US Air Force Building ‘Space Fence’ To Keep American Satellites Safe

The US Air Force is developing a space fence to protect spacecraft from orbiting debris. The system will actually be a radar that will send signal into space to track tennis ball sized objects. A similar system was shut down in 2013.

The radar system is reportedly scheduled to become operational in 2018 from Marshall Island's Kwajalein Atoll. Compared to its predecessor, the new space fence will have a 1,000 times higher frequency that will make it more effective in tracking small objects. The radar will be to detect orbiting junk which is as small as four inches in diameter, in comparison to the 30 inch limit of the previous system. The space fence will provide the Air Force with measurement, tracking and unprompted detection of, primarily low-earth orbit, space objects using ground based radars. According to current estimations, there are more than 20,000 items of space debris that is currently trapped in the orbit of our planet, which includes non functional satellites, old engine parts and other debris created from collisions in space or space missions.

"The new space fence will have much greater sensitivity, allowing it to detect and track and measure an object the size of a softball, orbiting more than 1,200 miles in space,' said Captain Nicholas Mercurio, from Vandenberg Air Force Base in California. 'So one of the big reasons why the military is investing in the new space fence is to track those objects."

The radar system will be built with a 'S-band phased-array radar' that will have thousands of transmitters and receivers. An alert will be triggered by a radar beam when an object flies through it. Following which, the object's characteristics and trajectory will be estimated by a computer, and subsequently it will update records if the junk is already cataloged, however new objects will be tracked until the confirmation of its orbit.

Apart from tracking space junk, the radar system will also be used to keep US assets in safe space by deterring enemy attacks, especially in the wake of shoe sized cube satellites that could launch attacks on larger satellites.  Currently, a scaled down version of the system, known as the Integration Test Bed (ITB) is being tested and trained in New Jersey.