Your interviewer is hoping to get a look into your future career goals and aspirations during your interview time with them, so they pose this question as a very open ended one to let you take your answer in your own direction. As you prepare an answer for this type of question, try to focus on your career goals and where you really want to grow within the aerospace industry. As well, be sure to research the company you are interviewing for to ensure that your future goals align with the goals of the organization. In the end, your interviewer will really be looking to gauge your long-term fit with their organization and you have the ability to really sell that with your answer to this question.