Science as a Human Endeavour: Newton’s Laws Spaceflight It was March the 16th 1926 when the first modern liquid-fuelled rocket was launched by Robert Goddard. On the 12th of April, 35 years later (1961) Yuri Gagarin became the first man to orbit the earth in Vostok 1. These milestones were only made possible because of the understanding of the laws of physics and their application in space technology. Sir Isaac Newton, a British mathematician and scientist born in 1642, is known as one of the most influential scientists in all of time. Newton discovered what are known now as ‘Newton’s 3 Laws of Motion.’ A force can be described as anything that causes change. The four forces in the universe consist of Gravity, Electromagnetic, Strong Nuclear …show more content…
When the engines ignite the rocket’s thrust unbalances the forces and the rocket is propelled upwards. When far away enough from any sources of gravity in space, the rocket will be free from any unbalanced forces and therefore remains in its state of motion. To put this scenario into Newton’s First Law it can be interpreted as, ‘when the rocket is at rest it requires an unbalanced force to make it move. If the rocket is already in motion it requires an unbalanced force to stop it or change its direction or …show more content…
The larger the mass of the object, the more force required to accelerate it. This law sums up what most people are commonly aware of, the heavier the object the more difficult it is to move. A rocket must burn a large mass of fuel and eject it as fast as possible. Newton’s second law is utilised in rockets and spacecrafts: ‘the more fuel burned, the faster the gas produced can escape the engine and therefore the thrust of the rocket will be greater.’ The third and final law of motion states that for every action there is an equal and opposite reaction. This law means that for every force there is a reaction equal in size but opposite in direction. When an object pushes another object, it receives the same force back in the opposite direction equally as strong. The action of the gas being expelled out from the spacecraft engine demonstrates Newton’s third law. From this action the rocket is pushed upwards (in the opposite direction). For a rocket to successfully lift off the launch pad the thrust from the engine must be greater than the mass of the rocket. In space however, even the tiniest of thrust will cause the rocket to change direction. Rockets are more effective in space than in air. When exhaust gas leaves the engine, it must push away the surrounding air, this uses up energy. This is why in space rockets work with more efficiency as the exhaust gasses can escape