DOD turns to more flexible ground terminals to combat anti-satellite threats
- By Katherine Owens
- Apr 11, 2017
As DOD moves to a more commercial satellite acquisition program managed by the Defense Information Systems Agency (DISA), measures are being taken to counter threats from emerging anti-satellite (ASAT) technology.
According to an industry representative, the satellite communications shift toward commercial acquisition and support has meant continued reliance on Low Earth Orbit (LEO) satellites, as those are currently more prevalent in the commercial industry.
LEO satellites orbit at 100 to 200 miles above the earth’s surface, and one full orbit takes 90 minutes, according to NASA reports. The proximity of LEO satellites means that they are the easiest to insert and remove from orbit, and to repair once in space.
However, LEO satellites have proved more vulnerable to ASAT technology.
Pentagon officials cited China’s ASAT program as a particular threat after they shot down a LEO satellite.
“As long ago as 2007, they launched an ASAT test of a low-altitude interceptor. They struck and destroyed a defunct Chinese weather satellite and created tens of thousands of pieces of debris. Much of that debris is still in orbit,” Winston Beauchamp, the former Deputy Undersecretary of the Air Force for Space, told Defense Systems last year.
The solution to the emerging ASAT threat to the commercially-oriented satellite communications initiative is flexibility, according to Dr. Brian S. Teeple, a Principal Director to DOD’s Deputy Chief Information Officer.
This flexibility is manifested in two ways. The first is ground terminal flexibility, meaning that the ground control systems will have the ability to switch their trackers and data transmission receivers from one satellite to another, in the event that the satellite they are following is compromised.
“Something that we are building into the overall DOD plan is to have more flexible ground terminals that can take advantage of many satellites, so relying less on having a satellite that can avoid everything and protect itself, but instead being able to change to different satellites on demand,” explained Teeple.
An ability to change satellites is key to satellite defenses as it is part of the Air Force redundancy strategy, an approach which seeks to operate multiple satellites as a way to preserve functionality in the event that a satellite is shot down.
Behind this capability is the Controlled-reception Pattern Antenna or smart antenna technology, which allows the antenna to be electronically steered and focused directly on specific satellites.
Technology is also being developed to create more versatile gateway ground terminals,
which directly receive and transmit data to and from the satellite in orbit.
The second component of flexibility is the ability to vary the frequency at which the satellite communication technology operates.
Flexible broadband technology and inertial measurement units can be activated to provide passive backup tracking coverage that is immune to jamming, according to developers at Spectracom.
“We have some multi-pin terminals and we are pushing out more that will allow us…to use different frequencies to get around either physical attacks or jamming,” said Teeple. “We need to make sure...that we have the right cyber protections in place. Once again we are adjusting; we are taking advantage of the new information that’s out there.”
According to the Pentagon, DISA is now responsible for about 95 percent of satellite acquisition through the new commercial-based program