Voyager 1 is a space probe launched by NASA on September 5, 1977. Part of the Voyager program to study the outer Solar System, Voyager 1 was launched 16 days after its twin, Voyager 2. Having operated for 42 years and 17 days as of September 22, 2019, the spacecraft still communicates with the Deep Space Network to receive routine commands and to transmit data to Earth. At a distance of 146 AU (21. 8 billion km; 13. 6 billion mi) from Earth as of July 11, 2019 it is the most distant man-made object from Earth.