Planned trips to Alaska by William Oefelein and fellow astronauts have been scrubbed. Oefelein was scheduled to appear Feb. 19 at the Challenger Learning Center in Kenai. On March 7, he and the entire shuttle crew were booked at his alma mater, West High in Anchorage. He also had a planned appearance at the Atwood Concert Hall on March 8. The trips have been indefinitely postponed by NASA, said a spokeswoman for Conoco Phillips, which sponsored the events. No reason was given.