Ion Thrusters

After launching satellite or any equipment in space by rocket they are to be placed in particular orbits or on particular path but sometime they tend to deviate from their path due to either gravity of other planet or debris in space ,which is not good, I mean they can crash or lost forever, so to maintain their path/orbit they need some thrust. They can’t be equipped with a chemical thruster as it would be heavy and the fuel supply needed is also huge, so we need something efficient, something which can provide sufficient acceleration for sufficient time. The concept of ion thruster is effective and satisfies all requirements for now but with proper development it can be used on large scale.

What is Ion Thruster or Ion Drive?

It is a kind of propulsion system which works by accelerating ions in the form of a concentrated beam to provide thrust to spacecraft. Now there are two types of such thrusters:

Electrostatic ion thruster-It works on the concept of electrostatics where ions are accelerated by Coulomb's force in the direction of electric field.

Electromagnetic ion thruster-It works on the concept of electromagnetics where ions are accelerated by Lorentz force and electric field is not in the direction of acceleration. 

Ion thrusters currently in use have an input of 1kW to 7kW and can change velocity of craft by 20 to 50 km/s. Efficiency of ion thrusters is about 80-90% whereas for chemical thrusters its 35%. The major benefit of this propulsion system is that they use electricity to ionize the noble gas and it can be easily available from solar panels or from nuclear power from miniature reactors  (they can be used where the sunlight is not efficient). Now all we need are noble gases like Xenon or Krypton which are expensive and rare but storage is no longer a problem. Xenon is preferred as it can be compressed and ionized easily but it is more expensive than krypton, Krypton is used in starlink constellations. 

The maximum force generated by ion thruster is equivalent to the force needed to hold a paper so it cannot overcome air resistance, thus this propulsion system currently cannot be used for launching purpose but with appropriate modifications in future it may be possible to use these thrusters for launch, but for now it can slowly accelerate the craft to higher velocities. This system is mainly used for maneuvers like increasing or decreasing orbits and for changing velocities. 

For present if we apply some modification to thrusters like increasing output thrust then we can shorten our time durations to mars or moon, all we need will be chemical rockets to get us in orbit of the Earth and from there ion thruster would help to reach our destination. It is matter of time when we find the key to such a propulsion system and explore the unknown but human kind is not going to stop till it finds the end of the Universe.