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Do you think these findings from the Defense Intelligence Agency are overstating capability? > Directed Energy Weapons. China likely is pursuing laser weapons
by Diesel555 5y ago
Do you think these findings from the Defense Intelligence Agency are overstating capability?
> Directed Energy Weapons. China likely is pursuing laser weapons to disrupt, degrade, or damage sat- ellites and their sensors and possibly already has a limited capability to employ laser systems against satellite sensors. China likely will field a ground-based laser weapon that can counter low-orbit space-based sensors by 2020, and by the mid-to-late 2020s, it may field higher power systems that extend the threat to the structures of non-optical satellites.
https://aerospace.csis.org/wp-content/uploads/2019/03/20190101_ChallengestoSecurityinSpace_DIA.pdf https://aerospace.csis.org/wp-content/uploads/2019/03/201901...
Here is a more academic article discussing the risk from ground based Satellite Laser Ranging systems to optical sensors, specifically when they are imaging the area near the SLR. I'm guessing the power required to damage structure vs optical sensors are probably orders of magnitude different.
> This density is 100 times the damage threshold of 106 J/m2, and will damage the pixel unless the laser light is filtered. In this case both the pixels and the filter may be damaged.
(There is a caveat to the above statement based on timing probability being very low)
https://scienceandglobalsecurity.org/archive/sgs17butt.pdf https://scienceandglobalsecurity.org/archive/sgs17butt.pdf
- rocqua 5y agoI think these are trying to overload/damage the sensors on a satellite. Rather than damaging the body of the satellite. Makes sense, given that the sensors are made to be more sensitive.
- Diesel555 5y agoFor the first quote DIA stated > ...it may field higher power systems that extend the threat to the structures of non-optical satellites Just conjecture?
- rocqua 5y agoThe math here is doable. Approximately the inner angle of the cone of light comming from a laser beam is 1.22 2lamda/d (source: airy disk wikipedia). Where lamda is wavelength and d is the aperture. Lets pick lamda so 1.222lamda is 1000nm (blueish light). Then by smal angle approximation, the size of a beam at 500km (starlink height) is 500km * 1000nm / d Say we want our beam to be 50m wide. That gives an aperture requirement of 1cm. Huh, that seems reasonable. So in a vacuum, it could perhaps be done. Atmospheric effects would make this worse ofcourse. And a 50m beam is not going to dump much heat, but it seems somewhat plausible in the near future.