Many Lasers Become One In Lockheed Martin's 30 kW Laser Weapon 202
Zothecula writes "In another step forward for laser weapons that brings to mind the Death Star's superlaser, Lockheed Martin has demonstrated a 30-kilowatt fiber laser produced by combining many lasers into a single beam of light. According to the company, this is the highest power laser yet that was still able to maintain beam quality and electrical efficiency, paving the way for a laser weapon system suitable, if not for a Death Star, for a wide range of air, land, and sea military platforms."
Re:Excuse me... Excuse me?!!! (Score:5, Informative)
Too many unknowns to get exact numbers, but assuming visible light and 10cm aperture, we are probably talking about few mm per each km of distance. Geostationary satellites are completely out of range, but lets take ISS as example - 400km. This means that 30kW would be spread over circle with 2m or so. ISS has a speed of 7-8km/s (as all low orbit satellites, otherwise they would fall down). This means that each part of station would be in the beam 'focus' for 0.005 seconds. Given radius of the beam and speed, there would be no localized damage - just total energy transferred to station. Assuming it goes in most unfavorable way, it can probably get around 100m of length through the beam, giving a total of 0.013s exposure. So, in most unfortunate situation, we are talking about 390 joules of energy being transferred to the ENTIRE station. For comparison, light shining on _earth_ hits with 1000 joules per second for each square meter (a probably a lot more in space). So, we are talking about effect being few hundred times smaller than sun radiation station received each second.
Please note that we are talking about _collateral_ damage due to missed shots, not active tracking of satellites. But even with perfect tracking and a lot more powerful lasers, it would be very hard to do lasting damage. Current anti-satellite laser developments are about _blinding_ satellites, not blowing them up.
If you think that collateral, non-tracked shot from realistic laser with 30kW of power can do any damage to any satellite, please provide your calculations. Otherwise, too much watching StarWars, not enough science.
Re:Newtonian physics and ballistics don't apply! (Score:5, Informative)
The physics of electromagnetism and photonics will somehow stop an errant beam from destroying anything else as it travels onwards? Nope, of course not.
Okay so you clearly have no idea how lasers work, or the physics of electromagnetism.
For one thing, they defocus over long distances. At sufficiently high energies they lose energy because they turn the air to plasma and bleed off intensity as heat. It's been a struggle to make ranged laser weapons work, because you can't exceed a couple of kw/cm2 before the air turns to plasma and your beam blooms out of existence.
And for the example given, lasers are much less likely to cause collateral damage - they can "unfired" instantly, and they will travel at a tangent to the Earth meaning that once headed any amount above the horizon they will never fall below it. Bullets, missiles, bombs - well those always come down and they are lethal when they do.
Re:Excuse me... Excuse me?!!! (Score:4, Informative)
Laser weapons as they are being developed just don't work that way. The pulse is actually quite short when applied, and the target goes boom. You've watched way too many science fiction movies.
They are also far more accurate than kinetic energy delivery weapons (big bullets).
Re: Excuse me... Excuse me?!!! (Score:5, Informative)
They dissipate due to defocusing and interaction with the atmosphere. It's not a problem.
Re:Dubious (Score:4, Informative)