Voyager 1 was the first human-made object to reach interstellar space.
NASA’s Voyager 1 crossed the heliopause in August 2012, becoming the first spacecraft to enter interstellar space. The heliopause is the boundary where the solar wind’s influence gives way to the surrounding interstellar medium. NASA announced the result in 2013 after analysis of measurements from the spacecraft’s instruments.
Voyager 1 launched on 5 September 1977 from Cape Canaveral, Florida. Its original mission focused on close encounters with Jupiter and Saturn, but its successful trajectory allowed the spacecraft to continue outward. It used a gravitational-assist path and returned famous observations, including detailed data about the outer planets and their moons.
The spacecraft carries a gold-plated copper record containing sounds, images, and greetings from Earth. Voyager 2 also crossed the heliopause, doing so in 2018, but Voyager 1 remains the first. “Interstellar space” does not mean the craft has reached another star; it is still traveling through the space between stars within the Milky Way.