Space: China Builds A Backup GPS System for Wartime


p> March 23, 2007: China is building a satellite positioning system that they may reserve solely for military use, and only in wartime at that. This would enable China to jam GPS, or destroy GPS satellites, while using their more distant (and thus more difficult to destroy) satellite positioning system. All this came out of what was shaping up to be a technological disaster.


Chinas foray into military space satellites has produced a lot of failed experiments, as have their other efforts to develop high tech. For example, back in 2003, China completed a satellite navigation system called BeiDou. Think of it as GPS light, and different, and potentially not very useful. BeiDou only covers East Asia, but not all of China. But it covers the areas along the coast, and Taiwan. The BeiDou system is less accurate than GPS, slower, but it does allow two way traffic. This is useful for sending short messages (up to 120 Chinese characters so, about a hundred words). Sort of IM (Instant Messaging) class stuff. The system can only handle a few hundred thousand users, but that would be sufficient for the number of Chinese troops involved in any major operation. BeiDou also suffers some reliability problems, and is apparently very vulnerable to jamming and spoofing. Because of all that, it is believed that BeiDou is just a first generation system. A training system, one where China learns the ins and outs of building satellite navigation systems.


China realized that the only way to make BeiDou into something useful was to keep the system secret. Or at least off line most of the time. Normally, China uses GPS, and soon the Russian GLONASS and eventually the European Galileo satellite positioning system. But having a backup system, in BeiDou, could be a decisive military asset. The BeiDou satellites are geostationary, and thus farther away from earth (and harder for killer satellites to get to.) Not invulnerable, just more of a hassle to deal with. In wartime, even hassles can be useful.