Elapsed Mission Time:
Glenn flew out of range of the Hawaii tracking station, and static hissed in his ear. While waiting to acquire the signal from the Point Arguello tracking station, he input a series of commands into the spacecraft’s flight computer. He was still flying manually, compensating for the erratic behaviour of the automatic system. He couldn’t actually see yet, but he knew that the coast of California would soon be sliding over the horizon. He hear Wally Schirra’s voice in his ear.
“Friendship 7, Point Arguello, we would like you to leave your thruster pack in place until after you pass over Texas.”
“Roger that,” replied Glenn. The RETRO FIRE warning light winked on, and Glenn’s eye instinctive flicked to the mission clock in the centre of his instrument panel. It was almost time.
At 4:33:07 the retro thrusters thrummed to life. Glenn was pushed forward into his restraints. Outside his cockpit window, the Earth seemed to have suddenly reversed its rotation.
“I feel like I’m heading back to Hawaii,” said Glenn.
Schirra laughed. “Don’t do that,” he said. “You want to head to the East Coast.” The retro rockets had exhausted their fuel and Glenn could feel that his speed had been subtly reduced. His on-board computer indicated that his forward velocity had slowed by approximately 300 miles per hour.
“Wally, do you have an ETA for retro jettison?”
“Not at this time, Friendship 7,” answered Schirra. “Texas will give you that information.”
Glenn could see California sliding into view. He was able to readily identify El Centro and the Imperial Valley. The Salton Sea shone emerald in the bright sunlight. He flew quickly across the American Southwest. The mountains of California, Nevada and New Mexico reared up and fell away, to be replaced by the broad deserts of Arizona and the rolling cattle country of Texas.
“Friendship 7,” said the Corpus Christi Capcom, “we are recommending that you leave your retro pack in place during the entire re-entry.”
“Copy,” said Glenn.
“You will have to override the .05 G switch.” While the Capcom was still talking, Glenn flipped the appropriate switch from AUTO to MANUAL. The switch in question was connected to sensors that sensed the steady thickening of the atmosphere and automatically started the on-board computer’s re-entry program. The Capcom was still talking. “Re-entry is expected to start at 04:43:58. You will also have to manually retract your periscope. Do you copy, Friendship 7?”
Glenn’s eyes flicked to the mission clock again. 04:38:47. “Roger, copy instructions,” he said. “Do you have a reason for this manoeuvre?”
“Negative, Friendship 7. These are Cape’s instructions,”
“Understood,” answered Glenn. His thoughts couldn’t help but stray to the three metal straps the held the retro pack to the bottom of the spacecraft. He wasn’t sure if he wanted to know if this situation have even been thought of when the Mercury spacecraft had been designed, but he reasoned that the flight controllers on the ground at Cape Canaveral were banking on the straps not breaking until the spacecraft had bitten deeply in the atmosphere, which case the thickening air should be enough to hold the heat shield in place. Or at least, Glenn reckoned that that was the plan. If the flight controllers were wrong, the spacecraft, and its occupant would be consumed in a ball of plasma.
Al Shepard’s voice spoke in Glenn’s ear. His voice crackled more loudly. The friction generated by the heat shield was starting to affect the air to ground communication loop. “Friendship 7, we recommend that you go to re-entry attitude and retract your periscope at this time.”
“Copy that,” said Glenn. “I am switching to FLY-BY-WIRE.” Glenn flipped a switch. “I am down to 15% fuel on manual.”
“Acknowledged, Friendship 7,” replied Shepard. “We recommend that you keep a zero angle for re-entry.”
“Copy that,” answered Glenn. His eyes flicked to his instruments. His altitude was 55 miles. Glenn pulsed his thrusters once, sending the spacecraft into a slow spin, which would help the spacecraft keep its direction and orientation. Outside, the world spun lazily and Glenn began to feel the faint and persistent tug of gravity, as he sank deeper and deeper into the atmosphere. As Glenn began shed altitude, he began to rattle off instrument readings in a continuous stream. At the same time, he began to feel the persistent tug of gravity, as the heat shield bit into the atmosphere. The spacecraft began to buffet as the heat shield encountered resistance. As the friction increased, the turbulence got stronger and a cloud of ionized plasma began to form around the spacecraft. Glenn continued to call out his instrument readings. The crackle of static got increasingly louder in his ear.
He thought he heard Al Shepard’s voice say, “We….ec….mend….at….,” then the static drowned out the air to ground loop completely. Glenn was alone now, in a proverbial tin in freefall in the middle of a 3,000 degree fireball. He kept trying to raise the Cape. “Friendship 7, Cape. Do you read me?” Glenn looked out the cockpit window. He saw the sky change from black to blue to pink to fiery orange and then lemon yellow. His eyes slid across his instruments, reading each one in turn. He felt as though an elephant was sitting on his chest. It was almost impossible to breathe. He tried calling the Cape again “Friendship 7, Cape. Please respond.” Static. Glenn felt a particularly hard jolt and a piece of the retro pack strapping stuck to his window. He stared at it for a few seconds as it burned to a cinder, then blew away, a wisp of ash. Glenn’s eye flicked to his G force indicator. The needle was hovering at 8 Gs. His eyes next slid to his altitude indicator, which was pin wheeling rapidly as the spacecraft fell.
Outside, the yellow-orange glow began to fade. At the same time, the G load began to ease. Glenn tried his radio again. “Friendship 7, Cape. Do you read me?” Static. He tried again. “Friendship 7, Cape. How do you read?”
Alan Shepard’s voice spoke in Glenn’s ear with a burst of static. “….endship 7, how do you read?”
“Mercury Control, I read you 5 by 5.” Glenn read Shepard his instrument readings again.
“Roger, Friendship 7.”
Glenn glanced at his altitude and air speed indicators. He passing through fifteen miles and travelling roughly at Mach 2. He stole a quick glance out his window and saw his twisting white contrail. The spacecraft was rocking back and forth, buffeted by the winds in the high atmosphere. In his headset, Glenn could hear the chatter of the recovery team.
“Friendship 7, Steelhead, we have you in sight and are in bound to your position. Our ETA is one hour”
“Roger, Steelhead,” answered Glenn, “see you in an hour.”