Entry Date:
October 25, 2000

WIND-SWE Satellite

Principal Investigator John Richardson

Co-investigator Leslie Finck


The Wind spacecraft carries a Faraday Cup plasma detector built at MIT. The spacecraft was launched in 1994 and is now in a halo orbit about the L1 Lagrange point 200 Earth radii in front of the Earth. The instrument provides plasma densities, speeds, and temperatures for protons and alpha particles.

NASA's WIND satellite was launched 1 November 1994. The spacecraft carries an array of scientific instruments for measuring the charged particles and electric and magnetic fields that characterize the interplanetary medium (or solar wind) - a plasma environment.

WIND provides nearly continuous monitoring of the solar wind conditions near Earth. These measurements are being used to investigate the disturbances and changes in the solar wind that drive important geomagnetic phenomena in the near-Earth geospace (such as aurorae and magnetic storms), as detected by other satellites and ground-based instruments. A primary goal of WIND is to advance understanding of the relationship between the dynamic solar wind and the near-Earth geospace. Additionally, WIND measurements are being used to study the nature of the solar wind itself.

The WIND satellite is one of a number of satellites, ground-based experiments, and theory investigations that are all part of the International Solar Terrestrial Physics (ISTP) program. Also included in the ISTP program are NASA's IMP-8 satellite , launched in 1973, NASA's POLAR satellite , launched in February, 1996, and the ISAS's Geotail satellite , launched in July, 1992.

The WIND SWE (Solar Wind Experiment) instrument includes 2 Faraday cup ion detectors provided by the MIT Center for Space Research. The Faraday cup detectors were activated on 12 November 1994, and have operated perfectly since then. The Faraday cups provide measurements of the solar wind protons and alpha particles at energy/charge up to 8 keV, and MIT is responsible for analysis of the Faraday cup data.

The SWE instrument also carries an array of detectors built at NASA-GSFC (Goddard Space Flight Center) for characterizing the solar wind electrons. The SWE on-board data system was provided by the University of New Hampshire.

The WIND group at MIT works jointly together with the other members of the SWE instrument team, which is directed by SWE Principal Investigator Dr. Keith W. Ogilvie of NASA GSFC. Dr. Alan J. Lazarus and Justin Kasper are the investigators at MIT. The SWE group at the University of New Hampshire Space Physics Lab is led by Professor Roy B. Torbert.