"Project Mercury was America's first man-in-space effort. The McDonnell-Douglas Corporation developed the Mercury spacecraft in the familiar bell shape. It was

"Project Mercury was America's first man-in-space effort. The McDonnell-Douglas Corporation developed the Mercury spacecraft in the familiar bell shape. It was barely large enough for its single occupant and had no independent maneuvering capability save attitude control jets. Its orbital path was completely dependent on the accuracy of the guidance of the Atlas booster rocket. Re-entry was calculated by a realtime computing center on the ground, with retrofire times and firing attitude transmitted to the spacecraft while in flight. Therefore, it was unnecessary for the Mercury spacecraft to have a computer, as all functions required for its limited flight objectives were handled by other systems." http://history.nasa.gov/computers/ch1-1.html http://history.nasa.gov/computers/ch1-1.html