Sputnik 1 was a steel ball twenty-three inches (fifty-eight centimeters) in diameter and weighing 184 pounds (83 kilograms). Attached to its surface were four flexible antennae, ranging from 2.2 to 2.6 yards (201 to 238 centimeters) long. Sputnik 1 transmitted radio signals at two frequencies and gathered valuable information about the ionosphere and temperatures in outer space.