Space Shuttles in Motion

Space is the final frontier for mankind. It is the most unknown aspect of human life. The most effective way for further exploration and to conduct experiments in space is the travel into space using space shuttles. Space travel is important but it is a high risk procedure. If something happens to a shuttle while in launch, orbit or landing, it is near on impossible for the lives of the astronauts to be saved. This is why the design of the space shuttle needs to be perfect. To achieve this, the physics behind the motion of the space shuttle must be well known. Today I will be talking about the main parts of the space shuttle, the physics behind the launch, obit and re-entry of the space shuttle, as well as the way space shuttles prevent burning up when returning to the atmosphere.

There are three main parts to a space shuttle which are the Orbiter Vehicle, the external tank and the solid rocket boosters. The Space Shuttle Orbiter is the orbital vehicle of the Space Shuttle. It can be said to be a space plane because it's a mixture of rocket, spacecraft, and airplane. The orbiter launches astronauts into Earth orbit, performing on-orbit operations, then re-enters the atmosphere and lands like a glider to return the astronauts to earth. Three main engines are connected on the Orbiter. These three engines can swivel 11 degrees up and down and 8.5 degrees from side to side during ascent. This is to change the direction of the thrust and steer the shuttle, this is in accordance with Newton's 2nd law of motion since the shuttle is accelerating in the direction the force is being applied which depends on the directions of the engines.

The Space Shuttle External Tank contains the liquid hydrogen fuel and liquid oxygen oxidizer and supplies them under pressure to the three space shuttle main engines in the orbiter during lift-off and ascent. The External Tank is ejected from the space shuttle around eight and a half minutes after launch. This is because the main engines are no longer needed for the space shuttle so the external tank has no use anymore.

The solid rocket boosters provide the main thrust to lift the Space Shuttle off the pad and up to an altitude of about 45.7 km. Also, the two Solid rocket boosters carry the entire weight of the external tank and orbiter and transmit the weight load through their structure to the mobile launcher platform. These are also ejected from the space shuttle, but unlike the external tank, is reusable.

The fundamental reason why space shuttles will rise into the atmosphere is that the force applied in an upwards motion on the space shuttle will be larger then the gravity applied by the earth. This is in accordance with Newton's third law of motion. The force that is applied downwards from the engines to the ground must have an opposite reaction, since momentum is conserved. This opposite force is applied upwardly and causes the space shuttle to liftoff. As I mentioned earlier, the main thrust that is applied is given by the solid rocket boosters which provide about 83% of the total thrust, and in total has a force of 11, 520 kN on the space shuttle.

Once the space shuttle has reached a high enough altitude and speed, it may, depending on the mission of the space shuttle, start to orbit around the earth in a stable orbit. This can be done without the need for steering as the space shuttle is being acted upon by the Earths gravitational force. This can be explained using one of Sir Isaac Newton's propositions. While he was working on his theory of gravitation, he was observing the Moon and then he reasoned that if the force of gravity from Earth was not acting on the Moon, it would travel in a straight line, tangent to its orbit. He then concluded that the moon was falling but was traveling fast enough to fall all the way around the earth. He displayed this by conducting an experiment where he shot a cannonball horizontally with low speed from the top of a mountain, then another cannonball horizontally at a