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Post by shurugal on Dec 5, 2016 20:20:17 GMT
IRL using only large mirror lasers would be good enough, since with a large mirror you could still choose to not focus the beam to its tightest. Also you could fire at longer range, burning away fibre armor at 10,000km, before closing in to cut the metal underneath. I wish there were an option to control the laser beam waist depending so that it holds constant depending on target range, rather than going for the tightest focus all the time. good luck spotting a target a 10Mm. Even one of our 20GW radiating monsters would only have an apparent intensity of 200 μW at that range. Starlight is brighter.
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Post by goduranus on Dec 5, 2016 20:45:42 GMT
Wut man? Wut? But there is no stealth in space, they said.
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Post by zuthal on Dec 5, 2016 20:50:18 GMT
Actually, a 20 GW light source at 10 Mm distance has an apparent magnitude of -6.9, which is brighter than Venus, and much brighter than any star.
Plus, the ships will be moving against the background of the stars, and will be able to be differentiated in that way.
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Post by lieste on Dec 5, 2016 22:20:28 GMT
Actually, a 20 GW light source at 10 Mm distance has an apparent magnitude of -6.9, which is brighter than Venus, and much brighter than any star. Plus, the ships will be moving against the background of the stars, and will be able to be differentiated in that way. Any star *except* Sol.
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Post by zuthal on Dec 5, 2016 22:23:16 GMT
Okay, yeah, I'll grant you that much. But if your targetting software cannot distinguish an enemy ship from Sol, I would recommend not going for the lowest bidder next time
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Post by amimai on Dec 6, 2016 4:40:11 GMT
Actually, a 20 GW light source at 10 Mm distance has an apparent magnitude of -6.9, which is brighter than Venus, and much brighter than any star. Plus, the ships will be moving against the background of the stars, and will be able to be differentiated in that way. Mhm... ship emitting 1MW would be pretty much invisible at anything past 9Mm... how many crew quarters can we run on a 1MW signiture reactor?
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Post by newageofpower on Dec 6, 2016 5:31:11 GMT
Problem is your engines will emit a ton more than 1 MW heat, unless you have a ridiculously low thrust...
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Post by dragonkid11 on Dec 6, 2016 10:31:57 GMT
Problem is your engines will emit a ton more than 1 MW heat, unless you have a ridiculously low thrust... Use MPD? And have the sole weapon being stealth drone that also use MPD to launch missiles away from the main craft? ... I actually like this idea.
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Post by shurugal on Dec 6, 2016 13:22:55 GMT
Actually, a 20 GW light source at 10 Mm distance has an apparent magnitude of -6.9, which is brighter than Venus, and much brighter than any star. Plus, the ships will be moving against the background of the stars, and will be able to be differentiated in that way. Really? I'd be interested to know the maths on that. I just went with inverse square law, but I probably screwed up units somewhere.
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Post by amimai on Dec 6, 2016 13:48:56 GMT
Btw for reference average star is 2e-9W/m^2 or less math it out yourselves to work out at what range a craft of X signiture vanishes from visibility... Rough benchmarks 1GW:300Mm 1MW:9Mm 1kW:300km (Really some drones and most missile should technically be totally invisible... but I guess radar?)
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Post by zuthal on Dec 6, 2016 13:54:51 GMT
Those ranges are only roughly where it is as bright as the background stars, though. It will still likely be brighter than the background between the stars, and it will also be moving against the background.
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Post by ross128 on Dec 6, 2016 14:01:38 GMT
Well, there's unaided visibility, and then there's telescopes. Even small telescopes can pick up significantly more than an unaided eye, and you'd only need a mirror diameter of 2.4m to get the equivalent of the Hubble Space Telescope, so you could probably stick a few of those on what would essentially be an AWACS ship or drones.
With a good infrared telescope you could probably pick up the exhaust plumes from drones and missiles, as long as your on-board computer could filter out the background.
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Post by amimai on Dec 6, 2016 15:12:03 GMT
Well, there's unaided visibility, and then there's telescopes. Even small telescopes can pick up significantly more than an unaided eye, and you'd only need a mirror diameter of 2.4m to get the equivalent of the Hubble Space Telescope, so you could probably stick a few of those on what would essentially be an AWACS ship or drones. With a good infrared telescope you could probably pick up the exhaust plumes from drones and missiles, as long as your on-board computer could filter out the background. what exhaust fumes? missiles are running silent, the only emissions they would ever make after the last corrective intercept burn would and waste heat from whatever processing systems their targeting software runs on... same for drones, you would only have a signature when the weapons systems are on and shooting you full of hot lead optical systems would be at best unreliable particularly against missiles that are 5-10cm across painted in space camo black at several hundred thousand kiloneters
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Post by goduranus on Dec 6, 2016 15:20:17 GMT
I am not totally sure on this, but I think black body radiation forumla says that painting stuffs black increases their IR signature.
Maybe paint it chrome?
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Post by ross128 on Dec 6, 2016 17:32:24 GMT
Well, there's unaided visibility, and then there's telescopes. Even small telescopes can pick up significantly more than an unaided eye, and you'd only need a mirror diameter of 2.4m to get the equivalent of the Hubble Space Telescope, so you could probably stick a few of those on what would essentially be an AWACS ship or drones. With a good infrared telescope you could probably pick up the exhaust plumes from drones and missiles, as long as your on-board computer could filter out the background. what exhaust fumes? missiles are running silent, the only emissions they would ever make after the last corrective intercept burn would and waste heat from whatever processing systems their targeting software runs on... same for drones, you would only have a signature when the weapons systems are on and shooting you full of hot lead optical systems would be at best unreliable particularly against missiles that are 5-10cm across painted in space camo black at several hundred thousand kiloneters They can't run silent the whole flight: they need an initial burn to start heading toward you and a terminal burn to secure a hit. Their trajectory in-between can be calculated using simple Newtonian mechanics, so your ship's computer can keep track of their expected location between burns. Though once they're inside PD range, at that point they'd likely be close enough to track with radar or lidar.
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