Space warfare

There’s a hidden side of space exploration that few people speak publicly about: space warfare.

It is an area of military conflict that has not been fully explored, but is becoming increasingly relevant as more countries develop their own space capabilities. The idea of warfare in space is not new, with science fiction works depicting space battles for decades, but the reality of space warfare is likely to be quite different from its fictional counterparts. The four types of engagement covered below are Earth to orbit, orbit to orbit, orbit to Earth and the lunar surface.

One of the advantages claimed for space warfare is surprise. In theory, a weapon already in orbit could strike with less warning than one launched from the ground, leaving an enemy little time to prepare. In practice, launches and objects in orbit are watched closely, so a physical attack would be hard to hide; jamming and cyberattacks are where attribution gets hard. In addition, space-based weapons systems have the ability to attack multiple targets simultaneously, making it difficult for an enemy to defend against them.

However, space warfare also has its drawbacks. One of the biggest of these is the cost of development and maintenance of space-based weapons systems. These systems are incredibly expensive to develop and maintain, and the cost of launching them into orbit is also high. This means that only a few countries would be able to afford to develop and maintain these systems.

Another drawback of space warfare is the fact that it would likely lead to the destruction of many satellites, which would disrupt global communications and navigation. This would be particularly problematic for countries that rely heavily on satellite-based systems for their communication and navigation needs.

Render of a satellite with long solar wings above the Earth, beside an inset of a side section opening to show warheads inside — Concept art of a satellite carrying warheads, by MeckanicalMind (2013).

Render of a long, boxy platform with a single panel array, orbiting high above the Earth — Concept render of a weapon platform in orbit, by FR0S7.

Types of engagement

Earth-to-orbit

Also known as Anti-satellite (ASAT) weapons. The most likely scenario for space warfare would be an engagement between Earth and orbit, with countries using ground-launched weapons to strike at an enemy's satellite systems. This would include the use of anti-satellite weapons, which are capable of destroying or disabling an enemy's satellites. This would greatly affect the ability of countries to communicate and navigate, as well as their ability to launch new satellites. As of writing, this is the most advanced of all the types of engagement, having been tested by countries such as the United States, the Soviet Union, China, India, and Russia.

An F-15 fighter climbing steeply into a blue sky, the missile just released below it — A US Vought ASM-135 ASAT missile launch on 13 September 1985, which destroyed P78-1

A missile rising from a warship on a tall column of orange-brown smoke — The launch of the SM-3 missile used to destroy USA-193

An interceptor with an orange body lifting off from a launcher among trees, smoke spreading on both sides — Launch of India's DRDO's Ballistic Missile Defence interceptor missile for an ASAT test on 27 March 2019

A globe of the Earth wrapped in dense red rings of orbit lines — Known orbit planes of Fengyun-1C debris one month after its disintegration by the Chinese ASAT

A white missile leaving a ship's deck launcher in a burst of yellow flame — A RIM-161 Standard Missile 3 launched from USS Lake Erie, a US Navy Ticonderoga class cruiser, 2005

Blue-toned illustration of a large turret on a building firing a beam into the sky, a radome beside it — Soviet Terra-3 ground-based laser ASAT

Orbit-to-orbit

Orbit-to-orbit engagements would involve the use of weapons systems that are based in orbit and are capable of attacking other satellites or spacecraft. This would include the use of kinetic weapons, such as projectiles, as well as directed energy weapons, such as lasers. These systems would have the advantage of being able to strike at an enemy's satellites without ever having to enter the Earth's atmosphere.

Painting of a cylindrical craft bursting into a spray of fragments above the Earth, a satellite in the upper corner — A 1986 DIA illustration of the IS system attacking a target

Orbit-to-Earth

Orbit-to-Earth engagements would involve the use of space-based weapons systems to strike at targets on the ground, such as an enemy's military bases and industrial complexes. In mid-2021, China tested two weapons that flew long distances in low-Earth orbit before releasing hypersonic gliders into the atmosphere toward targets in Chinese territory. Much is unknown about these tests.

The X-37B, a small white and black spaceplane, parked on a runway — The X-37B space drone, rumored to be able to work as an orbital weapon delivery system

Render of a satellite carrying a ring of long rods, one rod falling away from it — USAF's proposed kinetic bombardment system; unlike orbiting nuclear weapons, kinetic projectiles (as well as space-based lasers) are legal under the 1967 Outer Space Treaty

Illustration of satellites over the Earth, one carrying a bundle of rods, with projectiles streaking down toward the ground — An illustration of Project Thor, a US idea from the 1950s for dropping metal rods from orbit; it was never built.

IISS diagram, “Aerial trajectories of three weapons-delivery systems”, comparing a ballistic missile, a hypersonic glider and an orbital glider-release system around the Earth — The paths of a ballistic missile, a hypersonic glider and an orbital glider-release system from a launch site to a target site.

Planetary surfaces: Moon

Lunar surface skirmishes and warfare is an area of space warfare that has not been explored in reality, but is an active area of research and speculation. Lunar surface warfare would be vastly different from warfare on Earth due to the lack of an atmosphere and the reduced gravity.

In terms of handheld weapons, it's likely that they would have to be modified to function in the harsh lunar environment and account for the reduced gravity. For example, weapons would need to be designed to function in vacuum. Soldiers would need suits that protect them from extreme temperatures, radiation, and micrometeoroids. With a sixth of Earth's gravity, a soldier would also have less grip on the ground to brace against a weapon's recoil.

Another challenge of lunar surface warfare would be mobility, due to the reduced gravity and rugged surface. It would be difficult to traverse the lunar surface quickly or move heavy equipment, and mobility would likely have to be assisted by vehicles or other specialized equipment.

Finally, the lack of an atmosphere on the Moon would change how explosive weapons work. Chemical explosives carry their own oxidizer and detonate in vacuum, but with no air there would be no blast wave; the damage would come from fragments, which nothing slows down. Furthermore, the lack of an atmosphere would also make it difficult to hide from surveillance and target acquisition, thus making it more difficult for surprise attacks.

Two astronauts with gold visors aiming rifles among boulders on the Moon — Scene from Apple TV's For All Mankind season 2, Astronauts on the moon engage in weaponized conflict.

Over a Soviet cosmonaut's shoulder, two astronauts stand among boulders on the Moon — Perspective from Soviet astronaut. Scene from Apple TV's For All Mankind season 2, Astronauts on the moon engage in weaponized conflict.

Two astronauts crouching close together as shots kick up dust beside them — Scene from Ad Astra of a kinetic weapon conflict on the Moon's surface.

Astronauts riding open lunar rovers in a line across grey ground, with a dark vehicle at the far end and a yellow streak at the right — Scene from Ad Astra of a convoy of lunar rovers on the Moon's surface, with a streak of fire at the right edge of the frame.

Types of weapons that might be used in space conflict

Weapon Type	Use-case	Damage Level	Countermeasures
Kinetic Kill Vehicles (KKVs)	Destroying or disabling satellites in orbit or attacking ground-based targets	High	Hardening of satellite components, use of decoys or other defensive systems, missile defense systems
Directed Energy Weapons (DEWs)	Disabling or destroying satellites or other space-based assets or attacking ground-based targets	High	Hardening of satellite components, use of decoys or other defensive systems, passive cooling systems
Electronic Warfare (EW)	Disrupting or jamming communications or other electronic systems on satellites or other space-based assets or ground-based assets	Moderate to High	Use of encryption, use of frequency hopping or other communication hardening techniques, use of anti-jamming systems
Cyberattacks	Disrupting or disabling satellite or ground-based control systems, stealing or destroying data	Moderate to High	Cybersecurity measures such as encryption, firewalls, and intrusion detection systems, developing backups and redundancy plans
Ground-based Anti-satellite (ASAT) missiles	Destroying or disabling satellites in low-Earth orbit	High	Hardening of satellite components, use of decoys or other defensive systems, Surveillance, early warning and tracking systems
LEO-to-Earth Stealth aerial deployment weapons	Attacking ground-based targets from low-Earth orbit. Deploying assets such as drones or other equipment from fast descent capsules anywhere on the planet	High	Missile defense systems, hardening of critical infrastructure and military assets, early warning and tracking systems
Nuclear Weapons	Attacking ground-based targets from low-Earth orbit with concealed nuclear weapons on descent stages.	Extreme	Missile defense systems, civil defense measures, early warning and tracking systems
Asteroid diversion (more far-fetched)	Diverting an asteroid and aiming it to an enemy ground territory.	Extreme	Civil defense measures, early warning and tracking systems

Nuclear weapons in orbit around the Earth are banned by the 1967 Outer Space Treaty.

Impact of ASATs and in-space conflicts

Anti-satellite (ASAT) weapons, when used, can have a destructive impact on satellites. This can lead to the creation of thousands to millions of pieces of debris, known as "space debris," that can orbit the Earth for decades at high speeds.

The Union of Concerned Scientists states that the destruction of a single 10-ton satellite can produce between 8 and 14 million pieces of debris measuring between 1 mm and 1 cm, 250,000 to 750,000 pieces measuring between 1 cm and 10 cm, and 5,000 to 15,000 pieces measuring greater than 10 cm. These pieces add to the existing 8,800 metric tons of space debris that are already present in space. These debris pieces can travel at speeds of up to 29,000 km/h which make them a serious threat to other objects in orbit. The International Space Station has even had to conduct 29 debris avoidance maneuvers since 1999 to avoid collisions with debris.

The Earth inside a dense cloud of dots for tracked debris, thickest close to the planet, with a looser ring farther out — Current projected space debris orbiting the Earth as of 2019, by ESA.

References

"Understanding Space Strategy: The Art of War in Space" by John J. Klein
"Original Sin: Power, Technology and War in Outer Space" by Bleddyn E. Bowen
"Space Warfare in the 21st Century: Arming the Heavens" by Joan Johnson-Freese (Cass Military Studies)
"Accessory to War: The Unspoken Alliance Between Astrophysics and the Military" by Neil deGrasse Tyson and Avis Lang
"Space Security: Emerging Technologies and Trends" by Puneet Bhalla (KW Publishers, 2017)
"The Militarization of Space: U.S. Policy, 1945–1984" by Paul B. Stares
"Anti-Satellite Weapons, Countermeasures, and Arms Control", US Office of Technology Assessment, 1985
"Space Debris from Anti-Satellite Weapons", Union of Concerned Scientists, the source of the debris figures above. ucs.org
"Global Counterspace Capabilities", Secure World Foundation, an annual open-source survey of who can do what to whose satellites. swfound.org
"Handbook for New Actors in Space", Secure World Foundation. swfound.org