The New Horizons Mission

The New Horizons spacecraft launched on January 19, 2006 – beginning its odyssey to Pluto and the Kuiper Belt. New Horizons was the first mission to Pluto, completing the space-age reconnaissance of the planets that started 50 years earlier. It was also the first mission to explore the solar system's recently discovered "third zone," the region beyond the giant planets called the Kuiper Belt.

But New Horizons began long before launch, starting with many years of work to design and propose the mission, build the spacecraft and its array of instruments, and plan the operations and scientific observations that would bring these new worlds into focus for the first time. The flyby of Pluto on July 14, 2015, was a resounding success, and New Horizons sent home data that resulted in profound new insights about Pluto and its moons. These data will continue to be analyzed for many years to come.

In its first mission extension, New Horizons continued on its unparalleled journey of exploration with the close flyby of a Kuiper Belt object called 2014 MU69 – officially named Arrokoth (Powhatan/Algonquian for "sky") – on January 1, 2019.

The Kuiper Belt is a scientifically rich frontier. Its exploration has important implications for better understanding comets, small planets, the solar system as a whole, the solar nebula and disks around other stars. It's a laboratory for studying well-preserved primitive material from the planet formation era 4.5 billion years ago.

New Horizons approached Arrokoth (nicknamed "Ultima Thule" at the time) three times closer than it came to Pluto, resulting in even more detailed pictures and other kinds of data. The spacecraft obtained the first high-resolution geological and compositional maps of a small Kuiper Belt object (KBO), while conducting sensitive searches for atmospheric activity, satellites and rings.

Now in its second mission extension, New Horizons takes advantage of its distant position to execute otherwise unachievable and impactful investigations benefiting all three of NASA’s Science Mission Directorate space science divisions — Planetary Science, Heliophysics and Astrophysics.

Planetary Science

  • Multiple, unique studies of distant KBO populations.
  • Unique, high-phase studies of several Kuiper Belt dwarf planets.
  • Large-phase angle studies of the ice giants Uranus and Neptune that also have direct application to ice giants around other stars.
  • Otherwise unobtainable measurements of in situ Kuiper Belt dust density as a function of distance from the Sun.


  • Outer heliosphere measurements not performed by the Voyager or Pioneer spacecraft of particle populations and processes that ultimately shape the various heliospheric boundaries.
  • Observations of dust and hydrogen gas in the outer solar system.
  • Important collaborative observations with other heliophysics missions covering the space from the inner solar system to the very local interstellar medium.


  • Potentially paradigm-shifting astrophysical studies of the cosmic optical and ultraviolet backgrounds with unprecedented sensitivity, thanks to New Horizons’ position beyond the sunlight scattered by interplanetary dust (known as zodiacal light).
  • Unique ultraviolet observations of the local interstellar medium (LISM).