Approximately 15,000 miles per hour (Mach 20; 24,000 km/h; 6.7 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 IIintercontinental ballistic missile.[1]: 34-37 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 27 September 1991. Headquarters SAC was given approval by the Joint Chiefs of Staff to deactivate the 494L payloads beginning 1 October 1992.[2] However, Headquarters SAC believed it was inefficient and unnecessary to support ERCS past fiscal year 1991, and kept the accelerated deactivation schedule.
Mission
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 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.[3][4][5][6]
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).[7]
ERCS was deactivated and taken out of the inventory as other means of emergency communication (i.e. ISST and Milstar) came online.[8]
Nomenclature
ERCS was also known as Project 279 (Blue Scout version) and Project 494L (Minuteman version). Sources report that the Project 279 was also known as Project Beanstalk;[9][10]: 74-79 while the Minuteman system may have been designated LEM-70A.[11]
Interface with ERCS hardware was provided by three modes:
A land line through ground grouping points (North Bend, Nebraska and Red Oak, Iowa) allowed the airborne command post interface with 494L equipment[12]
Headquarters Strategic Air Command had the ability to make inputs directly into the missile. The Numbered Air Forces could direct the missile crew to make the inputs. In the case of the airborne command post, inputs could be made directly into the missile and missile launch could be made from the aircraft.[12]
After the system was declassified, the ten ERCS sorties were powered down and removed from their launch facilities. During these power-down operations, the location of the sorties were:
29 September 1961 – HQ USAF issues Specific Operational Requirement (SOR) 192, for ERCS (designated Program 279)
27 December 1961 – Interim configuration finalized of three rockets with 1 KW transmitters, stationed around Omaha, Nebraska; four sites with three rockets each
5 April 1962 – Amendment to SOR 192 to include two east coast ERCS complexes, based on CHROME DOME routes and SAC elements in Europe
21 September 1962 – SAC study recommends use of Minuteman missile, to eliminate Program 279 and its proposed expansion
7 June 1962 – SAC proposes changes to SOR 192, such as using six Minuteman missiles selected from among the flights of an operational wing; this was envisioned not to impair the alternative capability of substituting nuclear warheads should future circumstances warrant.
11 July 1962 – Program 279 attains Initial Operating Capability (IOC); UHF transmitter payloads attached to three MER-6A Blue Scout rockets at three sites near Wisner, West Point, and Tekamah, Nebraska
13 December 1966 – A Minuteman II launched from Vandenberg AFB, Calif. carried the first Minuteman ERCS payload into space for testing and evaluation[16]
17 April 1967 – Third, and last, test of the ERCS using a Minuteman booster; Emergency Action Message was inserted into the transmitter from an ALCS aircraft.
10 October 1967 – First two Program 494L ERCS payloads put on alert at Whiteman AFB, Missouri; IOC obtained for Program 494L ERCS[16]
1 January 1968 – Full Operational Capability (FOC) obtained for Program 494L ERCS; Program 279 ERCS inactivated by SAC[17]
23 October 1974 – ERCS test, designated GIANT MOON 6, launched from Vandenberg AFB. Test was monitored on two frequencies by ground facilities. PACOM at Hickam AFB maintained valid reception of the JCS WHITE DOT ONE message for 22 minutes and another message for 14 minutes[18]: 341
27 September 1991 – President George H. W. Bush terminated SAC's alert force operations, which included taking Minuteman II ICBMs (including ERCS sorties) off-alert.
^Parsch, Andreas (2002). "Boeing LEM-70 Minuteman ERCS". Directory of U.S. Military Rockets and Missiles. designation-systems.net. Archived from the original on 15 December 2010. Retrieved 10 January 2011.