7 ms·
To shoot down a missile with a laser, you need a segment of light about 30-50 cm long, so the target doesn't move too much whilst burning a hole in it. In that
by CapitalistCartr 10y ago
To shoot down a missile with a laser, you need a segment of light about 30-50 cm long, so the target doesn't move too much whilst burning a hole in it. In that little segment has to be the energy of at least a .50 BMG, so 20k joules of energy. In a portable form that can fire repeately, reliably. That's doable, but not easily.
- JoeAltmaier 10y agoThat's about one nanosecond of light. E.g. travelling 1000mph is about a foot per millisecond. I think your light could be 1000 times that long and still hit essentially the same point on the target?
- CapitalistCartr 10y agoTravelling 1000mph is about mach 1.3. Hypersonic is mach 5 to perhaps mach 15, if our space launch research goes well. The target has to travel less than about 5 mm in that time. A foot would schmear the light too far. [Edit] OK, I've done a bit of calculating, and I think you're right. The laser pulse could be a maximum of about 175 meters long.
- JoeAltmaier 10y agoA foot of light is necessary if you focus on a millionth of a foot of target. A longer bolt is acceptable if tolerances are looser than that. And they probably are. 5mm is about 1000X larger than that.
- LoSboccacc 10y agoyeah it's hard to do now, I agree, but it's not like hypersonic weapons are readily available, so I'm gonna wager lasers would get viable defenses in time.