HS-66 is the second part of Triad. It is a multi-purpose, three-stage missile system that can be launched by land, sea, or air. Designed and developed by the China Aerospace Science and Technology Corporation, the system consists of a rocket booster, a mid-course steering section and a terminal guidance system. The rocket booster is capable of carrying a payload of up to 2 tons, while the mid-course steering section provides precision guidance during the flight. The terminal guidance system has an advanced infrared seeker, a GPS option and a data link for transmission of tracking signals from the ground to the missile. The HS-66 is designed to engage both surface and air targets, with a range of up to 180 kilometers and a circular error probability of less than 30 meters. The system is also capable of loitering and regenerating modes for greater accuracy and target selection.