American Institute of Physics
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Press Release

Trial by Fire: The Legacy of Apollo 1

JUL 15, 2019

By Savannah Mandel

Apollo 1 astronauts Gus Grissom, Ed White and Roger Chaffee CREDIT: NASA

Astronauts Gus Grissom, Ed White, and Roger Chafee

NASA

On Jan. 27, 1967, fire broke out at Cape Canaveral Air Force Station Launch Complex 34. Fueled by an exhaustive and fast-burning oxygen-rich atmosphere, the Apollo 1 command capsule ignited from the inside out. Within minutes its crew, astronauts Virgil “Gus” Grissom, Ed White and Roger Chaffee, lost their lives to the blaze. Two years later, humankind put boots on the ground at Tranquility Base, 238,900 miles away, on the surface of the moon. The events that occurred at these two locations share a history that spurred technological innovation and secured the future of reliable and safe human space exploration.

The unforgettable and catastrophic results of the Apollo 1 fire led to increased safety measures, and through the Apollo 204 Accident Review Board, recommendations were developed to ensure the safety of future spacefaring humans. Because of these changes, humans not only put “boots on the moon” July 20, 1969, but also returned home safely July 24, 1969.

The first crewed mission of the Apollo program, Apollo 1 was planned to be a low-Earth orbital test of the command and service module with a crew. Scheduled to launch Feb. 21, 1967, Apollo 1 was to demonstrate performance, launch operations and control facilities of the Apollo-Saturn 5 launch vehicle.

During a test to determine whether the command module would operate nominally on internal power while detached from cables and umbilicals, an electrical arc occurred. Nine seconds later, Grissom yelled that a fire had broken out within the command module.

Due to an excess of combustible materials and a pure oxygen atmosphere inside the command module, the fire was intense, uncontrollable and fast. It took five minutes for the pad workers to open all three hatch layers, and they could not drop the inner hatch to the cabin floor as intended.

Autopsy reports of the Apollo 1 crew confirmed primary cause of death as cardiac arrest caused by high concentrations of carbon monoxide. The report stated extensive burns were suffered postmortem.

NASA flight director Gene Kranz held himself and NASA accountable for the Apollo 1 fire. He addressed his branch and flight control team the Monday morning following the incident:

“Spaceflight will never tolerate carelessness, incapacity, and neglect. Somewhere, somehow, we screwed up. It could have been in design, build or test. Whatever it was, we should have caught it. We were too gung-ho about the schedule, and we locked out all of the problems we saw each day in our work. Every element of the program was in trouble and so were we. The simulators were not working, Mission Control was behind in virtually every area, and the flight and test procedures changed daily. Nothing we did had any shelf life. Not one of us stood up and said, “Dammit, stop!” I don’t know what Thompson’s committee will find as the cause, but I know what I find. We are the cause! We were not ready! We did not do our job. We were rolling the dice, hoping that things would come together by launch day, when in our hearts we knew it would take a miracle. We were pushing the schedule and betting that the Cape would slip before we did.”

Kranz, NASA and the American government made immediate changes to safety measures and security protocol after the incident. These were maintained throughout the Apollo program, which ended in 1975.

Recommendations came largely from the Apollo 204 Accident Review Board (created by NASA as a result of the incident) and were based on investigations made by committees in both houses of the U.S. Congress as well as the review board itself immediately after the incident. While the Apollo program was put on hold, the review board identified five areas of concern: spacecraft atmosphere, combustible materials, electrical components, hatch design and mismanagement. These factors directly related to the cause of accident, the delayed response of emergency personnel and the recovery of the Apollo 1 crew.

To decrease weight within the cabin and sustain atmospheric stability, the Apollo 1 command module atmosphere was 100% oxygen. Although North American Aviation engineers questioned the use of a pure-oxygen atmosphere, NASA maintained the potential risk was manageable by trained crew due to the low-pressure environment (5 pounds per square inch).

The pure-oxygen environment provided a fast-burning fuel source for fire. On March 14, 1968, upon a recommendation by engineer Max Faget, NASA agreed to change the launch atmosphere of future spacecraft to a 60-40 ratio of oxygen and nitrogen.

Investigators found that the fire began because of an electrical short, due to the choice of Teflon as the covering for the wiring within the space capsule. Although Teflon is known as a flame-resistant material, the wires covered in Teflon and chosen for the command module were easily penetrated and damaged.

In a meeting held with Apollo spacecraft program manager Joseph Shea a week before delivery of the capsule, the Apollo 1 crew expressed concern about the excess of flammable materials, although the spacecraft was given approval in terms of safety. A walk-through to confirm that flammable materials were at a minimum and a safe distance from ignition sources was planned for Jan. 29, 1967 -- two days after the fire. After the disaster, a material was developed to coat the wiring that was both more durable and noncombustible even in a pure-oxygen environment.

The Apollo 1 fire was not only a result of a potentially explosive atmosphere but also an interior filled with combustible materials, such as nylon netting, foam pads and an excess of Velcro. Velcro that covered the inside of the spacecraft caught fire explosively in the pure-oxygen environment. As a result of the incident, new, noncombustible materials were developed for spaceflight with fire safety as a priority.

The hatch on the Apollo 1 command module opened inward and consisted of three parts: a removable inner hatch, a hinged outer hatch and an outer hatch cover. Each hatch opened independently and with different tools.

During training, the Apollo 1 crew practiced opening these hatches within a 90-second window. This goal was never achieved. Due to this, spacecraft hatches were redesigned with simplicity and safety in mind and now open outward.

Kranz summarized NASA’s mismanagement issues in the aforementioned address. The crew and project teams were overworked, rushed and inconsistent, and emergency preparedness procedures were insufficient. Kranz finished his address with a promise;

“From this day forward, Flight Control will be known by two words: ‘Tough and Competent.’ Tough means we are forever accountable for what we do or what we fail to do. We will never again compromise our responsibilities. Every time we walk into Mission Control, we will know what we stand for. Competent means we will never take anything for granted. We will never be found short in our knowledge and in our skills. Mission Control will be perfect. When you leave this meeting today, you will go to your office, and the first thing you will do there is to write ‘Tough and Competent’ on your blackboards. It will never be erased. Each day when you enter the room, these words will remind you of the price paid by Grissom, White and Chaffee. These words are the price of admission to the ranks of Mission Control.”

Although spaceflight-related disaster has echoed through the history of human interactions with space, our species continues push onward and upward. Apollo 1 left behind a legacy that shook the Apollo program and every subsequent mission into space. Without the changes to safety measures made after the Apollo 1 fire, humankind might not have made it to the moon. Humanity’s path of space exploration was paved through the lessons learned about safety and precaution on Jan. 27, 1967, as well as the brave dedication of astronauts Grissom, White and Chaffee.

Velcro that covered the inside of the spacecraft