Starman’s Quest - Robert Silverberg

Twin brothers separated by space travel live vastly different lives—one aboard a faster-than-light starship, the other on an unchanging Earth. Alan Donnell, the shipbound twin, becomes determined to find his lost brother and uncover the truth behind an ancient mystery that could change humanity’s future. His search takes him across worlds, revealing the loneliness and isolation of spacefaring life. The story blends adventure and introspection, exploring time, identity, and the human longing for connection.