Cassini is a canister-shaped payload about 22 feet (6.8 meters) long and 13 feet (4 meters) across. A large umbrella-shaped antenna mounted at one end of the spacecraft is its widest feature. Its long radar boom stretches about thirty-five feet (eleven meters) sideways out the side of the spacecraft. Together with the Huygens lander, the spacecraft weighed two and a half metric tons, and carried another three tons of fuel at launch. Cassini has twelve scientific instruments aboard, and Huygens has six more.