Lunar Lander, Surveyor (T-21), Soil Mechanics/Surface Sampler

This is an extendable scoop manufactured by the Hughes Aircraft Company in support of the Surveyor missions, which explored the lunar surface. This particular sampler was used on the T-21 (Touchdown 21) engineering model. The scoop is a claw-like device at the end of a frame that extends several feet through a gear drive and electrical motor. This engineering model of the soil mechanics surface scoop (SMSS) is an example of those carried on Surveyor Lunar Landers 3, 4 and 7. These spacecraft, launched starting in 1966, were used to survey the moon's surface and select a safe landing site for the Apollo lunar landings. The scissors jack-like arm of the sampler was hinged to the frame of the spacecraft. The motor driven arm was extendible up to five feet and able to range over a surface area of twenty-four square feet. The scoop at the end of the arm was used to dig trenches in lunar soil. Images of the trenches sent back by the on-board TV camera, as well as strain gages on the arm, provided data on the mechanical properties of the surface of the moon. The SMSS was manufactured by Hughes Aircraft.

It was transferred to NASM by GSA in 1969.

The soil mechanics surface sampler was designed to pick up, dig, scrape, and trench the lunar surface, and transport lunar surface material while being photographed so that the properties of the lunar surface could be determined. The sampler consisted primarily of a scoop with a container, a sharpened blade, and an electric motor to open and close the container. The flat foot of the scoop incorporated two embedded rectangular horseshoe magnets. The scoop was mounted on a pantograph arm that could be extended about 1.5 m or retracted close to the spacecraft motor drive. The arm could also be moved from an azimuth of +40 deg to -72 deg or be elevated 130 mm by motor drives. It could also be dropped onto the lunar surface under force provided by gravity and a spring. The scoop was mounted below the television camera in a position that allowed it to reach the alpha-scattering instrument in its deployed position and redeploy it to another selected location. The instrument performed 16 bearing tests, seven trenching tests, and two impact tests. It also freed the alpha-scattering instrument when it failed to deploy on the lunar surface, shaded this instrument, and moved this instrument for evaluation of other samples.