Second Kuiper Belt Extended Mission (KEM2) Science

KEM2 Overview

New Horizons is in an unexplored, distant region of the Kuiper Belt, more than 50 times farther from the Sun than Earth, speeding along at some 300 million miles (or roughly 500 million kilometers) a year — a pace that would cover the distance between Earth and the Sun in about four months.

In October 2023 NASA announced an updated plan to extend New Horizons mission operations until the spacecraft exits the Kuiper Belt, which is expected in 2028 or 2029. New Horizons will search for a future flyby target and plans to collect unique cruise science data that can be obtained while still preserving the spacecraft resources. This path allows for the possibility of using the spacecraft for a future close flyby of a Kuiper Belt object (KBO), should one be identified.

New Horizons will also continue to work with Earth-based telescopes (both ground- and space-based), incorporate improved super-computing capacity, and add additional artificial intelligence programming to its search for a potential future flyby target.

In its second extended mission, New Horizons will traverse the space between 54 and 75 astronomical units (AU) from the Sun, observing and analyzing objects ranging from nanometer-sized dust particles to dwarf planets and larger worlds, while incorporating heliophysics and astrophysics investigations that can be made only from the spacecraft’s unique position in the outer heliosphere.

New Horizons KEM2 science goals span all three of NASA’s Science Mission Directorate space science divisions:

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

Heliophysics »

  • Irreplaceable outer heliosphere measurements not performed by the Voyager or Pioneer spacecraft of particle populations and processes that ultimately shape the various heliospheric boundaries
  • Novel 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

Astrophysics »

  • 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)