The U.S. believes that China again tested its ASAT (anti-satellite) system on March 13th, when a Chinese Dong-Ning 2 rocket was successfully launched for the first time. This was described as a scientific mission, but American analysts studied the March 13 launch carefully and deduced it as actually the third test of the Chinese ASAT system. This test apparently sought to put a KillSat (Killer Satellite) in a high enough (20,000 kilometers) orbit that could threaten the American GPS network.
The first such test was in January 2007, when China successfully tested a satellite destruction system. They used a smaller rocket to put a KillSat in orbit that destroyed an old Chinese weather satellite that was about 850 kilometers up. That's at the upper range of where most reconnaissance satellites hang out. Three years later a second test was conducted but a satellite was not actually destroyed.
Back in 2008, Russia and China urged the UN to outlaw the development or testing of systems that can destroy space satellites. The impetus for this new enthusiasm over satellite destruction was the February 22nd, 2008 destruction of a broken U.S. spy satellite by a U.S. warship firing an anti-aircraft missile modified to intercept ballistic missiles. What upset China and Russia was that this feat put all their satellites in a low earth orbit (160-2,000 kilometers up) at risk. The U.S. cruiser used its Aegis radar to locate the satellite some 220 kilometers above and then fired a single SM-3 missile to destroy the SUV sized satellite.
Throughout the Cold War, Russia and China always worried about new American military technology. A lot of these nasty surprises were not even American (like composite armor, which is a British development). But U.S. surprises like smart bombs, stealth aircraft, and truly bullet proof body armor kept the fear alive. Now, there's this anti-missile system that doubles as a destroyer of low flying satellites. Lots of spy satellites have low orbits.
The Aegis system only operates from warships (cruisers and destroyers that have been equipped with the special software that enables the AEGIS radar system to detect and track incoming ballistic missiles). Since the satellite was destroyed at a low altitude, the fragments will quickly fall into the atmosphere and burn up. A Chinese 2007 anti-satellite test was done 850 kilometers up, and nearly all those fragments are still in orbit.
The U.S. Navy has also been working on launching various types of satellites from its submarines. One variety is the KillSat that can reach birds in higher orbits. While the solid fuel SLBMs (sea launched ballistic missiles) can only put a ton or so (usually less) into orbit, U.S. engineers have long been known for getting a lot of capability into small packages. Smaller satellites can be put in orbit quickly using SLBMs.
While the U.S. Air Force lays claim to all things space, the U.S. Navy is quick to demonstrate that sailors are able to operate up there as well. The implications are that maybe the navy should get more of the billions being spent on space operations. Back in the 1980s, the air force had developed a system (ASM-135) for knocking down low orbit satellites, using a missile launched from a high flying jet fighter. This was done in response to news that Russia was developing a similar system. The Russian system relied on killsats and was never that effective. A successful test of ASM-135 was conducted in 1985, but the program was shut down three years later because the air force preferred to spend the money elsewhere. The navy developed their anti-satellite capability without making a lot of noise, which has caused quite a fuss at air force headquarters.