The recent Pentagon document leak included the suggestion that China was developing sophisticated cyberattacks for the purpose of disrupting military communications satellites. While this is unconfirmed, it is certainly possible, as many sovereign nations and private companies have considered how to protect themselves from signal interference.
Almost every aspect of our lives is enabled by satellite communication, from financial transactions, navigation, weather forecasting and internet services to more remote places. However, given the number of satellites in orbit, while the effect might be felt on a portion of the population, if one or two satellites were lost there would be no major problem.
But when we consider the military advantages of satellites, immediate communication is vital for early warning and tracking systems. How easy would it be to shut down these services?
China’s space program is advancing at a faster pace than that of any other country. China’s first successful launch was in 1970, but in 1999 its space program leapt forward with the launch of Shenzhou-1, the first in a series of increasingly sophisticated uncrewed, then crewed, space missions.
China conducted just over 200 rocket launches between 2010 and 2019. In 2022, it set a record with 53 rocket launches in one year, with a staggering 100 percent success rate.
As such, the National Space Administration of China (CNSA) has become a major player in global space activity and has a lot of experience with satellite communications. The leaked document suggests that the Chinese are seeking the ability to “take control of a satellite, rendering it ineffective for supporting communications, weapons or intelligence, surveillance and reconnaissance systems.”
It’s also entirely possible that the United States and other nations are also developing such capabilities.
Satellites orbit our planet at different altitudes. The lowest stable orbits are at about 300 km, the International Space Station and the Hubble Space Telescope are at an altitude of 500 km, and geostationary satellites are at about 36,000 km (about six times the radius of the Earth).
The idea of physically capturing or detecting a satellite has been considered a largely impossible task, although it has famously appeared in films such as “You Only Live Twice,” in which a large orbiting cylinder engulfs a manned spacecraft.
In recent years, smaller craft designed to clear space debris from orbit have been launched. But the practical challenges of capturing a fully functional and operational satellite are far greater (particularly due to the recoil of the firing harpoons).
However, are there any methods to disrupt and even take over satellite communication?
Three ways to disrupt satellite communications
This is the simplest method. Satellites communicate by transmitting on a specific set of radio or microwave frequencies. Bombarding the receiving station or the satellite itself can effectively drown out the signal. It is especially effective with location information.
This is a method of diverting the communication signal from reaching the satellite or ground control station. This requires high power signals to fool one or the other that the jamming signal is the primary transmitting station as a communication will stall on the strongest source.
This method of interference works best when the disturbing signal contains no information, so the receiver assumes there is no data transmission (a human would hear silence or just a tone).
3. Send command
This is an infinitely more complicated procedure. The original signal must be silenced or overwhelmed, 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 type of information cannot be easily guessed, which means knowledge of launch systems and companies is required.
To make these three techniques easier to understand, imagine you’re in a restaurant and your partner is sitting across from you. You’re talking to them normally and then the background music kicks up really loud. You may be able to distinguish some words but not all – this would be saturation.
Now the waiter comes by and starts talking to you loudly diverting your attention – this would be a jam.
Now your partner goes to the bathroom and you get a call that appears to be from them but is actually from someone who has taken their phone and is impersonating them – this would be sending a command.
This last example is infinitely more difficult to make but has the most disruptive potential. If you can trick a satellite into thinking it is the real command source, then not only are communications jammed, but false information and images can be sent to ground stations.
When a satellite goes out of communication, we call it a zombie satellite. It essentially cannot perform any of its intended tasks and orbits with only 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 spikes. In some cases this results in unreliable data, but it can also cause loss of communication.
The most famous of these cases was the Galaxy 15 communications satellite, which lost communication with the ground station in 2010 but continued to transmit communications to customers.
While the military can’t replicate coronal mass ejections, signal hijacking is possible. The leaked document provides no evidence of China’s capabilities, or even the current US progress in this area.
All we can say is that our understanding of atmospheric physics and of wave propagation in the upper atmosphere is likely to increase rapidly as this becomes increasingly important.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
Ian Whittaker does not work for, consult with, own shares in, or receive funding from any company or organization that would benefit from this article and has disclosed no relevant affiliations beyond their academic appointment.