Project Mercury was the first human spaceflight program of the United States led by its newly created space agency NASA. It ran from 1959 through 1963 with the goal of putting a human in orbit around the Earth, and doing it before the Soviet Union, as part of the early space race. It involved seven astronauts flying a total of six solo trips. On May 5, 1961, Alan Shepard became the first American in space in a suborbital flight after the Soviet Union had put Yuri Gagarin into orbit one month earlier. John Glenn became the first American to reach orbit on February 20, 1962. He was the third person to do so, after Soviet Gherman Titov made a day-long flight in August 1961. When the project ended in May 1963, USA was still behind the Soviet space program, but the gap was seen as closing.
The space race started in 1957 with the launch of the Soviet satellite Sputnik 1. This came as a shock to the American public and led to the creation of NASA to gather the efforts in space exploration already existing in the US. After the launch of the first American satellite in 1958, manned space flight became the next goal. The spacecraft was produced by McDonnell Aircraft; it was cone shaped with room for one person together with supplies of water, food and oxygen for about one day in a pressurized cabin. It was launched from Cape Canaveral in Florida by a modified Atlas D or Redstone missile, and had an escape tower for protection from a failing rocket. The whole flight could be controlled from the ground through the Manned Space Flight Network, a system of tracking stations which also allowed communication with the astronaut. If necessary, the astronaut could take manual control. For reentry into Earth's atmosphere, small rockets were used to bring the spacecraft out of its orbit. A heat shield would protect the spacecraft from the heat of reentry, and a parachute would slow the craft for a water landing. Here both astronaut and spacecraft were picked up by a ship.
From a slow start with humiliating mistakes, the Mercury Project became popular worldwide and the manned flights were followed by millions on radio and TV not only in United States, but around the world. Apart from the manned missions, Mercury had a total of 20 unmanned launches as a part of the development of the project. This also involved test animals, most famously the chimpanzees Ham and Enos. Mercury laid the groundwork for Project Gemini and the follow-on Apollo moon-landing program, which was announced a few weeks after the first manned flight. The astronauts were collectively known as the "Mercury Seven" and they named their spacecraft with a "7" at the end. The project name was taken from Mercury, a Roman god. It is estimated to have cost $1.73 billion (current prices) and have involved the work of 2 million people.
Project Mercury was officially approved on October 7, 1958 and publicly announced on December 17. Originally it was called Project Astronaut, but President Dwight Eisenhower thought that it gave too much attention to the pilot. Instead, the name Mercury was chosen from Greco-Roman mythology, which already lent names to rockets like the Atlas and Jupiter It absorbed military projects with the same aim such as the Air Force Man-in-Space-Soonest.
Following the end of World War II, a nuclear arms race evolved between the US and the Soviet Union to develop long-range missiles. At the same time both sides also developed satellites for espionage. Most of this took place in secret, therefore it came as a shock to the American public when the Soviet Union placed the first satellite into orbit in October 1957 and there was a growing fear in the US that the country was falling behind. A month later, the Soviets launched a dog into orbit and though the dog was not recovered, it was obvious that they were striving for manned spaceflight Unable to tell the public about the progress of military space projects, President Eisenhower decided to create a civilian space agency known as the National Aeronautics and Space Administration, based on the NACA, a federal aeronautical research agency. NASA was placed in charge of civilian and scientific space exploration and after having orbited an American satellite in 1958 the next goal became to put a man in space.
The limit of space was defined as an altitude of 62 mi (100 km) and the only way to reach it was by rocket. This created risks for the pilot, including explosion, subjection to high g-forces and vibrations during lift off through the atmosphere. In space, the pilot would experience zero gravity, a condition where he might suffer from disorientation. In this altitude he had to be in a pressurized chamber or suit and supplied with fresh air. Further possible risks were radiation from space and micrometeoroids, from which the air would normally protect him. At reentry to the denser part of the atmosphere, air compression would heat the spacecraft to more than 10,000 °F (5,540 °C). All these obstacles, however, seemed possible to overcome. Experiences from satellites suggested that the risk from micrometeoroids was negligible. As to the medical questions, experiments in the early 1950s with simulated weightlessness and high g-forces on humans, together with experiments of sending animals to the limit of space gave the conclusion that problems could be overcome by known technology. Finally, reentry was studied using the nuclear warheads of ballistic missiles. From this, the best solution to the heating problem was found to be a blunt heat shield facing the direction of movement during reentry, since it created a shock wave that let most of the heat flow around the spacecraft or warhead.
T. Keith Glennan had been appointed administrator of NASA with Hugh L. Dryden (last director of NACA) as his deputy from the creation of the agency on October 1, 1958. Glennan would report to the president through the National Aeronautics and Space Council. The group responsible for Project Mercury was NASA's Space Task Group and the goals of the program were to orbit a manned spacecraft around Earth, investigate the pilot's ability to function in space and to recover both pilot and spacecraft safely. Existing technology and off-the-shelf equipment would be used wherever practical, the simplest and most reliable approach to system design would be followed, and an existing launch vehicle would be employed together with a progressive test program. Spacecraft requirements included: a launch escape system to separate the spacecraft and its occupant from the launch vehicle in case of impending failure; attitude control for orientation of the spacecraft in orbit; a retrorocket system to bring the spacecraft out of orbit; drag braking blunt body for atmospheric reentry; and landing on water. To communicate with the spacecraft during an orbital mission, an extensive communications network had to be built. To begin with President Eisenhower hesitated to give the project top national priority (DX rating), which meant that it had to wait in line behind military projects for materials; however, this rating was granted in May 1959.
Twelve companies bid to build the Mercury spacecraft on a $20 million ($162 million) contract. In January 1959, McDonnell Aircraft Corporation was chosen to be prime contractor for the spacecraft. Two weeks earlier, North American Aviation, based in Los Angeles, was awarded a contract for Little Joe, a small rocket to be used for development of the launch escape system. The World Wide Tracking Network for communication between the ground and spacecraft during a flight was awarded to the Western Electric Company. Redstone rockets for suborbital launches were manufactured in Huntsville, Alabama by the Chrysler Corporation and Atlas rockets by Convair in San Diego, California. For manned launches, the Atlantic Missile Range at Cape Canaveral Air Force Station in Florida was made available by the USAF. This was also the site of the Mercury Control Center while the computing center of the communication network was in Goddard Space Center, Maryland. Little Joe rockets were launched from Wallops Island, Virginia. Astronaut training took place at Langley Research Center in Virginia, Lewis Flight Propulsion Laboratory in Cleveland, Ohio, and Naval Air Development Center in Johnsville. Langley wind tunnels together with a rocket sled track at Holloman Air Force Base at Alamogordo, New Mexico were used for aerodynamic studies. Both Navy and Air Force aircraft were made available for the development of the spacecraft's landing system, and Navy ships and Navy and Marine Corps helicopters were made available for recovery. South of Cape Canaveral the town of Cocoa Beach boomed From here, 75,000 people watched the first American orbital flight being launched in 1962.
The principal designer of the Mercury spacecraft was Max Faget who started research for manned spaceflight during the time of the NACA. The spacecraft was 10.8 feet (3.3 m) long and 6.0 feet (1.8 m) wide; with the launch escape system added, the overall length was 25.9 feet (7.9 m). With 100 cubic feet (2.8 m3) of habitable volume, the spacecraft was just large enough for the single crew member. Inside were 120 controls: 55 electrical switches, 30 fuses and 35 mechanical levers. The heaviest spacecraft, Mercury-Atlas 9, weighed fully loaded 3,000 pounds (1,400 kg). Its outer skin was made of René 41, a nickel alloy able to withstand high temperatures.
The spacecraft was cone shaped with a neck at the narrow end. It had a convex base, which the heat shield was mounted on (2). It was composed of an aluminum honeycomb structure covered with multiple layers of fiberglass. Strapped to it was the retropack (1)which consisted of three rockets meant to brake the spacecraft for reentry. Between these were three minor rockets for separating the spacecraft from the launch vehicle at orbital insertion. The straps that held the package could be severed when it was no longer needed. Next to the heat shield was the pressurized crew compartment (3). This contained the astronaut strapped to his couch with the instruments in front of him and his back to the heat shield. Underneath the seat was the environmental control system, which supplied him with oxygen and heat. The system also cleaned the air of CO2, vapor and odors, as well as (on orbital flights) collect urine. The recovery compartment (4) at the narrow end of the spacecraft contained three parachutes: one drogue to stabilize free fall and two main parachutes of which only one was used, with the other as a reserve. Between the heat shield and the inner wall of the crew compartment was a landing skirt, which was deployed by letting down the heat shield before landing. On top of the recovery compartment was the antenna section (5) containing antennas for communication with the Earth and scanners for guiding the orientation of the spacecraft. Attached to it was a flap used to ensure that the spacecraft was faced in the correct direction (heat shield first) during reentry. A launch escape system (6) was mounted to the narrow end of the spacecraft. In case of failure during the first minutes of launch, three small solid-fueled rockets would fire for a second to bring the spacecraft free of the launch vehicle so it could deploy its parachute and land at sea.
Mercury-Atlas 7, launched May 24, 1962, was the fourth flight of Project Mercury, the first manned space program of the United States. The Mercury spacecraft, named Aurora 7, made three Earth orbits, piloted by astronaut Scott Carpenter. He was the sixth human and the fourth American in space.
A targeting error during reentry took the spacecraft 250 miles (about 400 km) off-course, delaying recovery of Carpenter and the spacecraft. The mission used Mercury spacecraft No. 18 and Atlas launch vehicle No. 107-D.
The original prime crew for Mercury Atlas-7 was to have been Deke Slayton, with Schirra as his back-up. However Slayton was removed from all flight crew availability after the discovery of cardiac arrhythmia during a training run in the g-loading centrifuge. If Slayton had flown MA-7, his spacecraft would have been named Delta 7, as this would have been the fourth manned flight and Delta (Δ) is the fourth letter in the Greek alphabet.
Mercury spacecraft No. 18 was delivered to Cape Canaveral, Florida on November 15, 1961. Atlas No. 107-D was rolled out of the Convair factory in San Diego, California on February 25, 1962. It was delivered to Cape Canaveral on March 6, 1962.
The focus of Carpenter's five-hour mission was on science. The full flight plan included the first study of liquids in weightlessness, Earth photography, and an unsuccessful attempt to observe a flare fired from the ground. At dawn of the third and final orbit, Carpenter inadvertently bumped his hand against the inside wall of the cabin and solved a mystery from the previous flight. The resulting bright shower of particles outside the spacecraft - what John Glenn had called "fireflies" - turned out to be ice particles shaken loose from the spacecraft's exterior.
Like Glenn, Carpenter circled the Earth three times. Total time weightless 4 h 39 min 32 s. The performance of the Mercury spacecraft and Atlas launch vehicle was excellent in nearly every respect. All primary mission objectives were achieved. The single mission-critical malfunction which occurred involved a failure in the spacecraft pitch horizon scanner, a component of the automatic control system. This anomaly was adequately compensated for by the pilot in subsequent in-flight operations so that the success of the mission was not compromised. A modification of the spacecraft control-system thrust units was effective. Cabin and pressure-suit temperatures were high but not intolerable. Some uncertainties in the data telemetered from the bioinstrumentation prevailed at times during the flight; however, associated information was available which indicated continued well-being of the astronaut.
Equipment was included in the spacecraft which provided valuable scientific information; notably that regarding liquid behavior in a weightless state, identification of the airglow layer observed by Astronaut Glenn, and photography of terrestrial features and meteorological phenomena. An experiment which was to provide atmospheric drag and color visibility data in space through deployment of an inflatable sphere was partially successful. The flight further qualified the Mercury spacecraft systems for manned orbital operations and provided evidence for progressing into missions of extended duration and consequently more demanding systems requirements.
Partly because he had been distracted watching the fireflies and partly because of his busy schedule, and a malfunction of the automatic alignment system, Carpenter overshot his planned reentry mark and splashed down 250 miles (402 kilometers) from target.
Aurora 7 is displayed at the Museum of Science and Industry in Chicago, Illinois.