NASA has announced the successful launch of the MMS (Magnetospheric Multi Scale) Mission on 12 March 2015. This mission is dedicated to the study of magnetic reconnection, a fundamental process for transferring magnetic energy to charged particles in the form of heating and acceleration. It consists in a set of four satellites which will make measurements of charged particles and electromagnetic fields in the environment related to the magnetosphere, the ionized environment of the Earth where the particle motion is controlled by the Earth’s magnetic field. Many US, European and Japanese laboratories are involved in the NASA’s MMS mission, including two French laboratories, the Laboratoire de physique des plasmas (LPP-CNRS/Ecole Polytechnique/UPMC/Université Paris-Sud/Observatoire de Paris) and the Institut de Recherche en Astrophysique et Planétologie (IRAP-CNRS/Université Toulouse III Paul Sabatier), supported by CNES.
The magnetic reconnection phenomenon is deemed to be present at different scales in the Universe (active galactic nuclei, pulsars, stellar accretion disks, solar flares, planetary magnetosphere, etc.). It is one of the possible mechanisms to transfer energy from the magnetic field to the charged particles in the form of thermal (heating) and kinetic (acceleration) energy. It plays a crucial role in the exchange of energy between the Sun and Earth. This phenomenon is also studied in laboratory, including within research related to the stability of the plasma confinement by the magnetic field used in fusion reactors (tokamaks). Many theoretical and numerical studies are led, including at the LPP and the IRAP, to better understand it.
The objective of the MMS mission is to study in situ magnetic reconnection, particle acceleration and plasma turbulence at the scale of the electrons in the Earth’s magnetosphere. In this environment, collisions between particles are so rare that they can not provide the energy dissipation required for the magnetic reconnection mechanism.
As in the European Cluster mission, the four satellites of the MMS Mission will evolve in tetrahedral formation and provide three-dimensional measurements of the plasma and the electromagnetic fields. Through particles measurements of very high temporal resolution (30 ms for the electrons and 150ms for the ions) and inter satellite distances of the order of 10 to 100 km, MMS will track the fast dynamics of the electrons and understand their role in the process of magnetic reconnection and sudden release of energy in the hot astrophysical and laboratories plasma.
France, through the IRAP and the LPP, provided two instruments or parts of instruments onboard. The first one is dedicated to the study of rapid changes in the Earth magnetic field and the second one to the study of ions and electrons. The LPP has designed the magnetic antenna called SCM (Search Coil Magnetometer) aimed to measure the fluctuating magnetic fields and their calibration software. The IRAP contributed to the design of the eight instruments dedicated to the detection of charged particles. The two French laboratories, with the support of CNES, will actively participate in the scientific analysis of the results and their interpretation.
- Website dedicated to the MMS mission : http://mms.gsfc.nasa.gov/
- NASA Press Release : NASA Spacecraft in Earth’s Orbit, Preparing to Study Magnetic Reconnection
Involvement of the IRAP
IRAP has contributed to the mission through the provision, the characterization and the calibration of all 32 pairs of detectors (microchannel wafers) of the Ion measurement experiment being part of the FPI (Fast plasma Investigation) consortium. Thank you to all members of the IRAP team who has allowed the realization of this important contribution!
- Benoit Lavraud : Benoit.Lavraud@irap.omp.eu
IRAP staff involved
- Lavraud Benoit, Sauvaud Jean-André, André Nicolas, Aoustin Claude, Dandouras Iannis, Fedorov André, Fruit Gabriel, Génot Vincent, Jacquey Christian, Le Comte Eric, Louarn Philippe, Marchaudon Aurélie, Mazelle Christian, Penou Emmanuel, Pitout Frédéric, Rème Henri, Rouillard Alexis, Rouzaud Jean, Seran Henry-Claude, Tur Anatoly