China, Russia and the United States are all revisiting space-based missile defense and anti-satellite weaponry concepts to counter rapidly developing and proliferating hypersonic missiles, a great power contest that promises to accelerate the militarization of outer space.
Space-based missile defenses add another layer to existing anti-missile defenses and would most likely focus on intercepting missiles during the early stages of their powered boost flight phase. This increases the chance of successful intercepts compared to mid-course and terminal intercepts where missiles could perform evasive maneuvers at hypersonic speeds.
Space-based defenses could target satellites that are critical links in hypersonic weapons’ so-called kill chain, which are all the necessary things, people and processes involved in launching missiles and guiding them to their targets.
Armed satellites can also attack enemy satellites in several ways, including through physical attacks, directed energy or conventional weapons, electronic warfare, chemical sprays or even direct collision.
This month, China’s Shijian-21 satellite used a robotic arm to pull a dead Beidou satellite out of its normal geosynchronous orbit and into a distant graveyard orbit designated for satellites nearing the end of their operational lives.
In addition to Shijian-21, China’s Tiangong Space Station, Beijing’s answer to the International Space Station, features a robotic arm that has similar capabilities. As such, satellites equipped with robotic arms could also be designed to grab military satellites out of orbit, or even physically destroy them.
Military satellites can sport mounted weaponry to engage enemy satellites. The US has plans in 2023 to mount directed-energy weapons such as lasers and neutral particle beams on its military satellites.
While primarily intended for missile defense, these weapons can be used to destroy enemy satellites linked to an adversary’s kill chain.
Military satellites can also be armed with conventional weaponry, with Russia successfully firing an autocannon mounted on its Salyut space station in 1975. Russia also had plans for a follow-on missile-armed Almaz space station but the concept was shelved in 1978.
Satellites themselves can be used as anti-satellite weapons via direct collision. Civilian satellites can be weaponized for this mode of attack, as they can be controlled by their operating country to crash into its adversary’s satellites.
This also has the potential to turn outer space into a grey zone or hybrid warfare domain, wherein the distinction between state, non-state and civilian entities is blurred, alongside the employment of conventional and irregular warfare. It also adds an element of plausible deniability to such operations.
In a possible demonstration of the privatization of grey zone warfare in space, last year the US may have intentionally staged a near-collision between one of its Starlink SpaceX satellites and China’s Tiangong Space Station. While China mounted a formal diplomatic protest, the US did not respond.
Russia made similar maneuvers in 2014 when its Luch satellite came dangerously close to a US Intelsat satellite, which raised suspicions that Russia might be stealing data from the US satellite and rang alarms about collision risks.
Moreover, the development of 6G next-generation technology for military applications and hypersonic weapons has significantly increased the value of military satellites, which in turn makes them even more inviting targets.
In this direction, China has reportedly developed 6G technology that solves the communication blackout problem at hypersonic speeds. Hypersonic weapons face difficulties maintaining communication due to the hot, ionized gas that appears on their surface, which blocks electromagnetic waves during hypersonic flight.
Chinese scientists have reportedly developed a 6G laser device that generates a continuous beam of electromagnetic waves in the terahertz band, a frequency range that is also used for 6G technology. Ground tests have reportedly shown that the device can penetrate the plasma layer surrounding hypersonic weapons.
Such technology could be integrated in military satellites to provide reliable communications and relay targeting data to hypersonic weapons. Last year, China launched the world’s first 6G satellite with terahertz technology, while SpaceX has announced plans to upgrade its Starlink satellites with laser connectivity.
Both concepts may soon be adapted for military applications, especially for hypersonic weapons.