Orbital test flight of the Saturn-IV upper stage of the Saturn-1 (Block-2) launch vehicle.
The Saturn I was a rocket designed as the United States' first medium lift launch vehicle for up to 20,000-pound (9,100 kg) low Earth orbit payloads.
In July 1959, NASA chose the Redstone missile as the basis for the Mercury-Redstone Launch Vehicle to be used for suborbital test flights of the Project Mercury spacecraft. Three unmanned MRLV launch attempts were made between November 1960 and March 1961, two of which were successful. The MRLV successfully launched the chimpanzee Ham, and astronauts Alan Shepard and Gus Grissom on three suborbital flights in January, May and July 1961, respectively.INFO WIKI