How to change path from field of IT to field of Space sciences?
Getting in any neighboring field is not always a matter of basic education. Space agencies indeed need engineers, but they for sure have a huge demand on IT specialists as any modern tech company. But you need to first search what kind of ITs are engaged in space industry (automation, simulation, modeling, integrated systems etc.). Then if you would like to do a master degree, choose one which will give you necessary skills. Furthermore, you can try searching internship/practice in a space-related company during your study. It is very probable they would hire you, if you did well.
Having an IT degree gives you pretty a lot of perspectives, but nowadays it is really about skills and what you learn by yourself. Google, visit career days, make personal contacts, learn and prosper.