Earth's magnetosphere measured accurately from space

As part of the mission, four identically equipped satellites are performing highly accurate three-dimensional measurements of the Earth’s magnetosphere. The ambitious goal of this mission is to explore the dynamics of the magnetosphere, measuring with extreme accuracy very small variations in the Earth’s magnetic field. The research effort spearheaded by the Space Research Institute (based in Graz, Austria) is focused on the so-called magnetic reconnection, which is a physical process in which the Earth’s magnetic energy is converted to kinetic energy, thermal energy, and particle acceleration.

Magnetic reconnection is one of the mechanisms responsible for the aurora, as well as for temporary disturbances in the Earth's magnetosphere. Like all measurement instruments and equipment in satellites, the Space Research Institute’s magnetometer has to be as small and light as possible, while consuming very little power. In addition, it must offer very high accuracy under harsh conditions such as very low temperatures and radiation.

Developed by the Fraunhofer Institute for Integrated Circuits IIS in co-operation with the Space Research Institute, a tiny custom ASIC enables the satellites’ Digital Flux-Gate (DFG) magnetometer to acquire highly accurate three-dimensional measurements of the magnetosphere while drawing ultra-low current. The DFG sensor was supplied by the University of California, Los Angeles.

Operating at a resolution of 10 picoTesla, which is several thousand times more sensitive than a conventional electronic compass, the device is able to sense the smallest variations in magnetic flux. The Fraunhofer ASIC was fabricated by ams on its specialty 0.35µm CMOS (C35) process technology, which allows for the design of complex analogue/mixed-signal integrated circuits. Based on a unique process architecture, the rad-hard C35 technology is suited for use in space and aerospace applications.

The Fraunhofer and Space Research Institute design team also benefited from ams’ turnkey solutions for IC design, which include a comprehensive Process Development Kit and IP block portfolio, advanced process technologies as well as product qualification services and supply chain management capabilities. These enable ams’ foundry customers to significantly mitigate their development risks and to reduce the duration of the development cycle.

“The ams speciality 0.35µm CMOS process enabled the team of researchers and scientists at Fraunhofer IIS to develop a complex analogue/mixed signal IC that impressively outperformed our expectations in all respects – performance, power consumption, die area and reliability”, said Johann Hauer, Project Manager, ASIC Development, Fraunhofer IIS.

“After two months in space, we are very proud to confirm that the chip-based magnetometer significantly surpasses the requirements of accuracy and stability,” added Werner Magnes, Deputy Director, Graz Space Research Institute.

“During almost 25 years of co-operation with Fraunhofer IIS, ams has successfully developed a vast number of complex ICs for both research as well as industrial programs. We are happy that ICs manufactured by ams now operate reliably in outer space and contribute to a better understanding of the Earth’s physics” stated Markus Wuchse, General Manager, Full Service Foundry division, ams AG.