Answer:
The correct answer to the question: What part of the rocket reaches space, would be: the upper stages.
Explanation:
In rocket launching, especially space flight rockets, the amount of stages, and where they will be detached from the entire rocket, will depend on whether the rocket is intended simply for suborbital travelling, meaning just to go around the Earth´s atmosphere and not beyond, or if they are meant for orbital travelling. In the latter case, these rockets are called multistage rockets, and usually the first two stages, will fall off as soon as they burn out all their fuel, the first within Earth´s atmosphere, the second, reaching the limits between the atmosphere and outer space. The one part that reaches outer space completely, is called the upper stage, or the topmost part. This one will do the space travelling, and will also be responsible for the final arrival back to Earth. It is the engines on these upper stages that have the capacity to break against the pull of both Earth´s and the Sun´s gravities, to reach their goal.
