The US$200 million 1225 kg (2700 lbm) DSCS phase 3 satellite was built by Lockheed Martin Space Systems. The satellite system is used for high priority communications and to transmit space operations and early warning data to various systems and users. Each satellite utilizes six ultra high frequency transponder channels capable of providing worldwide secure voice and high rate data communications. Each satellite also carries a single channel transponder used to disseminate emergency action and force direction messages to nuclear capable forces. Currently, ten Phase 3 DSCS satellites operate in geosynchronous orbit. One of the primary satellites currently in operation will be transitioned to the reserve fleet to make room for the new satellite in the main constellation. Once in the backup fleet, that middle-aged craft will replace the 15-year old DSCS B4 satellite, which will be boosted out of its operational orbit.