Could ya put mirrors on outside of space ships to reflect laser beams?

[needle44]

Title says it all, just questioned it. Assuming lasers were weaponized and space combat becomes somewhat normal. Could some kind of mirror plating protect ships?

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[Drydess]

http://physics.stackexchange.com/questions/70698/will-high-power-laser-penetrate-mirror
most likely it would work as a temporary shield but not as a permanent solution due to the fact that mirrors wouldn't 100% reflect harmful lasers

[The Resonte!]

http://physics.stackexchange.com/questions/70698/will-high-power-laser-penetrate-mirror
most likely it would work as a temporary shield but not as a permanent solution due to the fact that mirrors wouldn't 100% reflect harmful lasers

what about lots of prisms

[$trinick]

what about lots of prisms

Redirection would be a good countermeasure, especially because you could redirect the laser right back at what shot it. However, prisms also don't redirect 100% of light, so they would suffer the same integrity issues when they heat up.

[RedGajin]

so what would a laser do to armor plating made out of pure diamond?

[Alkatjo]

so what would a laser do to armor plating made out of pure diamond?

assuming the manufacture of the ship is using pure cut expensive as forget diamond plating, the laser would probably just produce smaller myriad lasers and dissipate in all directions.

[Magus]

To quote the excellent website Atomic Rockets:

Now I know all you older science fiction fans still remember Johnny Quest and The Mystery Of The Lizard Men where Dr. Quest demonstrates that one can defend oneself against a weapon-grade laser beam with a dressing-room mirror. Sorry, it doesn't work that way in reality. No mirror is 100% efficient, and at these power levels, the fraction that leaks through is more than enough to vaporize the mirror armor. The same goes for "ablative armor." One zap and the impact point is abruptly as bare of armor as a baby's behind.

Inside a laser cannon, a relatively diffuse laser beam is generated. This prevents the beam from vaporizing the cannon's internal optics. At the business end, a parabolic mirror focuses the diffuse beam down to the aforementioned megaJoule pinpoint on the hapless target.

so what would a laser do to armor plating made out of pure diamond?

It'd melt all the same.

However, some spacecraft are already mirrored, not because of lasers, but to keep that pesky solar radiation from heating up the craft even further while it tries to cool itself off with radiators.


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[RedGajin]

wait but what if it was really thick? wouldn't that be enough to stop at least lower grade laser guns?

[Magus]

wait but what if it was really thick? wouldn't that be enough to stop at least lower grade laser guns?

Unless it were perfectly, 100% reflective, it would just lengthen the time it takes to burn through. Depending on the thickness, the power of the laser, the heat generated by the laser, and the radiators on the other craft (assuming this takes place in space), you might be able to hold off long enough for your attacker to have to shut off the laser to let it (and the ship) cool off.

[Drydess]

Unless it were perfectly, 100% reflective, it would just lengthen the time it takes to burn through. Depending on the thickness, the power of the laser, the heat generated by the laser, and the radiators on the other craft (assuming this takes place in space), you might be able to hold off long enough for your attacker to have to shut off the laser to let it (and the ship) cool off.

also it'd be stuff expensive, not only for the diamond itself, but also the extra fuel to get the diamond-plated spaceship off the earth

[Magus]

also it'd be stuff expensive, not only for the diamond itself, but also the extra fuel to get the diamond-plated spaceship off the earth

And the extra fuel the diamond ship needs to carry around in order to get anywhere, as well as the extra armor to armor the extra fuel. Damn rocket equation.

[RedGajin]

so hold up, what about when you shine a laser from underwater up towards the surface, doesn't that reflect the laser 100%? if it does isn't there some way you could use that and make armor for something?

[Drydess]

so hold up, what about when you shine a laser from underwater up towards the surface, doesn't that reflect the laser 100%? if it does isn't there some way you could use that and make armor for something?

well I mean it could partially reflect off of a turtle shell before it goes straight through the turtle, so I'd guess about 90%

[Magus]

so hold up, what about when you shine a laser from underwater up towards the surface, doesn't that reflect the laser 100%? if it does isn't there some way you could use that and make armor for something?

It does not reflect the laser. It diffracts the laser. The radiation is spread out through the water. However, the energy is still being absorbed, and thus the water heated.

[Nonnel]

reminder that diamond prices are inflated and they aren't actually rare
hopefully we've fixed that problem by the time we're involved in space attacks