I am trying to find out the name of an arcade game that I used to play in the 80's

It was pretty similar to Galaxians or the later Galagon in look and play. The main difference was that the after clearing each level the players ship would move to the top of the screen and you would have to use the position controls to dock with
an additional rocket stage which would appear at the bottom of the screen.

If you managed to dock your firepower was increased as both stages had guns. I think if you failed to dock you remained with your single gun ship and had to clear a more difficult round to reach the docking stage again.

I think there were 3 stages to the docking process.

I have tried to find the name on quite a few websites but never managed to find it.

Anyone else remember it ?

Thanks