by Tech. Sgt. Mike Andriacco
U.S. Air Forces Central Command Public Affairs
3/7/2013 - SOUTHWEST ASIA (AFNS) -- More
than 22,000 miles away, spinning silently through the vacuum of space,
is one of the most critical components to air, space and cyberspace
superiority today; a satellite.
The mission to defend and protect the operability of that satellite
rests a little closer to home, at the U.S. Air Forces Central Command
Combined Air and Space Operations Center within the Combat Operations
Division's Space Cell.
"We have five priority missions we support," said Capt. Brandon
Davenport, the Space Cell chief. "Theater missile warning, personnel
recovery support, satellite communications, GPS constellation health and
modeling as well as battle space characterization."
One of the biggest threats to satellite communications and GPS missions
is its vulnerability to electromagnetic interference, or EMI, which
causes the signal to be "jammed."
Jamming, at its most basic level, is denying a satellite the ability to
communicate by overwhelming it with energy where it would expect to see
the friendly signal. This is basically like someone using a bullhorn to
drown out someone else's conversation. This type of occurrence can be
intentional, in which case it is considered hostile, or accidental. The
most common causes of accidental EMI are easily found and remedied.
Hostile jamming, however, can require a more creative solution.
"To assure minimal operational impact, our communicators systematically
work through actions to quickly restore the services affected," said Lt.
Col. Jason Knight, the director of Space Force's assigned space weapons
officer. "If the EMI is determined to be intentional, we engage up the
chain and through other governmental agencies to apply non-lethal or
lethal national instruments of power in order to quickly restore
services and resolve the problem."
EMI resolution would not be possible without cross-combatant command and
cross-agency collaboration between space and cyber professionals, or
one of the most technical aspects of the space cell's mission,
geolocation of a hostile jamming signal.
"Our focus is to track down a jamming signal with high-confidence and
say 'it's this guy,'" Knight said. "By combining our cyber and space
expertise at the operational and tactical levels we are better able to
attribute and identify sources of interference, and eliminate
intentional denial of SATCOM by our adversaries."
Because the satellite transmission spreads out as it travels toward
Earth at the speed of light, each satellite covers an area approximately
one-third of the planet's surface from its perch far into outer space.
This allows for overlap between several satellites and grants U.S.
forces the flexibility to shift to another satellite if necessary to
complete the mission.
The linchpin in this whole process is Operation Silent Sentry, run by
members of the 379th Expeditionary Operations Squadron. The Silent
Sentry team's mission is to monitor hundreds of satellite transmissions
every week using the Rapid Attack Identification Detection Reporting
System and help detect and locate signals that do not belong on U.S.
satellites, such as a jammer.
"The Silent Sentry antennas and our satellites represent two known
locations and the jammer a third, unknown location," Davenport said.
"Because we start knowing two out of three points, and have both
frequency and time values available to us, we can use algebra to figure
out a line running north south as well as a line running east and west
of possible locations. Where those lines cross, we'll find the offending
Though the technology does not yet exist to prevent jamming, the
available actions that the U.S. military and its allies may take can be
swift and decisive.
"Most emitters that put our systems at risk can be identified by our
teams," Davenport said. "During combat, an adversary could technically
jam our satellite signals, but we can recover fairly quickly, attribute
the source of interference and respond accordingly."