The title of this work refers to the Space Fence, which might sound like science fiction but is in fact the informal name for an advanced U.S. Air Force radar surveillance system designed to track orbital objects passing over the country. When the original system was built, it was considered the most powerful continuous-wave radar station in the world. Because the microwaves it emitted are invisible to the human eye, Paglen, whose work often deals with surveillance, went to the master transmitter at Lake Kickapoo in Texas and worked with an amateur radio astronomer to shift the transmitter’s frequency into the visible spectrum. In March 2020 a new Space Fence was launched. Whereas the air force claimed the old system could detect objects as small as basketballs, the new one is reportedly sensitive enough to track something the size of a marble.

—Text taken from the Carter Handbook (2023)