AMS is a major cosmology experiment. AMS will observe the properties of electrons, positrons, protons, antiprotons, and nuclei in high-energy radiation from space. These observations may answer important questions about the Big Bang, including "Why did the Big Bang make so little antimatter"? and "What makes up the Universe's invisible mass?"
AMS is a major particle-physics experiment. Some types of particles - predicted by theorists, and searched for in collider experiments - may be present already in cosmic rays. AMS may observe them, thus learning about the particles themselves as well as their distant astrophysical sources.
AMS is a manifestly international, cooperative project. Like the Space Station itself, AMS is possible only due to the hard work and expertise of many people and many nations. The AMS collaboration involves over 200 people from 31 institutions and 15 countries, in addition to invaluable subcontractors and suppliers all over the world. Scientifically, AMS builds on the collective knowledge and experience of dozens of excellent cosmic-ray experiments - on balloons, on spacecraft, and on the ground - of the past thirty years.