John Glenn was not popular with the other astronauts. Glenn was the backup pilot for Shepard and Grissom on the first two manned Project Mercury flights, the sub-orbital missions Mercury-Redstone 3 and Mercury-Redstone 4. Glenn was selected for Mercury-Atlas 6, NASA's first manned orbital flight, with Carpenter as his backup. Putting a man in orbit would achieve one of Project Mercury's most important goals. Shepard and Grissom had named their spacecraft "Freedom 7" and "Liberty Bell 7". The numeral 7 had originally been the production number of Shepard's spacecraft, but had come to represent the Mercury 7. Glenn named his spacecraft, number
Spacecraft design Spacecraft design The design of spacecraft covers a broad area, including the design of both robotic spacecraft (satellites and planetary probes), and spacecraft for human spaceflight (spaceships and space stations). Spacecraft design was born as a discipline in the 1950's and 60's with the advent of American and Soviet space exploration programs. Since then it has progressed, although typically less than comparable terrestrial technologies. This is for a large part due to the challenging space environment, but also to the lack of basic R&D, and to other cultural factors within the design community. On the other hand, another reason for