Complex sentence: James Benson Irwin (March 17,1930--August 8,1991) was an American astronaut, and as Lunar Module pilot for Apollo 15, the fourth human lunar landing, the eighth man to walk on the Moon.
Split into simpler sentences: James Benson Irwin (March 17,1930--August 8,1991) was an American astronaut. He served as Lunar Module pilot for Apollo 15, the fourth human lunar landing; he was the eighth man to walk on the Moon.