Introduction
A decision by National Aeronautics and Space Administration Headquarters in October 1961 extended the Mercury program by adding 1-day missions after three- and- six-orbit flights. Also, during the same year, follow-on manned space programs, later known as Projects Gemini and Apollo, began to take form. These events were rather unusual, for here was program expansion on a higher level of difficulty prior to the time that the basic objectives of Project Mercury, the launch and safe return of a man from earth orbit, had been attained. Obviously, Project Mercury, first guided by the Space Task Group and then by the Manned Spacecraft Center (the successor organization), had built up a high confidence factor as to the potential success of the space venture. To a large degree, this action was graphically supported at that point in time by the highly successful suborbital flights of Alan Shepard and Virgil Grissom and the orbital flight of the "mechanical astronaut."
Project Mercury’s formal program approval date was October 7, 1958, and 8 years and 2 weeks from the award of the development and production contract by NASA to the McDonnell Aircraft Corporation of St. Louis, Missouri, the orbital flight of John Glenn aboard the Mercury spacecraft, "Friendship 7," transpired. When this uncommonly brief time scale is compared with other major programs of national note and urgency, the question of how man was committed so soon to orbital flight is certain to be posed.
The key to this phenomenal success was concurrency of effort. That is, all facets of the program leading to manned space flight were guided along a simultaneous route and not by the concept of qualifying each phase before development work began on another. From the outset, work was being accomplished on all components of the spacecraft, adapting the launch vehicles, readying the worldwide tracking network, selecting and training astronauts, and developing ground support equipment for systems checkout and astronaut training. No detail was too small to warrant the attention of scientists and engineers who were charged with making the awesome decisions that would commit man to orbital flight. Every organization that had acquired any technical proficiency or had built up a capability in a particular field that could be applied to the space program was visited, and arrangements were made for assistance, facilities, or the use of equipment. Also, the test and reliability program to which Mercury hardware was subjected was exhaustive and thorough. In fact, this unusually close attention refutes the "crash program" connotation often cited. The term "accelerated" more aptly describes the effort. That the managers were not
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