims. To Gene Kranz, the sims were the reason the missions succeeded. “I could say it’s hard work, perseverance, all of those things. But it was the training process that did several things to you. First of all, it humbled you. And you’d have your successes too, and you felt good about them. You learned to pay exquisite attention to detail. You learned the nuances of the voices that are talking to you on these loops. By the time you’re finished, they have worked you over so much and so well and so thoroughly that you never considered failure.”

In Mercury days, the sims had been primitive. Harold Miller, a young Langley engineer from Tennessee, had been put in charge of developing Project Mercury’s simulation capability. He didn’t know anything about simulations—nobody did—but somebody had to do it, and, as he later recalled, he didn’t know enough to say no. He began to put together a team—Dick Koos was one of his early additions—and they tentatively began to build digital tapes that would, for example, simulate a trajectory that was not quite up to orbit. Then they would see if the tape produced realistic effects on the flight controllers’ meters (in those days, everything was on meters instead of C.R.T.s, which were not yet available). Sometimes it worked and sometimes it didn’t. Lightning from the afternoon thundershowers at the Cape, attracted by all the antennae on the roof of the Mercury Control Center, would produce power surges that set the meters back to their zero state. The computers broke down. And sometimes the men in the sim room broke down: Because they didn’t yet have programs that could automatically adjust the scenario to respond to the actions of the flight control team, the simulation controllers had to do it by hand, frantically turning knobs on a panel, trying to calibrate their responses so that the telemetry streams looked reasonably plausible to the people in the control room. They got more adroit as time went on, but it remained pretty rough.

The remote sites gave the Mercury and Gemini sims a special flavor as well. Though Mercury Control at the Cape had voice links with the remote sites, they couldn’t transfer flight data back and forth in real time. Each remote site therefore had to be a miniature Mercury Control, with its local director and FIDO and CapCom, passing on instructions from the Cape but also prepared in an emergency to take action on its own.

For the sim guys, the absence of a data link meant that they had to prepare separate data tapes for each of the remote sites. They would have a worldwide countdown, so that the tapes would all begin at the same moment and everyone around the world would have a view of the same problem at the same time. But this also put a considerable burden on the SimSup to anticipate events during the course of the sim. “The SimSup had to guess what you were going to do and when you would do it,” one of the controllers recalled, “which was the tough thing to do. You’d make a decision to abort now, but the tape didn’t say abort now, so the damned thing would keep flying.”

In those days, simulations also provided a prime opportunity for practical jokes. As the space program grew, the jokes tapered off, but in the early years nobody was sacrosanct, not even Chris Kraft. Things happened in the Mercury and Gemini sims that would have been unthinkable five years later. For example: Chris Kraft’s console in the Mercury Control Center included a screen that showed a live television shot of the launch pad. During simulations, the Redstone or Atlas of course just sat there, but the camera was nonetheless always turned on. One day a controller named John Hatcher substituted a tape of a launch for the live picture. Hatcher synchronized the tape with the simulated countdown and waited for the moment of launch. As always during Mercury, Chris Kraft was the flight director. At T–0, as Kraft pushed the little gear lever that started the clocks, the Redstone on the television screen belched smoke and fire and lifted off the pad.

The gear lever wasn’t hooked up to anything that could conceivably have launched a rocket, but the sight was too compellingly realistic to be discounted. “Look at that!” Kraft yelled in dismay to Kranz, who was sitting beside him at the assistant flight director’s console. Kranz, in on the joke, sat expressionless. “Did you see that?!” Kraft cried out again, pointing insistently at the screen, and a story was born that would be told and embroidered upon for years to come.

The sobering presence of Chris Kraft normally kept such behavior within bounds. Out at the remote sites, life was more unbuttoned. Ed Fendell was one of the many free spirits sent out to run a remote site. As local director at the Hawaii site during sims for Gemini VII, he was dissatisfied with his CapCom, an Air Force officer in training for what was expected to be the Manned Orbiting Laboratory (later canceled). The guy thought that all he had to do was to pass on what Fendell told him; he couldn’t understand that he had to dig in and learn for himself how the systems worked. So Fendell took it into his head to show the Air Force CapCom that he had to learn how to take charge. Fendell got on the phone with Carl Shelley, a SimSup back in Houston (where the Control Center had moved after Gemini III), and arranged that during the next sim Fendell would fake a heart attack. Shelley gave his approval. Fendell told his Surgeon what he was up to. At the appropriate point during the simulation, Fendell clutched his chest, groaned loudly, and toppled out of his chair. The Surgeon rushed over, announced that Fendell was hors de combat, and motioned for CapCom to take over.

The indolent CapCom was shaken. “Honolulu, this is Gemini Seven; Honolulu, this is Gemini Seven,” he called in confusion, and began to find out why he was supposed to be on top of things. Fendell was pleased. In fact, he was loving it, until a second physician waiting to come on shift, an elderly Navy doctor whose presence Fendell had not anticipated, rushed over to examine him. Fendell held his breath. “I think he’s dead,” the old gentleman announced, and began to administer cardiopulmonary resuscitation.

It still would have been okay, except that, back in Houston, Shelley had forgotten to tell Chris Kraft that it was all a charade. For the next few hours there were messages coming in from Houston inquiring solicitously about the status of Fendell. “Later on, of course, it came out that it was all part of the sim,” Fendell said, “and Kraft just went berserk. He like to killed Shelley.” But it worked, Fendell added. “The CapCom took over, ran a series of passes, and we had a good time.”

The jokes notwithstanding, the sims were deadly serious business, no more so than in the elemental, life-and-death decision named “abort.” An abort during Mercury and Gemini usually meant de-orbiting and coming home early. An abort during Apollo could mean coming home early or it could refer to halting an attempt to land on the moon and returning the LEM to the command module in lunar orbit.

The worst abort situation would be during powered flight, with the astronauts strapped to a Saturn rocket that could kill them within seconds. “I approached each launch and rode through each five minutes of powered flight in a state of petrified terror,” recalled tough old Walt Williams of the Mercury launches, and it didn’t get any easier for the people who controlled the Gemini and Apollo flights.

Of all the possibilities of catastrophe during powered flight, the worst was what the simulation people called “the pad fallback case,” in which the booster lost power within seconds after liftoff. The astronauts could have survived such an event, at least theoretically. The escape tower on the Apollo spacecraft generated 134,000 pounds of thrust on an 11,000 pound spacecraft for three seconds, an experience that would have left the astronauts battered by the g forces, but would have gotten the spacecraft away from the Saturn before the fireball engulfed it. But the abort decision in such a case would have to be made instantly by sensors within the booster that were supposed to detect the incipient catastrophic failure, before the Control Center or the astronauts would have time to react.

If the launch vehicle had risen a few hundred feet above the pad, then Booster had about four seconds to look at his data, decide something was wrong, and call an abort. Booster therefore had an independent abort capability on his console, consisting of a toggle switch with a red cover to light the onboard abort light and a voice link with the spacecraft (all aborts required both cues). To Kranz, “that was the worst, worst case,” and the sims included one every so often, to keep Booster mentally prepared to give up so abruptly on the mission.

After the vehicle had gained some altitude, the abort decision became more leisurely. Two people in addition to Booster had abort switches, and now they played decisive roles. One was of course Flight himself. The other was FIDO. Neither one of them actually caused an abort to happen by flipping his switch; instead, they lit an alarm light informing the crew that an abort situation had arisen, leaving it to the crew to take the action to initiate the abort. The abort itself could take one of two forms, depending on the situation: separating the spacecraft from the rest of the stack and firing the escape rocket, or casting off a malfunctioning first or second stage and continuing to ascend on the S-IVB. Unlike Booster during the first moments of launch, FIDO did not have the authority to call an abort unilaterally. His switch was to be reserved for situations in which Flight and the flight crew had already decided to abort but were waiting to reach a particular range and velocity before they did so. In such a case, FIDO would use his switch to tell them when that moment had arrived.

But these were only a limited subset of the many situations in which an abort might become necessary. During powered flight, the rule of thumb was that the flight controllers had from about fifteen to twenty seconds to make an abort decision. For anything more exigent than that, the crew would take action based on their onboard displays. But for a problem that involved control of the vehicle—multiple engine failures, a hard-over engine (meaning an engine that had gone out of control and gimbaled to its limit), or trajectory deviations—the astronauts would have, in Kranz’s words, “no clue in the world what the hell had gone on,” and the controllers would have to take the lead. If the controllers took longer than twenty seconds, a spacecraft caught in a turning motion would probably break the tension ties that held the C.S.M. to the rest of the vehicle, and then they would have a whole new set of problems to worry about. “So what we had to do was get our timing down for that case where we had lost control just due to engine hard-overs,” said Kranz. “And we had to get the crew off before we had structural failure.” The SimSups “kept working, working, working that case.”

The difference between the earlier manned programs and Apollo was that all of the old problems had multiplied. In Mercury and Gemini, there had been one period of powered flight, the launch phase, and three abort modes: return to earth using the escape tower to separate; at higher altitudes, separation without the escape tower; and, in the latter stages of powered flight, abort to orbit. In Apollo, there were six separate instances of powered flight: the launch phase, translunar injection, lunar-orbit insertion, lunar descent, lunar ascent, and trans-earth injection. During all of those phases except lunar ascent and trans-earth injection, there were multiple abort modes to worry about. In Apollo, the flight control team had to be prepared to fly two completely separate spacecraft, each with its own maze of systems.