Space Plasma Physics

STEREO SUCCESSFULLY LAUNCHED

On 26.10.2006 00:52 UT the NASA Mission STEREO (Solar TErrestrial RElations Observatory) was successfully launched with a Delta-II rocket at Cape Caneveral in Florida / USA. The mission consists of two almost identical spacecraft that are first injected into an orbit around the Earth - Moon system. After the 2 months commissioning phase the spacecraft use a close lunar swing-by to achieve the final orbit around the sun. The heliocentric orbits are such that the distance in heliolongitude increases by 45° per year. This provides for the first time observations of active regions at the Sun and of coronal mass ejections (CMEs) from different viewing directions, i.e. a stereoscopic view, and thus allows the reconstruction of 3D images.

MPE participates in the PLASTIC (PLAsma and SupraThermal Ion Composition) experiment that was developed in an international collaboration under the lead of the Space Science Department of the University of New Hampshire (UNH), Durham, USA (PI A. B. Galvin). PLASTIC is the primary sensor for the determination of the solar wind parameters density, velocity and temperature, and provides elemental and ionic charge composition of the solar wind and of suprathermal particles up to 80 keV/e.

Schematic view of the STEREO spacecraft and scientific payload.

The PLASTIC experiment in flight configuration.

Cluster will become the first multi-scale mission

On 10 February 2005, the ESA Science Programme Committee approved unanimously the extension of the Cluster mission, pushing back the end date from December 2005 to December 2009.
This extension will allow the first measurements of space plasmas at both small and large scales simultaneously and the sampling of geospace regions never crossed before by four spacecraft flying in close formation.

ESA web page

Day side orbit of Cluster. The initial orbit of 2001 and the orbit in 2009 are shown.
Picture: ESA

Night side orbit of Cluster. The initial orbit of 2001 and the orbit in 2009 are shown.
Picture: ESA

Since their dual launches in July and August 2000, ESA's four Cluster spacecraft have been flying in a tetrahedral formation around the Earth, sending back the first detailed, three-dimensional information about the magnetosphere and its interaction with the solar wind.

Orbits of the 4 Cluster spacecraft and of the 2 satellites of the Double Star mission, with a schematic picture of the magnetosphere of the Earth. With the missions Cluster and Double Star, coordinated measurements with up to 6 spacecraft are now becoming available for the first time.
Image: ESA

ESA Double Star web page

ESA Cluster web page