Good fences make good neighbors, which is why the United States is building a space fence.

But the first thing to understand about the space fence is that it’s not actually a fence — it’s radar. And when it’s operational, pulsing up from an atoll in the Pacific, it will be able to track objects in space that are softball-sized, the Air Force says.

The purpose? To keep track of space debris, but also for deterrence, in order to keep U.S. assets in space safe from other powers that might want to attack them.

‘Bubble of Uncertainty’