how fast does a rocket go
If a rocket is launched from the surface of the Earth, it needs to reach a speed of at least 7.9 kilometers per second (4.9 miles per second) in order to reach space.This speed of 7.9 kilometers per second is known as the orbital velocity, it corresponds to more than 20 times the speed of sound.Â© GFDL.he 'second cosmic velocity' is the so-called escape velocity from the Earth: 11.2 kilometers per second. This is the speed a rocket should attain in order to be able to escape from the Earthâs gravitational field and fly to other planets.