The U.S. space shuttle Discovery was leaking valuable water and suffering communications trouble as it raced toward NASA's last rendezvous with Russia's space station Mir, officials said Wednesday.

The problems were not expected to affect the docking with the station Thursday but would mean less water for the Mir crew and little television coverage of the flight, mission control commentator Ann Hutchison said.Discovery blasted off from the Kennedy Space Center on Tuesday to pick up Andrew Thomas, the last of seven NASA astronauts to serve on Mir.