Magnetospheric Multiscale Mission
Encyclopedia
The Magnetospheric Multiscale Mission (MMS) is a NASA
unmanned space mission, to study the Earth
's magnetosphere
using four identical spacecraft flying in a tetrahedral
formation. It is designed to gather information about the microphysics
of magnetic reconnection
, energetic particle acceleration, and turbulence
, processes that occur in many astrophysical plasmas
.
, but will surpass it in spatial resolution and in temporal resolution, allowing for the first time measurements of the critical electron diffusion region, the site where magnetic reconnection occurs. Its orbit is optimized to spend extended periods in locations where reconnection is known to occur: at the dayside magnetopause
—the place where the pressure from the solar wind
and the planets' magnetic field are equal—and in the magnetotail—which is formed by pressure from the solar wind on a planet's magnetosphere and which can extend great distances away from its originating planet.
Magnetic reconnection in Earth
's magnetosphere
is one of the mechanisms responsible for the aurora
, and it is important to the science of controlled nuclear fusion
because it is one mechanism preventing magnetic confinement of the fusion fuel. The study of turbulence in outer space involves the measurement of motions of matter in stellar atmospheres, like the Sun, and magnetic reconnection is a phenomenon in which energy is efficiently converted from the magnetic field to charged particles.
, assisted by an international team of investigators, both instrument leads and theory and modeling experts. The Project Scientist is Thomas E. Moore of Goddard Space Flight Center
. Education and public outreach is a key aspect of the mission, with student activities, data sonification, and planetarium shows being developed.
The mission was selected for support by NASA in 2005; it has a projected launch date of 2014. System engineering, spacecraft bus design, and integration and test will be done by Goddard Space Flight Center
in Maryland
. Instrumentation is being improved, with extensive experience brought in from other missions, such as IMAGE
, the Cluster
and Cassini missions. In June 2009, MMS was allowed to proceed to Phase C, since they passed their PDR. The mission passed its Critical Design Review in September 2010 . The launch is scheduled for August 2014 according to NASA . The craft will be carried to orbit by an Atlas V
421 rocket.
maneuvers.
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
unmanned space mission, to study the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
's magnetosphere
Magnetosphere
A magnetosphere is formed when a stream of charged particles, such as the solar wind, interacts with and is deflected by the intrinsic magnetic field of a planet or similar body. Earth is surrounded by a magnetosphere, as are the other planets with intrinsic magnetic fields: Mercury, Jupiter,...
using four identical spacecraft flying in a tetrahedral
Tetrahedron
In geometry, a tetrahedron is a polyhedron composed of four triangular faces, three of which meet at each vertex. A regular tetrahedron is one in which the four triangles are regular, or "equilateral", and is one of the Platonic solids...
formation. It is designed to gather information about the microphysics
Microphysics
The term microphysics refers to areas of physics that study phenomena that take place on the microscopic scale , such as:* Quantum mechanics* Molecular physics* Atomic physics* Nuclear physics* Particle physics...
of magnetic reconnection
Magnetic reconnection
Magnetic reconnection is a physical process in highly conducting plasmas in which the magnetic topology is rearranged and magnetic energy is converted to kinetic energy, thermal energy, and particle acceleration...
, energetic particle acceleration, and turbulence
Turbulence
In fluid dynamics, turbulence or turbulent flow is a flow regime characterized by chaotic and stochastic property changes. This includes low momentum diffusion, high momentum convection, and rapid variation of pressure and velocity in space and time...
, processes that occur in many astrophysical plasmas
Plasma (physics)
In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...
.
Background
The mission builds upon the successes of the ESA Cluster MissionCluster mission
Cluster II is a space mission of the European Space Agency, with NASA participation, to study the Earth's magnetosphere over the course of an entire solar cycle. The mission is composed of four identical spacecraft flying in a tetrahedral formation...
, but will surpass it in spatial resolution and in temporal resolution, allowing for the first time measurements of the critical electron diffusion region, the site where magnetic reconnection occurs. Its orbit is optimized to spend extended periods in locations where reconnection is known to occur: at the dayside magnetopause
Magnetopause
The magnetopause is the abrupt boundary between a magnetosphere and the surrounding plasma. For planetary science, the magnetopause is the boundary between the planet’s magnetic field and the solar wind. The location of the magnetopause is determined by the balance between the pressure of the...
—the place where the pressure from the solar wind
Solar wind
The solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons with energies usually between 1.5 and 10 keV. The stream of particles varies in temperature and speed over time...
and the planets' magnetic field are equal—and in the magnetotail—which is formed by pressure from the solar wind on a planet's magnetosphere and which can extend great distances away from its originating planet.
Magnetic reconnection in Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
's magnetosphere
Magnetosphere
A magnetosphere is formed when a stream of charged particles, such as the solar wind, interacts with and is deflected by the intrinsic magnetic field of a planet or similar body. Earth is surrounded by a magnetosphere, as are the other planets with intrinsic magnetic fields: Mercury, Jupiter,...
is one of the mechanisms responsible for the aurora
Aurora (astronomy)
An aurora is a natural light display in the sky particularly in the high latitude regions, caused by the collision of energetic charged particles with atoms in the high altitude atmosphere...
, and it is important to the science of controlled nuclear fusion
Nuclear fusion
Nuclear fusion is the process by which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus. This is usually accompanied by the release or absorption of large quantities of energy...
because it is one mechanism preventing magnetic confinement of the fusion fuel. The study of turbulence in outer space involves the measurement of motions of matter in stellar atmospheres, like the Sun, and magnetic reconnection is a phenomenon in which energy is efficiently converted from the magnetic field to charged particles.
Personnel and purpose
The principal investigator is James L. Burch of Southwest Research InstituteSouthwest Research Institute
Southwest Research Institute , headquartered in San Antonio, Texas, is one of the oldest and largest independent, nonprofit, applied research and development organizations in the United States...
, assisted by an international team of investigators, both instrument leads and theory and modeling experts. The Project Scientist is Thomas E. Moore of Goddard Space Flight Center
Goddard Space Flight Center
The Goddard Space Flight Center is a major NASA space research laboratory established on May 1, 1959 as NASA's first space flight center. GSFC employs approximately 10,000 civil servants and contractors, and is located approximately northeast of Washington, D.C. in Greenbelt, Maryland, USA. GSFC,...
. Education and public outreach is a key aspect of the mission, with student activities, data sonification, and planetarium shows being developed.
The mission was selected for support by NASA in 2005; it has a projected launch date of 2014. System engineering, spacecraft bus design, and integration and test will be done by Goddard Space Flight Center
Goddard Space Flight Center
The Goddard Space Flight Center is a major NASA space research laboratory established on May 1, 1959 as NASA's first space flight center. GSFC employs approximately 10,000 civil servants and contractors, and is located approximately northeast of Washington, D.C. in Greenbelt, Maryland, USA. GSFC,...
in Maryland
Maryland
Maryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east...
. Instrumentation is being improved, with extensive experience brought in from other missions, such as IMAGE
IMAGE
IMAGE , or Explorer 78, was a NASA MIDEX mission that studied the global response of the Earth's magnetosphere to changes in the solar wind...
, the Cluster
Cluster mission
Cluster II is a space mission of the European Space Agency, with NASA participation, to study the Earth's magnetosphere over the course of an entire solar cycle. The mission is composed of four identical spacecraft flying in a tetrahedral formation...
and Cassini missions. In June 2009, MMS was allowed to proceed to Phase C, since they passed their PDR. The mission passed its Critical Design Review in September 2010 . The launch is scheduled for August 2014 according to NASA . The craft will be carried to orbit by an Atlas V
Atlas V
Atlas V is an active expendable launch system in the Atlas rocket family. Atlas V was formerly operated by Lockheed Martin, and is now operated by the Lockheed Martin-Boeing joint venture United Launch Alliance...
421 rocket.
Formation Flying
In order to collect the desired science data, the four satellite MMS constellation must maintain a tetrahedral formation through a defined region of interest in a highly elliptical orbit. The formation will be maintained through the use of a next generation space rated GPS receiver, Navigator, to provide orbit knowledge, and regular formation maintenanceSatellite formation flying
Satellite formation flying is the concept that multiple satellites can work together in a group to accomplish the objective of one larger, usually more expensive, satellite...
maneuvers.