Emergency Rocket Communication System

Emergency Rocket Communications System
Emergency Rocket Communications System payload
Type	Intercontinental ballistic missile/Communications System
Place of origin	United States
Service history
In service	1963-1968 (Blue Scout) 1968-1991 (Minuteman II)
Used by	United States 510th Missile Squadron
Production history
Manufacturer	Boeing
Unit cost	$7,000,000
Specifications
Weight	78,000 lb (35,300 kg)
Length	59 ft 9.5 in (18.2 m)
Diameter	5 ft 6 in (1.7 m) (1st stage)
Warhead	1KW UHF Transmitter
Engine	Three solid-propellant rocket motors; first stage - Thiokol TU-122 (M-55); second stage - Aerojet-General SR-19-AJ-1; third stage - Aerojet/Thiokol SR73-AJ/TC-1
Operational range	8,100 miles (13,000 km)
Flight altitude	700 miles (1,120 kilometers)
Speed	Approximately 15,000 mph (Mach 23, or 24,100 km/h, or 7 km/s) (terminal phase)
Guidance system	Inertial
Launch platform	Silo

The Emergency Rocket Communications System (ERCS) was designed to provide a reliable and survivable emergency communications method for the United States National Command Authority, using a UHF repeater placed atop a Blue Scout rocket or Minuteman II intercontinental ballistic missile. ERCS was deactivated as a communication means when President George H.W. Bush issued a message to stand down SIOP-committed bombers and Minuteman IIs on September 27, 1991. Headquarters SAC was given approval by the Joint Chiefs of Staff to deactivate the 494L payloads beginning 1 Oct 1992. However, Headquarters SAC believed it was inefficient and unnecessary to support ERCS past fiscal year 1991, and kept the accelerated deactivation schedule.

The mission of the Emergency Rocket Communications System was to provide assured communication to United States strategic forces in the event of a nuclear attack. ERCS was basically a rocket or missile that carried a UHF transmitter as a payload instead of a nuclear warhead. In the event of a nuclear attack, ERCS would launch the UHF transmitter into low space to transmit an Emergency Action Message (EAM) to Strategic Air Command units.

The ERCS sorties had two possible trajectories, East and West, to inform SAC alert forces in the northern tier bases (i.e. Minot AFB, Fairchild AFB, Grand Forks AFB).

ERCS was deactivated and taken out of the inventory as other means of emergency communication (i.e. ISST and Milstar) came online.