Voyager I

Voyager 1

Voyager 1, artist's impression
Mission type	Outer planetary, heliosphere, and interstellar medium exploration
Operator	NASA / JPL
COSPAR ID	1977-084A
SATCAT №	10321
Website	voyager.jpl.nasa.gov
Mission duration	39 years, 5 months and 10 days elapsed Planetary mission: 3 years, 3 months, 9 days Interstellar mission: 36 years, 2 months and 1 day elapsed (continuing)
Spacecraft properties
Manufacturer	Jet Propulsion Laboratory
Launch mass	825.5 kg (1,820 lb)
Power	420 watts
Start of mission
Launch date	September 5, 1977, 12:56:00 (1977-09-05UTC12:56Z) UTC (39 years, 5 months and 10 days)
Rocket	Titan IIIE
Launch site	Cape Canaveral LC-41
Flyby of Jupiter
Closest approach	March 5, 1979
Distance	349,000 km (217,000 mi)
Flyby of Saturn
Closest approach	November 12, 1980
Distance	124,000 km (77,000 mi)
Flyby of Titan (Atmosphere study)
Closest approach	November 12, 1980
Distance	6,490 km (4,030 mi)

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 39 years, 5 months and 10 days, the spacecraft still communicates with the Deep Space Network to receive routine commands and return data. At a distance of 137 AU (2.05×10¹⁰ km) from the Sun as of December 2016, it is the farthest spacecraft from Earth as well as the farthest man-made object.

The probe's primary mission 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.

After completing its primary mission with the flyby of Saturn on November 20, 1980, Voyager 1 began an extended mission to explore the regions and boundaries of the outer heliosphere. On August 25, 2012, Voyager 1 crossed the heliopause to become the first spacecraft to enter interstellar space and study the interstellar medium.Voyager 1's extended mission is expected to continue until around 2025, when its radioisotope thermoelectric generators will no longer supply enough electric power to operate any of its scientific instruments.

In the 1960s, a Grand Tour to study the outer planets was proposed which prompted NASA to begin work on a mission in the early 1970s. Information gathered by the Pioneer 10 spacecraft helped Voyager's engineers design Voyager to cope more effectively with the intense radiation environment around Jupiter.