by Megan Ray Nichols
Imagine a fence surrounding your house. The purpose of a fence is to protect what’s rightfully yours and is contained inside your property. It shields you from potentially unwanted guests and gives you greater privacy.
The U.S. Air Force is taking that idea and launching into space — literally!
A lot of hard work and engineering goes into building and launching a satellite. Since satellites are built to withstand the elements in space and block out radio frequency (RF) and Electromagnetic Interference (EMI) in order to conduct experiments, it’s important that they remain safe. However, any space craft, could be lost in a second if a wayward piece of space junk is headed towards it.
Designed to track space junk as small as softballs, this “space fence” will protect American satellites from the debris that encircles the earth. It will also provide a first line of defense against adversaries that want to attack the satellites.
How It Works
Just to clear things up, the “space fence” isn’t an actual gigantic fence that stretches around the world. It’s called the “S-band phased-array radar,” and it’s an extremely thin beam with countless transmitters which are triggered when an object passes through it.
Details about the object, such as its size and trajectory, are provided by a computer. This computer has a back catalog of all known space junk — but it can create new files and update old ones to ensure that satellites are safe.
Out With the Old, In With the New
This isn’t the first time the United States has implemented a space fence. In fact, this new fence is designed to replace a system that had been in place since 1961 and went offline in 2013.
The band of frequencies at which the new fence operates is 1,000 times higher than the old fence. This means the new fence operates at shorter wavelengths and is therefore more accurate at detecting objects. It can track objects as small as four inches in diameter, a sharp improvement over the old fence’s 30-inch limit. The tracked objects are as far as 1,200 miles out in space. The new fence’s computer will also have a larger catalog of space junk: 200,000 known objects will be tracked, increased from the old fence’s 23,000 objects.
Keeping Out the Neighbors
The new fence will serve another purpose other than tracking space junk. It will preserve our national security in a place where war could someday break out.
The United States is a global superpower, with military units stationed on practically every continent. Where we have the least protection, however, is the great beyond, where our orbiting satellites are essentially exposed.
If fast-traveling space junk doesn’t hit them, the weapons of potential enemies could disrupt them or even destroy them. That’s why the space fence will be equipped with a classified asset called the Self-Awareness Space Situational Awareness system. It’s reported to be able to hunt down the location of a laser that is fired at a satellite.
Another potential threat to American satellites are “CubeSats,”or small satellites that pose a threat to large satellites. These tiny satellites weigh only 1 kg and measure 10.10 cm. While they are a great tool for organizations and schools to experience the firsthand launch of a satellite, the also pose a threat as many countries can use these smaller technological options to enter space and perform surveillance or hostile operations.
There are also hundreds of them currently in space. Almost 360,000 near-collisions have happened with orbiting objects. CubeSats cannot steer themselves to avoid collisions. The space fence will be able to track small, fast-moving objects like these that would normally be undetectable.
The system is expected to be up and running by early 2019. It will be completed in Kwajalein Atoll, an island southwest of Hawaii. From there, it will serve as the first of three stages in a route to send data to the Joint Space Operations Center at Vandenburg Air Force Base.
The other two stages include the surveillance satellite that collects data about the space junk and a space surveillance telescope in Australia, which is designed to locate objects 22,000 miles high in space.
Together, these systems make up the space fence — an idea that may seem truly out of this world, but one that will protect our satellites from unintentional collisions and the enemy.
About The Author
Megan Ray Nichols enjoys writing about astronomy and other scientific fields on her blog, Schooled By Science.
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