NASA tests the first Saturn I rocket in Mission Saturn-Apollo 1.

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. The rocket's first stage was built as a cluster of propellant tanks engineered from older rocket tank designs, leading critics to jokingly refer to it as "Cluster's Last Stand". Its development was taken over from the Advanced Research Projects Agency in 1958 by the newly formed civilian NASA. Its design proved sound and flexible. It was successful in initiating the development of liquid hydrogen-fueled rocket propulsion, launching the Pegasus satellites, and flight verification of the Apollo command and service module launch phase aerodynamics. Ten Saturn I rockets were flown before it was replaced by the heavy lift derivative Saturn IB, which used a larger, higher total impulse second stage and an improved guidance and control system. It also led the way to development of the super-heavy lift Saturn V which carried the first men to landings on the Moon in the Apollo program.

President John F. Kennedy identified the Saturn I, and the SA-5 launch in particular, as being the point where US lift capability would surpass the Soviets, after being behind since Sputnik.

The National Aeronautics and Space Administration (NASA ) is an independent agency of the U.S. federal government responsible for the civilian space program, as well as aeronautics and space research.NASA was established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA). The new agency was to have a distinctly civilian orientation, encouraging peaceful applications in space science. Since its establishment, most US space exploration efforts have been led by NASA, including the Apollo Moon landing missions, the Skylab space station, and later the Space Shuttle. NASA is supporting the International Space Station and is overseeing the development of the Orion spacecraft, the Space Launch System, Commercial Crew vehicles, and the planned Lunar Gateway space station. The agency is also responsible for the Launch Services Program, which provides oversight of launch operations and countdown management for uncrewed NASA launches.

NASA's science is focused on better understanding Earth through the Earth Observing System; advancing heliophysics through the efforts of the Science Mission Directorate's Heliophysics Research Program; exploring bodies throughout the Solar System with advanced robotic spacecraft such as New Horizons; and researching astrophysics topics, such as the Big Bang, through the Great Observatories and associated programs.