April 8, 2009: China is establishing satellite tracking facilities in Pakistan and Africa. These are used to keep an eye on spy satellites, which often change their orbits to look at new targets on the ground. Each station uses a combination of radar and telescopes to detect and identify spy satellites that pass overhead. With more such tracking stations, China has better knowledge when spy satellites will show up over China. This enables China to better hide things they don't want the satellites to see. This information also aids in efforts to knock down spy satellites.