The Global Geospace Science (GGS) Wind satellite is a NASA science spacecraft designed to study radio waves and plasma that occur in the solar wind and in the Earth's magnetosphere. It was launched on 1 November 1994, at 09:31:00 UTC, from launch pad LC-17B at Cape Canaveral Air Force Station (CCAFS) in Merritt Island, Florida, aboard a McDonnell Douglas Delta II 7925-10 rocket. Wind was designed and manufactured by Martin Marietta Astro Space Division in East Windsor Township, New Jersey. The satellite is a spin-stabilized cylindrical satellite with a diameter of and a height of .
The spacecraft's original mission was to orbit the Sun at the Lagrangian point, but this was delayed to study the magnetosphere and near lunar environment when the Solar and Heliospheric Observatory (SOHO) and Advanced Composition Explorer (ACE) spacecraft were sent to the same location. Wind has been at continuously since May 2004, and is still operating . , Wind currently has enough fuel to last over 50 more years at , until at least 2070. Wind continues to collect data, and by the end of 2022 had contributed data to over 6,780 scientific publications.
Mission operations are conducted from the Multi-Mission Operations Center (MMOC) in Building 14 at Goddard Space Flight Center in Greenbelt, Maryland. Wind data can be accessed using the SPEDAS software. Wind is the sister ship to GGS Polar.
Science objectives
The aim of the International Solar-Terrestrial Physics Science Initiative is to understand the behaviour of the solar-terrestrial plasma environment, in order to predict how the Earth's atmosphere will respond to changes in solar wind conditions. Wind objective is to measure the properties of the solar wind before it reaches the Earth.
Provide complete plasma, energetic particle, and magnetic field input for magnetospheric and ionospheric studies. Determine the magnetospheric output to interplanetary space in the up-stream region. Investigate basic plasma processes occurring in the near-Earth solar wind. Provide baseline ecliptic plane observations to be used in heliospheric latitudes by the Ulysses mission.
Instruments
The Wind spacecraft has an array of instruments including: KONUS, the Magnetic Field Investigation (MFI), the Solar Wind and Suprathermal Ion Composition Experiment (SMS), The Energetic Particles: Acceleration, Composition, and Transport (EPACT) investigation, the Solar Wind Experiment (SWE), a Three-Dimensional Plasma and Energetic Particle Investigation (3DP), the Transient Gamma-Ray Spectrometer (TGRS), and the Radio and Plasma Wave Investigation (WAVES). The KONUS and TGRS instruments are primarily for gamma-ray and high energy photon observations of solar flares or gamma-ray bursts and part of the Gamma-ray Coordinates Network. The SMS experiment measures the mass and mass-to-charge ratios of heavy ions. The SWE and 3DP experiments are meant to measure/analyze the lower energy (below 10 MeV) solar wind protons and electrons. The WAVES and MFI experiments were designed to measure the electric and magnetic fields observed in the solar wind. All together, the Wind spacecraft's suite of instruments allows for a complete description of plasma phenomena in the solar wind plane of the ecliptic.