The Pope was originally scheduled to address the crew earlier this month, but the Endeavour’s launch was pushed back twice before the shuttle finally took off Monday for a 16-day mission.
The connection will take place at 1:11 p.m. (Rome time). The Holy Father will address in particular the two Italian astronauts: Paolo Nespoli and Roberto Vittori.
The event may be followed live on television as well as on the Internet at the Vatican Radio-CTV site.
Endeavour is commanded by Mark Kelly, the husband of Gabrielle Giffords, the Arizona congresswoman who was shot in the head in an assassination attempt in January.
The Endeavour will be retired to a museum in Los Angeles after returning to earth.
