The missile is likely loosing the radio signal. So put a bigger radio on the missile. This version is and active which means that it uses radio. So connecting the hardpoint won't work. Use the non active version for unlimited range.

When the rocket flies 20 km, it loses the signal from the "target data" and simply crashes into the ground. when I tried to transfer the "target data" from the radio to the hardpoint, the rocket simply lost the signal and crashed into the ground. How can I fix this?

Works very effectively, and nicely customisable. I'm yet to intergrate it into a custom missile but it looks very promising.

First of all, thank you for creating this missile system. It works quite well, and can deliver a large payload at long range.

I have been trying to build a vertical launch version of this for one of my ships (with 2 fin sections). When I tried to remove the front fin section to make it more compact, (I re-connected the composite to the back fins) it won't steer towards the target correctly. I tried re-tuning the PID controllers, but it just oscillated a lot or didn't turn enough. Is it possible to make this setup work?