This spacecraft crashed after an otherwise flawless mission; telemetry contact was lost 2.5 minutes before touchdown.

The planned landing target was Sinus Medii (Central Bay) at 0.4° north latitude and 1.33° west longitude.

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.

[3] 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.

The solid-fuel retrorocket may have exploded near the end of its scheduled burn.