Capt. Dan Luckett of the Army’s 101st Airborne Division is assigned to one of the most dangerous parts of Afghanistan, the Zhari district just north of Kandahar city, where Taliban attacks are common. He goes on patrols, lifts weights in his spare time and is second in command of his company. That may not sound unusual. What is unusual is that Luckett is a double amputee, after injuries he received