Surveyor 4

Surveyor 4 is the fourth lunar probe of the Programme Surveyor American to explore the the Moon.

• Launching the July 14th 1967; lunar landing the July 17th 1967

• Mass with the lunar landing: 283 kg

This lunar probe or Space vehicle was crushed after the impeccable mission carried out by Surveyor 3, a few months earlier; the signal of telemetry disappeared 2 ' 30min before the landing, envisaged on Sinus Medii with 0.4° of Northern latitude and 1.33° of Western longitude.

This probe was the fourth of a series intended for lunar landings carefully and to transmit photographs of lunar surface in order to determine the characteristics of the ground to prepare the missions of Apollo lunar landings. The equipment on board was composed of a television camera, auxiliary mirrors, of a sampler of mechanical ground, strain gauges on the metal legs of the probe, and many technical probes. After an impeccable flight towards the the Moon, the signals of the Récepteur radio operator ceased during the final stage of descent. The contact with the probe restored forever, and the mission was a failure. The solid fuel retrorocket could have exploded a few moments before its programmed desactivation. The mission was a total success right before this incident. NASA concludes that the alunissor probably exploded at the time of the loss of the signals to 02:03 UT the July 17th 1967

Like Surveyor 3, Surveyor 4 was equipped with external claws (with one like in the claw) to detect and measure the ferrous elements in lunar surface.