The Aerospace Corporation and Project Mercury

A 1961 launch of the Mercury-Redstone rocket. The Army's Redstone, essentially an improved version of the V-2 rocket, was used in the first two Mercury suborbital flights of Alan Shepard and Gus Grissom. The Mercury-Atlas, a modified Atlas D rocket, had greater thrust power than the Redstone and was used for the orbital Mercury flights.

A Perfect Start to the Operation: The Aerospace Corporation and Project Mercury

Steven R. Strom

This year marks the 40th anniversary of America's first spaceflight with an onboard human pilot. The occasion provides an opportunity to reflect on the significant role played by The Aerospace Corporation in this monumental early effort in the history of astronautics.

During the early years of space exploration, America's progress in the space race with the Soviet Union coincided with the formative years of The Aerospace Corporation, which began operations in June 1960. As one of its first assignments from the U.S. Air Force, the newly formed corporation assumed responsibility for overseeing systems engineering of the Atlas launch vehicle of Project Mercury. The National Aeronautics and Space Administration (NASA) had initiated Project Mercury in 1958 to investigate the ability of humans to function in space by placing an astronaut in orbit around Earth and safely retrieving both pilot and spacecraft.

Aerospace also developed the Mercury Pilot Safety Program to increase the reliability of the Atlas and to provide additional safety features for the Mercury astronauts. These pivotal contributions, together with the efforts of the Air Force, NASA, and other Mercury team members, would lead to a 100-percent success rate for Project Mercury's manned flights by the program's conclusion in 1963.

The contributions of Aerospace to Project Mercury—the refinement of the Atlas missile, which had experienced earlier failures, and the success of the Pilot Safety Program—played a major role in the eventual success of America's earliest attempts at space travel. Robert Gilruth, the first director of NASA's Manned Spacecraft Center, acknowledged this important role in a letter of March 20, 1962, to Ivan Getting, the first president of Aerospace:

"We wish to extend congratulations to you and to all the people of your organization for their contribution to this project. The Aerospace Corporation, as a member of the Mercury team, should take pride in this event; their part in this undertaking was highly significant."

Origins of Project Mercury

Americans after World War II commonly perceived the Soviet Union to be a technologically backward nation incapable of major scientific advances. The Soviet Union thus stunned Americans with the launch of the Sputnik I satellite October 4, 1957, and further rocked them just one month later with the launch of Sputnik II carrying a dog into orbit. The flight of Laika, whose spacecraft was dubbed "Muttnik" by journalists, alerted members of the emerging American space community that the Soviets were most likely planning to launch a human into space. The successful flights also raised the ominous possibility that the Soviets might soon acquire the ability to launch a nuclear strike against the United States from their orbiting satellites.

Launch of Mercury-Atlas 6, carrying John Glenn into orbit February 20, 1962.

America had been pursuing its own research into rocket science during this time and exploring the possibility of human spaceflight. The interest of many American scientists and engineers in rocketry rapidly accelerated after the end of World War II. Wernher von Braun, leader of the German V-2 program, and his scientists had surrendered to the United States and been brought to this country. Relocated to the White Sands, New Mexico, area, they continued their research into ballistic missiles and space launch vehicle development, using captured V-2 rockets. America had also been conducting supersonic manned test flights to break the sound barrier, achieving that goal the first time with Capt. Charles "Chuck" Yeager's successful flight in October 1947.

As early as 1952, America began planning its involvement in the International Geophysical Year (IGY, July 1957–December 1958), the celebrated global program of coordinated observations of various geophysical phenomena. As part of its participation, the United States would launch small satellites during IGY, a proposal President Dwight D. Eisenhower endorsed in July 1955. A month later, the Soviets announced their own intention to launch a satellite during IGY. Most Western observers paid little attention to the Soviet announcement, shrugging it off as a propaganda ploy.

Ongoing efforts in both the United States and the Soviet Union throughout this period focused on developing an intercontinental ballistic missile (ICBM) to extend the delivery range of their nuclear arsenals. The only missile powerful enough at the time to boost space capsules into near-Earth orbit, the ICBM was requisite for orbital crewed spaceflight. The Soviets made the first successful launch of an ICBM in the summer of 1957. A modified form of this missile, the R-7, carried early Soviet satellites into orbit. By September 1959, the United States had its own ICBM in operation, the Atlas missile, which would become the launch vehicle for the orbital Mercury flights.

With these space-related developments and the Cold War rivalry between the United States and the Soviet Union, the launch of the Sputnik satellites became the catalyst for the U.S. man-in-space program. The United States officially entered the space race January 31, 1958, with the launch of the Explorer I satellite. Planning for what would become Project Mercury began soon after (see Project Mercury Timeline).

Problems with the Atlas

In the early stages of Project Mercury, oversight of systems engineering for the Atlas launch vehicle was assigned to Space Technology Laboratories (STL). In 1960, the Air Force transferred this responsibility to Aerospace, formally incorporated on June 3 that year. Aerospace was now responsible for ensuring that the problem-plagued Atlas rocket would successfully carry a manned capsule into orbit.

Julian Hartt (left) and Ivan Getting, the first president of The Aerospace Corporation, inspect a model of the Mercury-Atlas launch vehicle. In 1961, the year this photograph was taken, Hartt wrote The Mighty Thor: Missile in Readiness.

In his autobiography, All in a Lifetime, Getting recalled being reminded of this awesome responsibility on his first day at the new company before he had "become acquainted with all the buttons on my desk." Bernhard "Ben" Hohmann, head of STL's Project Mercury office, came into his office and said: "I think you should hire me right away." When the bemused Getting asked why, Hohmann replied, "You are responsible for launching into space the first American astronaut, and you will need me."

Getting took his advice, and Hohmann soon moved to Aerospace to direct the new corporation's Project Mercury efforts. He was well qualified for the job. During World War II, Hohmann had been a test pilot for the experimental German Messerschmitt Me163 rocket-propelled aircraft. He came to the United States after the war and served as chief of the flight development section at Wright Air Development Center from 1947 to 1957.

Although the Atlas missile was still in its infancy, NASA chose it as the launch vehicle for Project Mercury because it had sufficient thrust to boost the Mercury capsule into orbit. The capsule had proved considerably heavier than anticipated during its early design phase. Army Redstone rockets, eventually used with early suborbital Mercury flights, were not powerful enough for orbital launches. Ultimately, the Air Force assigned fourteen Atlas D rockets to the Mercury program.

Basic reliability of the Atlas at the time of its selection was estimated to be in the range of 75 percent. While this was adequate from a weapons standpoint, it was unacceptable for human flight. Joseph Wambolt, today Principal Director of the Aerospace Western Range Directorate, came to Aerospace from Rocketdyne in 1960 as a systems engineer for rocket engines. Wambolt recently recalled the challenge of making the Atlas reliable for launching a man into space: "This was a high-risk endeavor, and we were trying to make a safe flight in a rocket that was barely in development." Gilruth, in a 1987 oral history interview conducted by the National Air and Space Museum, described the Atlas at that stage of development bluntly as "a tough rocket to deal with."

Aerospace engineers discuss the Atlas launch vehicle in 1961. In the center are Ben Hohmann and Ernst Letsch.

From the beginning, Atlas D was hurriedly pressed into service because many military leaders, politicians, and weapons experts believed a sizeable "missile gap" existed between the United States and the Soviet Union. This belief generated a sense of urgency that prompted deployment of the rocket before adequate testing. The Atlas had experienced many problems in its early phases of development but was declared operational September 9, 1959. Problems continued, however, even after some successful tests. An Atlas rocket in its Mercury configuration (Mercury-Atlas 1) experienced a disastrous failure on the launchpad on July 29, 1960.

One month later on August 22, 1960, Aerospace became a formal participant in Project Mercury. During the following month most of the principal STL engineers associated with that company's Project Mercury office, including Ernst Letsch, one of Hohmann's chief associates, came to Aerospace. The transfer of key personnel with their invaluable expertise helped keep the core knowledge base of Project Mercury intact. Aerospace now had to simultaneously perfect the Mercury-Atlas rocket's launch performance and make the missile safe for human flight.

John Bazyk, currently of the Aerospace Medium Launch Vehicles office, joined the company in 1961 as a member of the Mercury team. His first job was quality control, specifically to assist in upgrading the Atlas to its highest level of reliability. Bazyk said that ensuring reliability of the Atlas was the focus at that early stage of the program: "Mercury came in at a time when the Atlas rocket was experiencing difficulties making a good launch performance. In the first couple of years, we were just trying to make the Atlas work."

Pilot Safety Program

Greater reliability for the Mercury-Atlas went hand in hand with the Pilot Safety Program. At the very beginning of the Mercury effort, Maj. Gen. O. J. Ritland, commander of the Air Force's Ballistic Missiles Division, believed that a program was needed to ensure the pilot's safety. He ordered studies to determine requirements for implementing the program, which he said were necessary "to ensure that nothing is left undone that could better the chances of the booster safely placing the astronaut in orbit."

Hohmann, Letsch, and other members of the original Mercury team began to formulate the Pilot Safety Program while still at STL. Development of the program continued at Aerospace when it assumed responsibility for Project Mercury systems engineering. Over the next three years, Aerospace worked with the Air Force Space Systems Division, NASA, and various contractors to continually refine the program.

Because NASA was striving for a reliability rate of 99 percent for the Atlas, extreme accuracy was critical to the program's success. Plans to televise each American manned mission worldwide added to the pressures of preparations for flight readiness. Although a televised launch would present a stark contrast to the secrecy surrounding Soviet launches, it allowed no room for engineering mistakes.

Given the severe time constraints of Project Mercury, Aerospace could not make major changes to the rocket's basic design, yet modifications would be required to ensure reliability and pilot safety. To satisfy these requirements, two programs were devised for the Pilot Safety Program.

Astronaut John Glenn completes final preparations prior to the launch of Mercury-Atlas 6 on February 20, 1962. The logo for "Friendship 7," the name Glenn gave his spacecraft, appears on the capsule.

The first program, to ensure basic booster reliability, included a quality assurance program and a factory rollout inspection. Quality assurance involved detailed checking and analysis of every principal rocket component prior to each launch. Inspection would guarantee that every Mercury-Atlas booster was fully functional and as close to flight configuration as possible before delivery to the Air Force.

The second program was intended to provide for the safety of the Mercury pilot. Reliability augmentation sought to reduce the gap between the existing reliability of the Atlas booster and the desired pilot safety level of 99.9 percent. The Flight Safety Review determined flight readiness of the Atlas booster prior to each launch.

Because the Atlas engine contained approximately 100 critical components, engineers faced an enormous quality-control task. Reliability augmentation concentrated on two areas: an effort to educate contractor personnel about the importance of company contributions to the overall Mercury project and a critical parts-selection program to ensure rejection of components with substandard performance levels or faulty inspection records.

Educational efforts included on-site visits by astronauts to meet with workers at component manufacturers. These meetings put a face on the Mercury pilots, so that workers would realize that parts they manufactured might have life-or-death consequences for the persons who would ride the Atlas's 1.632 meganewtons of thrust. Astronauts explained to workers how specific components were integrated into the launch vehicle and stressed that their lives depended on the best efforts of every Mercury team member.

The program mandated strict standards for manufacturing and worker performance, and Hohmann insisted on the most stringent levels of quality control. Wambolt remembers that "with the Pilot Safety Program, we were creating a pedigree for every component."

Members of the Project Mercury team at Cape Canaveral in 1962. From left: Walter C. Williams and Ben Hohmann of Aerospace with astronauts John Glenn and Scott Carpenter.

To provide an additional safety measure for the astronauts, engineers developed an abort sensing and implementation system (ASIS) designed to automatically detect a booster malfunction and eject the capsule from the Atlas by means of an escape tower. "Our goal was to put together a program that would protect the astronauts in the event of a flight failure," Wambolt said. "When you start thinking about trying to reach a reliability potential of close to 100 percent, there has to be some way to protect the pilot by means of ejection."

A variety of manual abort capabilities supplemented the automatic malfunction detection system. Although ASIS was tested on several Atlas flights, it was never needed during a Mercury manned mission.

Flight Safety Review before each mission determined flight readiness of the booster, providing the basis for a decision about whether the Atlas was ready for launch. Procedures were similar to Air Force practices for conducting safety inspections of experimental aircraft. They included careful review of technical readiness, the status of the interface between the spacecraft and booster, and the weather forecast for the launch day.

Technical flight readiness was determined by the Status Review Team, which relayed its "go" or "no-go" recommendation to the Flight Safety Review Board. The review board then accepted or rejected the recommendation and passed along its decision to the senior representative from NASA. The Flight Safety Review became a critical and integral part of each mission.

Atlas Tests

Aerospace continued to refine the Pilot Safety Program through 1960 and 1961, not in a theoretical, isolated environment, but within real day-to-day operations of Project Mercury. Ongoing Mercury-Atlas test flights were scheduled up to the first orbital mission. The launch of the Mercury-Atlas 1 on July 29, 1960, failed one minute after blastoff. Investigation of the failure delayed the next launch for seven months.

That next launch—the successful flight of Mercury-Atlas 2 on February 21, 1961—was the first Atlas test that included Aerospace engineering contributions. Elation over the successful test proved short-lived, however, when two months later, the flight of Mercury-Atlas 3 was terminated 40 seconds after liftoff. Investigation revealed a problem with electrical components in the Atlas autopilot. Mercury-Atlas 4, which flew on September 13, 1961, successfully performed all operations. This was the first time a Mercury spacecraft orbited Earth, returned, and was recovered.

Mercury-Atlas 5, the last test completed before an astronaut flew, was launched November 29, 1961. In this significant test, the capsule carried a chimpanzee named Enos. Two of the three planned orbits were completed, and Enos was retrieved in good condition. Both the Atlas rocket and the spacecraft used for Enos's flight contained refinements and modifications that were required before the flight of Mercury-Atlas 6 could occur. This was to be the first human orbital mission, piloted by astronaut John H. Glenn Jr.

John Glenn's Flight

In the months before America's first planned orbital flight, the U.S.-Soviet space race intensified. The Soviet Union achieved a major technology and propaganda victory April 12, 1961, by launching cosmonaut Yuri Gagarin, the first human in space, into a single orbit around Earth. In the United States, public pressure to launch an American intensified. Only three weeks after Gagarin's flight on May 5, 1961, astronaut Alan Shepard became the first American in space, with a successful suborbital flight. Gilruth recalled that Shepard's flight "was a very big thing for America, because people had thought we were dead and out."

On May 25, President John F. Kennedy, sensing the public's elation over Shepard's accomplishment, formally committed the United States to sending a man to the moon and back before the end of the decade. At that point, the United States had seen barely 15 minutes of flying time in space. Shepard's flight was followed on July 21 by a second suborbital mission, that of Virgil "Gus" Grissom. Aerospace did not directly participate in these flights, which employed modified Army Redstone rockets as their launch vehicles, but the two successful flights paved the way for Glenn's pathbreaking mission. They helped NASA improve its procedures for the reentry and recovery of the Mercury capsule.

Ben Hohmann (left), Ernst Letsch, and John Glenn following the Mercury-Atlas 7 review board meeting on May 23, 1962.

Americans were enthralled by the two suborbital missions and now waited anxiously for the nation's first manned orbital flight. After 11 delays caused by booster problems and bad weather, Mercury-Atlas 6 finally lifted into orbit. On the morning of February 20, 1962, John Glenn's spacecraft, which he named "Friendship 7," was launched from Cape Canaveral, Florida (Kennedy Space Center).

With the rest of the nation, Aerospace engineers, torn between exhilaration and apprehension, watched Glenn's launch. Getting's sober assessment described the enormous responsibility they felt: "To launch him safely fell on the shoulders of the AF-Aerospace-associate contractor team." About five minutes after launch, the Atlas rocket injected the Mercury capsule into orbit. "No message was more eagerly awaited than 'Orbit has been established,'" Getting wrote.

Glenn successfully completed his three-orbit mission after reaching an apogee of some 261 kilometers and attaining an orbital velocity of approximately 7.8 kilometers per second. The most serious problem encountered was the detection, by an engineer at Mercury Control Center, of signals indicating that the capsule's heat shield was loose. The signals caused some anxious moments for Glenn and the Mercury operations team. The retropackage, which normally would have been expended, was retained during reentry in an attempt to hold the heat shield in place. The sensor signal ultimately proved false, and the heat shield remained securely in place.

Friendship 7 splashed down safely about 1300 kilometers southeast of Cape Canaveral, in the British West Indies, near Grand Turk Island of the Turks and Caicos island group, after a total flight time of 4 hours, 55 minutes, and 23 seconds. NASA reported: "All mission objectives for this flight were accomplished. The astronaut's performance during all phases of the mission was excellent, and no deleterious effects of weightlessness were noted. [The flight of Friendship 7] established the practical value of manned flight in near-Earth orbit."

Summary

Glenn's flight earned him a permanent place in history as a genuine American hero, a status reinforced when he flew in space for a second time in 1998 as a crew member on the space shuttle. His three-orbit flight set the United States on track in the space race and helped restore the nation's confidence in American engineering and technology. When the Mercury missions were completed, NASA's Mercury Project Summary noted the magnitude of the successes:

Mercury astronauts John Glenn, Gus Grissom, and Alan Shephard appear before the backdrop of a Mercury-Redstone rocket in this public-relations photograph. (Photo courtesy of NASA)

"The United States' first manned space flight project was successfully accomplished in a 4 2/3 year period of dynamic activity which saw more than 2,000,000 people from many government agencies and much of the aerospace industry combine their skills, initiative, and experience into a national effort. These manned flights were accomplished with complete pilot safety and without change to the basic Mercury concepts."

Beyond the immediate accomplishment of Glenn's mission, Aerospace laid the groundwork for a stable, solid program that would help ensure success for the next series of crewed spaceflights. The success of the Pilot Safety Program, which was originated at STL, was proved by the later flights of Mercury astronauts Scott Carpenter, Wally Schirra, and Gordon Cooper. The Air Force asked Aerospace to continue the program during Project Gemini, the series of missions with two crew members that began in 1965.

Hohmann's insistence on meticulous attention to each detail associated with the launch vehicle ensured an outstanding success rate for the Atlas-launched Mercury flights. By program completion in June 1963, six consecutive successful Mercury-Atlas launches had taken place. "The AF-Aerospace-associate contractor team had pioneered in the U.S. manned space launch effort and the record was perfect," Getting wrote. "Each Mercury astronaut had been safely launched into the proper orbit."

From a systems engineering perspective, Aerospace made a number of significant accomplishments. It established highly refined hardware acceptance procedures; instituted the goal of delivering flight-ready launch vehicles to the Air Force; developed a closed-loop, time-oriented failure analysis process; conducted design reviews; and monitored flights of the Mercury-Atlas rockets. Aerospace provided technical direction for major Atlas modifications, including implementation of ASIS and review of the design of the rocket's electronics system.

As Project Mercury came to its conclusion, many members of the Aerospace Mercury-Atlas team were retained to work on the next series of manned space flights, Project Gemini. The new team included Mercury veterans (from left to right) Joe Wambolt, Nathan Silk, Ben Hohmann, and James W. McCurry. In this photo, circa 1963, they are posed before models of the Gemini-Titan and Mercury-Atlas rockets.

Aerospace contributions to Project Mercury were widely recognized. Gen. Ritland wrote to Getting, expressing his gratitude and praise: "Please accept my warmest congratulations and thanks for your vital contributions to the Mercury program, and extend my heartfelt appreciation to each member of your organization." Two weeks after Glenn's flight, NASA Administrator James E. Webb commended Aerospace: "The performance of the Atlas launch vehicle gave a perfect start to the operation and reflects the thorough and tireless work of your group."

Key Mercury participants understood that Aerospace expertise would be needed in the upcoming Gemini missions. In a note to Getting acknowledging Aerospace's contributions to Mercury, Gilruth alluded to what would indeed become many years of collaboration between Aerospace and NASA in the great endeavor of space exploration:

"The hard work in Mercury that led to the flight of John Glenn stands as a significant technical achievement. However, we must look upon it as but the initial step toward broader objectives of exploring space. We, at NASA, are looking forward to continued good relations with The Aerospace Corporation as we pursue together the difficult tasks that lie ahead."

Acknowledgment

Special thanks to Joseph Wambolt for his assistance with the research for this article. Not only did he clarify some of the major threads of The Aerospace Corporation's involvement with Project Mercury, he also provided original documents and photographs about the early days of the U.S. space program. Several photographs in this article are from his personal collection.