When I began writing, The Huralon Incident, I wanted to figure what would be a plausible “effective range” of future military lasers. I dug into Google and started researching. The number of different, and often contradictory answers, I found were legion. Nobody seems to know for sure, and even those who should know, say the end result depends on a huge number of factors. Safe to say, I didn’t get any really hard, useful information after reading so many articles my eyes turned red and they began to creak in a distressingly loud way.
Maximum Effective Laser Range
Having found no definitive data I, somewhat arbitrarily, decided that any distance within one light-second is point blank range. “That’s really close, E.A.” you might say. Actually, it isn’t. The distance from Earth to the Moon is 238,900 miles, and that is 1.28 light-seconds. So, here is the ISS space station, a large installation looking a bit diminutive, in orbit around the Earth:
We’re already some distance from the ISS, but you still cannot see the whole Earth. We’re too close. Now for comparison, here’s an Apollo 11 shot taken from the Moon, 1.28 light seconds away.
Now we can see the whole Earth, but where would the ISS be? Well, it would be a tiny little speck too small to see. And this distance would amount to a knife fight in a phone booth during futuristic space combat.
The reason I consider this point-blank range is because the information directing a firing a laser at this range is “only” two seconds old. One second for a light-speed radar range finder to reach the target, one second for the range information to come back and tell you how far away it is. Considering that a ship could move hundreds (instead of thousands) of kilometers from the location a radar tells you the target is located at, that’s not too incredibly awful. Futuristic computers, I wager, could work out where a target might be at that range. You’ll have a snowball’s chance in hell of actually hitting something, with a sophisticated AI.
At five light-seconds away, you’ve got little hope of hitting a maneuvering target. The enemy would be dodging his/her butt off because that’s a ship full of people who very much don’t want to die. Your information would be ten seconds old and when you fire your laser this beam of superheating destruction it will take a further five seconds to arrive on target. That’s a fifteen second lag time! Adding to the thinking is that every time you release the immense energies of your laser, you create heat in your own ship. Getting rid of heat in space is very difficult because there is no atmosphere to transfer the heat to. So, you want to fire your lasers when you can make the shots count. That means, at a range where you’ve got a hope of hitting.
And thus, is the logic for how I determined maximum effective range for a futuristic laser. What say you? Any thoughts to add? Let me know in the comments.