The XSM is a mobile phoned sized instrument, weighing just 200 grams and was built for measuring the X-ray spectrum emitted by the Sun.
The design and fabrication of a low noise sensor and electronics by Oxford Instruments Analytical Oy enables the measurement of very low energy (< 1 keV) X-rays. In space, the sensor will be bombarded by high energy particles, which forced the development of a miniature movable radiation shield. The scientific planning and utilisation is carried out by the Division of Geophysics and Astronomy, University of Helsinki.
The project was mainly funded by TEKES and the Academy of Finland.
The XSM was launched on the European Space Agency's (ESA) SMART-1 probe on the 28 of September 2003. SMART-1 reached moon orbit in 2005 and successfully completed its mission on 3rd September 2006. ASM
More about ESA project:
ESA SMART-1 Projecs
HU SMART-1 Project