The Mariner 2 unmanned space mission is launched to Venus by NASA.

Mariner 2, an American space probe to Venus, was the first robotic space probe to report successfully from a planetary encounter. The first successful spacecraft in the NASA Mariner program, it was a simplified version of the Block I spacecraft of the Ranger program and an exact copy of Mariner 1. The missions of the Mariner 1 and 2 spacecraft are sometimes known as the Mariner R missions. Original plans called for the probes to be launched on the Atlas-Centaur, but serious developmental problems with that vehicle forced a switch to the much smaller Agena B second stage. As such, the design of the Mariner R vehicles was greatly simplified. Far less instrumentation was carried than on the Soviet Venera probes of this period—for example, forgoing a TV camera—as the Atlas-Agena B had only half as much lift capacity as the Soviet 8K78 booster. The Mariner 2 spacecraft was launched from Cape Canaveral on August 27, 1962, and passed as close as 34,773 km (21,607 mi) to Venus on December 14, 1962.

Venus is the second planet from the Sun. It is often called Earth's "twin" or "sister" among the planets of the Solar System for its orbit being the closest to Earth's, both being rocky planets and having the most similar and nearly equal size and mass. Venus, though, differs significantly by having no liquid water, and its atmosphere is far thicker and denser than that of any other rocky body in the Solar System. It is composed of mostly carbon dioxide and has a cloud layer of sulfuric acid that spans the whole planet. At the mean surface level, the atmosphere reaches a temperature of 737 K and a pressure 92 times greater than Earth's at sea level, turning the lowest layer of the atmosphere into a supercritical fluid. From Earth Venus is visible as a star-like point of light, appearing brighter than any other natural point of light in Earth's sky, and as an inferior planet always relatively close to the Sun, either as the brightest "morning star" or "evening star".

The National Aeronautics and Space Administration is an independent agency of the US federal government responsible for the United States's civil space program, aeronautics research and space research. Established in 1958, it succeeded the National Advisory Committee for Aeronautics (NACA) to give the American space development effort a distinct civilian orientation, emphasizing peaceful applications in space science. It has since led most of America's space exploration programs, including Project Mercury, Project Gemini, the 1968–1972 Apollo program missions, the Skylab space station, and the Space Shuttle. Currently, NASA supports the International Space Station (ISS) along with the Commercial Crew Program and oversees the development of the Orion spacecraft and the Space Launch System for the lunar Artemis program.