The Past, Present and Future of Rocket Propulsion Engines | Ionic Propulsion
History of jet engines and rocket propulsion
Before World War II, in 1939, jet engines primarily existed in labs. The end of the war, however, illustrated that jet engines, with their great power and compactness, were at the forefront of aviation development. This is when the jet propulsion engines were first developed.
Present situation of propulsion system
A jet engine is a type of reaction engine which discharges a fast-moving jet that generates thrust by jet propulsion. This broad definition includes air breathing jet engines (turbojets, turbofans, ramjets, and pulse jets).In general, jet engines are combustion engines.
In case of rocket propulsion, 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. 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).
Limitation of present propulsion systems
The fuel efficiency of jet engines and rocket thrusters is very poor.
A plane like a Boeing 747 uses approximately 1 gallon of fuel (about 4 litres) every second. Over the course of a 10-hour flight, it might burn 36,000 gallons (150,000 litres= 86400$). According to some sources Boeing's 747 burns approximately 5 gallons (12$ per second) of fuel per mile (12 litres per kilometer).
And in the case of rocket thrusters, it uses approx 1 million dollars of propulsion to give thrust for just 150 second. That's a huge amount of money and energy resource wastage!!
All these stats provoked to a need for advancement and change in present propulsion technology and scientists of NASA came up with a new propulsion theory.
'IONIC PROPULSION' - The next generation flying machine.
The jet propulsion and rocket thrusters are causing too much loss of money and fuel. For this, scientists came up with an idea of ionic propulsion, an revolutionary idea of propulsion by using just ions of an atom or by just using plasma.
An ion thruster ionizes a neutral gas by extracting some electrons out of atoms, creating a cloud of positive ions. This creates thrust by accelerating positive ions via electricity.
From a very low fraction of fuel, propulsion for more than 5 days can be produced. This gives a very less amount of thrust, but can give that thrust consistently for a very long duration of time.
Why can't we use it right now?
The main reason is due to it's low speed of propulsion. It accelerates at a really dumb speed (around 24 miles per hour) which can't be used for aviation purposes. That's why these can't be used in jets at this moment but maybe after future enhancements.
But according to NASA, these engines can become very useful for using it in spacecrafts for travelling into the space.
There isn't any fuel source in space, making it hard to travel far planets.
So with these ionic thrusters, due to their good fuel economy and very light weight, they can be used to travel to some really far planets and help us find new life forms.
Or thousands of mini satellites can be sent into a far far away galaxy using a single rocket, making a huge network around that galaxy and a chain of satellites which it leaves on its way to the galaxy will transmit those information to the earth's base satellite using a chain of signal transmissions using some optical or other means of wireless communication. By learning about other life forms, we can study about their survival, do researches for human evolution and other activities.
Can you imagine how revolutionary is it?
But this technology still needs advancements for proper use in spacecrafts and making it practical for aircrafts too.
-Gurjit Singh Bitta