Which of these space probes were both launched in 1977?

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 launched 16 days after its twin, Voyager 2. Having operated for 40 years, 2 months and 11 days as of November 16, 2017, the spacecraft still communicates with the Deep Space Network to receive routine commands and return data. At a distance of 140 AU (2.09×1010 km) from the Sun as of September 22, 2017, it is the farthest spacecraft from Earth as well as the farthest man-made object. It is also the most distant object in the solar system whose location is known, even farther than Eris (96 AU) and V774104 (~103 AU).

The probe's objectives included flybys of Jupiter, Saturn and Saturn's large moon, Titan. While the spacecraft's course could have been altered to include a Pluto encounter by forgoing the Titan flyby, exploration of the moon, which was known to have a substantial atmosphere, took priority. It studied the weather, magnetic fields and rings of the two planets and was the first probe to provide detailed images of their moons.