The Scientific Investigations

The primary objective of Surveyor was developing and testing the soft landing technology for on the Moon. These lessons learned were then applied to the Apollo spacecraft design. The Surveyor program also had the objective of gaining scien­tific knowledge of the Moon. A number of experiments were designed into the Surveyor lander for scientific purposes. A comparison of the pre-Apollo Surveyor experiments and the Apollo ALSEP suite shows a continuity of scientific inquiry into the nature of the Moon.

Each spacecraft weighed 1000 kg at launch, was 3.3-m high, and had a 4.5-m diameter. The tripod structure of aluminum tubing provided mounting surfaces for scientific and engineering equipment. Onboard equipment consisted of a 3-m-square solar panel that provided approximately 85-W output, a main battery and 24-V non­rechargeable battery that together yielded a 4,090-W total output, a planar array antenna, two omnidirectional antennas, and a radar altimeter. The soft landing was achieved by the spacecraft free falling to the lunar surface after the engines were turned off at a 3.5-m altitude. Operations began shortly after landing.