The "Mars" dish, 70 meters in diameter, is the largest antenna at Goldstone. It stands 234 feet high and weighs almost 8,000 tons. The rotating portion, which alone weighs more than 3,500 tons, floats on a film of oil about the thickness of a sheet of paper. In this photo, the vehicles and people at its base give a sense of the dish's great scale. Despite its great size, it is an extremely accurate instrument in terms of shape (within 1 centimeter over an area of 3,850 square meters) as well as pointing accuracy (0.006 degrees).
The Deep Space Network's 70-meter dishes are used to communicate with the most distant space probes. The first of these spacecraft to explore the outer planets was Pioneer 10, launched in March 1972. It was the first spacecraft to pass through the asteroid belt, the first to obtain close-up images of Jupiter, and the first to pass the orbit of Pluto. Pioneer 10 was supposed to last only 21 months, but the Deep Space Network stayed in contact with it for more than 30 years. The last signal was received in January 2003, after Pioneer 10 had traveled 7.6 billion miles.