A body is orbiting very close to the earth surface with kinetic energy KE. The energy required to completely escape from it is

When a body is orbiting the earth, the centripetal acceleration is provided by the gravitational force of attraction from earth.
√GMmR²=mv²/R
√KE=mv²/2=GMm/2R
The gravitational potential energy=PE=-GMm/R
Hence the total energy=PE+KE=-GMm/2R
Therefore the energy that must be provided to the body to completely escape from its orbit=GMm/2R=KE