LOWELL, Mass. — Astronauts, scientists and entrepreneurs are celebrating the 60th anniversary of the start of the Space Age and looking ahead to the next frontiers at a conference in Lowell."Space Exploration in the Upcoming Decade: The Domestication of Space," will bring industry leaders from around the world to share their work.The conference will be held at the University of Massachusetts-Lowell from April 21 and April 22.