Moon Lander: How We Developed the Apollo Lunar Module (30 page)

On Schedule at Last

By the fall of 1968 Grumman was essentially on schedule with LM deliveries, placing us in good position to support the scheduled launches of Apollos 9,
10, and 11 in March, May, and July 1969. If all went well Apollo 11 might be the first landing on the Moon. We still could not ease up, however: there were too many scheduled PERT events to go, any one of which could be hung up or changed by unforeseen events. But at least we could glimpse, in the far-off and hazy distance, the tantalizing goal of our journey. The Moon was phasing into a destination with a schedule.

11

Tragedy Strikes Apollo

It was a Friday evening in midwinter, 27 January 1967 to be exact. I left work early, at a little after six o’clock. It was my son Edward’s eighth birthday, and I wanted to get home in time for dinner with the family, to sing “Happy Birthday” to Ed as he blew out the candles. I turned on the car radio to the news and listened glumly as the reporter described the escalating fighting in Vietnam. The familiar road wound ahead in the darkness through the bare woods and farm fields approaching Huntington. A special bulletin snapped me out of the quiet reverie of an oft-repeated drive: “NASA reports that there has been a fire in an Apollo spacecraft under test at Kennedy Space Center!”

No further details were forthcoming, but when I reached home my family was in front of the television and the children turned to me, the smaller ones shouting excitedly, “Daddy, there’s been a fire, and the astronauts were killed!”

Poor Edward had to share his birthday attention with the TV while Joan and I kept one ear cocked for further details. As I watched our happy little boy smilingly devour a large slice of birthday cake, more grim accounts filtered through. Three astronauts were dead: Gus Grissom, Ed White, and Roger Chaffee, the prime crew for the first manned Apollo mission. Spacecraft 012 had been scheduled for launch into Earth orbit atop Saturn 1B 204 on 21 February 1967. The fire had occurred during a practice launch countdown at Launch Pad 34, with the crew inside the Apollo command module, mounted with its service module on the huge, but unfueled, Saturn 1B booster rocket. Few other details were available.

The next morning I drove into work in the brilliant cold winter sunshine for an eight o’clock meeting with Tom Barnes to review advanced mission planning options. NASA was already thinking of upgrading the last few LMs for more ambitious lunar exploration, if the Saturn booster payload could be
increased to permit LM to grow heavier. Once there it was hard to concentrate on advanced missions with the previous evening’s disaster still unfolding as we spoke. From Herb Grossman, Grumman’s Engineering manager at KSC, I learned further disturbing details. The fire had been very hot and fast moving. Pressure buildup within the command module burst its crew compartment structure open within thirty seconds after the first alarm from the crew, leaving the interior a charred ruin. The ground crew in the white room adjacent to the command module was initially blown back by the fireball emitted when the cabin burst, and lacking protective equipment, were retarded by the intense heat and smoke in their efforts to remove the boost protective cover hatch and open the outer ablative hatch and the inner metal hatch, which opened inward and were each secured by several mechanical latches. Some of the ground crew watched in horror as the surveillance TV camera trained on the spacecraft briefly showed Grissom and White at the window, futilely fumbling with the hatch while outlined in an ominous orange glow of flame. It took five and a half minutes after the alarm to get the hatches open, and by then nothing could be seen inside except impenetrable black smoke. The crew never had a chance to escape, but they had the awful knowledge of what was happening to them.
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Gradually we realized that what had occurred was not only a personal tragedy to three astronauts and their families and friends but also a major setback to the Apollo program. The cause of the fire had to be isolated and removed, but beyond that, all other fire hazards must be identified and eliminated anywhere in the CM or LM. I was alarmed at the reports about laboratory tests done by NASA and the air force that showed extreme flammability of many materials in pure oxygen, even if they burned slowly in air. I asked Bob Carbee to assign our Materials engineers to gather the available information on this phenomenon.

Even worse, as I talked with Carbee and Barnes in the half-empty expanse of Plant 35 (many engineers had been given the weekend off), we worried about how we could all have been so blind to an ancient hazard, which in retrospect was blatantly obvious. If we were so obtuse about fire, how many other serious hazards had also escaped our faulty vision? At the very least a total, searching review of LM hazards and protective features would be required, with additional new eyes added to those of us who had ceased to see the apparent.

As at a wake, we shared stories about the deceased. I had only met Grissom briefly at the M-1 mockup review, but I had talked to White and Chaffee a few times when they were working on lunar egress during and after the M-5 review John Rigsby, Gene Harms, and Howard Sherman had worked very closely with White on the TM-1 with the Peter Pan rig, developing improved versions of the forward hatch, ladder, and descent-stage lunar experiment bay. We were all sobered and saddened by this grim turn of fate, made especially
painful by the feeling that someone, somewhere in the vast Apollo program should have recognized the fire hazard and spoken out about it. And that someone could have been me. (In fact, Hilliard Paige, general manager of General Electric’s Apollo Support Division, had sent ASPO manager Joe Shea a letter in September 1966, pointedly warning of the danger of fire during ground tests in pure oxygen and urging that action be taken to reduce the amount of flammable material in the crew cabin.)

It was little comfort to rationalize, as we briefly tried to do, that in a program as huge and complex as Apollo something was bound to go wrong. Or that three astronauts had already been killed in the line of duty, in crashes of their T-38 jet trainers.
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There was no way to avoid the realization that the Apollo program was in crisis and we were going to have to work very hard to dig our way out of it.

Reaction and Redesign

NASA and Congress each conducted investigations of the cause of the Apollo 1 fire and the recommended corrective actions.
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Prior to the fire, the U.S. manned spaceflight program had relied upon designing to eliminate potential ignition sources as the principal way to prevent fires. If a fire occurred in the crew cabin in space, it could be quickly extinguished by dumping cabin pressure, provided the crew were in their spacesuits. No special provisions were made for extinguishing cabin fires on the ground, nor was major effort made to minimize the amount of flammable material contained in the crew compartment.

The investigations concluded that the Apollo 1 fire had most likely been started by an electrical spark, probably in or near the environmental control system module, that ignited wire insulation. It quickly spread to the highly flammable nylon, including the ubiquitous Raschel netting used to stow checklists, flight plans, and other materials used by the crew, and then raced throughout the cabin. Aluminum lines containing flammable water-glycol coolant melted in the heat and sprayed more fuel into the fire. The plastics burned and gave off toxic gases and dense smoke, which asphyxiated the astronauts once their spacesuits ruptured. (They were not incinerated, as early reports had claimed.) With the cumbersome arrangement of a boost protective cover hatch and two inward opening spacecraft hatches, the crew’s doom was sealed. The white room support crew had no awareness of, or training and equipment for, fighting fire in the cabin, should it erupt.

Recommendations included: minimizing flammable materials in the cabin, protecting and providing fire breaks for any flammable material that remained, improving the quality of spacecraft wiring and plumbing, using stainless steel lines to carry water-glycol coolant, and studying two gas oxygen-nitrogen cabin atmospheres. These could apply to both CM and LM. Then
uniquely for the command module: provide a single quick release outward opening hatch, consider two gas atmosphere and fire-extinguishing systems for ground test, and train and equip the white room team for fire fighting. In addition the investigating board demanded correction of the conditions that caused the many deficiencies they found in command module design and engineering, manufacture, and quality control.

Long before the formal investigations were complete, Grumman embarked on a thorough inventory of all materials in the cabin, characterizing, by test if necessary, their flammability in the LM cabin environment of 5 psia pure oxygen. (LM ground tests and checkout were run with ambient air in the cabin.) NASA enlisted us in a major review, covering all aspects of safety hazards and spacecraft quality, with an emphasis on eliminating flammable materials, potential ignition sources, and quality defects. Spacecraft wiring and water-glycol coolant lines received special attention. NASA sent materials expert Robert L. “Bob” Johnston to Bethpage for several weeks to work with our Materials Group leadership organizing the materials characterization program and developing new design guidelines.

They banished nylon from the LM cabin, along with some forms of fiberglass cloth. It was replaced by Beta cloth, newly developed by Corning Glass. Beta cloth was nonflammable and nontoxic, but it had poor wear resistance and was prone to flaking. Velcro was largely replaced by metal snap fasteners, grommets, and Beta cloth ties. Other plastics, particularly polycarbonates, which gave off toxic fumes when burned, were replaced with sheet metal where possible. Kevlar insulation was used on electrical wiring; it was fire retardant—charring in flame but smoldering or going out when flame was removed.

New design guidelines for electrical wiring were adopted. First, wire bundles and connections were to be neatly combed and rigidly supported with clamps or Beta cloth ties at least every four inches. No “rats’ nests” (uncombed jumbles of wiring) were allowed at junction boxes, splices, and connectors. Second, fire-retardant potting (newly developed) was to be used on electrical connectors and switches and X-rayed after the potting cured. (When cured with a heat lamp, potting became firm but slightly flexible and adhered to the wires’ insulation and the connector, protecting the connector from moisture.) “Birdcaging” (wires pushed into an arc shape, rather than straight) was not allowed. Third, circuit breakers and some switches were to be covered on their back sides with hand-tied Beta cloth “booties,” providing fire protection to the plastic in the unit’s body or innards and preventing short circuits by floating metallic objects (such as screws, washers, etc.) in zero gravity.

In the ECS system, aluminum tubing in the LM cabin was changed to stainless steel and rerouted to shield it from accidental damage by the crew. We also increased the flow rate of the LM cabin dump valve to speed fire extinguishing if needed in space. We participated in a joint group with NASA and North American, which reexamined the cabin atmosphere issue for CM
and LM. For the command module a change proposed by Max Faget was adopted: For ground tests requiring spacesuited astronauts, the CM would be pressurized to 16.7 pounds per square inch absolute (psia)
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with 60 percent oxygen (O
₂
)/40 percent nitrogen (N
₂
), instead of pure O
₂
as before. After launch the cabin pressure would bleed down to 5 psia using pure oxygen for the spacesuit loop and for cabin leakage makeup.

Since LM only operated in space and was unmanned at launch, it could be kept at the 5 psia pure oxygen originally chosen. At launch, when LM was unmanned inside the spacecraft/LM adapter with all systems turned off, it had been planned to pressurize the LM cabin with 16.7 psia pure oxygen. (For both CM and LM, the 2 psi differential above ambient was used to keep humidity and contaminants from getting into the cabin.) In the postfire scrutiny, Marshall decided that this was unacceptable because oxygen leaking or venting from LM could combine with hydrogen leaking from the SIVB stage just below it, possibly causing a flammable or explosive mixture inside the SLA. To reduce this hazard, the LM cabin at launch was instead charged with 20 percent oxygen-80 percent nitrogen, which was bled down to 5 psia in space, with pure oxygen makeup. During a lunar mission the LM cabin was vented to permit opening the front hatch. Upon the first repressurization the cabin would contain 5 psia pure oxygen.

By the time implementation of these changes was in full swing, I had left LM Engineering to lead LM Spacecraft Assembly and Test. The engineering redesign effort was led by John Coursen, who succeeded me as LM Engineering director, and his deputy, Erick Stern. Sal Salina was in charge of the flammability test program, with major assistance from the Structural Design and the Materials Sections. While under heavy pressure from upper management to minimize the schedule slippage caused by the flammability changes, Coursen and Stern implemented them completely and efficiently. They deserve great credit for leading LM Engineering’s recovery from a dark hour.

About two weeks after the fire, and shortly after I transferred into S/CAT and moved into the temporary office trailer complex behind Plant 5, we were visited by a top Apollo management delegation from NASA led by George Mueller, Gen. Samuel Phillips, and Joseph Shea. After meeting with Lew Evans, Titterton, Gavin, and other executives, they spent the day holding meetings with large groups of Grumman LM people throughout Bethpage, assuring them that the Apollo program would continue despite the setback of Apollo 1, and that it was even more important for everyone to do his job correctly and efficiently. Schedule was important, but quality was even more so. “Do it right the first time” was the slogan of the day. Apollo’s salvation lay in the skill and dedication to quality of its people.