Aerospace 101 Space Security Counterspace Weapons 101 PublishedOctober 28, 2019 Last UpdatedJune 14, 2022 Caroline Amenabar / CSIS Counterspace weapons vary significantly in the types of effects they create, the level of technological sophistication required, and the level of resources needed to develop and deploy them. These diverse capabilities also differ in how they are employed and how easy they are to detect and attribute and the permanence of the effects they have on their target. There are four distinct categories of counterspace weapons: kinetic physical, non-kinetic physical, electronic, and cyber. Many different counterspace systems are either in development or are operational today. Depending on the technological capacity of a specific actor, one method may be preferred over another. Any of these types of weapons could be used against a satellite or the ground stations that support it, making it an anti-satellite (ASAT) weapon. Kinetic Physical Kinetic physical attacks attempt to damage or destroy space- or land-based space assets. They typically are organized into three categories: direct-ascent, co-orbital, and ground station attacks. The nature of these attacks makes them easier to attribute and allow for better confirmation of success on the part of the attacker. Direct-Ascent ASAT A direct-ascent ASAT is often the most commonly thought of threat to space assets. It typically involves a medium- or long-range missile launching from the Earth to damage or destroy a satellite in orbit. This form of attack is often easily attributed due to the missile launch which can be easily detected. Due to the physical nature of the attacks, they are irreversible and provide the attacker with near real-time confirmation of success. Direct-ascent ASATs create orbital debris which can be harmful to other objects in orbit. Lower altitudes allow for more debris to burn up in the atmosphere, while attacks at higher altitudes result in more debris remaining in orbit, potentially damaging other spacecraft in orbit. Examples: In January of 2007, China had its first successful test of a direct-ascent ASAT, destroying its own aging meteorological satellite. This event created 3,000 trackable pieces of debris, in addition to thousands of smaller pieces that are not currently trackable. This debris continues to threaten the safe operation of other satellites in low Earth orbit (LEO) to this day.1 China has continued non-debris-creating tests in the years since. The Department of State attributes the lack of debris-creating tests to the international outcry over the 2007 test.2 In 2008, President Bush ordered the destruction of an intelligence satellite that was in the process of deorbiting. The official purpose of this satellite destruction was damage mitigation, citing dangerous fuel contents that could have survived re-entry and posed a threat to people on the ground. However, some observers expressed skepticism that the risk was the entire motivation for the exercise.3 Through this test, the United States demonstrated its direct-ascent ASAT capability on cruisers and destroyers equipped with the Aegis missile defense system.4 To avoid an outcry similar to that against China in 2007, the United States conducted this mission at a much lower altitude, meaning most of the debris created was out of orbit within a week.5 Co-Orbital ASAT Satellites are also vulnerable to co-orbital ASAT attacks in which another satellite in orbit is used to attack. The attacking satellite is first placed into orbit, then later maneuvered into an intercepting orbit. This form of attack requires a sophisticated on-board guidance system to successfully steer into the path of another satellite. A co-orbital attack can be a simple space mine with a small explosive that follows the orbital path of the targeted satellite and detonates when within range. Another co-orbital attack strategy is using a robotic arm to grab another satellite for the purpose of moving or de-orbiting it. Co-orbital attacks can be attributable by tracking previously known orbital parameters to determine which satellite carried out the attack. These types of attacks can be either reversible or irreversible depending on the capabilities of the attacker and the type of attack used. Example: From the 1960s through the 1980s, the Soviet Union utilized a system of co-orbital ASAT weapons that would track a target and through a series of maneuvers, could relatively quickly be within tens of meters of the target. The attacking satellite would then detonate an explosive that propelled shrapnel into the target satellite. After about a decade of testing, this system was declared operational in 1973.6 Ground Station Attack Due to their location on Earth and often outside the United States, ground stations can be vulnerable to physical attacks by a variety of conventional military weapons, including guided missiles and rockets for long-range strikes or rocket-propelled grenades and small arms fire at a closer range. Ground stations can also be disrupted by attacking the electrical power grid, water lines, and the high-capacity communications lines that support them. Ground station attacks have variable attribution depending on the mode of attack and they are irreversible, but not always permanent, as ground stations can be repaired and rebuilt. Depending on the ground station, there may be a loss of control of multiple satellites and there is always the potential for loss of life at the ground station during an attack. Non-Kinetic Physical A non-kinetic physical attack is when a satellite is physically damaged without any direct contact. Non-kinetic physical attacks can be characterized into a few types: electromagnetic pulses, high-powered lasers, and high-powered microwaves. These attacks have medium possible attribution levels and often provide little evidence of success to the attacker. Electromagnetic Pulse Attack A high-altitude nuclear detonation is an indiscriminate form of attack in space. For example, a nuclear detonation in space releases an electromagnetic pulse (EMP) that would have near immediate consequences for the satellites within range. The detonation also creates a high radiation environment that accelerates the degradation of satellite components in the affected orbits. The detonation of nuclear weapons, including in space, is banned under the Partial Test Ban Treaty of 1963. While more than 100 countries have ratified this treaty, China and North Korea have not.7 Example: The 1962 Starfish Prime Test was designed to experiment with how the radiation belts in the Earth’s magnetosphere, known as the Van Allen belts, would react to a nuclear detonation. The nuclear explosion, taking place 400 km above the Johnston Atoll in the Northern Pacific, added to the radioactive intensity and altered the shape of the Van Allen belts. Additionally, the power of EMPs was revealed through this test, reportedly sending a power surge through military and civilian electrical devices 1,300 km away on the Hawaiian island of Oahu.8 High-Powered Laser A high-powered laser can be used to permanently or temporarily damage critical satellite components (i.e. solar arrays or optical centers). If directed toward a satellite’s optical center, the attack is known as blinding or dazzling. Blinding, as the name suggests, causes permanent damage to the optics of a satellite. Dazzling causes temporary loss of sight for the satellite. While there is clear attribution of the location of the laser at the time of the attack, the lasers used in these attacks may be mobile, which can make attribution to a specific actor more difficult because the attacker does not have to be in their own nation, or even continent, to conduct such an attack. Only the satellite operator will know if the attack is successful, meaning the attacker has limited confirmation of success, as an attacked nation may not choose to announce that their satellite has been attacked or left vulnerable for strategic reasons. A high-powered laser attack can also leave the targeted satellite disabled and uncontrollable, which could lead to collateral damage if the satellite begins to drift. A higher-powered laser may permanently damage a satellite by overheating its parts. The parts most susceptible to this are satellite structures, thermal control panels, and solar panels.9 Examples: In 2005, China claimed to have blinded a satellite successfully using a mounted laser gun in Xinjiang province.10 This claim, however, has not been confirmed through publicly accessible data. In 2006, reports surfaced of American satellites being dazzled when they passed over China.11 The attack itself did not affect the satellite’s ability to collect data, however, this demonstrated that China not only has the ability to dazzle satellites but has exercised its ability.12 China has no real barriers to achieving a highly operational capability to blind satellites, though it will take a considerable amount of effort to perfect the technology.13 High-Powered Microwave High-powered microwave (HPM) weapons can be used to disrupt or destroy a satellite’s electronics. A “front-door” HPM attack uses a satellite’s own antennas as an entry path, while a “back-door” attack attempts to enter through small seams or gaps around electrical connections and shielding. A front-door attack is more straightforward to carry out, provided the HPM is positioned within the field of view of the antenna that it is using as a pathway, but it can be thwarted if the satellite uses circuits designed to detect and block surges of energy entering through the antenna. In contrast, a back-door attack is more challenging, because it must exploit design or manufacturing flaws, but it can be conducted from many angles relative to the satellite. Both types of attacks can be either reversible or irreversible; however, the attacker may not be able to control the severity of the damage from the attack. Both front-door and back-door HPM attacks can be difficult to attribute to an attacker, and like a laser weapon, the attacker may not know if the attack has been successful.14 A HPM attack may leave the target satellite disabled and uncontrollable which can cause it to drift into other satellites, creating further collateral damage. Electronic Rather than attempting to damage the physical components of space systems, electronic attacks target the means by which space systems transmit and receive data. Both jamming and spoofing are forms of electronic attack that can be difficult to attribute and only have temporary effects. Jamming Jamming is an electronic attack that uses radio frequency signals to interfere with communications. A jammer must operate in the same frequency band and within the field of view of the antenna it is targeting. Unlike physical attacks, jamming is completely reversible—once the jammer is disengaged, communications can be restored. Attribution of jamming can be tough because the source can be small and highly mobile, and users operating on the wrong frequency or pointed at the wrong satellite can jam friendly communications. An uplink jammer is used to interfere with signals going up to a satellite by creating enough noise that the satellite cannot distinguish between the real signal and the noise. Uplink jamming of the control link, for example, can prevent satellite operators from sending commands to a satellite. However, because the uplink jammer must be within the field of view of the antenna on the satellite receiving the command link, the jammer must be physically located within the vicinity of the command station on the ground.15 Downlink jammers target the users of a satellite by creating noise in the same frequency as the downlink signal from the satellite. A downlink jammer only needs to be as powerful as the signal being received on the ground and must be within the field of view of the receiving terminal’s antenna. This limits the number of users that can be affected by a single jammer. Since many ground terminals use directional antennas pointed at the sky, a downlink jammer typically needs to be located above the terminal it is attempting to jam. This limitation can be overcome by employing a downlink jammer on an air or space-based platform, which positions the jammer between the terminal and the satellite. This also allows the jammer to cover a wider area and potentially affect more users.16 Ground terminals with omnidirectional antennas, such as many GPS receivers, have a wider field of view and thus are more susceptible to downlink jamming from different angles on the ground. Examples: U.S. forces experienced jamming in Iraq well after the fall of the Iraqi government, with at least five instances of hostile jamming of commercial SATCOM links documented.17 In recent years, Iran has been jamming satellite signal from Persian language satellite TV broadcasters from outside Iran. Iran jammed nearly 120 Persian language satellite TV channels going into Iran. These channels originate from both inside and outside of Iran. The incidents of jamming affected, most notably, the Voice of America and the BBC. The Iranian government has not officially accepted responsibility for the jamming of the satellites.18 Spoofing Spoofing is a form of electronic attack in which the attacker mimics a legitimate radio frequency signal to trick the target into locking onto the fake signal. An attacker can “spoof” the downlink from a satellite, causing users to lock onto a bogus signal and then use that signal to inject false data. An attacker can also spoof the command and control uplink signal to a satellite and take control of the satellite for nefarious purposes. Spoofing is generally reversible, but the effects may not be. If an attacker is able to take control of a satellite, and the satellite is then destroyed or otherwise damaged, then the attack is not reversible. The best protection against command and control uplink spoofing is the encryption of the signal, because an attacker will need to crack the encryption to produce a signal that appears to be legitimate. Like with jamming, omnidirectional antennas are more susceptible to these forms of attack due to their wider field of view. The use of highly directional antennas that block out signals from other directions can help prevent a satellite falling victim to a spoofing attempt. Spoofing has modest attribution, depending on the mode of attack. Unlike jamming, spoofing can subvert the loss-of-signal alarm system by fooling the system into believing that the fake signal is in fact real. Example: In the summer of 2013, a group of student researchers out of the University of Texas Austin successfully spoofed a private yacht causing it to veer off its course by hundreds of meters. They did this by using a small brief-case-sized spoofing device that emitted a fake GPS signal toward the yacht.19 Cyber Cyber attacks can be used to intercept data, corrupt data, or seize control of systems for malicious purposes. Unlike electronic attacks, which interfere with the transmission of data via radio frequency signals, cyber attacks target the data itself and the systems that use this data. Any data interface in the system is a potential intrusion point, including the antennas on both the satellites and ground stations, as well as the landlines connecting ground stations to terrestrial networks. The effects of a cyber attack on space systems can range from loss of data to widespread disruptions and can potentially lead to the permanent loss of a satellite. Data Intercept/Monitoring Data interception is a cyber attack which attempts to collect data as it is transmitted through a satellite system or monitor the flow of data to identify patterns of activity. Such an attack is difficult to attribute, as hackers can successfully hide their identities using proxy servers and other means. A satellite operator may not be aware of the attack when it occurs, or even afterwards, but the attacker will have near real-time confirmation of its success. Example: In 2009, it was revealed that insurgents in Iraq were using commercially available software to intercept and decode video over satellite communication links from U.S. surveillance aircraft. This was possible because some U.S. aircraft did not have the equipment needed to encrypt video feeds, and it enabled the insurgents to see what the U.S. military was seeing in near real-time.20 Data Corruption Data corruption can occur when an attacker infiltrates a system and alters the data to show false information. Such an attack is difficult to attribute, as hackers can successfully hide their identities, and can be fully reversible. Again, the satellite operator may not be aware of the attack when it occurs. Seizure of Control Cyber attacks can also be used to seize control of a satellite and execute commands on the satellite. This type of cyber attack is also hard to attribute and can be irreversible if the attacker gains complete control of the satellite and executes commands that are unrecoverable. The satellite operator will likely be aware of the attack but may not be able to stop it until it is too late. This attack can cause collateral damage if the target satellite is disabled and left to drift uncontrollably in orbit. Example: The U.S.-China Economic and Security Review Commission has cited examples in the past in which cyber attacks were used against the command and control systems of U.S. government satellites. According to the Commission’s 2011 report, one of the more successful attacks targeted NASA’s Terra EOS satellite in 2008.21 On two instances in June and October of that year, hackers reportedly gained control of the satellite for 2 minutes and 9 minutes, respectively, although they did not execute any commands.22 Return to the Aerospace 101 Archive
