Ahhh, well Im sorry for being a bit judgemental there. I was feelin a bit off today, it's just been one of those days. So please accept my deepest appoligies. :-[  If you dont mind my asking, where In Asia do you live? And also forgive me for not considering that possibility, again............it's been one of those days so I was short sighted in that respect. ;) Again, please forgive me. To make it up I'll try to help
you if I may.
No friend I dont think the OMS(Orbital manuvering system) engines are active in this first offering, nor are the main engines, it seems that only the re-entry phase of flight is possible. Besides the fact that even if they were they wouldnt be enough to fly it anyway as they are designed only to manuver the Shuttle in orbit With the exception of doing orbital operations in a limited way using the slew commands. FSX is in slew mode when you start the entry flight, as well as being paused, hence the "P" key being used to start things off.

I would suggest reading up in the three manuals availible from your start menu under "Captain Sim"
They are : Part I "Users Manual",  Part II "Systems", And part III "Flight Procedures"
There is also a real NASA manual located in the manuals folder within the main FSX folder in the Captain Sim folder. But it is not for use with the sim, but just there for the information on the real Shuttle, and is quite interesting. :D

Ok, I gotta get some food in me now that im back home and feeling like a human again. 8-)
See ya in orbit hopefully.................... ;)