Glenn glanced at the mission clock in the cockpit. “The clock is operating,” he said. “We’re underway!”
The great rocket rose up, gradually gathering speed. At thirteen seconds he could feel the vibrations starting as the Atlas forced its way through the air. “Little bumpy about here,” he reported.
The G forces began to build. 2 Gs . . . 3 Gs . . . 4 Gs. Glenn was forced back into his seat. After all those hours on the centrifuge, the pressure felt very familiar. Yet, he noticed, the real thing was a lot gentler than the Big Wheel!
Now the Atlas was pushing through the heavy atmosphere at a thousand pounds per square foot. This was “max Q,” maximum aerodynamic pressure. If the rocket were defective, this was the moment it would explode . . .
4 Gs . . . 5 Gs.
Suddenly, at 1 minute 16 seconds, the air thinned and the flight smoothed out. “Roger, you’re through max,” he heard Al Shepard say over the headset.
Whew, Glenn thought. He had passed through the first danger zones—and he was supersonic!
6 Gs. At 2 minutes 9 seconds, the booster engines that had thrust the Atlas off the launch pad switched off and fell away. Abruptly, the pressure dropped.
Now the rocket was free of the lower atmosphere. “Sky looking very dark outside,” Glenn reported to Mission Control. The Atlas sustainer engines kept pushing the capsule higher and faster, consuming fuel at one ton per second. The pressure started to build again, rising all the way up to 6 Gs.
Glenn read off the fuel, oxygen, cabin pressure, and battery measurements from the dials on the instrument panel. Everything was fine.
“Cape is go and I am go. Capsule is in good shape,” he reported.
“Roger. Twenty seconds to SECO,” said Shepard. At Sustainer Engine Cutoff, the Atlas rocket engine would insert the capsule into orbit. The bolts that held the Atlas and the capsule together unclamped, and rockets fired to push them apart. The Atlas was flung out into space.
Abruptly, Glenn dropped into zero-G. He was weightless!
Five minutes after liftoff, Friendship 7 was in orbit, 100 miles above the earth, circling it at 25,730 feet per second.
“Zero-G and I feel fine!” Glenn said exultantly. “Capsule is turning around.” The capsule was facing blunt end forwards, so that Glenn would be traveling backward throughout the voyage. It was a lot like sitting backward on a speeding train, with the landscape rolling by him in reverse.
Through the window, he could see the curved Earth far below, wrapped in its thin, filmy atmosphere. “Oh,” he exclaimed. “That view is tremendous!” The Atlas tumbled away from the capsule, shining in the light of the sun.
Thus far, it had been a perfect mission. From Mission Control, Shepard said, “You have a go, at least seven orbits.”
Seven orbits! It was more than Glenn had hoped for.
Glenn was going east, over the Atlantic Ocean. Far below him, the route was lined with capsule communications (capcom) stations that stretched around the globe: Bermuda; the Canary Islands; Kano, Nigeria; Zanzibar; a ship out on the Indian Ocean; Muchea, Australia; Woomera, Australia; Canton Island in the Pacific; Guaymas; California; Cape Canaveral. If all went well, Glenn would never be out of communication with the ground for more than a few minutes in the whole flight.
Most of the voyage would be spent running through a checklist of tasks—medical experiments, systems tests, instrument reports. The whole flight plan was typed on a tiny scroll of paper that he unrolled item by item.
“This is Friendship Seven,” he told Gus Grissom, the capcom at the Bermuda station. “Working just like clockwork on the control check, and it went through just about like the procedures trainer runs.”
Next, Glenn reached in to get his camera from the equipment kit located next to his right arm. The first item to float out was a little gray mouse with pink ears. Glenn grinned. He knew immediately that Al Shepard had left it as a joke. They both loved a popular comedy routine about poor mice that were sent into space in rocket nose cones.
The mouse was fastened to the pouch by a long string that kept it from floating away. So was the camera, an automatic 35 mm Glenn had picked out himself. NASA engineers had made alterations so someone wearing thick gloves could operate it. He snapped pictures of clouds over the Atlantic and dust storms over the Sahara Desert.
Above Zanzibar, Glenn exercised with a bungee cord attached under the instrument panel. Sure enough, his pulse rate went up, just as it did when he worked out back on earth. Apparently, weightlessness made no difference in ordinary body reactions.
So he tried some other tests. He read the eye chart and discovered that his vision was normal. Eyeballs did not change shape in zero-G after all. He moved his head from side to side and felt no dizziness. Altogether, weightlessness was a lot more pleasant than some of the tests he’d endured during his training!
Forty minutes into the flight came his first real treat—a sunset. To prepare for it, Glenn placed red filters over the lights on the instrument panel and turned on tiny flashlights at the end of his fingers. This way, the light inside the capsule would not interfere with the night lights outside.
He planned to watch the sunset through a photometer, which was equipped with a filter to protect his eyes. As the sun sank over the western horizon of Earth, the band of brilliant light on the horizon changed from white to orange, then burst into red, purple, and bright blue before finally fading away into black. It was more spectacular than a hundred fireworks displays. Glenn snapped another picture.
“The sunset was beautiful,” Glenn told the capcom stationed on a ship out in the middle of the Indian Ocean. “I still have a brilliant blue band clear across the horizon almost covering my whole window . . . the sky above is absolutely black . . . I can see stars, though, up above.” Friendship 7 was zooming so fast around the earth that the whole show lasted only five or six minutes.
He had expected that here above the atmosphere, the stars would look exceptionally bright. But they looked no different than they would on a clear night in the desert. The thick glass of the window, it seemed, acted like an atmospheric filter—it made stars appear fuzzy and indistinct. Still, he could recognize some of his favorite constellations, such as Orion and the Pleiades. As he had hoped, he was able to use Orion to maintain attitude.
As Glenn flew over Australia, he recognized Gordon Cooper’s voice through his earphones. “How are you doing, Gordo?” he greeted him. “We’re doing real fine up here. Everything is going very well. Over.”
“John, you sound good,” Cooper replied.
Glenn gave him the systems report, then added, “That sure was a short day.”
Cooper couldn’t quite hear him. “Say again, Friendship Seven.”
“That was about the shortest day I’ve ever run in to,” Glenn repeated.
“Kinda passes rapidly, huh?”
“Yes sir.”
Cooper suggested that Glenn keep his eyes open for lights on the ground. Glenn peered out into the darkness beneath him. Sure enough, he spied thousands of twinkling lights.
“Just to my right I can see a big pattern of lights apparently right on the coast. I can see the outline of a town and a very bright light just to the south of it.”
“Perth and Rockingham, you’re seeing there,” Cooper explained. Even though it was the middle of the night, Australians had switched on every light in their homes and businesses to welcome the space traveler circling above them.
Glenn was appreciative. “The lights show up very well and thank everybody for turning them on, will you?”
It was time for his first and only meal of the journey—applesauce. He placed the toothpaste tube in midair while he raised the visor on his helmet. Then he screwed on the straw and squeezed the applesauce into his mouth. Not a drop was lost.
His first sunrise came right in the middle of the Pacific Ocean, just thirty-five minutes after sunset. Because he was riding into it, he couldn’t see the sunrise directly, but had to view it backwards through the periscope. “The brilliant blue horizon coming up behind me; approaching sunrise,” he reported.
“Roger, Friendship Seven. You are very lucky.”
“You’re right. Man, this is beautiful.”
And then, he saw them, a million little swirling lights, just outside the capsule window.
Glenn drew his breath in sharply. What in the world could they be?