Luna 6

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Luna 6 was an uncrewed Soviet lunar lander, part of the Ye-6 series in the Luna program. Built by OKB-1 and weighing about 1,442 kg, it was launched from Baikonur on 8 June 1965 aboard a Molniya-M rocket to reach the Moon.

The mission lasted about 10 days. A planned mid-course correction late on 9 June failed because a command was mistakenly sent to the timer to shut down the engine, so the main engine burned until it ran out of propellant. Without a proper landing, Luna 6 flew past the Moon at a distance of about 160,000 km (roughly 99,000 miles) with its closest approach around 159,600 km. Ground controllers kept contact for several days, and the mission was used to simulate a landing for training purposes, providing useful data for future attempts.