5 ms·

I don't understand, why can't an interceptor missile change its course but a hypersonic missile can?

• sandworm101 5y ago
  Relative speeds. A slight turn by the inbound hypersonic will could move the impact/intercept point several hundred miles left or right. If you are the ground-launch interceptor that shift left or right requires a much larger turn, a turn requiring much greater energy on your part than the hypersonic spent making the smaller turn. Say the inbound hypersonic just turned a few degrees east. The interceptor fired towards the old western trajectory might now have to turn around and head east, meaning it no longer has enough energy to get to the new intercept point.
  • whiddershins 5y ago
    This doesn’t make intuitive sense. It’s all in how fast the interceptor updates to reflect the new trajectory. If it were magically simultaneous and their mass were the same, the energy would be the same, no? Or is this something I am lacking findamentL knowledge on.
    • whatshisface 5y ago
      The missile is faster and travels a greater distance, and the interceptor is smaller and slower. That's because every target needs to have interceptors nearby, but you only need one missile.
      • whiddershins 5y ago
        Why are interceptors always slower
        • whiddershins 5y ago
          Could an algorithm determine the possible evasion changes and provide full coverage with n interceptors per missle?
          • sudosysgen 5y ago
            What if the missile just turns away and comes back?
          • nradov 5y ago
            Sure, if you have unlimited budget to build those interceptors and the associated launch platforms. These are extremely complex and expensive weapons which no country is able to mass produce.
      • jcun4128 5y ago
        Laser on the interceptor?... edit: might not matter against a thing designed to fly in intense heat
    • deleted 5y ago
      [deleted]
    • sandworm101 5y ago
      Because, in this case, the incoming weapon dictates the fight. If you are chasing something down (think air-to-air missile) then every turn by the target allows the missile to catch up faster via a shorter path and smaller turn (a2+b2=c2, the missile follows c). A 45 degree turn by a fighter jet might mean only a few degrees turned by the sidewinder missile fired from behind. But with a hypersonic coming towards and the interceptor being slower, the opposite of a classic dogfight, the opposite becomes true. A small turn by the hypersonic means a larger turn by the intercepting missile to get to the new intercept point. If you draw the triangle then the intercept path is C, but the shorter of A or B. The hypersonic is following the longer of A or B.
      • whiddershins 5y ago
        Are interceptors always slower and why?
        • sudosysgen 5y ago
          For hypersonic weapons, yes. Firstly, the interceptor has to climb up to the altitude of it's target. Then, it has to fly through very thick atmosphere. It also has to do so rapidly enough for it not to be too late. It needs to be much cheaper than the weapon it's intercepting for it to make economic sense, also. Because of this, they won't be airbreathing, and even if they were they would be slower.
          • ALittleLight 5y ago
            I can imagine interceptors fired off near the enemy launch site that run down the hypersonic while it's still accelerating. Or, interceptors fired down from space either at the incoming hypersonic or along an expected path intending to converge.
            • sudosysgen 5y ago
              There's two problems with your first idea. The primary issue is that such an interceptor would need to be more expensive and more capable than the missile it's gonna hit, not even taking into account all of the supporting infrastructure necessary. The second issue being that if you're going to be operating near (horizon distance, so let's say 200km) of a missile launch site, you're going to be bombed or missile'd to smithereens. If you can prevent that, you could just bomb the launch site to begin with. As for interceptors fired down from space, you'd need to expend all the energy to get them into orbit, and then expend the energy to get them back into atmospheric flight, which itself is going to be 10x more expensive than it's target. There's also the issue that while in suborbital flight, the hypersonic missile can just adjust it's trajectory a bit and the whole trajectory is now useless.
• sudosysgen 5y ago
  Because the hypersonic missile has an air breathing engine and/or goes much faster, so it has a lot of energy to expend. Also, a very slight change in trajectory by a missile far away requires a much larger change in trajectory for the interceptor, because the interceptor has to go to where the missile is projected to be, meaning that the interceptor is always at a disadvantage.
  • nradov 5y ago
    Many of the hypersonic weapons currently under development use a boost-glide design and won't have an air breathing engine running during the terminal phase. https://www.scientificamerican.com/article/the-physics-and-hype-of-hypersonic-weapons/ https://www.scientificamerican.com/article/the-physics-and-h...