The only visitor to Uranus and Neptune

Voyager 2

Voyager 2 launched on 20 August 1977, two weeks before its twin, on a slower path that let it visit all four giant planets. It remains the only spacecraft to have explored Uranus and Neptune up close.

In November 2018 it followed Voyager 1 across the heliopause, becoming the second human-made object to reach interstellar space.

Key facts

Agency: NASA / JPL
Launched: 1977-08-20
Launch vehicle: Titan IIIE–Centaur
Power: Radioisotope thermoelectric generators (plutonium-238)
Mission type: Multi-planet flyby, then interstellar mission
Twin: Voyager 1
Status: Operating in interstellar space with a reduced set of instruments to conserve power

Where it is now

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Interstellar space. In about 40,000 years it will pass within about 1.7 light-years of the star Ross 248.

Mission objectives

A planetary alignment that occurs about once every 175 years made it possible to use gravity assists to hop from Jupiter to Saturn, Uranus and Neptune. Voyager 2's trajectory took full advantage of it in what became known as the Grand Tour.

Today it studies the interstellar medium and how the Sun's bubble, the heliosphere, interacts with it.

The spacecraft

Voyager 2 is identical in design to Voyager 1: a ten-sided bus with a 3.7 m high-gain antenna, a boom carrying its magnetometer and radioisotope power generators. It also carries a copy of the Golden Record.

A working plasma instrument

Unlike Voyager 1, Voyager 2 still had a functioning plasma science instrument when it crossed the heliopause, allowing it to measure the change in the surrounding plasma directly.

Discoveries and highlights

At Uranus in 1986 it discovered 10 new moons and two new rings and revealed the planet's strangely tilted magnetic field. At Neptune in 1989 it found the Great Dark Spot, Neptune's rings and nitrogen geysers erupting on the moon Triton.

Route and timeline

1977-08-20Launch, Cape Canaveral
1979-07-09Jupiter flyby
1981-08-25Saturn flyby
1986-01-24Uranus flyby
1989-08-25Neptune and Triton flyby
2018-11-05Crossed the heliopause into interstellar space

Surprising facts about Voyager 2

Voyager 2 launched before Voyager 1 — the names follow which would reach Jupiter first.
It has spent its whole mission flying past planets that no spacecraft has visited since.
Its encounter with Neptune used the planet's gravity to bend its path south of the plane of the planets.

Keep exploring

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