The earth is always pulling us to its centre with its gravity, a force to which all bodies on the planet are subjected to. In the beginning of the space program of United States, reduced gravity was an important matter on the general body behavior, making this study as a key on space exploration and transportation, and a capability of testing the personnel and equipment.

260 years of unsolved and unknown regime of high speed dynamics of gases were broken with the significant flight of the Bell X-1 research vehicle installed under the B-29 bomber of World War II vintage, on October 14, 1947 in the Mojave Desert in California.

Flights within the earth are possible taking into account our atmosphere composed of air. But when talking about flying through outer space or even an almost non-existent atmosphere or one that is composed of other gases like the planets in our solar system, propulsion methods and flight dynamics of the vehicles will be significantly affected.