Voyager 2
Launched two weeks before its twin, Voyager 2 is the only probe to have flown by all four giant planets: Jupiter, Saturn, then, a world first, Uranus (1986) and Neptune (1989). It reached interstellar space in 2018.
Objective
Carry out the 'Grand Tour' of the outer Solar System made possible by a planetary alignment that recurs only every 176 years, then extend the measurements in the heliosphere and beyond.
Mission profile
Simplified diagram of the main phases.
Challenges & risks
The mission's vocabulary
A trajectory exploiting the successive gravity assists of the giant planets, made possible by their alignment in the 1970s-80s.
A maneuver using a planet's gravity to gain speed and change course without fuel.
The questions everyone asks
To take advantage of a rare planetary alignment (every 176 years) with two complementary trajectories: Voyager 1 favored Titan, Voyager 2 pushed on to Uranus and Neptune.
No mission is committed to date: a Uranus orbiter is regularly ranked a priority by the US scientific community, without confirmed funding.
The confirmed elements of the mission (architecture, primary objectives).
The upcoming schedule and milestones, subject to technical qualifications.
The developments dependent on other building blocks of the program.