Is this the world's largest precision ground granite slab?
23 July 2012
The US Naval Research Laboratory has taken delivery of what is believed to be the largest precision ground single granite slab. It weighs 37.5ton and its surface varies by no more that +/-0.045mm over an area of 28m2.
The US Naval Research Laboratory Spacecraft Engineering Department's space robotics research facility recently took possession of a one-of-a-kind 37.5ton Gravity Offset Table (GOT) made from a single slab of solid granite.
Precision honed to within +/-0.045mm tolerance across its surface, the Gravity Offset Table (shown here being delivered on a low-loader) will allow scientists to emulate the inertia of space in the laboratory using full-size spacecraft and robotic arms.
To emulate the classical mechanics of physics found in space on full-scale replica spacecraft on Earth requires not only a hefty amount of air to 'float' the object, but a precision, frictionless, large surface area that will allow researchers to replicate the effects of inertia on man-made objects in space.
"We accomplish this by floating models of spacecraft and other resident space objects on air bearings — similar to the dynamics of an upside-down air hockey table," says space robotics specialist Dr Gregory Scott. "Based on the inertia of the 'floating' system, a realistic spacecraft response can be measured when testing thrusters, attitude control algorithms, and responses to contact with other objects."
Honed by Precision Granite to US Federal 'AAA' specifications, the 6,000mm x 4,500mm x 460mm single piece of granite was quarried from the Raymond Granite Quarry, Clovis, California.