The Suomi National Polar-orbiting Partnership (Suomi NPP), previously known as the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) and NPP-Bridge, is a

weather satellite A weather satellite or meteorological satellite is a type of Earth observation satellite that is primarily used to monitor the weather and climate of the Earth. Satellites can be polar orbiting (covering the entire Earth asynchronously), or ...

operated by the United States

National Oceanic and Atmospheric Administration The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditi ...

(NOAA). It was launched in 2011 and continues to operate in June 2022. Suomi NPP was originally intended as a pathfinder for the

National Polar-orbiting Operational Environmental Satellite System The National Polar-orbiting Operational Environmental Satellite System (NPOESS) was to be the United States' next-generation satellite system that would monitor the Earth's weather, atmosphere, oceans, land, and near-space environment. NPOESS sate ...

(NPOESS) program, which was to have replaced NOAA's

Polar Operational Environmental Satellites The Polar-orbiting Operational Environmental Satellite (POES) was a constellation of polar orbiting weather satellites funded by the National Oceanic and Atmospheric Administration (NOAA) and the European Organisation for the Exploitation of Mete ...

(POES) and the U.S. Air Force's Defense Meteorological Satellite Program (DMSP). Suomi NPP was launched in 2011 after the cancellation of NPOESS to serve as a stop-gap between the POES satellites and the Joint Polar Satellite System (JPSS) which will replace them. Its instruments provide climate measurements that continue prior observations by

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedin ...

's Earth Observing System (EOS).

Name

The satellite is named after

Verner E. Suomi Verner Edward Suomi (December 6, 1915 – 30 July 1995
, Space Science and Engineering Center, University of Wisconsin–Madis ...

, a Finnish-American meteorologist at the

University of Wisconsin–Madison A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United Stat ...

. The name was announced on 24 January 2012, three months after the satellite's launch. The satellite was launched from Space Launch Complex-2W (SLC-2W) at Vandenberg Space Force Base in

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

by a

United Launch Alliance United Launch Alliance (ULA), legally United Launch Alliance, LLC, is an American spacecraft launch service provider that manufactures and operates a number of rocket vehicles that are capable of launching spacecraft into orbits around Earth, a ...

Delta II Delta II was an expendable launch system, originally designed and built by McDonnell Douglas. Delta II was part of the Delta rocket family and entered service in 1989. Delta II vehicles included the Delta 6000, and the two later Delta 7000 va ...

7920-10C on 28 October 2011. The satellite was placed into a

Sun-synchronous orbit A Sun-synchronous orbit (SSO), also called a heliosynchronous orbit, is a nearly polar orbit around a planet, in which the satellite passes over any given point of the planet's surface at the same local mean solar time. More technically, it is ...

(SSO) above the

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's sur ...

History

NPOESS Preparatory Project (NPP) is intended to bridge the gap between old Earth Observing System (EOS) and new systems (JPSS) by flying new instruments, on a new satellite bus, using a new ground data network. Originally planned for launch five years earlier as a joint

NOAA The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditio ...

/ DoD project, NPP was to be a pathfinder mission for the larger

(NPOESS) until DoD participation in the larger project was dissolved. The project continued as a civilian weather forecasting replacement for the NOAA

(POES) series, and ensured continuity of climate measurements begun by the Earth Observing System (EOS) of NASA.

Launch

The spacecraft was launched on 28 October 2011 at from Vandenberg Space Force Base via a

in the 7920-10 configuration (Extra Extended Long Tank with RS-27A engine first stage, 9 GEM-40 solid rocket motors, type 2 second stage with

Aerojet Aerojet was an American rocket and missile propulsion manufacturer based primarily in Rancho Cordova, California, with divisions in Redmond, Washington, Orange and Gainesville in Virginia, and Camden, Arkansas. Aerojet was owned by GenCorp. I ...

AJ10 engine, no third stage and a 10-meter fairing). Additionally, the rocket deployed five

CubeSat A CubeSat is a class of miniaturized satellite based around a form factor consisting of cubes. CubeSats have a mass of no more than per unit, and often use commercial off-the-shelf (COTS) components for their electronics and structure. CubeSats ...

s as a part of NASA ELaNa III manifest.

Spacecraft

The Suomi NPP spacecraft has been built and integrated by BATC (Ball Aerospace and Technologies Corporation) of Boulder, Colorado (NASA/GSFC contract award in May 2002). The platform design is a variation of BCP 2000 (Ball Commercial Platform) bus of BATC of ICESat and CloudSat heritage. The spacecraft consists of an

aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It ha ...

honeycomb structure. The ADCS (Attitude Determination and Control Subsystem) provides 3-axis stabilization using 4

reaction wheel A reaction wheel (RW) is used primarily by spacecraft for three-axis attitude control, and does not require rockets or external applicators of torque. They provide a high pointing accuracy, and are particularly useful when the spacecraft must be ...

s for fine attitude control, 3 torquer bars for momentum unloading, thrusters for coarse attitude control (such as during large-angle slews for orbital maintenance), 2 star trackers for fine attitude determination, 3

gyroscope A gyroscope (from Ancient Greek γῦρος ''gŷros'', "round" and σκοπέω ''skopéō'', "to look") is a device used for measuring or maintaining orientation and angular velocity. It is a spinning wheel or disc in which the axis of rot ...

s for attitude and attitude rate determination between star tracker updates, 2 Earth sensors for safe-mode attitude control, and coarse Sun sensors for initial attitude acquisition, all monitored and controlled by the spacecraft controls a computer. ADCS provides real-time attitude knowledge of 10 arcsec (1 sigma) at the spacecraft navigation reference base, real-time spacecraft position knowledge of 25 m (1 sigma), and

attitude control Attitude control is the process of controlling the orientation of an aerospace vehicle with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc. Controlling vehicle ...

of 36 arcsec (1 sigma). The EPS (Electrical Power Subsystem) uses

Gallium arsenide Gallium arsenide (GaAs) is a III-V direct band gap semiconductor with a zinc blende crystal structure. Gallium arsenide is used in the manufacture of devices such as microwave frequency integrated circuits, monolithic microwave integrated c ...

(GaAs)

solar cell A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.

s to generate an average power of about 2 kW (EOL). The

solar array A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and ...

rotates once per orbit to maintain a nominally normal orientation to the Sun. In addition, a single-wing solar array is mounted on the anti-solar side of the spacecraft; its function is to preclude thermal input into the sensitive cryo radiators of the Visible Infrared Imaging Radiometer Suite (VIIRS) and Cross-track Infrared Sounder (CrIS) instruments. A regulated 28 ±6 VDC power bus distributes energy to all spacecraft subsystems and instruments. A nickel–hydrogen battery (NiH) system provides power for

eclipse An eclipse is an astronomical event that occurs when an astronomical object or spacecraft is temporarily obscured, by passing into the shadow of another body or by having another body pass between it and the viewer. This alignment of three c ...

phase operations. The spacecraft has an on-orbit design lifetime of 5 years (available consumables for 7 years). The spacecraft dry mass is about 1400 kg. NPP is designed to support controlled reentry at the end of its mission life (via propulsive maneuvers to lower the orbit perigee to approximately 50 km and target any surviving debris for open ocean entry). NPP is expected to have sufficient debris that survives reentry so as to require controlled reentry to place the debris in a pre-determined location in the ocean.

Instruments

The Suomi NPP is the first in a new generation of satellites intended to replace the Earth Observing System (EOS) satellites, which were launched from 1997 to 2009. The satellite orbits the Earth about 14 times each day. Its five imaging systems include:

Visible Infrared Imaging Radiometer Suite (VIIRS)

The Visible Infrared Imaging Radiometer Suite (VIIRS) is the largest instrument aboard of Suomi-NPP (National Polar-Orbiting Operational Environmental Satellite System ( NPOESS) Preparatory Project). It collects radiometric imagery in visible and

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of Light, visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from ...

wavelengths of the land, atmosphere, ice, and ocean. It will survey broad swaths of the land, oceans, and air, enabling scientists to monitor everything from

phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater ecosystems. The name comes from the Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'. ...

and other organisms in the sea, vegetation and forest cover, and the amount of sea ice at the poles. Data from VIIRS, collected from 22 channels across the

electromagnetic spectrum The electromagnetic spectrum is the range of frequencies (the spectrum) of electromagnetic radiation and their respective wavelengths and photon energies. The electromagnetic spectrum covers electromagnetic waves with frequencies ranging fro ...

, will also be used to observe active fires, ocean color, sea surface temperature, and other surface features.

Ozone Mapping and Profiler Suite (OMPS)

The

Ozone Mapping and Profiler Suite Ozone Mapping and Profiler Suite (OMPS), is a suite of instruments built by Ball Aerospace that measure the global distribution of ozone and, less frequently, how it is distributed vertically within the stratosphere. The suite flies on the Suomi N ...

(OMPS) measures the

ozone layer The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet radiation. It contains a high concentration of ozone (O3) in relation to other parts of the atmosphere, although still small in rel ...

in our

upper atmosphere Upper atmosphere is a collective term that refers to various layers of the atmosphere of the Earth above the troposphere and corresponding regions of the atmospheres of other planets, and includes: * The mesosphere, which on Earth lies between th ...

tracking the status of global ozone distributions, including the ozone hole. It also monitors ozone levels in the

troposphere The troposphere is the first and lowest layer of the atmosphere of the Earth, and contains 75% of the total mass of the planetary atmosphere, 99% of the total mass of water vapour and aerosols, and is where most weather phenomena occur. Fro ...

. OMPS extends out 40-year long record ozone layer measurements while also providing improved vertical resolution compared to previous operational instruments. Closer to the ground, OMPS's measurements of harmful ozone improve air quality monitoring and when combined with cloud predictions; help to create the Ultraviolet index. OMPS has two sensors, both new designs, composed of three advanced hyperspectral-imaging spectrometers.

Clouds and the Earth's Radiant Energy System (CERES)

The Clouds and the Earth's Radiant Energy System (CERES) will be used to study the Earth's radiation budget. Monitoring the amount of energy emitted and reflected by the planet, it measures both

solar energy Solar energy is radiant light and heat from the Sun that is harnessed using a range of technologies such as solar power to generate electricity, solar thermal energy (including solar water heating), and solar architecture. It is an essen ...

reflected by the

and heat emitted by our planet. This solar and thermal energy are key parts of the Earth's radiation budget. CERES instrument continues a multi-year record of the amount of energy entering and exiting from the top of the

atmosphere of Earth The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing fo ...

. It will provide scientists with needed long-term, stable data sets to make accurate projections of global climate change.

Cross-track Infrared Sounder (CrIS)

The Cross-track Infrared Sounder (CrIS) has 1305 spectral channels and will produce high-resolution, three-dimensional temperature, pressure, and moisture profiles. It measures continuous channels in the infrared region and has the ability to measure temperature profiles with improved accuracy over its predecessors. These profiles will be used to enhance weather forecasting models and will facilitate both short- and long-term weather forecasting. Over longer timescales, they will help improve understanding of climate phenomena.

Advanced Technology Microwave Sounder (ATMS)

The Advanced Technology Microwave Sounder (ATMS), works in conjunction with the Cross-track Infrared Sounder (CrIS) to make detailed vertical profiles of atmospheric pressure, heat, and moisture. ATMS, a cross-track scanner with 22 channels, provides sounding observations needed to retrieve profiles of atmospheric temperature and moisture for civilian operational weather forecasting as well as continuity of these measurements for climate monitoring purposes. CrIS will operate at infrared wavelengths, while ATMS will operate at much shorter, microwave, wavelengths.

Mission

The VIIRS sensor on board the spacecraft acquired its first measurements of Earth on 21 November 2011.VIIRS First Light
NASA also released a high resolution

blue marble ''The Blue Marble'' is an image of Earth taken on December 7, 1972, from a distance of around from the planet's surface. Taken by the crew of the Apollo 17 spacecraft on its way to the Moon, it is one of the most reproduced images in history. ...

image of the Earth showing most of

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

, which was created by NASA oceanographer Norman Kuring using data obtained on 4 January 2012 by the Visible Infrared Imager Radiometer Suite (VIIRS), one of five imaging systems aboard the satellite. That date was chosen because it was a fairly sunny day in most of North America. , beyond the initial 5-year mission, the spacecraft continues to operate.

Gallery

File:Delta II and NPP after service structure rollback.jpg, Delta II rocket carrying NPP. File:NPP Launch.ogv, NPP launch video File:US East Coast VIR 2011326 large.jpg, First image acquired by the VIIRS sensor. File:A Sky View of Earth From Suomi NPP.jpg, This composite image of southern Africa and the surrounding oceans was captured by six orbits of the satellite. File:2020augderecho-suomi-outages-animated.gif, Iowa power outage