ESA astronaut Roberto Vittori, from Italy, during the preflight training program called the Crew Equipment Interface Test, or CEIT, 8 November 2010. CEIT is held at NASA's Kennedy Space Center in Florida, prior to every mission.
Roberto Vittori is assigned to fly to the ISS on Space Shuttle Endeavour STS-134, targeted for launch on 29 April 2011.

The main cargo of the flight is the Alpha Magnetic Spectrometer (AMS-02), a massive scientific instrument that will be installed on the ISS central truss .

The purpose of the AMS is to help scientists to better understand fundamental issues on the origin and structure of the Universe by observing antimatter and dark matter. As a by-product, AMS will gather a lot of other information from cosmic radiation sources on stars and galaxies millions of light years from our home galaxy. Not only astronomers, but also particle physicists are zealously waiting for AMS data.

The AMS experiment is led by Nobel laureate Samuel Ting of the Massachusetts Institute of Technology (MIT) and it involves international team composed of 56 institutes from 16 countries. ESA's partner in the AMS collaboration is the Agency’s Directorate of Human Spaceflight. The first version of the experiment, AMS-01, was flown in June 1998 aboard the Space Shuttle Discovery and, after promising results the bigger and more capable version was accepted to be flown on the International Space Station (ISS).