Now the real training began. For the next two years, while NASA engineers worked furiously to build a better and safer rocket, the astronauts got ready for space flight.
The goal of Mercury training was not just to prepare the seven men for anything they might encounter during their missions. It was to overprepare them. The astronauts had to know exactly how space flight would feel and sound and look—long before one of them was locked into a small metal container and blasted into the outer void. Alone.
The Mercury Seven not only faced a tough training schedule, but they also had to prove the importance of their roles in the space program. Some of the other test pilots joked that astronauts weren’t real pilots at all. They were helpless robots, controlled by a computer back on Earth. After all, the test pilots pointed out, the first “astronauts” to make the trip into space would not be men at all—but monkeys! Hey, the famous Mercury Seven were really no better than “Spam in a can!”
Glenn, Grissom, Shepard, Cooper, Carpenter, Slayton, and Shirra were determined to prove all those envious test pilots wrong. Without their expert skills, they insisted, the Mercury program would fail. Only astronauts could make tough decisions on the spot if anything went wrong. Only pilots could guide a disabled spacecraft back to Earth again.
Throughout their training, the astronauts pushed for a more active role in the space flight. They wanted a hand controller that would let them guide the spacecraft if they needed to. They wanted a hatch on the spacecraft they could open themselves. But one of their demands seemed more important than all the rest.
They needed a window! The Mercury Seven were going to be the first human beings to venture into the immense universe beyond Earth—and there would be no way for them to see it! The NASA engineers had actually designed the Mercury capsule without a window. Sure, they would have a periscope, but that would give them a very limited view of the outside world. It was no substitute for the real thing.
The astronauts put their foot down. The spacecraft has to have a window, they told NASA.
A window will add too much weight, the design team argued.
No window, no mission, the Mercury Seven shot back.
So the designers went back to work. Finally the astronauts got their window.
For the next three years, the Mercury Seven worked harder than they had ever worked in their lives. First they had to educate themselves in space science. Since they would need to understand the mathematics of flight, they had to study physics. And astronomy, so they could plot their course by the stars. And physiology, so they would understand how their bodies reacted to weightlessness and the force of gravity. Becoming an astronaut, they soon discovered, was like getting a graduate degree in advanced science!
Then there was the physical training. The goal of the training was to imitate—or simulate—conditions within the capsule. For instance, astronauts had to get used to the high G forces of takeoff and reentry. A “G” is the unit that measures gravitational force. The pressure of one G is equal to the force of gravity on Earth.
To simulate G forces, the astronauts trained in a centrifuge machine—called the Big Wheel—attached to a 50-foot arm. At the end of the arm was a cab designed to look like the inside of a Mercury capsule.
Dressed in a pressure suit, the astronaut was strapped into a seat molded to the shape of his body. The centrifuge whirled the arm around, faster and faster. As it accelerated, he would be pressed back against the seat. The forces would climb to three, then five, then eight Gs, equal to the pressure he would feel when the rocket shot up to an altitude of 65 miles. When the spacecraft went into actual orbit, the G forces would disappear and the astronaut would become weightless. Afterwards, when the capsule reentered the atmosphere, the pressure would rise again.
Throughout the whole exercise, the astronauts were instructed to talk into their headsets, as if they were in actual flight. Fighting the pressure, they had to lift their arms to push buttons and pull levers on the instrument panel. They learned to perform the necessary tasks with minimum effort. And they got used to the Big Wheel, though training in it was never comfortable.
How many Gs could the human body stand? To find out, John Glenn and two others were chosen as human guinea pigs. This time, to reduce the pressure, Glenn lay down almost flat in his molded seat. He tested his reactions as the pressure gauge rose steadily.
8 Gs . . . 9 Gs . . . 10 Gs. Now Glenn could no longer raise his arms.
11 Gs . . . 12 Gs. He kept tensing his muscles to keep the blood moving.
13 Gs . . . 14 Gs. He started to grunt. This helped his heart pump the blood throughout the body. Otherwise, it would all pool in the middle.
15 Gs . . . 16 Gs. Now he had to fight to remain conscious. The seconds ticked by—and then the centrifuge slowed down. Glenn was dizzy, but okay.
NASA doctors decided that sixteen Gs was about as much as the human body could withstand. That was the equivalent of 2,800 pounds of push against the body!
Another potential problem was weightlessness. How would the human body react when it was no longer subject to the pull of gravity? No one knew—but the possibilities were frightening. Would eyes lose their shape? Would the throat be able to swallow? Would astronauts go blind, or choke on their food?
NASA engineers had no way to simulate zero-G for a long period of time. The best they could offer Glenn and the others was a few precious seconds of weightlessness—in parabolic flight. (A parabola is a U-shaped curve.)
The engineers had the astronauts travel as passengers in the back of training planes. After the pilot took the plane up to 40,000 feet, he dived down quickly and then soared up again, in one long, smooth arc. During the ride up, the gravity of the climb balanced the pull of Earth’s gravity—and the astronaut passengers were weightless for as long as sixty seconds.
Since they were strapped in, they couldn’t float around inside the airplane. But they could practice pushing buttons, eating, and drinking in zero-G. The astronauts experimented with eating pureed beef and drinking tomato or orange juice. Al Shepard liked to squirt the juice right into his mouth. Gus Grissom, though, got a kick out of spraying juice into the cabin—and then watching the big orange bubbles float around in front of his nose.
Another top priority for the astronauts was to learn to handle an orbiting spacecraft that was tumbling out of control. As experienced pilots, all the astronauts knew that the position of a craft in space is called its “attitude.” Attitude is determined by three movements: pitch, roll, and yaw. Pitch is the movement around the side-to-side axis of the spacecraft. Roll is the movement around the front-to-back axis. And yaw is the movement around its vertical axis.
Ordinarily, an automatic pilot system controlled the capsule. But if the automatic pilot failed, then the real pilot could step in and guide the capsule by hand. Just one control stick directed all three movements, pitch, roll, and yaw. Moving the stick back and forth controlled its up-and-down motion (pitch). Moving it right or left controlled its sideways turn (roll). And rotating it controlled its side-to-side motion (yaw).
To practice, the astronauts were strapped into a nasty machine known as MASTIF—Multi-Axis Space Training Inertial Facility. It consisted of three round metal frameworks, set one inside another. The outside framework pitched, the middle framework rolled, and the inner framework yawed. The astronauts sat inside, Gus Grissom wrote later, “spinning violently in three different directions at once—head over heels, round and round as if you were on a merry-go-round, and sideways as if your arms and legs were tied to the spokes of a wheel.” It was up to the astronaut to swivel the control stick until all the twisting and rolling stopped. Then he would stumble out—and lie down on a cot until the dizziness went away!
So far, their training had prepared the astronauts to cope with the challenges of space flight: high G forces, weightlessness, and an out-of-control spacecraft. Now their pretend spacecraft was falling back to Earth—and they had to prepare for a landing. What should they do?
Each mission would be provided with a standard survival kit, which included shark repellent, a raft, a dye marker, sunglasses, and zinc oxide for sunburn. If the capsule splashed down in the ocean, as it was supposed to, then these items would help keep the astronaut safe until a helicopter arrived to pick him up.
Out in the Gulf of Mexico, the astronauts practiced inflating their rafts and climbing out of a bobbing capsule with their pressure suits on. At one point, the waves were so high that Glenn’s raft turned over and he tumbled into the water. Another time, Deke Slayton took his helmet off before leaving his capsule. Seawater poured down his neck into his suit—and he almost drowned before he could reach his life raft. As a result, NASA engineers went back and designed a new waterproof neck seal.
So much for a water landing. But what if the spacecraft went off course and came down on solid ground instead?
Just in case, the astronauts took a survival class out in the hot, dry Nevada desert. There Glenn and the others learned how to turn their parachute into a sun-blocking poncho. To test the results of dehydration, they didn’t drink any water for twenty-four hours. As Glenn lay under the shade of a cactus at the end of the day, he was so weak he could barely raise his hand.
One instructor showed them how to suck the venom out of a snakebite wound. To prove the venom wasn’t poisonous if swallowed, he poured some water moccasin venom into a glass—and gulped it down!
Glenn grimaced. He’d do his best to stay away from the desert—and snakes!
Meanwhile, the astronauts continued to attend one rocket launch after another. On July 29, 1960, they went to a test flight of the final model of the Atlas missile. The Atlas was the missile that would eventually propel the Mercury capsule into orbit. (A smaller rocket, the Redstone, would propel the earlier suborbital flights.) Unfortunately, the Atlas had a failure rate of 45 percent. Discouraged, the public was beginning to grumble about the cost of the space program. NASA badly needed a success.
Hundreds of people—astronauts, Congressmen, and other VIPs—were invited to watch the launch from a nearby grandstand. On schedule, the mammoth missile fired in a burst of orange flame and rose slowly from the launch pad.
Spectators craned their necks to watch the rocket soar up into the clouds and disappear from view. Then, far off, came the sound of an explosion.
Another bust. With a sinking heart, Glenn realized that this latest failure would delay the first Mercury launch by months.
He tried to reassure his family, though. “They’ll go back to the drawing board and get it fixed,” he said.
Meanwhile, many Americans were concerned about the success of the Soviet space program. In 1957, Russians sent a dog into orbit around the Earth. In September 1959, they sent a probe to the Moon. NASA, on the other hand, couldn’t seem to get a rocket off the ground without having it explode.
Four months later, the VIPs came back for another launch, this time of a Redstone rocket. The Redstone had been much more successful than the Atlas, and everyone expected a smooth liftoff. The visitors settled back to watch a good show.
“Three . . . two . . . one! We have ignition!”
A blast of red and orange shot out of the tail of the rocket. The Redstone rose up about four inches off the launch pad—and then settled back down again. “It was like watching the fizzle of some gigantic Roman candle at a Fourth of July celebration,” Glenn said later.
A second later he heard a loud pop! as the escape tower on top of the capsule shot off. It drifted down gently under a parachute. It was another total disaster for NASA. Things were definitely not looking good.
All these public failures just made the astronauts more determined to make their contribution to the Mercury program a success.
The biggest question on their minds was: Who would make the first flight? The first man in space would be a world hero, the one astronaut guaranteed to go down in the history books. Naturally each one of these super-dedicated, super-achieving, super-competitive pilots wanted to be that man. “Anyone who doesn’t want to be first doesn’t belong in this program,” Glenn admitted at a press conference.
Secretly, Glenn believed he was the best qualified to go. He was sure NASA would pick him.
But Project Mercury chief Bob Gilruth surprised everyone. In fall 1960, he called the astronauts to a meeting and asked for a vote. “If you can’t make the first flight yourself,” he said, “who do you think should make it?”
Glenn was outraged. The Mercury program was supposed to be all about skill—not popularity!
After the astronauts had voted by secret ballot, Gilruth brought them all together again. NASA had made a decision, he said. The first man in space would be . . . Alan Shepard!
Glenn was stunned. He felt he’d missed his shot at immortality.
Gilruth continued. Gus Grissom and John Glenn would fly second or third, he announced. Glenn would be Shepard’s backup for the first flight. If anything happened to Al, John would take his place.
Being chosen backup was no consolation, Glenn thought. To make matters worse, the choice for the first flight had to remain a secret. The public assumed that John Glenn was the favorite. For the next few months, Glenn would have to pretend he still had a chance.
Glenn tried to swallow his disappointment and get back to work. The team came first, he told himself.
Now events moved rapidly ahead. On January 31, 1961, a Redstone rocket blasted off successfully with a male chimpanzee named Ham onboard. NASA had chosen a chimpanzee to make the test flight because chimpanzees were closer to humans, both physically and mentally, than were any other animals.
The chimp flight was far from perfect, though. Ham was subjected to seven Gs on the way up—and more than fifteen on the way down! That grin he flashed at the cameras when he was pulled from the water wasn’t a smile of happiness. It was a grimace of fear.
But he did come down, and he was alive. If a chimp could survive a space flight, so could Al Shepard.
The team threw itself into a frenzy of preparation. Shepard was scheduled to go up in a suborbital flight on March 24. But then the engineers decided the Redstone needed one more test, and more time passed . . .
The delay was costly. On April 12, 1961, a Soviet cosmonaut named Yuri Gagarin completed one full orbit around the Earth.
The Russians had won the race to send a man into space!