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, 3 months and 27 days as of January 1, 2020, the spacecraft still communicates with the Deep Space Network to receive routine commands and to transmit data to Earth. At a distance of 148.65 AU (22.2 billion km; 13.8 billion mi) from Earth as of December 26, 2019 it is the most distant man-made object from Earth.