It means taking out adversarial missiles or aircraft. When they're travelling so fast, they might not need any homing technology. The state of the art F22 Rapto

It means taking out adversarial missiles or aircraft. When they're travelling so fast, they might not need any homing technology. The state of the art F22 Raptor has a top speed with afterburners of Mach 2 for reference. The railgun projectile is travelling at Mach 6 per the article. If the plane is within range, it might not be able to run away from one of these if they get the aiming correct.