According to a recent report in The Space Review, Russia is building a new ground-based laser facility to interfere with satellites orbiting overhead. The basic idea is to flood the optical sensors of other nations’ spy satellites with laser light to dazzle them.
Laser technology has evolved to the point where this kind of anti-satellite defense is plausible, but there is limited evidence to show any country that has successfully tested such lasers.
If the Russian government can build a laser, it could shield most of the country from the sight of satellites with optical sensors. The technology also sets the stage for the ominous potential of laser weapons that can permanently disable satellites.
How a laser works
A laser is a device for producing a narrow beam of directed energy. The first laser was developed in his 1960s, and since then several types have been created that use different physical mechanisms to produce photons or particles of light.
Gas lasers deliver large amounts of energy into certain molecules such as carbon dioxide. Chemical lasers are driven by specific chemical reactions that release energy. Solid-state lasers use customized crystalline materials to convert electrical energy into photons. In all lasers, photons are then amplified by passing through a special type of material called a gain medium and focused into a coherent beam by a beam director.
laser effect
Depending on the photon intensity and wavelength, a directed beam of energy formed by a laser can produce different effects at its target. For example, a laser can deliver light to its target if the photons are in the visible part of the spectrum.
If the stream of high-energy photons is large enough, the laser can heat, vaporize, melt, or even burn the target material. The ability to provide these effects is determined by the laser’s power level, the distance between the laser and its target, and the ability to focus the beam on the target.
laser application
The various effects produced by lasers are widely applied in everyday life, such as laser pointers, printers, DVD players, retinal and other medical surgeries, and industrial manufacturing processes such as laser welding and cutting. Researchers are developing lasers as an alternative to radio technology to enhance communications between spacecraft and the ground.
Lasers are also widely applied in military operations. The best known is the Airborne Laser (ABL), which the US military was supposed to use to shoot down ballistic missiles. ABL included a very large, high-power laser mounted on a Boeing 747. The program was ultimately doomed by the challenges associated with thermal management and maintenance of chemical lasers.
A more successful military application is the Large Aircraft Infrared Countermeasures (LAIRCM) system, used to protect aircraft from heat-seeking anti-aircraft missiles. The LAIRCM uses a solid-state laser to illuminate the missile sensor as the missile approaches the aircraft, blinding the weapon and making it lose sight of the target.
The evolving capabilities of solid-state lasers are proliferating new military applications. The US military has lasers on Army trucks and Navy ships to defend against small targets such as drones, mortar shells and other threats. The Air Force is researching the use of lasers on aircraft for defensive and offensive purposes.
Russian laser
A new Russian laser facility with a good reputation is called Kalina. This is intended to dazzle and temporarily blind the satellite’s optical sensors gathering information overhead. Similar to his LAIRCM in the US, blinding light requires saturating the sensor with enough light to render it non-functional. To achieve this goal, a sufficient amount of light must be accurately delivered to the satellite sensors. Given the very long distances and the fact that the laser beam must first pass through the Earth’s atmosphere, this is not an easy task.
Pointing lasers precisely into the far reaches of space is nothing new. For example, his 1971 NASA Apollo 15 mission placed a meter-sized reflector on the Moon. This reflector is targeted by lasers on Earth and provides location information. Providing sufficient photons over long distances comes down to the laser power level and its optical system.
Kalina reportedly operates in infrared pulsed mode, producing about 1,000 joules per square centimeter. By comparison, pulsed lasers used in retinal surgery are only about 1/10,000th the power. Kalina delivers most of the photons it produces over the long distances the satellite orbits overhead. This is possible because lasers form highly collimated beams. In other words, the photons travel parallel, so the beam does not diverge. Carina uses a telescope several meters in diameter to focus the beam.
Spy satellites that use optical sensors tend to operate in low earth orbit at altitudes of hundreds of kilometers. It usually takes several minutes for these satellites to pass a particular point on the surface of the earth. This requires Kalina to be able to operate continuously for that period of time while maintaining a permanent track with its optical sensor. These functions are performed by the telescope system.
Based on reported telescope details, Kalina can target overhead satellites with paths of hundreds of miles. It will be possible to protect against information gathering by optical sensors. 40,000 square miles is roughly the size of Kentucky.
Russia claims to have deployed a less capable truck-mounted laser dazzle system called Peresvet in 2019. However, there is no confirmation that it was used successfully.
Laser power levels will likely continue to increase, and beyond the temporary glare effect, can permanently damage the sensor’s imaging hardware. Although the development of laser technology is heading in that direction, the use of such lasers has important policy considerations. Permanent destruction of space-based sensors by nation states could be viewed as an act of aggression leading to rapid escalation of tensions.
cosmic laser
An even bigger concern is the potential deployment of laser weapons into space. Such a system would be very effective as the target range would likely be significantly reduced and there would be no atmosphere to weaken the beam. The power levels required for space-based lasers to seriously damage a spacecraft are greatly reduced compared to ground-based systems.
Additionally, space-based lasers can be used to target satellites by pointing the lasers at propellant tanks and power systems. This completely disables the spacecraft if damaged.
As technology continues to advance, the use of laser weapons in space becomes more likely. The question looks like this: What are the results?
Iain Boyd, Professor of Aerospace Engineering Science, University of Colorado Boulder
This article is reprinted from The Conversation under a Creative Commons license. Please read the original article.