Editing Escape velocity (section)

=== Practical considerations ===
In most situations it is impractical to achieve escape velocity almost instantly, because of the acceleration implied, and also because if there is an atmosphere, the hypersonic speeds involved (on Earth a speed of 11.2&nbsp;km/s, or 40,320&nbsp;km/h) would cause most objects to burn up due to [[aerodynamic heating]] or be torn apart by [[atmospheric drag]]. For an actual escape orbit, a spacecraft will accelerate steadily out of the atmosphere until it reaches the escape velocity appropriate for its altitude (which will be less than on the surface). In many cases, the spacecraft may be first placed in a [[parking orbit]] (e.g. a [[low Earth orbit]] at 160–2,000&nbsp;km) and then accelerated to the escape velocity at that altitude, which will be slightly lower (about 11.0&nbsp;km/s at a low Earth orbit of 200&nbsp;km). The required additional [[delta-v|change in speed]], however, is far less because the spacecraft already has a significant [[orbital speed]] (in low Earth orbit speed is approximately 7.8&nbsp;km/s, or 28,080&nbsp;km/h).