Surveyor 3 was the second spacecraft of the Surveyor series to achieve a lunar soft landing. The primary objectives of the Surveyor program, a series of seven robotic lunar softlanding flights, were to support the coming crewed Apollo landings by: (1) developing and validating the technology for landing softly on the Moon; (2) providing data on the compatibility of the Apollo design with conditions encountered on the lunar surface; and (3) adding to the scientific knowledge of the Moon. The specific objectives for this mission were to: (1) perform a soft landing on the Moon within the Apollo zone and east of the Surveyor 1 landing site; (2) obtain postlanding television pictures of the lunar surface; (3) obtain information on lunar-surface bearing strength, radar reflectivity, and thermal properties; and (4) use the surface sampler to manipulate the lunar surface and observe the effects with the television camera.

References
http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1967-035A