New Horizons Spacecraft Mission to Pluto

The New Horizons spacecraft is an interplanetary space probe intended to study Pluto, its moons and the Kuiper belt.

The spacecraft was launched in January 2006 and the approach phase of the spacecraft to Pluto began in January 2015. It successfully flew within 7,750 miles of Pluto’s surface to gather images and scientific data in July 2015.

The New Horizons spacecraft was designed and built by Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, US.

It was developed as part of Nasa’s New Frontiers Programme, which is aimed at exploring the solar system.

The science payload of the spacecraft was developed under direction of the Southwest Research Institute (SwRI) in association with Nasa’s Goddard Space Flight Center, the University of Colorado, Stanford University, Ball Aerospace Corporation and Johns Hopkins University APL.

Mission details of New Horizons

The New Horizons science payload investigates the global geology, surface composition and temperature, and atmospheric pressure, temperature and escape rate of Pluto and its moons.

The spacecraft will study Pluto and its five moons, Charon, Styx, Nix, Kerberos and Hydra.

The spacecraft is on a one-way journey to the Kuiper Belt and beyond and will not return to Earth after the mission.

It receives and returns scientific data, as well as information on the spacecraft’s temperature and power, using a radio transmitter link and will return all data using a radio transmitter and an 83in (2.1m) diameter antenna.

New Horizons spacecraft design features

Weighing 478kg at launch, the spacecraft structure includes an aluminium central cylinder that supports the body panels.

An interface connects the spacecraft and its radioisotope thermoelectric generator (RTG) power source. The spacecraft also includes a propellant tank and an aluminium honeycomb core with ultra-thin aluminium face sheets.

The power distribution unit (PDU) contains 96 connectors and more than 3,200 wires. The spacecraft carried 77km of hydrazine, stored in a lightweight titanium tank at the time of launch.

Instruments on board New Horizons

The science payload of the spacecraft comprises seven instruments. The first instrument, Ralph, is a 10.3kg visible and infrared imager or spectrometer developed by Ball Aerospace Corporation, Nasa Goddard Space Flight Center and SwRI. It provides colour, composition and thermal maps.

The second instrument, Alice, is a 4.5kg ultraviolet imaging spectrometer developed by SwRI. It analyses the composition and structure of Pluto’s atmosphere and looks for atmospheres around Charon and Kuiper Belt objects (KBOs).

Radio Science Experiment (REX), a 100gm instrument developed at Johns Hopkins University APL, Stanford University, is the fourth instrument, which is used to measure atmospheric composition and temperature.

Long Range Reconnaissance Imager (LORRI) is an 8.8kg telescopic camera developed by Johns Hopkins University APL. It obtains encounter data at long distances, maps Pluto’s farside and provides high-resolution geologic data.

The 3.3kg Solar Wind Around Pluto (SWAP) instrument is a solar wind and plasma spectrometer developed by SwRI. It measures atmospheric escape rate and observes Pluto’s interaction with solar wind.

The 1.5kg Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) instrument is an energetic particle spectrometer intended to measure the composition and density of plasma escaping from Pluto’s atmosphere. The instrument was developed by Johns Hopkins University APL.

Venita Burney (VB) dust counter, a 1.9kg instrument built and operated by students at the University of Colorado, Boulder, US, measures the space dust peppering New Horizons during its voyage across the solar system.

Launch vehicle

The spacecraft was launched on an Atlas V 551 rocket manufactured by Lockheed Martin. The rocket launched off the spacecraft in three stages.

On the first stage, the rocket was powered by an RD-180 engine, the second stage by Centaur and the third stage by a STAR 48B solid rocket.

The spacecraft was launched from Space Launch Complex-41 at Cape Canaveral Air Force Station, Florida, US.

Ground control station

The New Horizon spacecraft is controlled by a Mission Operations Center (MOC) located at the APL in Howard County, Maryland, while navigation is performed from a number of contractor facilities.

The Naval Observatory Flagstaff Station through Nasa and the Jet Propulsion Laboratory (JPL) provides navigational positional data and related celestial reference frames.

Science instruments of the spacecraft are operated from the Clyde Tombaugh Science Operations Center (T-SOC) located in Boulder, Colorado.