Northrop RF-5 Tigereye (76-1544)

I give up. What’s the markings?

If it's a US NAVY plane, why does it carry the red star of the Russian army?

They train navy pilots using Russian air tactics. It works on the same principle as Red Flag in Los Vegas Nevada for training Air Force pilots using Russian painted aircraft.

There are different type of aircrafts used as plastrons Micky… (targets)

Just for everyone's information: This aircraft (76-1544) is a straight F-5E Tiger II. It flew for the Swiss AF before going to the US Navy.