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Silent Sentry: Protecting Space Communications

  • Published
  • By Master Sgt. Phil Speck
  • 379th Air Expeditionary Wing Public Affairs
More than 20,000 above the Earth’s surface, communication satellites orbit the planet, listening for a signal. Once they receive a signal, they repeat it and send it back down to the surface.

The U.S. Air Force uses many types of satellite communications to transmit data all around the globe. With the encryption of data, the U.S. Air Force denies prying eyes the ability to read critical information. However, desperate enemies often try a number of subterfuge methods to disrupt SATCOM.

This is where the 379th Expeditionary Operations Support Squadron’s Silent Sentry (OSY) flight comes into play - to protect critical satellite communication links by employing multiple weapons systems for electronic warfare.

These space operators are from the 16th Space Control Squadron and the Air Force Reserves 380th Space Control Squadron at Peterson Air Force Base, Colorado Springs, Colorado.

If hostile forces relied on kinetic attacks, or trying to shoot down satellites with missiles, attacks on U.S. communications would become expensive. Alternatively, those that want to deny our satellite communication capabilities are more likely to try jamming which is broadcasting powerful radio waves that overwhelm our ability to receive information.

Silent Sentry’s space control mission defends against these jamming attacks. They monitor satellites and watch radio signals that the satellites send down. Normal communications have certain characteristics or “fingerprints” to them, and according to Capt. Dirk Haller, commander of Silent Sentry, when these signals look different, the Airmen of the 379th OSY know something is wrong and someone may be trying to jam them.

“We watch radio signals going up and down from space and make sure that the signals we’re sending are getting where they need to go and not being interfered with,” Haller said.


Since satellites are critical for remotely piloted aircraft operators, they are major customers of Silent Sentry, who help ensure effective operation. Silent Sentry Airmen are able to communicate with the pilots via an internet relay chat. If the pilot starts to notice problems with video they are receiving or the flight controls, they notify Silent Sentry as they could be getting jammed.

Silent Sentry then inspects the satellite being used to relay the signals to the RPA and to the pilot to see if there are any disturbances in the radio waves being transmitted.

If they detect electromagnetic interference, space control operators can track the EMI and by using different tools, can triangulate the location of the interference.

Silent Sentry completes their mission in coordination with the Combined Air and Space Operations Center, Haller said.

Occasionally, it is possible that an amateur radio enthusiast could have his radio frequencies pointed at the wrong satellite and accidentally interferes with the military communications. However, if the interference is determined to be malicious, the CAOC can decide what methods they want to use to stop the jamming, which includes the possibility of a kinetic attack on the source.

“Our enemies are aware of our massive reliance on our space assets. We can no longer assume we have complete freedom to operate in the space domain as we could 20 years ago,” Haller said. “Silent Sentry is the Air Force acknowledging that the space domain is a contested environment, and that we must now defend it as we would any of the other domains.”