Pentagon Leaks Suggest China Developing Ways to Attack Satellites – Here’s How They Might Work

However, there are methods of disrupting and even taking over satellite communication?

Three Ways to Disrupt Satellite Communications
1. Saturation
This is the easiest method. Satellites communicate by broadcasting on a specific set of radio or microwave frequencies. By bombarding the receiving station or the satellite itself you can effectively drown out the signal. It is particularly effective with positioning information.

2. Jamming
This is a method of diverting the communication signal from reaching the satellite or the ground control station. This requires high-power signals to fool one or the other that the jamming signal is the main transmitting station as a communication will lock onto the strongest source.

This method of interference works best when the jamming signal contains no information, so the receiver assumes there is no data transmission (a human would hear silence or just a tone).

3. Command sending
This is an infinitely more tricky procedure. The original signal needs to be silenced or overpowered and the replacement signal must be able to accurately communicate and fool a satellite.

This usually requires knowing an encryption key that would be used as well as the correct commands and syntax. This sort of information cannot be easily guessed, meaning knowledge of the launch systems and companies is required.

To make these three techniques easier to understand, imagine you are at a restaurant and your partner is sitting opposite you. You are talking to them normally and then the background music gets turned up really loud. You may be able to make out some words but not everything – this would be saturation.

Now the waiter comes past and starts talking loudly at you taking your attention away – this would be jamming.

Now your partner goes to the toilet and you receive a call that appears to be from them but is actually from somebody who has taken their phone and is impersonating them – this would be command sending.

This final example is infinitely more difficult to achieve but has the most potential for disruption. If you can trick a satellite into thinking you are the true command source, then not only are communications blocked but false information and images can be sent to the ground stations.

Zombie Satellites
When a satellite does go out of communication, we refer to it as a zombie satellite. Essentially it cannot do any of its intended tasks and just orbits with little chance of recovery.

This can happen naturally during coronal mass ejections, when the Sun releases large amounts of energetic charged particles that can interact with satellites causing electrical surges. In some cases this results in untrustworthy data, but can also result in communication loss.

The most famous of these cases was the Galaxy 15 telecommunications satellite, which lost ground station communication in 2010 but continued to broadcast communications to customers.

While the military cannot replicate coronal mass ejections, the hijacking of signals is possible. The leaked document does not provide any proof of China’s capabilities, or indeed the United States’ current advancement in this field.

All we can say is that our understanding of atmospheric physics and wave propagation in the upper atmosphere is likely to increase rapidly as this becomes more and more important.

Ian Whittaker is Senior Lecturer in Physics, Nottingham Trent University. This article is published courtesy of The Conversation