USA 1964 Gemini 1

Project Gemini was a series of manned flight missions that came between Mercury and the Apollo program. Its main purpose was to test the theories that would be utilized in Apollo - rendezvous and docking of two spacecrafts, working outside the spacecraft in extra-vehicular activities or spacewalks, precision re-entry, and living in space for extended period of time.

Gemini 1, launched on April 8, 1964, was the first unmanned test flight of the Gemini spacecraft.
Gemini 1 "Orbit Covers" cancelled on launch day at Cape Canaveral, signed by Von Braun's rocket team member, Arthur Rudolph.