The P-3C Orion is a four-engine turboprop anti-submarine and maritime surveillance aircraft. It was originally designed as a land-based, long-range, anti-submarine warfare (ASW) patrol aircraft, the P-3C's mission has evolved in the late 1990s and early 21st century to include surveillance of the battlespace, either at sea or over land. Its long range and long loiter time have proved invaluable assets as it can view the battlespace and instantaneously provide that information to ground troops, especially U.S. Marines. The P-3C can carry a mixed payload of weapons internally and on wing pylons.