Ion thruster is basically a much better and faster propulsion system than any other propulsion system already in use.
It sounds like an assertive claim. But you can belive it. Its superior than chemical propulsions in many ways.
Its an electric propulsion created by accelerating ions. By the method of accelerating ions these thrusters differ as electrostatic and electromagnetic ion thrusters.
Copyright: ESA, Illustration Medialab
In my opinion they are better than chemical thrusters in many ways.
-Power and speed of the spacecraft
-The range of a spacecraft.
-Cruising cost
-Pulse preciseness
I will try to explain...
Conventional chemical spacecraft propulsion systems create thrust by thermodynamically expanding heated propellant as through a nozzle. Which can be effective but these systems are limited by the available reaction energies and thermal transfer considerations to exhaust gas velocities of a few thousand metres per second. Electric/electromagnetic propulsion can produce a higher velocity increment for the vehicle.
Comparison of propulsion technologies
| |||
Chemical
|
Electric
| ||
Small monopropellant thruster
|
Fregat Main Engine (S5.92M)
|
SMART-1 Hall Effect Thruster(PPS-1350)
| |
Propellant
|
Hydrazine
|
Nitrogen tetroxide / Unsymmetrical dimethyl hydrazine
|
Xenon
|
SpecificImpulse (s)
|
200
|
320
|
1640
|
Thrust (N)
|
1
|
1.96 x 104
|
6.80 x 10-2
|
Thrust time (s)
|
1.66 x 105
|
877
|
1.80 x 107
|
Thrust time (h)
|
46
|
0.24
|
5000
|
Propellantconsumed (kg)
|
52
|
5350
|
80
|
TotalImpulse (Ns)
|
1.1 x 105
|
1.72 x 107
|
1.2 x 106
|
Fregat produces ~ 14 times the total impulse of SMART-1's engine, but uses nearly 70 times more propellant mass to do so. The hydrazine thruster produces less than a tenth as much total impulse while using 65% of the propellant mass.
| |||
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=34201
Another limitation of any chemical propulsion system faces is the storage of the energy or storage of the source of the energy. There are two problems of storage. First it can store a limited supply second they are big and heavy. Bigger and heavier objects are harder to carry to space.
While chemical propulsion systems store their energy in the propellants, the energy required by electric propulsion systems is generated by solar panels so there is no storage to carry to space and there is no limited energy source.
Thats why this could be the only way for mankind to explore outer space.
Applications
"The Variable Specific Impulse Magnetoplasma Rocket, or VASIMR, uses radio waves to create and speed up free-flying, electrically charged particles known as plasma. The concoction is then herded through nozzles made of magnetic fields, not metals like traditional rocket engines."
http://dsc.discovery.com/news/2008/08/07/plasma-rocket.html
LISA Pathfinder
Which is a very important part of space flight and navigation.
http://www.esa.int/esaSC/120397_index_1_m.html#subhead7
http://www.rssd.esa.int/index.php?project=LISAPATHFINDER
References
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