The OG2 mission is the first set of a series of 17 satellites that will replace the first generation of Orbcomm's constellation of communications satellites. Built by the Sierra Nevada Corporation and weighing about 170 kg (375 lb), the satellites are reportedly larger and more efficient than previous Orbcomm spacecraft, and are capable of faster data feeds and can cover higher latitudes on the Earth's surface. In addition, they can be used for tracking Automatic Identification System (AIS)-equipped ships, allowing their owners and emergency services to keep tabs on them.