First this cheat will only work only if you have the latest dystroyer ship 
(the dystroyer v.5) or dystroyer v.4.If you have enough plasma (cash) you can 
buy a powerful missile called nk 3000 or was it nk 4000?Anyways buy about ten 
of those nk (nuclear explosion missiles that dont damage your ship and your 
droids) and if your ship is very damaged use 1nk missle it will dystroy all 
alien ships on the screen including turrets on the ground and in air.