The U.S. Navy christened the first of a new class of amphibious ships on July 19th. The ship will enter service in 2005. The USS San Antonio is the first of twelve LPD 17 class ships. Each is 24,900 tons displacement and 684 feet long. The navy crew is 360, and 720 marines and all their equipment are carried. There is 25,000 square feet for vehicle storage and a 24 bed hospital, with two operating rooms and the ability to set up another hundred beds in an emergency. Onboard weapons include two Bushmaster II 30mm Close In Guns and  and two Rolling Airframe Missile (RAM) launchers to defend against anti-ship missiles. The RAM missiles use infrared seeker from the Stinger missile and the warhead, rocket motor, and fuze from the Sidewinder missile to produce a system that requires no shipboard support (from a radar or control system)  after the missile is launched.  The ship is designed to carry and use two LCAC (Landing Craft Air Cushion vehicle), and 14 of the new AAAV (Advanced Amphibious Assault Vehicle), as well as the current AAV. The MV-22 (Osprey tiltrotor aircraft), as well as current helicopters, can operate off the ships flight deck. The AAAV and MV-22 are expected to be in service in the next few years. Each LPD 17 costs about $800 million. The LPD 17 class replaces four other classes of amphibious ships (LPD 4, LSD 36, LST 1179 and LKA 113).