While researching a topic, a student has taken the following notes:
- In 1977, NASA launched the twin probes Voyager 1 and Voyager 2 to explore the outer solar system.
- Both spacecraft took advantage of a rare planetary alignment to conduct flybys of Jupiter and Saturn.
- Voyager 2 continued onward to complete the first flybys of Uranus (1986) and Neptune (1989).
- In 2012, Voyager 1 crossed the heliopause and entered interstellar space.
- In 2018, Voyager 2 also crossed into interstellar space.
- Both probes continue to transmit scientific telemetry back to Earth using the Deep Space Network.