|Mission type||Military communications|
|Operator||US Air Force|
|Mission duration||14 years|
|Launch mass||6,168 kilograms (13,598 lb)|
|Start of mission|
|Launch date||18 September 2013, 08:14 UTC|
|Rocket||Atlas V 531 (AV-041)|
|Launch site||Cape Canaveral, SLC-41|
|Perigee altitude||35,770 kilometers (22,230 mi)|
|Apogee altitude||35,819 kilometers (22,257 mi)|
USA-246, also known as Advanced Extremely High Frequency 3 or AEHF-3, is a military communications satellite operated by the United States Air Force. It is the third of six spacecraft to be launched as part of the Advanced Extremely High Frequency program, which replaced the earlier Milstar system.
The USA-246 spacecraft was constructed by Lockheed Martin, and is based on the A2100 satellite bus. The spacecraft has a mass of 6,168 kilograms (13,598 lb) and a design life of 14 years. It will be used to provide super high frequency and extremely high frequency communications for the armed forces of the United States, as well as those of the United Kingdom, the Netherlands, and Canada.
USA-246 was launched by United Launch Alliance, aboard an Atlas V 531 flying from Space Launch Complex 41 at the Cape Canaveral Air Force Station. After a number of weather-related delays, the launch occurred at 08:10 UTC on 18 September 2013, placing the spacecraft in a parking orbit of 178 kilometers by 1,041 kilometers. A second burn placed the satellite into a geosynchronous transfer orbit with a perigee of 225 kilometres (140 mi), an apogee of 50,051 kilometres (31,100 mi), and 20.52° inclination. The satellite was successfully deployed in this orbit 50 minutes after launch.
After raising its orbit using its onboard propulsion systems, AEHF-3 was declared operational in late July 2015. It is currently in a 0.8 degree inclination orbit with a perigee of 35,770 kilometers (22,230 mi) and an apogee of 35,819 kilometers (22,257 mi).