The only probe that has reached Neptune so far was Voyager 2.
No space missions have landed on Neptune or flown by it. The only spacecraft that has visited Neptune is Voyager 2, which conducted a flyby of the planet in 1989. There are no current plans for future missions to Neptune.
Only one spacecraft has visited Neptune: NASA's Voyager 2 probe, which made a flyby of the planet in August 1989. Voyager 2 provided our first close-up images and scientific data of Neptune and its moons.
The answer depends on "before what".
Donkies
All of the eight planets have been visited or orbited by space probes.
No space missions have landed on Neptune or flown by it. The only spacecraft that has visited Neptune is Voyager 2, which conducted a flyby of the planet in 1989. There are no current plans for future missions to Neptune.
Only one spacecraft has visited Neptune: NASA's Voyager 2 probe, which made a flyby of the planet in August 1989. Voyager 2 provided our first close-up images and scientific data of Neptune and its moons.
Voyager 2 is the only spacecraft to visited Neptune.
The answer depends on "before what".
Donkies
Voyager 2 passed by Neptune on August 23, 2009
All of the eight planets have been visited or orbited by space probes.
The Voyager probes 1 and 2, both launched in 1977, visited Jupiter and Saturn before heading into deep space. Voyager 2 also visited Uranus and Neptune.
The Voyager 2 went to Neptune on it's last stop in the solar system.
At current we have sent, or are sending, probes to all of the planets in our solar system. The probe Voyager has visited several planets, including Jupiter and Neptune, while Cassini is currently in orbit around Saturn.
All but Pluto, which is currently being visited.
The Viking space probes visited the planet Mars