How does the spaceshuttle overcome gravity?

Well, first of all, the last Space Shuttle mission flew in July of 2011, and the shuttles

are all in museums now. (Held there, I'm pretty sure, by gravity.)

When they did fly, the shuttle certainly needed powerful rocket boosters to raise it

above the atmosphere, and accelerate it to a high enough tangential ('sideways')

speed to maintain orbit. But once that job is done, it doesn't take any more work

to stay in orbit. I mean, look at the Moon !

And actually, for that matter, you would not want the shuttle to overcome gravity,

because gravity is what keeps things in orbit.