Looks a bit confusing…
Communications via a military headquarters and its subordinate units has always been crucial in warfare from semaphore (communicating via flags) to homing pigeons, satellite communications to even using calling cards on a payphone to request artillery (this actually happened during the 1983 Greneda conflict). With missile sites, the importance is absolute and required a number of different strategies.
The Minuteman Launch Control Center received its Emergency War Order (EWO) messages via the Primary Alerting System (PAS). On a regular test basis, these would actually enter the site using plain telephone wire or the (HICS) Hardened Intersite Cabling System network . The Strategic Automated Command and Control System (SACCS – sorry, more acronyms) primarily utilized phone lines but due to the fact that phones would go down during a nuclear war, other plans were devised.
HF or High-Frequency radio antennas were set up at Minuteman sites as they became operational. Using Single-Side Band (SSB) radios, an antenna could fairly reliably communicate over some distance. “Receivers” built at the sites had an antenna that could be raised out of a protective enclosure, if that antenna was lost there were five more reloads. Only Squadron Command Posts or Alternate Command Posts had “Transmitters”.
VHF or Very-High Frequency was used to communicate with nearby maintenance and security teams in the area driving in vehicles. It had a backup ability to communicate with nearby Launch Control Centers and even the Wing Command Post back at Grand Forks AFB but was
UHF or Ultra-High Frequency was fairly long ranged but relied on a line-of-sight approach. This meant that airplanes could utilize this type of transmission fairly well at higher altitudes. Back on the ground at Oscar-Zero a hardened UHF antenna (that looks like a white cone) could communicate the the Airborne Command Post of the Strategic Air Command, code-named “Looking Glass”. This modified 707 airliner could take over the command role from Strategic Air Command Headquarters in Omaha, Nebraska in case that had been destroyed.
SLFCS or Survivable Low Frequency Communications System entered the picture a little later during the 1960s. It transmitted both on Very-Low Frequency or High Frequency channels from a few different sources, special radio towers once located in Nebraska and California or by airplane (like “Looking Glass” or later the Navy’s rough equivalent E-6 Mercury airplane). VLF transmits more slowly but is better protected against the Electro-Magnetic Pulse of detonating nuclear weapons that can bring power spikes to electronics, disabling or destroying them.
One of the last strategic improvements in communications seen at Oscar-Zero was the ICBM Super-High Frequency Satellite Terminal (ISST) which can be seen as a white dome sitting above the Launch Control Facility today.
After the 321st Missile Group stood down in 1997, there have been continuing communications improvements with the Minuteman system at other bases.
Lastly, Medium Frequency (MF) transmissions were only used at Wing VI (Grand Forks AFB) and a single updated squadron at Malmstrom AFB Montana. A transmission antenna extended out beyond the LCF in a field and allowed a backup ability to launch missiles miles away in the Launch Facilities should a breakdown in the HICS system occur (Hardened Intersite Cabling was the primary way to launch missiles and communicate with the silos if maintenance was ongoing).
Whew…we actually wrote this article for some collaborative education and encourage readers with a better knowledge of the Minuteman communications system to share their thoughts. Historical information pertaining to these systems are less frequent on the internet and we hope to construct a better understanding of the Minuteman communications system.