Mercury Rising

“Why don’t you fix your little problem and light this candle?” radioed astronaut Alan B. Shepard Jr. impatiently from atop his Redstone rocket at Launch Complex 5, Cape Canaveral, Florida. The 37-year-old Navy test pilot from Derry, New Hampshire, had endured weeks of launch delays, and now a series of weather and mechanical problems that morning of May 5, 1961. He had been strapped on his back in his cramped Mercury spacecraft for more than three hours; the frustration of the man his colleagues called “the Icy Commander” mirrored the nation’s anxiety over the Soviet Union’s decided advantage in the contest to put humans into space. Just three weeks earlier, 27-year-old Yuri Gagarin, a Russian air force flier, had become not only the first man in space but also the first to orbit the planet. Shepard’s planned suborbital hop could not remotely match Gagarin’s complete Earth orbit, but it would at least get America off the ground, an important step forward in overtaking the USSR on this highest frontier. At that point, it was by no means certain that the United States could catch up with the Soviets.

Origins

Fifty years ago, responding to the Soviets’ Sputnik satellite triumph, President Eisenhower had signed into law the act establishing the National Aeronautics and Space Administration (NASA), which incorporated the existing civilian National Advisory Committee for Aeronautics (NACA) and key elements of the military’s missile and rocketry programs. The new agency’s primary mission was to outdo the Soviets on the space frontier. The Russians, employing powerful boosters developed to carry heavy thermonuclear warheads, had jumped off to a commanding lead in that fraught first year. Putting a human into orbit was their next and most obvious goal.

Even before NASA’s debut on October 1, 1958, a team at NACA’s Langley Research Center in Virginia was working with the military to overcome the physics and engineering challenges of orbiting a human being. Responding to a remarkable run of Soviet achievements (including their launch of the dog “Laika” on November 3, 1957), the U.S. military proposed an array of initiatives. The Navy suggested a hypersonic reentry vehicle, which would deploy inflatable wings, as the centerpiece of its Manned Earth Reconnaissance program. Rocket engineer Wernher von Braun, now working at the Army Ballistic Missile Agency, envisioned a joint services project, building on Air Force high-altitude balloon flights and the Army’s Redstone booster, to launch a pressurized cabin on a suborbital arc beyond the atmosphere. Project “Man Very High” did not fly with management, and so von Braun then pitched the all-Army Project Adam. Unsurprisingly, its eventual payoff—deploying combat forces around the globe aboard suborbital rocket transports—did not gain traction, either.

The drumbeat of events in 1958 quickly concentrated the services’ efforts on the Air Force’s Man in Space Soonest (MISS) project, which proposed to launch a 2,000- to 3,000-pound sphere atop a multistage version of the Thor intermediate range missile. But this system proved too costly, leaving the Air Force to zero in on the Atlas ICBM, despite its shaky test record. With the Russians’ frightening lead in space technology never far from anyone’s mind, the Pentagon’s Advanced Research Projects Agency came through with $99 million for MISS that summer.

Meanwhile, engineers at Langley’s Pilotless Aircraft Research Division, led by the gifted aerodynamicist Max Faget, were struggling to design a “capsule” that could withstand the acceleration and heat imposed by hypersonic flight and reentry. Missile warheads could survive near-orbital velocities and searing reentry temperatures, but a human being was far more delicate than a hydrogen bomb. A space capsule would avoid high missile deceleration forces by taking a shallower path back through the atmosphere, but that trajectory would expose the ship to more prolonged heating. Extensive testing by Faget’s team produced a “blunt body,” differing from the rounded or pointed warhead configuration. The truncated cone housing the pilot was sufficiently aerodynamic to slip through the atmosphere on launch; just before reentry, it would reorient its broad, gently curved heat shield “into the wind.” The blunt shield would generate a shock wave that would deflect most of the heat into the ambient atmosphere. The conical cabin, topped with a squat cylinder housing a recovery parachute, became the basic shape that would evolve into the Mercury spacecraft.

The Birth of Mercury

President Eisenhower’s signing of the National Aeronautics and Space Act in late July 1958 spelled the end of the MISS project; he wanted the new civilian agency to lead the highly visible national effort. NASA opened its doors with a team already in place. Experienced Langley manager Robert L. Gilruth would run the new Space Task Group; future Mercury flier M. Scott Carpenter, who soon went to work for him, remembered him as “eminently respectable, with an eye toward the future.” Gilruth handpicked a few dozen NACA veterans; Langley’s Faget and Charles Donlan, along with George M. Low from Cleveland’s Lewis Research Center, formed the nucleus of the team. On December 17, NASA formally announced that America’s bid for human spaceflight would be called Project Mercury.

Named after the fleet-footed messenger of the Roman gods, Mercury would attempt to orbit and recover an astronaut and, by doing so, would also demonstrate a human’s ability to survive and work in an environment beset by vacuum, extreme temperatures, radiation, micrometeoroids, and free fall (or “weightlessness”). No one in the Space Task Group doubted that they would succeed—they had to. If the Soviets were intent on going there, then the United States, still smarting from the Sputnik debacle a year earlier, had to do the same and more.

The Pilots

Just before Christmas, NASA issued a call for applicants for the position of research astronaut-candidate. Starting salary would be $8,330 to $12,770, depending on qualifications. Over the holidays, however, Eisenhower himself directed that the nation’s pool of military test pilots furnished a sufficient reservoir of talent; by January 1959 NASA had adopted formal selection criteria for its crews:

1. Age—less than 40.

2. Height—less than 5 feet, 11 inches.

3. Excellent physical condition.

4. Bachelor’s degree or equivalent.

5. Graduate of test pilot school.

6. 1,500 hours total flying time.

7. Qualified jet pilot.

That winter a rigorous screening process winnowed the 100 or so applicants to 32, who were subjected to the simulated stresses of spaceflight and a battery of uncomfortable medical tests at New Mexico’s Lovelace Clinic. “They went into every opening on the human body just as far as they could go,” remembered Marine Corps pilot John Glenn. The 18 survivors were whittled down further to those men who exhibited “the most outstanding professional background and knowledge in relation to the job requirements.”

These “Original Seven” selectees were unveiled in a frenetic Washington press conference on April 9, 1959: Lt. Comdr. Alan B. Shepard Jr., Navy; Capt. Virgil I. Grissom, Air Force; Lt. Col. John H. Glenn Jr., Marine Corps; Lt. Malcolm Scott Carpenter, Navy; Lt. Comdr. Walter M. Schirra Jr., Navy; Capt. Donald K. Slayton, Air Force; and Capt. Leroy Gordon Cooper Jr., Air Force.

By late April they were hard at work at Langley, undergoing survival training and learning the inner workings of the spacecraft. From the start, they played a key role in the program, bringing their test piloting and engineering experience to the design and testing process. “At Langley,” remembered Carpenter, “we had one big office with seven government-issue desks, one building over from the managers.” Each of the pilots took on a key spacecraft technology. Glenn had cockpit instrumentation and layout, controls, and simulation. Carpenter took on communications and navigation gear; Grissom reviewed the new reaction control system, hand controllers, and autopilot. Slayton worked with the Atlas booster and escape system.

A month later, all seven gathered at the Cape for the launch of an Atlas D ICBM, the booster that would carry Mercury into orbit. “The engines lit, and the rocket lifted off slowly in a blast of orange flame and billowing smoke,” Glenn recalled in 1999. A minute after liftoff, the booster detonated “like a hydrogen bomb going off right over our heads, so close we ducked.” As the crash of the detonation faded into an uncomfortable silence, only Shepard spoke up: “Well, I’m glad they got that out of the way.”

The Spacecraft

In January 1959 NASA chose McDonnell Aircraft as the prime contractor for the spacecraft. Each “manned instrument satellite capsule” measured just over 11 feet long, six feet in diameter across the heat shield, and weighed about 2,800 pounds. The structural frame was composed of high-strength, lightweight titanium, sheathed in heat-resistant nickel-steel alloy panels. On orbital missions the cabin was protected from 3,500ºF reentry temperatures by a resin-and-fiberglass ablative heat shield, whose charring and partial melting carried away the scorching heat. Atop the capsule perched a 15-foot, latticework steel tower, supporting a solid-fueled escape rocket, which would yank the capsule free from an exploding booster. The pilot was shoehorned, knees up, into the capsule, trussed tightly on his back into a custom-contoured foam couch designed to help him endure powerful launch and reentry forces.

Mercury would make its first flight atop von Braun’s Redstone booster, a direct descendant of World War II’s German V-2 rockets. But the Redstone, a single-stage ballistic missile designed to deliver a thermonuclear warhead upon a target 200 miles away, could not accelerate a human-carrying capsule to orbital velocity. NASA would need the Air Force’s Atlas, which could take Mercury above 115 miles at a velocity of five miles per second.

Rocketed into orbit, Mercury would coast around the planet, completing a revolution every 90 minutes. To return, the pilot would trigger three small retrorockets mounted on the heat shield, which would fire against the direction of flight and slow the spacecraft enough to initiate its descent into the atmosphere. Once through the reentry phase and falling at subsonic speed to 10,000 feet, the spacecraft would deploy a single 63-foot parachute to slow it to about 25 miles per hour for a water landing.

The astronauts argued the designers into a “man-in-the-loop” control philosophy. As test pilots, they demanded and got the capability to steer their spacecraft manually and override its autopilot. Each flight would expand the maneuvering envelope of the vehicle, exploring its piloting characteristics and handling qualities. This approach differed sharply from that of the Soviets, whose early cosmonauts flew largely as passengers, with automatic systems carrying out each step in the flight plan, giving them only a limited ability to intervene, even in an emergency. “Spam in a can”—the sobriquet some of their test pilot colleagues threw at the Mercury Seven—was an unfair characterization of men who would soon be flying hands-on at unprecedented speeds and altitudes.

Mercury’s managers proceeded as rapidly as successful testing permitted, aiming for a first suborbital flight by late 1960. No one knew when the Soviets would be ready to make their next move, but NASA still hoped to fly first. Initial tests of Mercury mated to its Redstone and Atlas boosters were hardly encouraging. The first Atlas, carrying an unmanned production Mercury capsule, thundered off the launchpad on July 29, 1960. One minute into the flight, accelerating under 360,000 pounds of thrust through the region of peak aerodynamic stress, it crumpled and mushroomed into a fireball, raining booster and spacecraft wreckage into the Atlantic seven miles off Cape Canaveral.

In November the first Mercury-Redstone test vehicle, MR-1, roared to life on Launch Complex 5. The Mercury Seven watched intently from the blockhouse as the booster just rose four inches before experiencing total engine failure. The Redstone, loaded with more than 18 tons of liquid oxygen and alcohol, dropped precariously but intact back onto the launch ring—an armed and extremely dangerous bomb. Fooled by the engine fizzle, the flight sequencer jettisoned the escape rocket in a smoky blaze of orange flame. Out of the capsule’s nose popped the drogue and main parachutes, stirring lightly in the breeze as they dangled down the Redstone’s side. Von Braun and his launch team feared that a sudden gust might topple the Redstone, but an adroit and heroic technician scurried out to the fuming rocket to depressurize the propellant tanks, ending the immediate danger. The spacecraft was saved to fly again, but the press derided the failure.

The Russians Forge On

The Soviets were not standing still. In September 1959 their Luna 2 probe had struck the Moon, and on Sputnik’s second anniversary, October 4, Luna 3 blasted off to return images of the never-before-seen far side of the Moon. The Russians had the rocket muscle to hurl a human into orbit, but the headlong race to be first caused them to take risks as well. On October 24, 1960, Marshal Mitrofan Nedelin, frustrated by mechanical problems delaying the launch of the new R-16 ICBM, ordered technicians to repair the missile while it sat fully fueled on its pad at Baikonur. As the men swarmed over the rocket, an electrical fault ignited the second-stage engines and triggered a hellish explosion, killing about 120, including Nedelin himself. Nevertheless, by early 1961 the Soviets had launched and recovered several dog-carrying orbital spacecraft. When would they risk a cosmonaut?

After the booster failures late the previous year, NASA launched Mercury-Redstone 2 on January 31, 1961, to test the viability of Mercury’s life-support systems. Its “pilot” was Ham, a 37-pound, 44-month-old chimpanzee. MR-2 gave him a smooth ride at first, but the Redstone burned too long, overshooting the landing target by about 50 miles and subjecting him to reentry forces 17 times that of gravity. But Ham had performed his trained tasks well, and other than suffering a bruised nose was little the worse for wear. His 15-minute flight, although inviting jokes from famed test pilot Chuck Yeager about astronauts having to sweep monkey waste off their seats, seemed to clear the way for humans.

But NASA had its worriers. Managers in Washington were skittish over the Redstone’s overspeeding, its high g-loads, and a life-support malfunction that dropped the cabin pressure to one psi. (Ham, in an airtight enclosure, was unhurt.) Scott Carpenter remembers that flight surgeons also recommended more centrifuge training: “They didn’t know what they were talking about.” But Gilruth and the cautious von Braun ordered another Redstone test, just to make sure. The booster flew perfectly on March 24, 1961; a human would fly next.

But not an American: on April 12, 1961, Yuri Gagarin rode into orbit in Vostok (“East”) atop an R-7 ICBM. He reported few problems and circled the globe, reentering north of the Caspian Sea 78 minutes after launch. Shortly before touchdown, Gagarin was automatically ejected as planned from the descending Vostok and landed under parachute some two miles from its impact. Villagers from nearby Smelovka in the Saratov region cautiously approached the space-suited cosmonaut, thinking at first he might be some sort of foreign spy. Two days later, Gagarin received a hero’s welcome in Moscow.

Gagarin’s achievement was another stunning disappointment to NASA, especially for the Mercury Seven, who believed that NASA’s engineering conservatism had cost them the chance to be first, if only on a brief suborbital flight. If they had to wait until every minor booster and spacecraft “funny” was fixed, they argued, they would never fly. Shepard, secretly chosen for the first flight, “was very disappointed,” recalled Carpenter. “He felt the extra Redstone flight robbed him of the distinction of being first.” Envy was natural, but they still felt kinship with Gagarin: “We felt that we were all on the same side, in confirming it was man’s place to go there,” stressed Carpenter.

Mercury Rising

But that made them no less anxious to match Gagarin’s feat. On May 5, 1961, three days after bad weather had scrubbed the first attempt, Commander Shepard strode out to Launch Complex 5. He stopped only to gaze up at his capsule, which he had christened Freedom 7, on its perch atop the frost-wreathed Redstone, and rode the elevator to a tiny vestibule called the White Room.

Sliding awkwardly into the cramped cockpit on his back, Shepard saw that Glenn had taped an eye-catching centerfold over the instrument panel, along with a note: “No handball playing in this area.” Shepard smiled at this unexpected gesture from the serious Glenn, whom he knew was keenly disappointed at not being first himself. The hatch bolted shut, and then the taciturn Shepard had to endure four hours on the pad, through a weather hold and maddening countdown glitches, before the launch team finally fixed a balky pressure regulator and was cleared to light “the candle.”

At 9:34 a.m. Shepard felt the turbopumps stir beneath him as alcohol and liquid oxygen surged into the thrust chamber. Seconds later, his Redstone rose smoothly on a jet of white-hot exhaust, arcing over the Atlantic toward its peak altitude of 116 miles. “OK, José, you’re on your way!” called Deke Slayton. (Comedian Bill Dana had gained fame with his character José Jiménez, “the reluctant astronaut.”) Vibrations during “Max Q,” the period of maximum aerodynamic pressure, shook Shepard so hard that he was briefly unable to read his panel gauges. Under the iron force of six g’s, which squeezed him back into his seat, he managed to grunt out, “Freedom 7 is still go.” The slipstream howl died away as he left the air behind, yet he could still feel the shaking through his seat structure as the booster powered to a peak velocity of 5,100 miles per hour, nearly Mach 7. When the Redstone burned out 142 seconds into the flight, he instantly lost all sensation of weight. Straps, dust particles, and a loose washer drifted about the cabin.

During the five minutes of free fall, he was able to rotate and point the capsule manually, test-firing his retrorockets. During his steep descent, Shepard coped with 11 g’s of deceleration before his main parachute opened up at 10,000 feet; 15 minutes and 22 seconds after liftoff, Freedom 7 smacked down into the Atlantic, 303 miles from the Cape. A helicopter plucked pilot and capsule from the ocean and delivered them to the deck of the carrier Lake Champlain. America had joined the Russians in space.

The next suborbital hop went to the Air Force’s Gus Grissom aboard Liberty Bell 7, complete with a crack painted on the bell-shaped capsule. On July 21, 1961, he reached 118 miles and duplicated Shepard’s successful flight profile. But just after splashdown, the capsule’s explosively triggered side hatch unexpectedly blew open, flooding the cabin with seawater. Grissom scrambled out and rescue choppers moved in. One put a line on the waterlogged capsule, but its weight nearly dragged the UH-34 into the swells, forcing it to cut the spacecraft loose. Liberty Bell 7 went down in more than 16,000 feet of water. (A team led by deep-sea expert Curt Newport recovered the ship in 1999.)

Grissom himself nearly drowned when his spacesuit began taking in seawater. By the time a second helicopter pulled him out, he was nearly overcome by exhaustion but entirely undaunted. With a deliberate wink at fate, he later nicknamed his Gemini 3 spacecraft Molly Brown, after the indomitable survivor of the Titanic.

The Redstone series was over, but in August 1961 Gherman Titov orbited the Earth 17 times aboard Vostok 2, widening the Russian lead. Pressure was mounting on NASA to get an American into orbit before the year was out, but nagging delays beset both the Atlas and the orbital version of Mercury. A second chimpanzee, Enos, flew aboard a Mercury-Atlas in late November, and Marine Col. John H. Glenn Jr. would pilot the next mission, MA-6. The patient Glenn would suffer through nine launch delays before finally strapping into Friendship 7 on February 20, 1962.

With Scott Carpenter calling “Godspeed, John Glenn,” the 125-ton Atlas booster thundered off Cape Canaveral’s Pad 14, aiming for an orbital point 143 miles up and a velocity of 17,526 miles per hour—about five miles per second. At shutdown, the first American in orbit exulted in the sense of freedom brought on by free fall. “Zero g, and I feel fine,” radioed Glenn. Below, the deep green-browns of central Africa slid beneath Friendship 7; Australia’s ruddy outback loomed ahead. Above, the daylight sky was a velvet-black, almost tangible void. Through the portal he spotted a swarm of “brilliant specks, floating around outside the capsule,” glowing, tumbling “fireflies” that fascinated him but were later found to be nothing more than ice crystals formed by water venting from the capsule’s life-support system.

Glenn encountered only minor control problems through his first hours in space. But capsule telemetry disturbingly indicated that the heat shield had come loose. Flight director Chris Kraft suspected a false sensor reading; but if he was wrong, Friendship 7 would burn up like a meteor on reentry.

The ground had Glenn check switch positions; he found nothing out of order, but Mission Control did not fully communicate their concern to him, fearing that they might alarm him needlessly. From the radio chatter, however, he suspected the possible heat shield failure, along with its grim implications.

On the last orbit, Wally Schirra radioed up instructions to leave the expended retrorocket package strapped in place over the heat shield. Mission Control hoped that, even if the shield was loose, the retro package straps would restrain it until aerodynamic forces could pin it into position. Over four and a half hours into the flight, Glenn monitored a successful retrofire and began his descent.

As the capsule passed through 55 miles, the searing plasma generated by outside friction tore the retro package loose. “Flaming pieces of something started streaming past the window,” Glenn wrote. “I feared it was the heat shield. . . . The fiery glow wrapped around the capsule, with a circle the color of a lemon drop in the center of its wake.” Unable to communicate because of the searing gases around him, Glenn felt “every nerve fiber . . . attuned to heat along my spine; I kept wondering, ‘Is that it? Do I feel it?’”

He endured nearly eight g’s before emerging from the blackout, heat shield still intact. Glenn raised Shepard on the radio: “My condition is good, but that was a real fireball, boy.” Friendship 7 thumped solidly into the ocean just six miles from the destroyer USS Noa, on whose deck Glenn soon emerged, grinning with a relief shared by the whole nation.

Three more Mercury orbital flights followed. Scott Carpenter flew Aurora 7 through three revolutions on May 24, 1962. The pilot was awed by the series of “visual surprises” in the stunning views from orbit: the beauty of a sunrise and sunset” (he saw three of each); the “progression of intense colors” that each offered; and the exquisite sight of stars setting through the faint orange luminosity of the “atomic airglow.”

His attitude control fuel running low owing to a faulty horizon scanner, Carpenter was unable to achieve a proper retrofire attitude, and he overshot the landing zone by 250 miles. While search planes scoured the ocean, CBS’s Walter Cronkite grimly prepared his viewers for the worst. Thirty-six minutes after splashdown, Carpenter was found in fine shape, bobbing in his life raft next to Aurora 7.

Wally Schirra rode a redesigned thruster system to a six-orbit “textbook” flight in Sigma 7 in October 1962. His nine-hour mission removed what few doubts remained over human performance potential in space. (Titov had reported nausea during his daylong flight the previous year.)

On May 15, 1963, Gordon Cooper followed with a 22-orbit flight, coping with Faith 7’s series of worsening control problems, electrical failures, and life-support malfunctions. “Things are beginning to stack up a little,” he told the ground, coolly taking manual control and flying Faith 7 to a pinpoint reentry. Schirra pointed out that “he had no automatic control system at all. No horizon, reference from the horizon scanners . . . none of that worked. . . . That son of a gun landed closer to the carrier than I did!” Cooper stepped stiffly onto the deck of the carrier Kearsarge soaked in perspiration, having lost seven pounds during his 34-hour flight. But “Gordo” had delivered an impressive finale to the Mercury program.

Alan Shepard lobbied hard for another Mercury flight, MA-10, a three-day mission to seize the space duration record from the Soviets. But managers vetoed the idea, focusing on the future—the two-man Gemini program. Gemini was a technical bridge toward President Kennedy’s Apollo goal of a lunar landing by 1970. Shepard’s 15-minute success in May 1961 had given the president the confidence to issue that challenge 20 days later.

Aurora 7’s Scott Carpenter says that the Mercury design “worked well.” He believes that Mercury’s conservative managers made the right call: “All of these steps were wisely chosen . . . [they were] necessary for the progression of spaceflight. Getting the machine to work was satisfying, but what was most memorable was the teamwork.” Gilruth, Donlan, Low, Faget, Kraft, the astronauts, and NASA’s thousands “proved that we could do this.”

Mercury’s success offered an example of what America could do through determination, ingenuity, engineering skill, and collective effort. The United States struggles today to find the resources and will to achieve safe, reliable orbital access after the shuttle retires. Building the new Orion spacecraft is a daunting task, but no more difficult than that which NASA faced in its original race with the Soviets. “They were still ahead in 1963; we were playing catch-up,” says Carpenter. “But you don’t quit because you’re behind.”

Former astronaut Thomas D. Jones is a planetary scientist, consultant, writer. and speaker who flew on four shuttle missions. His new book is Planetology: Unlocking the Secrets of the Solar System. See www.AstronautTomJones.com.