The Russians would have built a blinding laser by satellite | Kiowa County Press

A strong enough laser beam could blind spy satellites. MuthuKutty/Wikimedia, CC BY-SA

Iain Boyd, University of Colorado Boulder

Russia is building a new ground-based laser facility to interfere with satellites orbiting overhead, says a recent report in The Space Review. The basic idea would be to dazzle the optical sensors of other nations’ spy satellites by flooding them with laser light.

Laser technology has evolved to the point where this type of anti-satellite defense is plausible, although there is limited evidence of any country successfully testing such a laser.

If the Russian government is able to build the laser, it would be able to shield much of the country from the sight of satellites with optical sensors. The technology is also setting the stage for the more ominous possibility of laser weapons that can permanently disable satellites.

How lasers work

A laser is a device for creating a narrow beam of directed energy. The first laser was developed in 1960and since then several types have been created that use different physical mechanisms to generate photons or particles of light.

Gas lasers pump large amounts of energy into specific molecules such as carbon dioxide. Chemical lasers are powered by specific chemical reactions that release energy. Semiconductor lasers use custom crystalline materials to convert electrical energy into photons. In all lasers, the photons are then amplified by passing them through a special type of material called the average gain then focused into a coherent beam by a beam director.

The physics of lasers explained.

laser effects

Depending on photon intensity and wavelength, the directed beam of energy formed by a laser can create a range of effects on its target. For example, if the photons are in the visible part of the spectrum, a laser can deliver light to its target.

For a high enough flux of high energy photons, a laser can heat, vaporize, melt and even burn the material of its target. The ability to produce these effects is determined by the power level of the laser, the distance between the laser and its target, and the ability to focus the beam on the target.

Laser applications

The various effects generated by lasers find many applications in daily life, including laser pointers, printers, DVD players, retinal surgery and other medical procedures, and industrial manufacturing processes such as welding and laser cutting. Researchers are developing lasers as an alternative to radio wave technology to improve communications between spacecraft and the ground.

Lasers also find widespread application in military operations. One of the best known is the Airborne Laser (ABL), which the US military intended to use to shoot down ballistic missiles. The ABL involved a very large, high-powered laser mounted on a Boeing 747. The program was ultimately doomed by challenges with thermal management and maintenance of its chemical laser.

A large four-engined jet plane painted light gray and a large iridescent object attached to its nose
The US military has experimented with mounting a powerful laser on a large jet aircraft, with the aim of shooting down incoming ballistic missiles. United States Missile Defense Agency

A more successful military application is the Large Aircraft Infrared Countermeasures (LAIRCM) system, which is used to protect aircraft against heat-seeking anti-aircraft missiles. LAIRCM shines light from a solid-state laser into the missile sensor as the aircraft approaches, causing the weapon to glare and lose its target.

The evolution of semiconductor laser performance has led to a proliferation of new military applications. The US Army installs lasers on army trucks and navy ships to defend against small targets such as drones, mortar shells and other threats. The Air Force is studying the use of lasers on aircraft for defensive and offensive purposes.

The Russian laser

The new famous Russian laser facility is called Kalina. It is intended to dazzle, and therefore temporarily blind, the optical sensors of satellites collecting intelligence above their heads. As with the American LAIRCM, glare consists of saturating the sensors with enough light to prevent them from functioning. Achieving this goal requires accurately delivering a sufficient amount of light into the satellite sensor. This is no small feat given the very large distances involved and the fact that the laser beam must first pass through the Earth’s atmosphere.

Accurately aiming lasers at great distances in space is nothing new. For example, NASA’s Apollo 15 mission in 1971 placed meter-sized reflectors on the Moon which are targeted by lasers on Earth to provide positioning information. Delivering enough photons over large distances depends on the power level of the laser and its optical system.

Kalina would work in pulsed mode in the infrared and would produce about 1,000 joules per square centimeter. In comparison, a pulsed laser used for retinal surgery is only about 1/10,000th as powerful. Kalina delivers much of the photons it generates over the great distances where satellites orbit overhead. It is able to do this because the lasers form highly collimated beams, meaning the photons travel in parallel so the beam doesn’t spread out. Kalina focuses her beam using a telescope several meters in diameter.

Spy satellites using optical sensors tend to operate in low Earth orbit at an altitude of a few hundred kilometers. It usually takes a few minutes for these satellites to pass over a specific point on the Earth’s surface. This requires Kalina to be able to run continuously for that long while maintaining a permanent trace on the optical sensor. These functions are provided by the telescope system.

Based on reported details from the telescope, Kalina would be able to target an airborne satellite hundreds of miles into its path. This would protect a very large area – on the order of 40,000 square miles (about 100,000 square kilometers) – from intelligence gathering by optical sensors on satellites. Forty thousand square miles is about the size of the state of Kentucky.

Russia claims that in 2019 it fielded a less capable truck-mounted laser glare system called Peresvet. However, there is no confirmation that it has been used successfully.

Laser power levels should continue to increase, allowing the temporary glare effect to be exceeded to permanently damage sensor imaging hardware. Although the development of laser technology is moving in this direction, there are important political considerations associated with using lasers in this way. The permanent destruction of a space sensor by a nation could be considered an act of aggression, leading to a rapid escalation of tensions.

laser in space

Of even greater concern is the potential deployment of laser weapons in space. Such systems would be very effective as distances to targets would likely be greatly reduced and there is no atmosphere to weaken the beam. The power levels needed for space lasers to cause significant damage to spacecraft would be significantly reduced compared to ground-based systems.

Additionally, space lasers could be used to target any satellite by aiming lasers at propellant tanks and power systems, which, if damaged, would completely disable the spacecraft.

As technological advancements continue, the use of laser weapons in space becomes more likely. The question then becomes: What are the consequences?

The conversation

Iain Boydprofessor of aerospace engineering science, University of Colorado Boulder

This article is republished from The conversation under Creative Commons license. Read it original article.

About Florence M. Sorensen

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