• the presence or absence of antimatter in distant galaxies through the detection of cosmic anti-nuclei as anti-Helium and anti-Carbon.
  
  
• the origin and structure of dark matter which is believed to make up 90% of the known universe
  
  
• the origin and the composition of charged cosmic rays as well as other phenomena which may exist in nature which we have not yet imagined or had the tools to discover

The same technology used for research in particle physics is adapted in AMS for space application.
The charge sign and magnetic rigidity of cosmic rays will be determined by the deflection of their trajectory in the magnetic field of the instrument, while an array of precision particle detectors will perform redundant measurements of charge magnitude, velocity and energy. With an acceptance of 0.7m2sr, AMS will be one of a kind detector operating in space.

The operation principles of the apparatus have been tested in the space environment during a precursor flight of the experiment , 10 days of successful data taking onboard of the shuttle DISCOVERY in June 1998. A limit of 10E-6 on the ratio as well as accurate measurements of proton, helium, lepton and deuteron energy spectra are among the physics results already published from the analysis of the data taken during the precursor flight.