Cast of ER Cast of ER "ER" is an American drama series that aired on NBC from September 19, 1994 until April 2, 2009. The series featured a large ensemble cast that changed dramatically over its long run. The main cast was augmented by a wealth of recurring characters and award-winning guest stars. The original starring cast consisted of Anthony Edwards as Dr. Mark Greene, George Clooney as Dr. Douglas "Doug" Ross, Sherry Stringfield as Dr. Susan Lewis, Noah Wyle as medical student (later Dr.) John Carter, and Eriq La Salle as Dr. Peter Benton. Julianna Margulies guest starred in the pilot as
AGM-84H/K SLAM-ER targets. The SLAM-ER can be remotely controlled while in flight, and it can be redirected to another target after launch if the original target has already been destroyed, or is no longer considered to be dangerous (command guidance). The SLAM-ER is a very accurate weapon; as of 2009 it had the best circular error probable (CEP) of any missile used by the U.S. Navy. The SLAM-ER obtained initial operating capability in June 2000. A total of three SLAM-ER missiles were fired by the U.S. Navy during the Iraq War, and the missile was also used during Operation Enduring Freedom in