<p>In order to improve aircraft ejection seats, Dr. (Col.) John Stapp risked his life to test the effect of acceleration on the human body. In test experiments using a rocket sled, Stapp served as his own guinea pig. He achieved over 600 miles an hour in about six seconds, and decelerated to zero in less than two seconds. When asked why he would repeatedly strap himself into the rocket sled and suffer cracked ribs, broken wrists and retinal hemorrhages, he simply said, “I have a missionary spirit. When asked to do something, I do it. I took my risks for information that will always be of benefit. Risks like those are worthwhile.”</p>
<p>In 1946, he became a research officer in the Aeromedical Laboratory of Wright Field, Ohio, where he studied problems of escaping from aircraft at high altitudes.</p>
<p>Provided the effectiveness of a liquid oxygen breathing system and established preventative measures for high altitude bends and dehydration.</p>
<p>At Muroc AFB, California, he made 26 rocket-powered sled runs to test human reactions to high rates of acceleration (35 times that of gravity) and deceleration.</p>
<p>At Holloman AFB, New Mexico, he attained a ground speed record at 636 mph in 1953 in a higher powered rocket sled, slamming to a stop in 1.25 seconds.</p>
<p>His experiments proved that an ejection seat could be used safely at supersonic speeds.</p>
<p>In 1954, he invited representatives of the military and auto industry to review his research on the necessity of seat belts.</p>
<p>John Stapp was born in Bahia, Brazil to missionary parents. When he was 12, his parents decided that he should receive a more formal education and in 1922 enrolled him in the San Marcos Academy in Texas. As a young man, Stapp wanted to become a writer and enrolled in Baylor University. But his finances were so meager that he had to wash dishes and cook for a group of students, while during the summer he sold aluminum pots and pans.</p>
<p>During his 1928 Christmas vacation a tragic incident occurred that would change his life forever. While visiting an aunt and uncle, his two-year old cousin crawled into a blazing fireplace and was badly burned. He helped nurse his cousin for 63 sleepless hours before the child finally succumbed. Stapp was appalled by the fact that nothing could be done to save the child. Later he said, “It was the first time I had seen anyone die. I decided right there and then that I wanted to be a doctor as a result.” When Stapp returned to Baylor, he switched to science courses. When he graduated from Baylor in 1931 with a bachelor of arts degree, he didn’t have enough money to enter medical school, so he remained at Baylor and earned a master’s degree in Zoology, graduating with honors. After teaching zoology and chemistry at Decatur Baptist College, Stapp enrolled in the University of Texas graduate school and earned a Ph.D. in biophysics in 1939. Finally, at the age of 29, Stapp entered the University of Minnesota Medical School to pursue his dream of becoming a medical doctor. When he graduated, he interned at St. Mary’s hospital in Duluth, Minnesota, before enlisting in the U.S. Army Medical Corps during World War II. After completing the Medical Field Service School and the School of Aviation Medicine, Stapp served on general duty as an industrial medical officer.</p>
<p>In 1946 Dr. John Paul Stapp of the Army Air Forces Medical Corps became a research officer in the aeromedical laboratory at Wright Field. There, as a flight surgeon, he became convinced that a significant pattern lay behind the way some Air Force men died and others survived seemingly equally violent crashes. he set out to discover the reasons by using a high-speed sled at Muroc Air Base to test human reactions to high rates of acceleration and deceleration.</p>
<p>The sled, named the Gee Whiz and powered by Jato rockets, glided on a 2,000-foot long track, and had a very effective braking system. Stapp planned a series of tests on humans and set out to develop a harness to hold them to the sled. First, however, he used a dummy named “Oscar Eight-Ball” to perfect the harness. Finally, after 32 sled runs, he was ready to test it on human beings. On December 10th, 1947, Stapp, who elected to be his own guinea pig, was harnessed into the sled facing aft. He was now jeopardizing his life to prove Man’s ability to survive unbelievable crashes. He refused anesthetics because he wanted to learn how he would react psychologically to high rates of acceleration and deceleration. When the rocket ignited with a roar, Stapp slammed against the harness as the sled accelerated to 90 miles per hour. Then his body was crushed against the seat back as the sled ground to a sudden stop. In withstanding 10 Gs, ten times the force of gravity, he suffered only a few sore muscles and later said: “It was an easy first ride!” Within a year, Stapp had made sled runs at speeds of up to 150 miles per hour and stopped in as little as 19 feet. He withstood forces 35 times that of gravity and proved that the human body can withstand such forces. In doing so, Stapp suffered headaches, concussions, a fractured rib and wrist, and a hemorrhaged retina. But he was elated and said: “The men at the mahogany desks thought the human body would never take 18 Gs, here we’re taking twice that with no sweat!”</p>
<p>When Stapp’s commanding officer learned that he had been his own test subject, he ordered him to stop the experiments. His motivation seemed to be selfish rather than out of concern for Stapp: the officer feared that he wouldn’t earn a promotion if Stapp were killed. However, Stapp secretly continued the tests using chimpanzees and discovered that when they are strapped in position to avoid collisions with other solid objects, they survived forces many times those experienced in most plane crashes. From this data, Stapp concluded that crash survival does not depend upon a body’s ability to withstand the high forces involved, but rather on its ability to withstand the mangling effects of the vehicle in which it is housed. To validate these conclusions, Stapp again unofficially began tests on humans and by 1948 had made 16 sled runs facing aft. During these runs, Stapp proved that it is safer to face to the rear in a vehicle. However, pilots must face forward during flights for obvious reasons, and Stapp redesigned the sled for forward-facing tests. During his 4.5 years at Muroc, Stapp made 26 high-speed sled runs. 11 other volunteers participated in the program, but even so, before every run by a volunteer, he tested himself first on the sled. Thus, Stapp took the greatest risks, while also losing six fillings from his teeth, cracking several more ribs, and breaking his wrist a second time. But Stapp proved that the lethal element of the flight is the apparatus surrounding the body. For this historic work, he received the coveted Legion of Merit Medal. After Chuck Yeager broke the sound barrier, supersonic aircraft brought new problems, as escape from them is extremely dangerous. To solve this dilemna, Stapp developed a higher-speed sled called Sonic Wind No. l. It contained a more sophisticated data recording and water braking system.</p>
<p>To conduct this new research, Stapp headed an aeromedical field laboratory established at Holloman Air Force Base in New Mexico. There he began his studies by again using dummies, when one named “Sierra Sam” withstood forces much higher than he had experienced, he decided to begin tests again using himself as the test subject. In March, 1954, in his first ride on the new sled, Stapp attained 421 miles per hour, and was called the “Fastest Man on Earth.” However his concerned insurance man asked: “Ye gods, what are you going to do next?”</p>
<p>But now his great concern became the need to protect Air Force pilots bailing out of supersonic aircraft. Before ejection seats could be perfected, Stapp recognized the need to know the maximum stress that a pilot could endure. On December 10th, 1954, after a thorough examination, Stapp sat down in a sled chair that simulated an ejection seat. He wore a special crash helmet and his body was lashed to the seat. His wrists were tied together in front of-him. His only major concern was that the rapid deceleration might cause him to go blind! At the end of the countdown, the sled leapt forward as if shot from a cannon. Stapp slammed against the seat with a force that threatened to crush his bones, and his vision blurred. Then Stapp blacked out. After the rockets burned out, the sled’s brakes set and all of the forces reversed and his body tried to break the restraining harness. His lungs collapsed and his eyeballs bulged from their sockets. The pain was almost unbearable as the sled came to a sudden stop. When crewmen rushed forward to free Stapp from the sled, he mumbled: “I can’t see.” Stapp was rushed to the hospital, and his eyesight gradually returned. In a checkup doctors found that he had suffered no major injury. An hour later, Stapp was eating a hearty lunch.</p>
<p>Stapp not only set a ground speed record of 632 miles per hour, but withstood the windblast experienced by pilots bailing out at 1,000 miles per hour at 35,000 feet, and proved an ejection seat can be used at supersonic speeds. He was called “One of the bravest men in the world” and honored by Air Force Chief of Staff Nathan Twining for his deeds. This was the last of Stapp’s 29 sled runs. Asked why he did them, he said: “I have the missionary spirit. When asked to do something, I do it. I took my risks for information that will always be of benefit. Risks like that are worthwhile.” Later he told the American Rocket Society that experiments with the rocket-powered sled may pioneer the way to an early fulfillment of the vision of human space flight. Because of his expertise in auto safety, the Air Force loaned Stapp to the National Highway Traffic Safety Administration in 1967 as a medical scientist. Upon retirement from the military with the rank of colonel in 1970, Stapp became a professor in the University of Southern California’s Safety and Systems Management Center. Later, he became a consultant to the Surgeon General of the United States, and to NASA.</p>
<p>John Paul Stapp died at his home in New Mexico on November 13th, 1999.</p>