‘Change in Velocity’: Remembering Deke Slayton’s Unrealized Mercury Mission (Part 1)

AS-6.13.13-ASTP-563-S75-23429 Retro Space Images post of NASA photo of Apollo astronaut Deke Slayton posted on AmericaSpace
Deke Slayton, one of the “Original Seven” NASA astronauts, was grounded from his Mercury mission 55 years ago, this month. Photo Credit: NASA

Fifty-five years ago, America was a nation in euphoria. Astronaut John Glenn returned triumphantly to Earth on 20 February 1962, after orbiting Earth three times in his Mercury capsule—named “Friendship 7”—and further flights were on the horizon. In April 1962, fellow astronaut Donald “Deke” Slayton would repeat Glenn’s accomplishment, spending almost five hours in space. Although his mission would not perform any significantly “new” tasks, Slayton was excited as the opportunity to become the United States’ fourth spacefarer drew closer. Yet 55 years ago, this coming week, Slayton’s excitement evaporated, when a medical problem which he and others deemed a minor irritant returned to bite him. Little could he have known, but March 1962 would not only change his life, but also the future of America’s space program.

In keeping with the tradition of the “Mercury Seven”—which, in addition to Slayton and Glenn, also included Al Shepard, Virgil “Gus” Grissom, Scott Carpenter, Wally Schirra and Gordo Cooper as NASA’s first class of astronauts—the mission name was suffixed by default with the numeral “7”. Since it was also the fourth manned Mercury mission, Slayton opted to call it “Delta 7”. In his autobiography, Deke, he explained that the fourth letter of the Greek alphabet also represented “a nice engineering term that described a change in velocity”. Unfortunately for the 38-year-old Slayton, his own velocity in high-performance jets and spacecraft changed markedly, thanks to a minor, yet persistent heart conditions, known as “idiopathic atrial fibrillation”.

Launch of Friendship 7, the first American manned orbital space flight. Astronaut John Glenn aboard, the Mercury-Atlas rocket is launched from Pad 14. Photo Credit: NASA
Launch of Friendship 7, the first American manned orbital space flight. Had Deke Slayton’s Delta 7 mission gone ahead, it would have followed a similar flight profile. Photo Credit: NASA

Shortly after his selection by NASA in April 1959, occasional irregularities would be detected in a muscle at the top of his heart. Shortly after his selection as an astronaut in April 1959, traces of sinus arrhythmia came to the attention of aerospace physicians at the centrifuge at the Naval Air Development Center (NADC) in Johnsville, Penn. In response to the finding, NASA flight surgeon Dr. Bill Douglas obtained a clinical electrocardiogram at the Philadelphia Naval Hospital, which concluded that Slayton had a slight “flutter” in his heartbeat. Further tests at the School of Aviation Medicine at Brooks Air Force Base in San Antonio, Texas, seemed to indicate that the condition should not adversely affect his duties as an astronaut.

Two years later, Slayton had been assigned as prime pilot for the second orbital Mercury mission, slated for launch atop an Atlas booster from Pad 14 at Cape Kennedy in Florida, no sooner than April 1962. Backing him up for the mission—due to last five hours and complete three orbits of Earth—was fellow astronaut Wally Schirra.

Then, in the days before John Glenn’s launch aboard Friendship 7, speculation arose that he had a heart problem. In his autobiography, Slayton noted that the call had come from U.S. Air Force physician Dr. George Knauf, detailed to NASA Headquarters in Washington, D.C., and originated from “a source higher than the Department of Defense”. Responding to Knauf, Bill Douglas denied that Glenn or his backup, Scott Carpenter, had such a problem, but raised awareness that Slayton had long been known to have a minor heart condition. He expected this admission to prove satisfactory and draw a line under the affair.

It didn’t.

One of the flight surgeons who examined Slayton in 1959, Dr. Larry Lamb, had become convinced that the condition should disqualify him from spaceflight. He had not said so at the time, but in early 1962 he returned his voice to the fore. “I don’t think it was anything personal,” Slayton wrote. “This was just his medical opinion.” However, Lamb was Vice President Lyndon B. Johnson’s cardiologist and within days NASA Administrator Jim Webb had reopened Slayton’s file. The astronaut and Douglas were summoned to the office of Air Force Surgeon-General Olivas Niess in Washington.

It came as something of a surprise for Slayton, who had been wrapping up a simulator session in Hangar S at Cape Canaveral with Schirra, when he received the summons. “I didn’t know what this was all about,” he wrote later in Deke, “but I got changed, went over to Patrick Air Force Base and jumped in a T-33.” On 13 March, a panel of “at least 20” military physicians signed him off as fit to fly and their decision was endorsed by Air Force Chief of Staff Curtis LeMay.

However, Secretary of the Air Force Eugene Zuckert requested an examination by a panel of civilian physicians at NASA Headquarters, ahead of the granting of formal clearance for Slayton to fly his mission. Two days later, on 15 March, Dr. Proctor Harvey of Georgetown University, Dr. Thomas Mattingly of the Washington Hospital Center and Dr. Eugene Braunwell of the National Institutes of Health (NIH) measured the astronaut’s cardiac health. When they finished their tests, they asked Slayton to await their decision. A few minutes later, NASA Deputy Administrator Dr. Hugh Dryden entered the room and told Slayton, point-blank, that he was grounded.

“I hadn’t expected anything like this,” the astronaut later wrote. “I was devastated.” In his mind, the situation was worsened by the fact that Harvey, Mattingly and Braunwell had found no medical reason to keep him from flying Delta 7; rather, their consensus was that if NASA had astronauts without heart conditions, it would be advisable to fly them instead.

By now, the launch date for Slayton’s would-be mission had slipped into May 1962, leaving his replacement just eight weeks to prepare for flight. Many observers considered the decision to have been a political one, but Slayton—despite his justifiable frustration—was philosophical; at least, that is, in the pages of his autobiography, many years later. “NASA knew it would have to publicly disclose my heart condition prior to my flight,” he wrote, years later. “There would be medical monitors at tracking stations, all over the world, who wouldn’t know how to react otherwise. Everybody expected this to be a big deal. NASA would be opening itself up to a lot of medical second-guessing.”

The Mercury seven astronauts. Top row, from left: Al Shepard, Virgil “Gus” Grissom and Gordon Cooper. Lower level from left: Wally Schirra, Deke Slayton, John Glenn and Scott Carpenter. Photo Credit: NASA

If Slayton had fibrillated on the pad, inevitable questions would be raised; should the launch be aborted…or not? Still, many senior NASA personnel were confident that Slayton was the best person to follow John Glenn. They were prepared to take the heat for the decision, but Jim Webb was not.

The head of NASA feared that a disaster could trigger adverse headlines. “It didn’t matter that a whole lot of doctors thought I didn’t have a problem,” Slayton wrote of Webb’s judgement. “He was only going to listen to the few who did.” To be fair to Webb, a launch abort could subject the astronaut to gravitational loads as high as 21 G and, perhaps, with Slayton fibrillating and dehydrated, the mission could have fatal consequences. NASA itself was only four years old and President John F. Kennedy’s promise to land a man on the Moon before the end of the decade was far from certain. A dead astronaut threatened to destroy Kennedy’s plan and NASA would suffer as a result.

On 16 March 1962, the day after the decision, Deke Slayton sat through a lengthy press conference, during which the medical minutiae were examined. One journalist asked the astronaut if stress had caused the problem, to which Slayton responded—with a barbed hint of caustic irony—that the only stress in the space business was the press conference! Hugh Dryden explained that he might still be eligible for future assignments, although that seemed unlikely. Slayton gave up drinking, started working out more regularly—“quit doing everything that was fun, I guess,” he wrote—and even secured an appointment with Dr. Paul Dudley White, the cardiologist of former President Dwight Eisenhower.

White acknowledged that the astronaut did not seem to have a problem, but endorsed the judgement of Harvey, Mattingly and Braunwell: that other astronauts should fly in his stead. Poor Slayton had no chance of drawing another Mercury mission assignment, and he was told that his condition would make him a “hard sell” to NASA management for Gemini, too. The hammer blow came when the Air Force decided that Slayton no longer met the requirement for a Class I pilot’s licence—he could no longer fly solo—and in November 1963, with the rank of Major, he resigned from the service.

Yet in a true example of determination and grit, he never gave up on the space program, or on the possibility of someday flying into space. In tomorrow’s article, Slayton’s decade-long career at the helm of the Flight Crew Operations Directorate and his eventual return to flight status—and a long-awaited space mission—will be explored.


The second part of this article will appear tomorrow.



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One Comment

  1. Good Day Ben, are You Okay ?? Waited All day for Part 2…..Hopefully All Is Well with you Sir & your Family,,,

    David Paquette

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