05.05.2015 23:24

Recently, DARPA released a video that shows bullets which are capable of changing their course in-flight, depending on the movement of their target:

The technology is honestly pretty amazing. A quick Google search gives me a rough lower limit of 800m/s for a .50 caliber bullet, and something like 180.000rpm rotational speed for gyroscopic stability. Now, it is of course possible that some kind of fins are included in the bullet, which could possibly eliminate most of the rotational velocity, leaving only the actual travel speed to deal with.

Even then, things have to happen pretty darn fast. It's not clear how far away the target is, so I'm making a rough guess at 1.000m, which would put the flight time at 1.25s. In the videos, there are around 7-8 thruster firings for the course corrections, so one course correction every 150ms. In those 150ms, the controlling computer has to:

  • Expose a series of images
  • Track and extrapolate the path of the target
  • Track and extrapolate the flight path of the bullet
  • Compute a new trajectory for the bullet based on those two pathes
  • Estimate a thruster configuration to put it on the new flight path
  • Transmit the data from the control computer to the bullet
  • Fire the thrusters
  • Wait for the thrusters to burn, and for the bullet to overcome its inertia and take on the new path

Rinse and repeat. 150ms is a pretty darn tight time budget for all of those operations, especially since most of it would be taken by the sampling intervals for the captured images, so it's not a trivial achievement, and can probably only be done with a tightly integrated custom hardware/software stack.

The question then is - how does DARPA attract the technical talent to pull this off? The world's richest companies are fighting over the best hardware and software engineers, paying ridiculous salaries and stock bonuses, and trying really hard to fulfill their wishes. So it's not exactly like there is a surplus of engineers, and they don't have much career paths other than joining the military. People with the matching skill set have a choice, and even if they can't make it to the top-tier companies, there is a real demand for people with real-time computer vision skills pretty much anywhere.

What, then, is it that makes people forego some of the most desirable jobs in the world, and design killing machines instead? There is no dual use for homing bullets, they are better at killing people, and that's it. Are people really capable of convincing themselves that this will make the world a better, safer, happier place?