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Comment by bee_rider | Hacker News Reader

It definitely looks neat.

I don’t really see the point of doing this for one target per missile (other than aesthetics which is a perfectly valid reason!)

But, if multiple were heading at a single target, I guess they’d be harder to dodge? Multiple trajectories and all that.

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The real-life reason for this wild spiraling behavior would be that the launch tube isn’t pointed directly at the target and the missile overcorrects. That’s actually how the sidewinder missile got its name.

This kind of mid-flight course change is a characteristic of real missiles in other cases , though:

* almost anytime a submarine or ship launches, the missile goes straight up for a little bit to clear the ship before sharply turning

* if you shoot a guided missile straight up unguided to clear terrain (eg a hill) before turning on guidance you’ll see this

* cruise missiles in the gulf wars famously did this by following the street grid - even turning at street light

* if you launch a torpedo in a random direction then activate guidance later it can disguise where you are, since the torpedo is coming from a different direction

I always assumed the Sidewinder missile was named based on the snake's ability to sense prey by thermal radiation.

It was a bit of both, really (and the snaking path was only present in early versions of the missile).

Sorry to mislead!

> cruise missiles in the gulf wars famously did this by following the street grid - even turning at street light

That's fascinating! Do you have more info on this?

Apparently HIMARS rockets do it too to avoid counter-battery fire. In videos from Ukraine you can see them launch at one angle then change direction after clearing a good distance from the launcher.

The Russian Onyx missiles also have an interesting-looking initial phase of the launch [1]

[1] https://youtu.be/2-22myhg_nE?t=9

Ohohoh. The craziest reason for the missile to go a little conky has got to be the energy management steering maneuver in THAAD (dunno if other missiles do it as well) - https://en.wikipedia.org/wiki/Terminal_High_Altitude_Area_De...

Another was Sprint. Turning towards the target before it gets too fast. Limiting the stress on the airframe and energy required.

https://en.wikipedia.org/wiki/Sprint_(missile) https://youtu.be/YZZV464z9g8

Good points! I was 100% thinking of this from the point of view of a video game, without stating it, haha.

I always assumed having missiles behave like this would have some neat advantages (harder to shoot down, harder to predict the intended target, harder to automatically trace back to the launcher, etc.) and that the only reason real missiles didn't typically do it was the complexity of making sure they didn't hit each other or something else sitting outside of the shortest path.

It seems like it could be done, e.g. pre-program all of the missiles with randomized paths that didn't intersect, and sweep the entire potential flight path area with radar or similar and exclude volumes with obstructions. That really is an awful lot of complexity that could make things go wrong, though.

Not just dodge, but it would be harder to counter them all with flak or Close In Weapon Systems (CIWS) as well.

https://en.wikipedia.org/wiki/Phalanx_CIWS

I think they behave a bit too wild in the first stage of flight.

I think I'd create separate launch animation that smoothly morphs into this flight animation.

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