I am a 2nd year undergraduate student. What should I do now to prepare for my PhD? I am a 2nd year undergraduate student in Aerospace Engineering, in India. I am really willing to go into Academia as a researcher. I am specifically interested in Aerospace Controls. Some points to consider :

1) I love the fast internet access in university, so that I can research and learn all I want.

2) I have read up a few research papers regarding error reduction in GPS measurements, when I was doing a Supervised Project under a professor. Reading research papers are gruelling, but after 2-3 days of bending your mind over them and finally understanding what the author intended to say, I feel elated.
In this specific case, I read up a few algorithms and got excited on the prospect of developing my own algorithms for error reductions.

3) I have a fair academic standing with a cumulative grade point of greater than 9 out of 10

So I would like a few pointers on what I can do now, as an undergraduate student to prepare for my PhD.
As an undergraduate student, the best thing you can do to help your admissions case is to get involved in research. This will allow you to demonstrate that you have the capability to do good research, which is one of the biggest things admissions committees and individual professors are looking for when choosing among applicants. Maintaining a solid academic record is also useful, and having an understanding of the literature in the field you're interested in is also good. However, direct experience will let you see if academia really is what you want to do or not.