Roberto Vittori of Viterbo, Italy is preparing for launch on the Shuttle Endeavor, bound for the International Space Station.
The Endeavor, which was set to launch last week, has delayed takeoff until at least the 10th of May.
Italian Air Force-trained Vittori has already been on two trips to the International Space Station. His previous flights, in 2002 and 2005, were both on Russian spacecrafts.
When Endeavor docks at the International Space Station, Vittori will be carrying the Italian flag with him. The flag was presented to him by Italian President Giorgio Napolitano during a ceremony celebrating the 150th anniversary of the unification of Italy.
His task is to perform experiments capturing cosmic rays, in order to establish the existence of antimatter.
Vittori will be the last non-American astronaut to fly on the Shuttle Endeavor. Endeavor is set for retirement after this final voyage.