(04/17/1969) -- Astronaut Eugene A. Cernan is lunar module pilot for Apollo 10, scheduled for launch from the nation's spaceport on May 18. Cernan and Apollo 10 Commander Thomas P. Stafford are to detach the lunar module after the spacecraft enters lunar orbit and drop down to within 10 miles of the Moon's pockmarked surface before rejoining John W. Young, command module pilot, orbiting the Moon in the command/service module. The Apollo 10 mission is a dress rehearsal for a manned lunar landing later this year.