Old Man's War: Book 1

In John Scalzi's Old Man's War, 75-year-old John Perry joins Earth's military to start anew, undergoing a transformation that grants him a genetically enhanced body for space combat. As he serves in the Colonial Defence Force, he faces the perilous realities of defending humanity's colonies from hostile alien species. This gripping series explores the dangers of war and the costs of enlistment in a universe filled with unpredictable threats.