The X-15 was a hypersonic research jet designed to help NASA researchers learn about high velocity air dynamics, hypersonic control mechanisms, material design at hypersonic speeds, reentry techniques, and designs for instruments that would work at these high speeds. Considered the ancestor of the first rockets that would be later sent to space under the Apollo, Mercury, and Gemini programs, the X-15 was a highly experimental aircraft that only saw 199 test flights—13 being above 50 miles, the Air Force barrier to space—with 5 models. It is also considered the fastest manned aircraft ever designed, with a top recorded speed of 7,274 km/hr or Mach 6.72.
Considered the first real attempt at spaceflight by NASA, Project Mercury began on October 7, 1958 with the objective to put a man in orbit around the Earth and bring him back safely. With a distinct reticence to new technology not commonly found in today’s world, the Project wished to use existing tech whenever possible, so as to maximize simplicity and ease of understanding for such a large project. This project took the efforts of nearly 2 million scientists and workers and the equivalent of $2 billion 2015 USD to send a man to space, but sparked the beginning of spaceflight.
Project Gemini was designed to be the supporting mission to Apollo, with the project testing the capabilities of space flight for both the astronauts and the rockets they would fly in. Specific goals were proposed and then met by the Program: