Rockerty Report - Robert Hutchings Goddard

Rocketry Report

By: Alexis Dewitt

9/27/11 Block: 4

The first person to develop rockets was Robert Hutchings Goddard. Goddard used them for finding methods to raise weather recording tools higher than sounding balloons. While conducting that he discovered mathematical theories of rocket propulsion. By 1926, Goddard had triumphantly made and tested the first rocket using liquid fuel. Coincidentally, Robert Goddard also first developed liquid fuel rockets. This was a significant breakthrough because it led to more experimenting on how to go beyond earth's atmosphere. His first launch only went 41 feet but in time they were climbing to thousands and only helped perfect rockets in the near future. The first multistage rocket was developed in 1914 when Goddard got a U.S. patent for it. This was a tremendous breakthrough because it drops mass throughout the burn so it can go higher up.

There are 3 Newton's laws of motion. Newton's first law states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. Newton's second law explains how force is equal to the change in momentum (mV) per change in time. For a constant mass, force equals mass times acceleration. Newton's third laws tells how for every action, there is an equal and opposite re-action. Well, Newton's first law applies to the launching and flight of rockets because when a rocket is at rest gravity is acting on it so it won't go anywhere. The force needed to do so would have to be massive not only to get it going but also to overcome the gravity pushing on the rocket while at rest. Newton's second law applies because the bigger the mass of the rocket, the more force is needed to accelerate. The smaller the rocket, the less force is needed to launch the rocket. Newton's second law can be related as the greater the mass of rocket fuel burned, and the faster the gas produced can escape the engine, the faster the force of the rocket. Newton's third law applies because the liquid or gas rushing out the back is an action force while the rocket propelling up is a reaction force. The law of conservation of momentum helps explain how a rocket launches because before launch, the rocket is at rest on the launch pad, so its momentum is zero. When the rocket is shot off, water or gas is pushing up from the back of the rocket. The total momentum of the rocket and fuel must remain zero. The escaping gas and the rocket itself are traveling in opposite direction. So the rocket must have a momentum equal to the leaving substance but in an opposite (positive) direction. Therefore, the rocket goes up.

In class we discussed the use of nosecones and fins and how they help the rocket in different ways. It is good to use 3 small, even fins on your rocket. It helps balance it out