The 1966 Lunar Orbiter 1 robotic spacecraft mission, part of NASA's Lunar Orbiter program, was the first American spacecraft to orbit the Moon. It was designed primarily to photograph smooth areas of the lunar surface for selection and verification of safe landing sites for the Surveyor and Apollo missions. It was also equipped to collect selenodetic, radiation intensity, and micrometeoroid impact data. Mission controllers injected the spacecraft into a parking orbit around Earth on August 10, 1966, at 19:31 UTC. The trans-lunar injection burn occurred at 20:04 UTC. The spacecraft experienced a temporary failure of the Canopus star tracker (probably due to stray sunlight) and overheating during its cruise to the Moon.

Wikipedia: https://en.wikipedia.org/wiki/Lunar_Orbiter_1. Related NASA reference: https://science.nasa.gov/mission/lunar-orbiter-1/. Description adapted from Wikipedia contributors (CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0/).