Library Fact Sheets
ADVANCED EXTREMELY HIGH FREQUENCY SYSTEM|
Printable Fact Sheet
The Advanced Extremely High Frequency (AEHF) System is a joint service satellite communications system that will provide survivable, global, secure, protected, and jam-resistant communications for high-priority military ground, sea and air assets. Advanced EHF will allow the President, Secretary of Defenses and Combatant Commanders to control their strategic and tactical forces through all levels of conflict including nuclear war.
The AEHF System is the follow-on to the Milstar system, augmenting and improving on the capabilities of Milstar, and expanding the MILSATCOM architecture. AEHF will provide 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 system will consist of five satellites in geosynchronous earth orbit (GEO) that provides 10 times the throughput of the 1990s-era Milstar satellites with a substantial increase in coverage for users. First launched in late 2010, AEHF provides continuous 24-hour coverage between 65 degrees north and 65 degrees south latitude. The AEHF system is composed of three segments: space (the satellites), ground (mission control and associated communications links) and terminals (the users). The segments will provide communications in a specified set of data rates from 75 bps to approximately 8 Mbps. The space segment consists of a cross-linked constellation of five planned satellites as well as the five legacy 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 will operate in the extremely high frequency (EHF) range and downlinks in the super high frequency (SHF) range. The terminal segment includes fixed and ground mobile terminals, ship and submarine terminals, and airborne terminals used by all of the Services and international partners (Canada, Netherlands and UK).
Primary Function: Near-worldwide, secure, survivable satellite communications
Primary Contractor: Lockheed Martin Space Systems Company
Payload: Onboard signal processing, crossbanded EHF/SHF communications
Antennas: 2 SHF Downlink Phased Arrays, 2 Crosslinks, 2 Uplink/Downlink Nulling Antennas, 1 Uplink EHF Phased Array, 6 Uplink/Downlink Gimbaled Dish Antenna, 1 Each Uplink/downlink earth coverage horns
Capability: Data rates from 75 bps to approximately 8 Mbps
Flight 1 - Feb 7, 94
Flight 2 - Nov 7, 95
Flight 3 - Feb 27, 01
Flight 5 - Jan 15, 02
Flight 6 - Apr 8, 03
Space Vehicle 1 - Aug 14, 10
Space Vehicle 2 - May 4, 12
Space Vehicle 3 - Sep 18, 13
Space Vehicle 4 - TBD
Space Vehicle 5 - TBD
(Current as of March 15)
Point Of Contact: Space and Missile Systems Center, Public Affairs Office; 2420 Vela Way, Suite 1467; Los Angeles AFB, CA 90245-4659; DSN 833-0030 or (310) 363-0030.