Space Motion effect

SpaceShip.blend (505 KB)WAZZUP?!
This is my first ever time programming and i have decided to make a spaceship. When using Linear Motion in logic bricks and i stop pressing the button, the ship abruptly stops. Not very spaceship-like, Eh?

My goal is to make a motion that is continued infinitely until another force, like reverse thrusters, act against it. nothing works either!

If someone can explain, POST THE HECK OUTTA ME! i really need a solution. if someone can do it then they are officially the new Messiah [of blender]
MegaUpload:
http://www.megaupload.com/?d=JA7FMIIF
I also attached a file for those who think 45 seconds of wait is too much

Use “Force” instead of “Linear Velocity”. For the up force (z) use a value of 9.8 or if you want zero gravity on all objects then you can deactivate the gravity in the world settings --> Physics --> Gravity: 0.00.

Theoretically, for that kind of motion, you could set the “move forward” key to give the object a property (moveforward). Then a separate logic brick set could tell the ship to have linV of whatever whenever the ship has that property. Then, when another force acts upon it, just remove the property. (I don’t actually know how to do this exactly, having never used the property bricks, but I think it’s fairly simple.)