A gravity problem i came across.

Hello!

Im sure we're all familiar with the fact that energy can't be created, only changed into diffrent states. However, i've been thinking about this scenario i find rather strange:
If a space-shuttle is put in orbit around a planet or object with large gravity, the shuttle will accelerate around it. When the speed is high enough the gravity-field will not be able to keep the shuttle in orbit, and it will be thrown out into space again.

My question is: Have energy been created? Since the shuttle have greater speed after leaving the orbit than when it entered the orbit.

Im sure my problem is somehow invalid, i just want to get this one out of my head.

Thanks!