Voyager 1 exited the heliosphere and entered interstellar space in 2004

Both spacecraft actually left the heliosphere behind and entered interstellar space in the 2010s.

Voyager 2 – launched in August ... 1989. The probe left the heliosphere for interstellar space at 119 AU on November 5, 2018.

Voyager 1 crossed the heliopause and entered interstellar space on August 25, 2012, making it the first spacecraft to do so.

On Dec. 16, 2004, Voyager 1 reached the termination shock and entered the heliosheath. On Aug. 25, 2012, the spacecraft became the first to exit the heliosphere and begin measuring the interstellar environment.

No spacecraft has gone farther than NASA's Voyager 1. Launched in 1977 to fly by Jupiter and Saturn, Voyager 1 crossed into interstellar space in August 2012 and continues to collect data.

Voyager 1 reaching the interstellar boundary in 2012

NASA launched twin spacecraft from Earth 45 years ago, and both continue traveling farther than any other human-made object in interstellar space after completing the first tour of the solar system.

Scientists got their first good look at the heliopause on August 25, 2012, when Voyager 1 first entered interstellar space.

NASA's Voyager 1 spacecraft launched in 1977 and reached interstellar space 35 years later.

NASA's Voyager 1 spacecraft was 11 billion miles (18 billion kilometers) from the sun and scientists determined that the venerable spacecraft had crossed the boundary between the sun's influence ...