It was the sixth of twelve Block IIF satellites to be launched.

[3] The launch took place from Space Launch Complex 37B at the Cape Canaveral Air Force Station,[5] and placed USA-251 directly into medium Earth orbit.

[4] As of 17 May 2014, USA-251 was in an orbit with a perigee of 20,443 kilometers (12,703 mi), an apogee of 20,474 kilometers (12,722 mi), a period of 729.22 minutes, and 55.04 degrees of inclination to the equator.

[4] It is used to broadcast the PRN 06 signal, and operates in slot 6 of plane D of the GPS constellation.

The satellite has a design life of 15 years and a mass of 1,630 kilograms (3,590 lb).