Machines are part of our lives – even outside the human habitat. The machine that’s farther away from the Earth than any other is the Voyager 1 spacecraft. Since its launch on September 5, 1977, Voyager 1 has traveled more than 21 billion kilometers (13 billion miles) and every year the distance grows by another 540 million kilometers (335 million miles). On its flight, the machine weighing 825.5 kilograms (1,820 pounds) was accelerated to a speed of up to 62,140 km/h (38,612 miles) by the gravity of Jupiter and Saturn, and propelled to the edge of our solar system. It has since reached interstellar space. Voyager 1 is now so far away from the Earth that the transmission of a control signal takes 19 hours and 32 minutes – in spite of data transmission at the speed of light. Three radionuclide batteries that produce electricity from the decay of radioactive material supply the scientific instruments, the navigation and the communication systems with power. The batteries will continue to supply sufficient electricity until about 2025 before the last instruments and communication systems have to be shut off. Of the originally eleven scientific instruments three are still active for exploring magnetic fields, charged particles and the solar wind. Five systems have been deactivated, two are defective and one is damaged.

Our two greatest problems in the conquest of space are gravity and paperwork. We can lick gravity, but sometimes the paperwork is overwhelming.

Wernher von Braun
in response to the question of why the USSR launched a spacecraft before the U.S. did