No. First of all, that's imaginary technology, a laser beam is highly focused light, which is the opposite of a shield, it's narrow, you can't really use it to cover a wide area.

Second, the energy requirements would be absolutely prohibitive.

Third, this particles are moving at orbital speeds, no matter how high powered your laser is, it won't be fast enough.

Finally, even if you could do it, it'd be far heavier than having shielding.

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Erm, lasers move at light speed, which, as far as we know, is the only constant speed. There is no such thing as 'orbital speed'. You could collide with a speck of stardust at 1km/h or at 36km/s, it all depends on how both of you are travelling

You missed my point. Lasers aren't solid walls, a powerful enough laser could destroy a particle by heating it up. That energy transfer takes TIME. More often than not, that time is relatively long, which is why we don't have goddamn laser weapons.

A micrometeroid coming in at your ship would only cross that laser for an infinitesimal fraction of a second, and therefore no significant energy transfer would occur.

You don't need a high tech solution when a low tech one works. It's called a Whipple Shield

The problem is the 'fishnet spyral'. Basically, imagine your 'laser shield' as a fishnet. No matter how many laserheads you are using, some particles will always go through. And if I misunderstood your idea and you meant something like having laser turrets to melt incoming particles, well, the chances of the turret to succeed in that are highly reliant on your sensors being able to pick up the particle in time and discern it from background noise.

For shielding, the most interesting shielding I've seen in Sci-Fi media is a combination of hard layered armoured hull, similar to what Soviet tanks like T-64 had for the front of the turrets; and then the ship being surrounded at a certain distance by a fluid armour. Something like a magnetic field or a gravitational field or something holding a very thick layer of dense metal (Like Mercury -Hg- or lead -Pb-) around the ship. Alternatively, the field could be made out of plasma or some very hot gasses to melt incoming particles and dissipate their energy. The logic would be that the exterior layer absorbs as much energy from kinetic strikes, either through density or through pressure variations, keeps it's shape. because it's fluid, and what's left from the impactor is dealt with by the armour of the ship.

Of course, this is not perfect shielding, even if you manage to pull it off. There's always the ancient problem (I mean, literally, from times of Antiquity if not pre-history) of how exactly are you going to see what lies in front of the shield without the enemy stabbing you in the face

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It kinda depends on how you design the stuff. I mean, light has kinetic energy as well. And here we are not talking about melting a tennis ball made of wolfram, but rather changing the energy of a speck of dust. A strong enough laser beam probably has enough kinetic energy to deviate that speck of dust and the laser beam impacting the speck would be the equivalent of a building taking a nuclear blastwave in the face.

Also, this is irrelevant for what I said. You missed my point. You could collide with that thing at 1m/h, meaning you could have the thing in the laser sights for quite some time, because you are travelling 'behind it', basically making it look stationary for your ship, or you could collide head on at 36km/s because your velocity vectors are opposed to each other.

So at what range can you detect a dust particle? If you come creeping up behind it and gently nudge it, there's no need for lasers. And what if it IS a tennis ball sized bit of debris?

I posit that anything travelling at such high velocity as to endanger the ship, will not be detectable in time to get an energy weapon on it long enough to vaporize it and give it time to disperse.

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Remember. The practical is your pal!

No, wait, that’s something else…

No. If you collide with it at 1m/h, then it doesn't bloody matter, that thing is almost in the same orbit as you, and it presents absolutely no threat to your spacecraft.

You care about micrometeoroids when they collide with you at any significant speed, at which point a laser can't do ANYTHING about it.

Unless we turn OP's idea on its head, and instead of trying to do something shield-like with passive lasers, we do an active system with just one laser, and some kind of tracking system that detects potential collisions, and then targets and eliminates those threats at a distance. Which is even more impossible from an energy usage perspective, and the detection and tracking would be insanely difficult.

It all depends on how much power you have on hand for radar pulses. Provided you have the power requirements for the pulse you can detect anything that isn't made to evade radar, at pretty much whatever range you want.

I think it was the movie passengers that had some kind of net at the front. Looked cool but particles travelling at more that 17500mph are probably going through whatever they like. Some form of fluid airframe is more doable as in let it hit, absorb the impact and fill the gap but this is me thinking rather than any form of science. And I think radiation is probably as big if not bigger an issue. I presume proximity to planets would increase the likelihood of encountering things

Lasers can be aimed.

The larger the cross section the more objects you'd need to deflect, but also the more space you have for something like a nuclear reactor. If it's in orbit of a planet and small then it could be in the protection of larger stations on the ground or in orbit.

Orbital speeds are practically stationary compared to the speed of light, and lasers can be aimed incredibly fast.

I'm not sure how a laser array would be heavier than shielding. A Whipple shield would be lighter but if you're getting serious about shielding it's probably because you have to shield against some serious objects.

Alistair Reynolds uses ice shields. Essentially, the front of the ship is coated in meters of ice while in space. Holes are easy to repair by melting then refreezing the shield. It acts as a backup water supply if it's water ice. If it's not water, it's probably common and cheap. Either way, it gets added in space so this idea requires space-based shipyards. It helps that the ships are also thin and long, smaller profile to protect

lasers are concentrated into a small point, to make sure it covers a significant area they must have a lot of energy, and from there, consequences outweigh the benefits.

I mention this in another comment. I was answer OPs question, where he went for actual shielding, as in passive shielding. Which is basically impossible.

If you're instead going for detecting and tracking debris, and then aiming a laser at it, it's a different story. It's equally hard, and basically impossible with current technology once you take into account the size and mass of such a laser and its power requirements.

The point is that, if you can do this, then you don't need shielding. Same about the "serious objects" you talk about. If you have detected debris large enough to be detected, enough time in advance to point a laser at it, then you've detected it enough time in advance to maneuver and avoid it entirely. Shielding is precisely about smaller objects that you don't know about until they hit you.

All these comments talking about overly optimistic use of lasers and what various sci-fi authors have made up and essentially just blathering away, and then there's this one comment two sentences long with the actual technology that already does this job on actual spacecraft.

Too bad NTRS is all buggy now. Young man put up a way to make an electromagnetic field out in front of a space craft, essentially a force field. Mark Novak dreamed it up. Just tried to find it on NASA technical release server, to no avail.

Cheers

Pycrete was used in experimental aircraft Carrier binding in ww 2. But because the temperature was too high it failed. I Think that with better fiber material and ekstreme cold in space it could be a good building material

Shifting a relatively small object with a laser is much easier than shifting an entire spaceship. Right now shielding is for small things, but not forever. Isaac Arthur has some really good videos dealing with this and other topics.

This is a good response here. I want to reiterate and emphasize the challenge of sensors and detectors "seeing" the incoming micrometeoroid.

If you know a thing is coming then you can prepare for it. But much of the challenge is detecting incoming ballistics. And thats really really hard to do. Things like lasers only work if you know where to point it. Sometimes you do, but most of the time you dont.

Think of it like a bullet could come from any direction. A laser could melt a bullet, but trying to line up the laser beam with an incident bullet path is crazy hard. So it's easier to just to put on a bullet proof vest.

Actually a better tactic is using static electric fields on the ship (negative side facing forward) and an electron gun to charge the incoming dust so it's repelled to the side as the ship approaches. Neutralize the ship with positive particle emission to the rear such as an ion engine which gives you net positive thrust due to the ion's higher mass and velocity.

As an engineer (not aerospace though), I'm a huge fan of the KISS principle.

Keep It Simple Stupid!

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As a far future concept, it's viable. If you had a kilometres long ship on an interstellar voyage, with access to large amounts of power and traveling at a good fraction of lightspeed then this is a fairly good system to use. But for near term spaceflight it's simply unnecessary. Debris is widely scattered and nothing that a good Whipple sheild can't deal with

Well, I mean, technically, with a powerful enough laser, you don't need to precisely aim it. You can use the same technique radars use and do 'sweeps', with the lasers going from right to left or up and down, or perhaps having multiple layers doing the same thing. But, as mentioned, you will still have some holes in the 'fishnet' even with this method. The best strategy is a layered defence. Kinetic protection is the most sound choice when it comes to singular impacts, but overtime it's going to fail due to multiple impacts and radiation exposure. Especially if you go for the traditional 'armor' ideea (liquid metal armour, while more Sci-Fi, at least prevents the forming of cracks).

i suspect a laser disco ball concept is going to be way too power hungry, and that means it will be prohibitively massive with todays power technology.

The liquid metal armor idea isnt entirely scifi. Liquid armor already exists using non-Newtonian fluids. There are commercial products for motorcycle armor you can buy today. For Liquid metal armor, check out ferrofluid armor and the AFRL. Unfortunately, these arent worth the bang for the buck, in terms of protection versus mass compared to a traditional kinetic whipple shield.