Revolutionizing Rocket Science

We live in the 21^st century, where it is the age of science and technology dominating almost every aspect of life and things related and necessary for supporting a lifestyle. In the previous century, we learned and slowly mastered the science of flight. In 1905, the world witnessed the first flight technically achieved. And nowadays, many records are set in space flight and technology such as sending multiple satellites through a single space shuttle. It is all admirable, but we really need to know the little background behind it such that we can marvel at the very wonder about how these spacecrafts reach the skies no one ever imagined about. And the main reason for that is the engine of the rocket. The powerhouse, which creates enormous thrust in order to help the rocket break the barrier of atmosphere at 11.2km/s (escape velocity) and reach into the depths of space.

          A rocket engine uses stored rocket propellant mass for forming its high-speed propulsive jet. Rocket engines are reaction engines, obtaining thrust in accordance with Newton’s third law. Most rocket engines use combustion, although non-combusting forms (such as cold gas thrusters) also exist. Vehicles propelled by rocket engines are commonly called rockets. Since they need no external material to form their jet, rocket engines can perform in a vacuum and thus can be used to propel spacecraft and ballistic missiles. Compared to other types of jet engines, rocket engines are by far the lightest, and have the highest thrust, but are the least propellant-efficient (they have the lowest specific impulse).

          It has a very specific set of operations before the launch off the ground. It produces the thrust by expelling the fuel that is stored in the chambers by a combustion reaction. Combustion is most frequently used for practical rockets, as high temperatures and pressures are desirable for the best performance, permitting a longer nozzle, giving higher exhaust speeds and better thermodynamic efficiency.

          The efficiency is very important factor in the propulsion engine, and the main factor is the high amount of pressure difference in the ambient pressure and chamber pressure as it is the only main source of the thrust creation.

          In previous times, the liquid fuels were used for propellent engines, but they had their own disadvantages and drawbacks that made the engines degrade their performance and hence the flight was having less duration due to limited outcome of fuel energy. Generally, liquid oxygen was used as a propellent fuel, but it combined with nitrogen gas to give the toxic fumes of nitric oxide or dinitrogen tetroxide, therefore severely affecting the efficiency of the rocket. Similarly, of the liquid propellants used, density is worst for liquid hydrogen. Although this propellant is marvellous in many ways, it has a very low density, about 1/14^th that of water. This makes the turbopumps and pipework larger and heavier, and this is reflected in the thrust-to-weight ratio of engines that use it (for example the Space Shuttle Main Engine) compared to those that do not (NK-33).

An alternative in the aerospace technology is being tested and introduced; known as ion fuel technology. Ion thruster or ion drive is a form of electric propulsion used for spacecraft propulsion. It creates thrust by accelerating positive ions with electricity. The term refers strictly to gridded electrostatic ion thrusters, and is often incorrectly loosely applied to all electric propulsion systems including electromagnetic plasma thrusters.

An ion thruster ionizes a neutral gas like Xenon by extracting some electrons out of atoms, creating a cloud of positive ions. These thrusters rely mainly on electrostatics as ions are accelerated by the Coulomb force along an electric field. Temporarily stored electrons are finally reinjected by a neutralizer in the cloud of ions after it has passed through the electrostatic grid, so the gas becomes neutral again and can freely disperse in space without any further electrical interaction with the thruster. Electromagnetic thrusters on the contrary use the Lorentz force to accelerate all species (free electrons as well as positive and negative ions) in the same direction whatever their electric charge, and are specifically referred as plasma propulsion engines, where the electric field is not in the direction of the acceleration.           However, many theories and models were proposed and tested throughout the 20^th century, its applications are being put forth lately. This technology could bring the less area and greater pressure built-up in the gas chambers hence creating more thrust and more efficiency. The endurance of the engines is increased by very high amount due to this technology. We can expect this technology to reach even further heights in upcoming time, maybe harnessing the energy from heavier atoms than Xenon, like Radon and other radioactive elements which readily emit energy. That energy can be channelized in such a way that the energy emitted from those atoms could be utilised in order to increase the life of rocket, enabling the mankind to explore further depths of the expanding universe and understand how it works.