Electric Propulsion (EP) Technology: Meaning, Features and ISRO’s Achivements

Electric Propulsion (EP) technology uses solar energy to convert it into electrical power to enhance the propulsive performances of the satellite system. ISRO has been working since long to develop the Electric Propulsion System. This system was first used by ISRO in 2017 as a technology demonstrator in GSAT- 9 or the South Asian Satellite. This system converts solar energy available in space into electrical energy, which is then used to change the velocity of a satellite in space. This system, therefore, reduces the use of chemical propellant for carrying out propulsive action of the satellite.

Why it is required?

Currently, a 2,000-kg INSAT/GSAT-class communication satellite carries 800-1,000kg of chemical propellant. This chemical fuel is required for transferring the communication satellite from geosynchronous orbit to geostationary orbit. The new electric propulsion system will reduce the need of satellite to carry the chemical propellant in space because it is capable of converting solar energy available in space to electric energy and then use this electric energy for the satellite propulsion. Thus, the new system will promote cost effective satellite launches.

Salient Features of the New Electric Propulsion System

• Electric Propulsion system helps in orbit correction of a satellite
• It helps in maintaining a satellite on its path during its entire life duration of 10-12 years.
• This system provides small but accurate thrust to a satellite in its orbit.
• The new system converts solar energy available in the space into electrical energy and later to kinetic energy by generating thrust that propels a satellite.
• The system is provided with a solar panel and components for charging ions
• It reduces the quantity of chemical propellant carried on a satellite thereby increasing the payload capacity of the vehicle
• This system has been already tested by Russian space agency and NASA. It has immense capability to eventually lower the cost of launches.
• Recently, ISRO has planned to launch GSAT-20, based on electric propulsion technology which has helped in reducing the weight of the satellite to just 3.5 tonnes.

End Notes

Though the new system will reduce the need of satellite to carry the chemical propellant, the end weight reduction is only to the tune of 100-200kg, which is very less. This is because the chemical propellants act as the back-up power for correcting the orbit of the spacecraft. However, as per other space agencies like NASA and Russian Federal Space Agency (RFSA or Roscosmos), this new technology has huge potential and will be capable of lowering the cost of launches significantly in the near future.