Voyager 2 Reached Neptune Within 100 Kilometers After a 7.1 Billion-Kilometer Flight
Updated
Updated · spacedaily.com · Aug 7
Voyager 2 Reached Neptune Within 100 Kilometers After a 7.1 Billion-Kilometer Flight
1 articles · Updated · spacedaily.com · Aug 7
Summary
Voyager 2 hit Neptune’s aim point within 100 kilometers after traveling 7,128,603,456 kilometers over 12 years, a navigation error of roughly 14 parts per billion.
That precision was essential because the August 25, 1989 flyby had to pass 29,240 kilometers from Neptune’s center to let the planet’s gravity redirect the craft toward Triton about five hours later.
A 2-hour-33-minute midcourse burn after Uranus, repeated tracking updates, and upgraded Deep Space Network support—including 70-meter dishes, Parkes and the Very Large Array—made the targeting possible.
The one-off encounter produced six new moons, four rings, the Great Dark Spot and Triton plume observations, and remains humanity’s only close spacecraft visit to Neptune and Triton.
Interest in returning has grown as ice giants resemble many of the 5,000-plus known exoplanets, but the 2023–2032 decadal survey instead prioritized a roughly $4.2 billion Uranus orbiter and probe.