USA-304

USA-304 is a United States military satellite operated by the National Reconnaissance Office (NRO). Launched in 2009, it is widely assessed by experts in spaceflight and space security to be a member of the highly classified Advanced Extremely High Frequency (AEHF) constellation of communications satellites. These spacecraft provide global, secure, jam-resistant communications for high-priority assets, including the U.S. President, Department of Defense leadership, and deployed strategic forces such as those under United States Strategic Command.

Overview

As the second spacecraft in the Advanced Extremely High Frequency system, USA-304 succeeded the earlier Milstar satellite network, offering a substantial increase in data rate capacity and connectivity. The satellite forms a critical node in the Survivable Satellite Communications architecture, designed to maintain command and control links through various levels of conflict, including nuclear warfare. Its operations are managed jointly by the National Reconnaissance Office and the United States Space Force, specifically the Space Systems Command and Space Delta 8.

Development and launch

The Advanced Extremely High Frequency program was developed by Lockheed Martin as the prime contractor, with Northrop Grumman providing the payload. USA-304 was launched atop an Atlas V rocket, flying in the 531 configuration, from Space Launch Complex 41 at Cape Canaveral Space Force Station. The launch occurred on August 8, 2009, and the spacecraft was successfully placed into a geosynchronous transfer orbit. Following a series of intricate maneuvers using its onboard liquid apogee engine, it achieved its final operational orbit in geostationary orbit.

Design and capabilities

The satellite is based on the A2100 satellite bus, a reliable platform also used for other missions like the GOES-R series. Its primary payload includes advanced extremely high frequency (EHF) and super high frequency (SHF) transponders, enabling communication with a wide variety of terminals, from large fixed sites to mobile platforms like the E-6B and E-4B National Airborne Operations Center aircraft. Key features include a sophisticated nulling antenna for anti-jamming protection, crosslink capability with other AEHF satellites for a self-contained network, and significantly higher throughput than the Milstar II satellites, supporting tactical communications, battlefield management, and nuclear command and control.

Operational history

After completing extensive on-orbit testing by the National Reconnaissance Office and the United States Air Force, USA-304 entered operational service. It joined the first AEHF satellite, USA-214, to begin building out the global constellation. The satellite has been involved in numerous major exercises, such as those conducted by United States Strategic Command, and provides continuous support for global U.S. military operations. Its secure links are vital for connectivity with assets like the Ohio-class ballistic missile submarines, the B-2 Spirit stealth bomber fleet, and the White House Military Office.

Related systems and context

USA-304 is a cornerstone of a layered strategic communications architecture. It works in conjunction with other systems like the Family of Advanced Beyond Line-of-Sight Terminals (FAB-T) and the Secure Mobile Anti-Jam Reliable Tactical Terminal (SMART-T). The broader AEHF constellation, which includes later satellites like USA-263 and USA-311, is designed to interoperate with allied systems such as the United Kingdom's Skynet 5 and Canada's contribution to the program. This network ensures continuity with legacy Milstar terminals while paving the way for future systems under the Evolved Strategic SATCOM (ESS) and Protected Tactical SATCOM (PTS) initiatives managed by the Space Systems Command.