This spacecraft was the fourth in a series designed to achieve a soft landing on the Moon and to return
photography of the lunar surface for determining characteristics of the lunar terrain for
Apollo lunar landing missions. Equipment on board included a television
camera and auxiliary mirrors, a soil mechanics surface sampler,
strain gauges on the spacecraft landing legs, and numerous engineering sensors. Like
Surveyor 3, Surveyor 4 was also equipped with a surface claw (with a magnet in the claw) to detect and measure ferrous elements in the lunar surface. After a flawless flight to the Moon,
radio signals from the spacecraft ceased during the terminal-descent phase at 02:03 UT on July 17, 1967, approximately 2.5 minutes before touchdown. Contact with the spacecraft was never reestablished, and the mission was unsuccessful. The
solid-fuel retrorocket may have exploded near the end of its scheduled burn. ==See also==