Mercury program

Launch of the historic Mercury Atlas 6 mission in which John Glenn became the first American to orbit the Earth.

The Mercury Program was the first manned space program in the United States, developed between 1961 and 1963 as part of the space race. The beginnings of the project go back to October 7, 1958, one year and three days after the Soviet Union put Sputnik 1, the first satellite in space, into orbit around the Earth.

The program was named for Abe Silverstein, one of the program's engineers and managers, who also chaired the astronaut selection panel. This group of pilots selected for the program's missions—NASA's first astronauts and the West—they were known as the "Mercury Seven", which is why the ships were assigned a name followed by a 7.

Beginnings

The "Mercury Seven": (up, from left to der.) Alan Shephard, Gus Grissom and Gordon Cooper; (down, from left to left) Walter Schirra, Deke Slayton, John Glenn and Scott Carpenter.

Project Mercury was NASA's response to the leadership of the Soviet Union at the time, facing off against the United States during the Cold War.

During the Mercury program, American engineers were pressured by the challenges of building a safe spacecraft that would allow an astronaut to reach Earth orbit without being destroyed by the enormous accelerations involved. Another source of concern was the extremes of the space environment: vacuum, sudden temperature fluctuations, and the newly discovered space radiation. All of this was further complicated by the need to perform a high speed reentry into the atmosphere and to protect the astronaut from the high reentry temperatures through the use of heat shields.

The Mercury Capsule

The result was the creation of a wingless ballistically shaped vehicle that would make its re-entry into the atmosphere protected from a heat shield that would burn up during this stage. Mercury was designed by Max Faget, and was more versatile and instrumented than its Soviet rival Vostok.

The Mercury capsules used two types of rocket launchers (or boosters, in English). The first suborbital flights were launched by Redstone rockets designed by Wernher von Braun's team in Huntsville, Alabama. For orbital flights, the capsules were launched with the Atlas-D, rockets modified from a ballistic missile. Its steel cover was very thin to save weight, so its structural stability was provided by the pressure of the fuel inside (when it was empty it had to be pressurized with gas to prevent the launcher from collapsing). The next family of launchers for the Gemini program would have this same problem: the Titan II.

The human team

The first Americans to be chosen for spaceflight were selected from a larger group of 110 military pilots chosen for their experience in test flights and because they met the necessary physical characteristics. In 1957, 7 astronauts were selected for the Mercury missions:

• Alan B. Shephard
• Virgil I. Grissom (Fallecería en el incendio de su último misión: Apolo 1)
• Gordon Cooper
• Walter Schirra
• Deke Slayton (Department of the project by heart condition)
• John Glenn
• Scott Carpenter

Only 6 of the 7 selected astronauts flew. Deke Slayton was ruled out of the flight list due to a heart condition. Slayton continued in the space program as a mission controller until 1975, when he finally flew the purely political Apollo-Soyuz mission.

The first flight was by Alan Shephard aboard Freedom 7 (freedom means 'freedom'), the astronauts named their own ships and they all did adding the ending "7" in recognition of the original group of seven astronauts.

At just 12.33 m³, the Mercury capsule was large enough to accommodate just one astronaut. Inside the capsule were 120 switches, 55 electrical switches, 30 fuses, and 35 mechanical levers.

The Mercury Missions

For the safety of the capsule, the engineers had tested it the first time with rhesus monkeys, then with a chimpanzee known as Ham, and later they went on to do another test, but this time with an electronic mannequin that breathed, which it allowed scientists to determine the stability of the ship's internal environment.

Once the experimentation and training phase was over, on May 5, 1961, Alan Shepard made the first American suborbital flight. Given the Soviet leadership in space, the American government presented this suborbital flight to the world as space flight. It would not be until nine months later, on February 20, 1962, when astronaut John Glenn would become the first American to orbit the Earth, thus repeating the feat of Yuri Gagarin. At that time the Soviets had already launched 48 orbital missions and Valentina Tereshkova would become the first woman in space, twenty years before the first American in space, Sally Ride.

The six Mercury flights totaled 2 days and 6 hours of spaceflight and allowed us to learn that not only humans could reach space (as the Soviets had already shown) but also that the need for their presence was imperative for success of the missions. American ground engineers learned from these missions the need to use global communications networks that allowed them to maintain constant contact with manned flights.

The last flight of a Mercury project spacecraft was that of the Mercury Atlas 9 in the Faith 7 capsule with L. Gordon Cooper, Jr. on May 15, 1963, a mission that concluded at next day. After the project was complete, the focus of the flight program had shifted when President John F. Kennedy announced during a session of Congress the goal of landing an American on the moon and bringing him safely back.

By 1963, only 500 of the 2,500 people working at NASA's Manned Flight Center were still working for the Mercury program (the remaining 2,000 were busy working on the Gemini and Apollo programs with which NASA would make further advances and his only victory against the Soviets).

Issues related to the United States space program

• Gemini Project
• Apollo Program
• Apollo-Soyuz
• Skylab Programme
• Space Shuttle Programme
• List of American interplanetary probes