Within the scope of the European-Japanese MERMAG Consortium, magnetometers have been proposed and selected for both satellites. For the MMO magnetometer (MERMAG-M) IWF is the lead institution and for the MPO magnetometer (MERMAG-P) IWF is responsible for the overall technical management.
Both instrument designs are based on a digital fluxgate magnetometer which has previously been developed jointly with the Institute of Geophysics and Extraterrestrial Physics of the TU Braunschweig for magnetic field measurements aboard the Rosetta lander, MIR Space Station, Venus Express, and THEMIS. For the BepiColombo mission the design has to be adapted so that it can cope with the harsh thermal environment around Mercury. Furthermore, the general instrument concept differs between the Japanese MMO and the European MPO. Aboard MMO, the near-sensor electronics of the various sensors are mainly integrated in common electronics boxes and directly connected to common digital processing and power supply units. Aboard MPO, the instruments are designed as stand-alone devices with their own power supply and digital controller units. Both instruments will have a dynamic range of approx. ±2,000 nT and a maximum vector rate of 128 Hz.
The primary objective of the magnetic field investigation on the BepiColombo Mercury Magnetospheric Orbiter (MMO) is to study the formation and dynamics of Mercury's magnetosphere and the processes that control the interaction of the magnetosphere with the solar wind and with the planet itself. Emphasis will be placed on those effects and processes which are particular to the Hermean magnetosphere and distinguish it from the better known terrestrial one: (1) the weakness of the field, (2) the small dimension and possible greater importance of kinetic effects, and (3) the near-absence of an ionosphere. It is expected that these differences have a large impact on (1) the reconnection process, both on the dayside and in the magnetotail, (2) the structure and dynamics of field-aligned currents, and (3) the low frequency plasma waves.
The primary objective of the proposed magnetic field investigation on the BepiColombo Mercury Planetary Orbiter (MPO) is to provide the magnetic field measurements that will lead to the detailed description of Mercury's planetary magnetic field, and thereby constrain models of the evolution and current state of the planetary interior. It is recognized that the scientific objectives of the BepiColombo mission can be best met by the comprehensive scientific coordination of the magnetic field investigations which can be fulfilled by the MERMAG consortium.
Further information on MERMAG-M is found in a proposal of July 2004.