The permanent magnet has captured its first particle—a muon that passed through its magnetic field and traversed all AMS-02 tracker planes. Cosmic-ray data collection is officially underway!

The re-integration of the AMS-02 spectrometer is nearly complete. In the meantime, all subsystems are operational once again, and the first cosmic rays have been detected and recorded by the data acquisition system. The reconfigured Silicon Tracker, now with its 9 planes, is functioning well. In this computer-reconstructed image, you can see one of the first muons traversing the entire spectrometer, leaving detectable signals in the detector planes which allow its track to be reconstructed.

Over the next 15 days, the detector will undergo extensive testing and final integration of the thermal blankets. Following this, it will be exposed to a beam of high-energy particles at CERN for final calibration. Once these steps are complete, the spectrometer will be transported to Florida on a C5 aircraft of the US Air Force, departing from Geneva airport and heading for the Kennedy Space Center Shuttle landing strip.