The 19th century saw many unsuccessful efforts to build a vehicle that could fly, but in 1903, the Wright Brothers came up with a design based on the principle of the airfoil technology. The air foil technology explains, when an air foil object like a blade, turbine or wing, is made to flow in a medium, a force called the aerodynamic force is created perpendicular to the motion of the object. This force is also called as lift force, as it lifts the object up in the air. Airplanes are equipped with a turbo fan engine that consist of a compressor, a combustion engine and and a turbine rotating at high speeds. This helps the plane move forward and the moving air flow producers a lift force of the wings. Since every wing has a flaps, the curvature of the wings created on account of the movement of the flaps, regulates the lift force. Once the lift force underneath the wings is greater that the weight of the plane, the plane takes off.
This still does not explain why an airplane can’t fly into space. As mentioned earlier, the jet engine contains a combustion engine. Any kind combustion requires oxygen. The jet engine gets its oxygen from the atmosphere and thus the combustion within the airplane creates thrust force. As we reach higher altitudes, the oxygen becomes thinner. The oxygen levels at the summit of the M.t Everest is 1/3rd of the oxygen levels at sea level. This is why mountain climbers carry oxygen with them during high altitude treks. Planes usually can reach a maximum altitude of 7.5 miles or 12 kilometers. After such great heights, there is not enough oxygen to sustain the combustion engine. There are known flights like the SR-71 Blackbird of the US, that have reached a maximum height of over 15 miles or 44 kilometers. To achieve such an altitude, the SR-71 had to run at speeds as high as Mach 3.2, which is over 3 times the speed of sound.
To get an object into space, the object must first attain speeds over the escape velocity. This velocity is merely the speed required to escape the earth’s gravitational pull. If the SR-71 were to ever escape into outer space, it would need to be over 10 times faster, since the escape velocity needed is approximately Mach 33.
Even a spacecraft can’t reach speeds to escape the earth’s gravity. Hence, spacecraft’s are attached to rockets. A rocket works on the principle of Newton’s 3rd law, which states that “ Every action has an equal and opposite reaction.” The downward thrust or force generated by a rocket is so intense that it propels itself upwards at high velocities. To solve the problem of oxygen being thin at higher altitudes, the rocket is self-sufficient with liquidized oxygen and hydrogen. Since the rocket is too heavy to be lifted up all the way to space, a part of it detaches itself at a certain altitude and each stage of the rocket has its own propeller. In simple terms, multiple rockets are stacked up on top of each other.
Newton’s first law: Loosely stated, Newton’s fist law implies that when an object is set in motion, it will continue to move unless an external force is applied to it. Even though the final stage of the spacecraft will also eventually run out of fuel, the space craft will continue to orbit around the earth due to this law. Since space is a vacuum, there is nothing that slows down the velocity of the craft, and the only force acting it the earth’s gravitational force that binds the space object, similar to the moon.