On February 3, 1966 Luna 9 spacecraft was the first spacecraft to achieve a lunarsoft landing and to transmit photographic data to Earth. Several months after, Surveyor 1 launched on May 30, 1966; and landed on Oceanus Procellarum on June 2, 1966, also transmitting photographic data back to Earth. This spacecraft was the second of a series designed to achieve a soft landing on the Moon and to return lunar surface photography for determining characteristics of the lunar terrain for Apollo programlunar landing missions. Besides transmitting photos, Surveyor 2 was planned to perform a 'bounce', to photograph underneath its own landing site. It was also equipped to return data on radar reflectivity of the lunar surface, bearing strength of the lunar surface, and spacecraft temperatures for use in the analysis of lunar surface temperatures.
Failure
The target area proposed was within Sinus Medii. The Atlas-Centaur had placed Surveyor 2 on a path to the Moon that was only 130 km from its aim point. During the midcourse correction maneuver, one vernier engine failed to ignite, resulting in an unbalanced thrust that caused the spacecraft to tumble for its remaining 54 hours. Attempts to salvage the mission failed. Contact was lost with the spacecraft at 9:35 UTC, September 22. The spacecraft was targeted at Sinus Medii, but crashed near Copernicus crater. The spacecraft was calculated to have impacted the lunar surface at 03:18 UTC, September 23, 1966. Its weight on impact was 644 lb, and speed was about 6000 miles an hour, slightly over lunar escape velocity and similar to the impact velocities of the Ranger program spacecraft.
Aftermath
The next Soviet mission, Cosmos 111, was launched on March 1, 1966. The mission was also a failure. Surveyor 3 soft-landed on April 20, 1967 at the Mare Cognitum portion of the Oceanus Procellarum. It transmitted a total of 6,315 TV images to the Earth. There were seven Surveyor missions; five were successful. Surveyors 2 and 4 failed. Each consisted of a single uncrewed spacecraft designed and built by Hughes Aircraft Company. The precise location of the Surveyor 2 crash site is unknown.
