Moon Lander: How We Developed the Apollo Lunar Module (Smithsonian History of Aviation and Spaceflight)

by Kelly, Thomas J.

  On their second excursion Conrad and Bean walked to Surveyor, inspected and photographed it, and took back samples to show the effect of two and a half years of lunar “weathering” on various materials. They also gathered rock and soil samples from the rim of Snowman crater and other craters in the vicinity, packing more than seventy-five pounds of samples for return to Earth. They kept up a running commentary on what they were seeing and doing, including many excited cries of awe and wonder. It was a pleasure to share their delight in the new world they were exploring.

  As the time for lunar liftoff approached, tension mounted both aboard Intrepid and in Houston. Conrad told Bean not to worry because if the ascent engine did not work, they would become “the first permanent monument to the space program.”8 In SPAN I worried more about the rapid sequence of explosive-device firings that had to take place to separate the ascent and descent stages. All the pyrotechnics were fired by squibs of very thin wire—could the lightning strikes at liftoff have induced currents that burned them out? There was no way to tell. A positive sign was that all prior explosive devices had worked as commanded to deploy the landing gear and to pressurize the ascent and descent propellant tanks and the reaction control system. I just had to hope that the remaining devices were also unimpaired.

  The best thing about lunar liftoff was that you knew in an instant if it was successful. And it was, as the ascent stage separated smartly from the descent launch platform and rapidly accelerated toward lunar orbit, Yankee Clipper, and the waiting Dick Gordon. Rendezvous was again a majestic, slow-motion maneuver, precisely executed, and the spacecraft docked and latched together without problems. We heard the joyous cries as the long-separated shipmates embraced and congratulated one another on their good fortune. Apollo 12’s crew was expressive and demonstrative, and they sometimes forgot to turn their cabin microphone off, so we in Houston could briefly share in their joy.

  Soon the LM’s part of the mission was over, and the crew was Earthbound aboard Yankee Clipper. My colleagues and I returned to Bethpage and watched the splashdown and aircraft carrier recovery in the Mission Support Room. I savored the Apollo 12 experience—although there had been plenty to worry about, nothing had gone wrong. Except for failure of the portable TV camera, which Al Bean had burned out by pointing it at the Sun early in the first moonwalk, every mission objective had been met or exceeded. NASA was impressively able to handle unforeseen emergencies like the lightning strikes, and the entire mission support team, NASA and contractors, was growing more efficient and professional. We were learning from each mission and making many improvements in the way we operated. The number of LM anomalies during the mission was lower than on any previous mission—a positive trend for each mission thus far.

  Apollo 12 shifted the goal from landing on the Moon and surviving to purposefully exploring the Moon. Clearly the Apollo program was not just a stunt, as some detractors had charged, but a serious and unique opportunity to answer scientific questions that had long puzzled mankind. Where did the Moon come from? How was its origin related to Earth’s? How old was the Moon, and what was its geologic composition and history? We would soon have some answers to these and other cosmic questions.

  Swept forward on a rising tide of optimism, I decided not even to cover the next mission in Houston but to leave it in the capable hands of my colleagues while I stayed up at MIT in the Sloan Fellows program.

  Even at the great distance from Moon to Earth, the irrepressible, bubbling personality of Pete Conrad and his crew had made Apollo 12 unique—a highly successful and productive mission that was also an adventure and a privilege shared by all those who supported it.

  17

  Rescue in Space

  Apollo 13

  I groped for the ringing bedside telephone in the midnight darkness. Knocking the receiver to the floor, I groaned as I snapped on the light, shattering for good any pretense of sleep. I felt my wife stir protestingly beside me as I fumbled to retrieve the receiver, trying not to wake her.

  “Tom, have you heard the news?” asked the crisp, worried voice of my Grumman colleague Howard Wright.

  Negative grunt.

  “Well, turn on your radio—Apollo’s in trouble. There’s been an explosion or something. The company’s chartering a plane to fly us to Bethpage. Meet me at the general aviation terminal at Logan Airport at 1:30.”

  “Are they alive?”

  “Yes, but they’re in real trouble.”

  They were in trouble all right, and would probably have to use the lunar module as a lifeboat. There wasn’t time for Wright to tell me more than that. He promised to fill me in on the details at the airport.

  Joan looked at me wide-eyed with concern.

  “It’s Apollo,” I told her. “They want me to get down to Bethpage right away.” We were living in the Boston area on a temporary one-year assignment while I attended the Sloan Fellows management program at MIT. After seven years of total dedication to designing and building LM, and following the successful first lunar landing of Apollo 11, the company decided that I could use a change and allowed me to compete for a Sloan Fellowship, which I won. Howard Wright was also in Boston on company sponsorship attending an advanced management program at the Harvard Business School.

  The radio spewed out a stream of ominous phrases: “Apparently an explosion … difficulty maintaining control … fast running out of oxygen, water, and electric power … Mission Control assures us that the crew is, for now, safe, and has several options for survival.” As the announcers stumbled over unfamiliar technical terms and space jargon, there was no mistaking the excitement and concern in their voices. Could this be the night when America’s vaunted manned space program would go down to defeat and disgrace, after such a long string of stunning successes, including two manned lunar landings and explorations? The grim prospect loomed of three brave men gasping and suffocating in space while the whole world watched and listened, of their shriveled mummified corpses remaining permanently in orbit as a monument to mankind’s overreaching and America’s technological arrogance.

  Two of the three men who were exposed to the unrelenting peril of space were my friends and professional associates. Fred Haise and Jim Lovell had each spent many days at our Spacecraft Assembly and Test facility in Bethpage, putting the lunar module through its paces against test and checkout computers. The third astronaut, Jack Swigert, I had met briefly in Houston, but I knew he was cut from the same competent, no-nonsense test-pilot cloth as his crew mates. I could picture the three of them, jaws jutting, brows furrowed, as they tried to figure how to work their way out of yet another tight spot. They would be carefully checking all instruments on board the spacecraft, looking through the oxygen and electrical power system diagrams and emergency procedures, and discussing their options in calm, matter-of-fact voices. The imminence of danger would not alter their professional habits.

  It was exciting to think that the lunar module might become their lifeboat, the key to their rescue. After the first successful lunar landing, Volkswagen, whose VW Beetle was considered an ugly car, ran a full-page ad in the New York Times showing the LM with headlines trumpeting, “It may be ugly, but it gets you there.” Where LM was concerned, beauty was definitely in the eye of the beholder, and to me she was beautiful.

  Joan routed our oldest son David out of bed to stand watch over the rest of our six children while she drove me to the airport. I was still stuffing LM reference data into my briefcase as we left. It was a beautiful clear April night, and when I met Wright on the tarmac we both strained irrationally to see Apollo up there near the bright Moon. He had talked with some of our people in Bethpage and Houston and determined that NASA definitely planned to execute the LM lifeboat mission, and quickly, as life-sustaining supplies on the mothership command module were rapidly seeping from a mortal wound in its oxygen system resulting from the explosion of an oxygen tank in the service module. There seemed to be no reason not to try the lifeboat approach, for although it had neve
r been rehearsed with either the flight or ground crews or written into specific operational procedures, we had studied the rescue possibility early in the LM’s design and had provided additional oxygen, water, and power capacity to cover it.1 However, to go from a preliminary systems design study done six years earlier to real-time execution of a complex and unplanned sequence of space maneuvers by flight and ground crews untrained in its specifics was quite a leap. We would soon find out whether men and machines were up to it.

  During the flight to Grumman’s headquarters and main factory complex in Bethpage, Long land, Wright and I sat behind the pilot in the small, dark cabin of the light plane, lit only by the dim reddish glow of the instruments, looking at the night sky with the moonlit earth below. We talked briefly, trying to reassure each other that the lifeboat mission study we barely remembered had been carefully done and held out the promise that rescue was possible. Then we lapsed into silence, each worrying about whether indeed we could collectively pull it off. In the dark isolation of the cabin, I imagined that I was with my astronaut friends in Aquarius, the mission call-name for Apollo 13’s LM. How would they feel knowing their survival depended upon the ability of the LM to perform an emergency mission for which it had not been designed or tested? What could we all do, on board and on the ground, to improve the odds of this gamble? Doubtless it would be terrifying. But wouldn’t they feel a gradual growth in confidence as the LM continued to supply sustenance minute after minute, hour after hour, with the hiss of the air supply and whir of the fans providing the same reassurance that I derived from the steady baritone drone of the light plane’s engine? And they would know that thousands of engineers and technicians on the Apollo program all over the nation would be exercising their ingenuity to help them meet this challenge. By the time we landed at the brightly lit but deserted Grumman airport I was confident that whatever it took, we would find a way to bring our friends safely home.

  We were driven across the runway to Plant 5, where Grumman’s Apollo Mission Support Center was located. As we walked toward the front entrance, I met several of my engineering colleagues who were just arriving. Turning around on the front steps, I saw a flood tide of Grumman engineers heading toward the building, anxiety evident in their tense, lined faces. Although it was three o’clock in the morning, it looked like the normal day shift start time of 8:00 A.M.; only the bright moonlight jarred that illusion. No one had asked all these people to come into work—they had simply heard about the problem and decided to do whatever they could to help. It was evidence of the dedication of our Grumman team that I will never forget.

  Once inside the Mission Support Center, Wright and I met with the shift leader, John Strakosch, who filled us in on the current situation. During the time it took us to fly from Boston the astronauts had succeeded in stabilizing the spacecraft’s attitude, after the oxygen stream had ceased venting from the second, punctured tank. All three crew members were in Aquarius, sustained by the LM’s consumables. They were gradually learning how to maneuver the combined command/service modules and LM using the LM’s reaction control rockets. Because the mass and center of gravity of the combined modules were so different from that of LM alone, the spacecraft did not respond in anything like the normal manner to which the pilots were accustomed from ground simulations. It gyrated disconcertingly when given straightforward commands to roll, pitch, or yaw.

  At NASA’s Mission Control Center in Houston, flight controllers sat at their consoles, intently watching the instrumentation readouts from Apollo 13 as they flickered in greenish symbols on their video screens. In a small back room across the hall from the MCC, the SPAN Room, and at a nearby office building, a support team of about two dozen of Grumman’s top LM engineers was helping NASA find answers to urgent questions such as, What type of Earth return trajectory should be selected? How much time would it take to return? Would the LM’s consumables last that long? What techniques should be used to perform the return maneuvers? Questions requiring research or access to prior test data were forwarded from Houston to Bethpage where more people could be deployed to find the answers.

  Our Bethpage Center had four consoles with the same video displays of LM instrument readings beamed from space in real time as did the Mission Control Center. We were able to listen to the flight director, flight controllers, and astronauts on the audio network and talk by telephone with our Grumman people on the scene in Houston. When necessary we could call our subcontractors, suppliers, and consultants from all over the country. This was the first Apollo mission for which I had not been in the SPAN Room in Houston, as close to the center of action as spacecraft contractors were allowed. Despite the greater distance, our access to information and ability to participate in problem solving from Bethpage were excellent.

  The estimates of time required for Apollo to return varied between two and a half to four days, depending upon the type of trajectory. The flight director announced over the net that a modified “free return” trajectory had been selected, using the Moon’s gravity to whip Apollo around the Moon and send it falling toward the much greater gravitational pull of Earth. Once headed toward Earth, an additional rocket firing would speed up the spacecraft, reducing the return trip to about three and a half days. Two types of information were urgently required: procedures and exact data on timing, pointing, and other parameters for performing the trajectory maneuvers and accurate data of the rates at which each of the life-sustaining consumables was being depleted, together with recommendations on how to conserve them to last until splashdown. It was a good thing that all those Grummanites showed up for work in the middle of the night. Organized according to their technical specialties, the two hundred or more engineers in Bethpage were busy digging out data, conferring with experts by phone, running analyses and calculations, and studying the in-flight and prior ground-test performance of dozens of LM systems and components. We found that the LM batteries were being depleted at an alarming rate, and that immediate, drastic action to “power down” the LM must be taken to survive until reentry. The required power down was far more severe than any of us wanted. It forced shutdown of the inertial guidance system and the resultant loss of on-board data on Apollo’s position and velocity, leaving the crew freezing in the dark with only the weakest communication link to Earth still active. After double checking our numbers and scouring the possibilities for less drastic measures, we conferred with our Grumman colleagues in Houston and determined we were in agreement. Bolstered with our independent calculations and concurring opinions, they went forth to convince the NASA flight controllers that less-severe remedies would not suffice.

  While debates about how soon and how drastically to power down the LM raged on the floor and in the back rooms of the Mission Control Center, the remaining LM power continued to steadily seep away. A hastily prepared simulation in Houston, using the LM mission simulator, convinced NASA of the need for a sweeping LM power down and was used to develop the switch-by-switch procedures to be read up to the crew. With this argument settled, attention turned to the other less immediately critical consumables (water and oxygen), and to the vexing question of how to perform further return trajectory maneuvers without an aligned inertial platform on the spacecraft, if ground radar tracking data showed error buildups that required adjustment.

  Within a few hours, activity in the Bethpage Mission Support Center settled into a deceptively comfortable routine. One by one plans were developed to assure that each of the consumables would not be depleted prematurely. We provided a number of alignment and maneuver procedure recommendations for NASA to consider. From an initial feeling of impending doom, the atmosphere in the room had shifted to one of hope and optimism. By midafternoon I found myself drowsing at the console, and I slipped out to get a little sleep on one of the cots in the nurses’ office.

  I had not dozed very long before I was aroused by someone calling my name softly and shaking my shoulder. It was Don Schlegel, the shift leader, telling of a new problem: the car
bon dioxide (CO2) level was rising at rate that would exhaust the LM’s lithium hydroxide canisters in less than a day. We needed to find a way to use the command module’s canisters, but they did not fit into the LM’s system.

  The problem was that with three instead of two astronauts breathing LM’s oxygen, CO2 was building up 50 percent faster than the LM system design allowed. We would run out of lithium hydroxide, the chemical used to absorb CO2 to keep it from accumulating to toxic levels. Both the CM and the LM carried the lithium hydroxide in replaceable canisters about the size of a large juice can that were normally replaced every twelve hours. But this was one case we designers had not foreseen. The CM and LM canisters were not interchangeable—theirs was square in cross-section, ours was circular. We literally faced the problem of how to fit a square canister into a round receptacle.

  In the Mission Support Center we met with our environmental control system and crew systems engineers, including the resident Bethpage representative of Hamilton Standard, supplier of both the CM and LM’s ECS and the spacesuits. Discussions with Grumman and NASA in Houston and with Hamilton Standard at their plant in Windsor Locks, Connecticut, concluded that the best place to devise a solution was at Houston, where accurate mock-ups and some operating equipment of both spacecraft’s systems and the spacesuits were available, and astronauts and the most experienced engineers from NASA and the contractors were on-site. Under the leadership of NASA Crew Systems manager Ed Smylie, a NASA-contractor team in Houston was already at work, with the ground rule that any “fix” had to be something the crew aboard Aquarius could replicate with the materials they had at hand.