Saying non credible af here, but in theory one could add a upwards facing shotgun shells on top of the helmet, triggered by a Camera/proximity sensor if it detects a drone/falling grande.
Maybe add a gyroscope to check if the helmet is actually facing upwards before triggering.
All in all unit cost could be below 250$
My buddy's humvee got tagged by an rpg during desert storm, everyone inside lived but most were injured. He got away with shrapnel embedded in his arm for most of the next two or three days until it all got removed. Apparently his elbow got it pretty bad.
Fast forward to 98, he's basically lost feeling in two of his fingers except hot/cold and pressure. "it's not service related"
2005, most of his hand is partially numb. "it's not service related"
2013, he has no feeling below the elbow, except sharp pain and extreme hot/cold. "it's not service related"
2015, he has deadeend feeling from his shoulder to his elbow. "it's not service related."
2017, he has difficulty moving his hand now unless he's looking at it. Spatial awareness is gone. Elbow down completely numb. Shoulder down almost completely numb.
2017, two months later, for seemingly no reason. "It's service related. You're on 100% disability. You have 24 hours to quit your job."
Potentially, but at that point it probably would have lost its lethal velocity, so the worst that could happen is it gets stuck in your hair or falls into your shirt or something.
Drone dropped munitions rarely land directly on a soldiers head; rather they land nearby and injure surrounding soldiers with the blast/fragmentation. Without some sort of active aim, this thing will almost never hit, if it even triggers.
Let's kick it up a notch and get Raytheon working on a helmet-mounted Phalanx that fires .22LR. The old farts at the trap & skeet range are gonna be in for a surprise when I show up with that bad boy.
You need to MIC that shit up, there is no way our districts can profit off that.
Stick a multi strategy drone detector on an MRAP and pair it with an automated proprietary small bore shotgun chaingun. Like a baby Phalanx that shoots .4 bore.
It will take some time before it stops shooting birds, but all that can be taken care of in future iterations that require retrofitting that is not covered by the maintenance contract.
With no barrel to really direct the velocity, wouldn't it be more like attaching a tiny grenade or firecracker than a bullet? In that case the kickback force would be less than out of a regular rifle since the blast velocity is distributed in a radius and not in a singular direction.
The real deal use radar/lidar sensors, so you can replace the whole sensor suite with 4 90-degree sensors facing upwards with the added benefit of being able to track not just range but speed and trajectory.
Slap the computer on the back of the helmet, and it'll even work as a counterweight for the night vision goggles!