New Horizons


New Horizons is an interplanetary space probe launched as a part of NASA's New Frontiers program. It was launched in 2006, becoming the first spacecraft to perform a flyby study of the Pluto system in 2015. A secondary mission contained a flyby and study of one or more other Kuiper belt objects in the decade to follow, where it flew past 486958 Arrokoth in 2019. It was the first space probe to ever take high-resolution photographs of Pluto in 2015.
It was engineered by the Johns Hopkins University Applied Physics Laboratory and the Southwest Research Institute, with a team led by Alan Stern. New Horizons is the fifth space probe to achieve the escape velocity needed to leave the Solar System.
On January 19, 2006, New Horizons was launched from Cape Canaveral Space Force Station by an Atlas V rocket directly into an Earth-and-solar escape trajectory with a speed of about. It was the fastest human-made object ever launched from Earth. It is not the fastest speed recorded for a spacecraft, which, as of 2023, is that of the Parker Solar Probe. After a brief encounter with asteroid 132524 APL, New Horizons proceeded to Jupiter, making its closest approach on February 28, 2007, at a distance of. The Jupiter flyby provided a gravity assist that increased New Horizons speed; the flyby also enabled a general test of New Horizons scientific capabilities, returning data about the planet's atmosphere, moons, and magnetosphere.
Most of the post-Jupiter voyage was spent in hibernation mode to preserve onboard systems, except for brief annual checkouts. On December 6, 2014, New Horizons was brought back online for the Pluto encounter, and instrument check-out began. On January 15, 2015, the spacecraft began its approach phase to Pluto.
On July 14, 2015, at 11:49 UTC, it flew above the surface of Pluto, which at the time was 34 AU from the Sun, making it the first spacecraft to explore the dwarf planet. In August 2016, New Horizons was reported to have traveled at speeds of more than. On October 25, 2016, at 21:48 UTC, the last recorded data from the Pluto flyby was received from New Horizons. Having completed its flyby of Pluto, New Horizons then maneuvered for a flyby of Kuiper belt object 486958 Arrokoth, which occurred on January 1, 2019, when it was from the Sun. In August 2018, NASA cited results by Alice on New Horizons to confirm the existence of a "hydrogen wall" at the outer edges of the Solar System. This "wall" was first detected in 1992 by the two Voyager spacecraft.
New Horizons is traveling through the Kuiper belt; it is from Earth and from the Sun as of September 2025. NASA has announced its plan to extend operations for New Horizons until the spacecraft exits the Kuiper belt, which is expected to occur in either 2028 or 2029. The White House's proposed budget for FY2026 would have cut funding for New Horizons, however the continued funding of the mission was heavily debated in the United States Congressand a final budget of 24.44 billion guaranteed the mission continuation.

History

In August 1992, JPL scientist Robert Staehle called Pluto discoverer Clyde Tombaugh, requesting permission to visit his planet. "I told him he was welcome to it," Tombaugh later remembered, "though he's got to go one long, cold trip." The call eventually led to a series of proposed Pluto missions leading up to New Horizons.
Stamatios "Tom" Krimigis, head of the Applied Physics Laboratory's space division, one of many entrants in the New Frontiers Program competition, formed the New Horizons team with Alan Stern in December 2000. Appointed as the project's principal investigator, Stern was described by Krimigis as "the personification of the Pluto mission". New Horizons was based largely on Stern's work since Pluto 350 and involved most of the team from Pluto Kuiper Express.
The New Horizons proposal was one of five that were officially submitted to NASA. It was later selected as one of two finalists to be subject to a three-month concept study in June 2001. The other finalist, POSSE, was a separate but similar Pluto mission concept by the University of Colorado Boulder, led by principal investigator Larry W. Esposito, and supported by the JPL, Lockheed Martin and the University of California.
However, the APL, in addition to being supported by Pluto Kuiper Express developers at the Goddard Space Flight Center and Stanford University were at an advantage; they had recently developed NEAR Shoemaker for NASA, which had successfully entered orbit around 433 Eros earlier that year, and would later land on the asteroid to scientific and engineering fanfare.
In November 2001, New Horizons was officially selected for funding as part of the New Frontiers program. However, the new NASA Administrator appointed by the Bush administration, Sean O'Keefe, was not supportive of New Horizons and effectively canceled it by not including it in NASA's budget for 2003. NASA's Associate Administrator for the Science Mission Directorate, Ed Weiler, prompted Stern to lobby for the funding of New Horizons in hopes of the mission appearing in the Planetary Science Decadal Survey, a prioritized "wish list", compiled by the United States National Research Council, that reflects the opinions of the scientific community.
After an intense campaign to gain support for New Horizons, the Planetary Science Decadal Survey of 2003–2013 was published in the summer of 2002. New Horizons topped the list of projects considered the highest priority among the scientific community in the medium-size category; ahead of missions to the Moon, and even Jupiter. Weiler stated that it was a result that " administration was not going to fight". Funding for the mission was finally secured following the publication of the report. Stern's team was finally able to start building the spacecraft and its instruments, with a planned launch in January 2006 and arrival at Pluto in 2015. Alice Bowman became Mission Operations Manager.

Mission profile

New Horizons is the first mission in NASA's New Frontiers mission category, larger and more expensive than the Discovery missions but smaller than the missions of the Flagship Program. The cost of the mission, including spacecraft and instrument development, launch vehicle, mission operations, data analysis, and education/public outreach, is approximately $700 million over 15 years. The spacecraft was built primarily by Southwest Research Institute and the Johns Hopkins Applied Physics Laboratory. The mission's principal investigator is Alan Stern of the Southwest Research Institute.
After separation from the launch vehicle, overall control was taken by Mission Operations Center at the Applied Physics Laboratory in Howard County, Maryland. The science instruments are operated at Clyde Tombaugh Science Operations Center in Boulder, Colorado. Navigation is performed at various contractor facilities, whereas the navigational positional data and related celestial reference frames are provided by the Naval Observatory Flagstaff Station through Headquarters NASA and JPL.
KinetX is the lead on the New Horizons navigation team and is responsible for planning trajectory adjustments as the spacecraft speeds toward the outer Solar System. Coincidentally the Naval Observatory Flagstaff Station was where the photographic plates were taken for the discovery of Pluto's moon Charon. The Naval Observatory itself is not far from the Lowell Observatory where Pluto was discovered.
New Horizons was originally planned as a voyage to the only unexplored planet in the Solar System. When the spacecraft was launched, Pluto was still classified as a planet, later to be reclassified as a dwarf planet by the International Astronomical Union. Some members of the New Horizons team, including Alan Stern, disagree with the IAU definition and still describe Pluto as the ninth planet. Pluto's satellites Nix and Hydra also have a connection with the spacecraft: the first letters of their names are the initials of New Horizons. The moons' discoverers chose these names for this reason, plus Nix and Hydra's relationship to the mythological Pluto.

Mementos

In addition to the science equipment, there are nine cultural artifacts traveling with the spacecraft. These include a collection of 434,738 names stored on a compact disc, a collection of images of New Horizons project personnel on another CD, a piece of Scaled Composites's SpaceShipOne, a "Not Yet Explored" USPS stamp, and two copies of the Flag of the United States.
About of Clyde Tombaugh's ashes are aboard the spacecraft, to commemorate his discovery of Pluto in 1930. A Florida state quarter coin, whose design commemorates human exploration, is included, officially as a trim weight, as is a Maryland state quarter to honor the probe's builders. One of the science packages is named after Venetia Burney, who, as a child, suggested the name "Pluto" after its discovery.

Goal

The goal of the mission is to understand the formation of the Plutonian system, the Kuiper belt, and the transformation of the early Solar System. The spacecraft collected data on the atmospheres, surfaces, interiors, and environments of Pluto and its moons. It will also study other objects in the Kuiper belt. "By way of comparison, New Horizons gathered 5,000 times as much data at Pluto as Mariner did at the Red Planet."
Some of the questions the mission attempts to answer are: What is Pluto's atmosphere made of and how does it behave? What does its surface look like? Are there large geological structures? How do solar wind particles interact with Pluto's atmosphere?
Specifically, the mission's science objectives are to:
  • Map the surface compositions of Pluto and Charon
  • Characterize the geologies and morphologies of Pluto and Charon
  • Characterize the neutral atmosphere of Pluto and its escape rate
  • Search for an atmosphere around Charon
  • Map surface temperatures on Pluto and Charon
  • Search for rings and additional satellites around Pluto
  • Conduct similar investigations of one or more Kuiper belt objects