Advanced Extremely High Frequency (AEHF) System


The Advanced Extremely High Frequency (AEHF) system is a joint service satellite communications system providing survivable, global, secure, protected and jam-resistant communications for high-priority military ground, sea and air assets. AEHF also provides protected satellite communications to our international partners Canada, the United Kingdom, Netherlands and Australia. AEHF will allow the National Security Council and Unified Combatant Commanders to control their tactical and strategic forces at all levels of conflict through general nuclear war, and support the attainment of information superiority.


Bought and shepherded by the U.S Space Force’s Space and Missile Systems Center, the nation’s launch and satellite procurer of choice, the AEHF system is the follow-on to the Milstar system, augmenting and improving upon the capabilities of Milstar, and expanding the Military Satellite Communication (MILSATCOM) architecture. AEHF s connectivity across the spectrum of mission areas, including land, air and naval warfare; special operations; strategic nuclear operations; strategic defense; theater missile defense and space operations and intelligence.


The AEHF system consists of six satellites in geosynchronous Earth orbit providing 10 times the throughput of the 1990s-era Milstar satellites — offering a substantial increase in coverage for users. First launched in late 2010, AEHF will provide continuous 24-hour coverage between 65 degrees north and 65 degrees south latitude. The AEHF system is composed of three segments: space (satellites), ground (mission control and associated communications links), and terminals (users).

The Space and Missile Systems Center is responsible for the acquisition of the space and ground segments. The Army and Navy acquire their own terminals.

The segments provide communications in a specified set of data rates, from 75 bits per second to approximately 8 megabits per second. The space segment is consists of a cross-linked constellation of six AEHF satellites and five Milstar satellites. The mission control segment controls satellites on orbit, monitors satellite health and provides communications system planning and monitoring. This segment is highly survivable, with both fixed and mobile control stations. System uplinks and crosslinks operate in the extremely high frequency (EHF) range and downlinks in the super high frequency (SHF) range. The terminal segment includes fixed and mobile ground terminals, ship and submarine terminals and airborne terminals, used by all the Services and International Partners (Canada, Netherlands, UK, and Australia).


  • Primary Function: Near-worldwide, secure, survivable satellite communications
  • Primary Contractor: Lockheed Martin Space
  • Payload: Onboard signal processing, crossbanded EHF/SHF communications
  • Antennas: Two SHF Downlink Phased Arrays, Two Crosslinks, two Uplink/Downlink Nulling Antennas, one Uplink EHF Phased Array, six Uplink/Downlink Gimbaled Dish Antennas, one each Uplink/downlink Earth-coverage horns
  • Capability: Data rates from 75 bps to approximately 8 Mbps
  • Launch vehicle: United Launch Alliance Atlas V
  • Orbit altitude: 22,500 miles (Geosynchronous)
  • Weight: Approximately 14,500 lbs at launch, 9,000 lbs on orbit

PRIME CONTRACTOR: Lockheed Martin Space