China now has the capability to jam the Global Positioning System, widely used by both the military to, say, guide precision weapons and by civilians to, for example, provide timing for telecom networks, according to the annual Defense Department report on "Military Power of the People's Republic of China".
Richard Garwin suggests a compromise space weapons treaty that would prohibit new anti-satellite weapon tests, but still allow for temporary and reversible attacks (ex. jamming, concealment, interference with the line of sight, etc) on non-strategic space assets.
The U.S. already has a counter-space strategy that is different from the kinetic method employed recently by the Chinese, according to knowledgeable space experts and former intelligence officials. They say the United States has adopted a method that relies on spy satellites' most vulnerable aspect: the need for constant housekeeping from the ground.
Commercial satellite operators say they're willing to pay for anti-jamming and other protective systems on their spacecraft to assuage the security concerns of government users, but only if the government will restructure its procurements to encourage such investments.
Boeing has said that it will attach sophisticated antennas to its new satellites as part of a broader push - supported by the Pentagon - to counteract concerns that these space assets may be disrupted by terrorists and hostile governments.
Paris-based satellite company Eutelsat is investigating "unidentified interference" with its satellite broadcast services that temporarily knocked out several television and radio stations. The company declined to say whether it thought the interference was accidental or deliberate.
The Israeli government is openly considering jamming Hezbollah's Al-Manar TV broadcasts -- which stayed on the air, despite repeated aerial and electronic attacks -- despite the fact that these transmissions are carried by commercial satellites.
Britain and the United States have complained to Libya after two international satellites were illegally jammed, knocking off air TV, radio and other communication channels.
The U.S. military is bracing for future attacks in space, and the Air Force has deployed an electronic-warfare unit capable of jamming enemy satellites, the general in charge of space defenses says.
In advance of the presidential elections, Iran appears to be actively jamming satellite television signals. Experts are concerned that the jamming could threaten not only the possibility of democracy but also the health of Iranian citizens.