How Much Energy Is Needed to Launch a Satellite into Orbit?

[Effective]

Homework Statement

How much energy is required to launch a 200 kg satellite from the surface of the Earth into a circular orbit with radius 8.0 * 10^6 m?

G=6.67*10^-11

Homework Equations

Ep= -GMm/r

The Attempt at a Solution

I calculated the gravitational potential energy of the object on the earth, then I calculated the gravitational potential energy of the object in the circualr orbit and then I subtracted the two and apparently that's not the correct way to tackle the problem.

 

[tiny-tim]

Welcome to PF!

How much energy is required to launch a 200 kg satellite from the surface of the Earth into a circular orbit with radius 8.0 * 10^6 m?
…
potential energy of the object on the earth, then I calculated the gravitational potential energy of the object in the circualr orbit and then I subtracted the two and apparently that's not the correct way to tackle the problem.

Hi Effective! Welcome to PF!

That will only give you enough energy to get it up there …

you need it to stay up also! ​

… you got to be practical!​