No no, don't study engineering. What I am saying is you don't need a degree in engineering to be an engineer. Go look at the IEEE Gold Medal winners. What degree do most have? Physics (including Astrophysics). Study what you like. If it is Astrophysics then study Astrophysics. One of our systems engineers has a physics degree, one of our quality engineers has a physics degree, we have several in optics with physics degrees and in algorthms... None of these people studied engineering one moment in school. Did it hurt their careers, no not at all.
Study your Astrophysics. It that doesn't work out, many companies will hire you as an engineer.