The Si tracker for the AMS-02 experiment on the Space Station

The AMS-02 particle spectrometer will be installed on the International Space Station (ISS) in fall 2005. We describe the design of the 7 m2 AMS-02 tracker, which is based on the experience with AMS-01—successfully operated in space for 10 days in 1998. We report on beamtests with AMS-02 ladders showing that the charge of cosmic particles can be measured up to rigidities of 3 TV. The novel AMS tracker alignment control scheme based on IR laser rays detected by the Si sensors is described briefly.