Why in news?
The European Space Agency (ESA) is building Air-Breathing Electric Thruster (ABET) that can possibly extend the working life of satellites by years and even help with interplanetary travel using just the air around it as a propellant.
FACTS FOR PRELIMS
An air-breathing engine works by collecting the sparse air at the edge of the atmosphere and compresses it to a point that it becomes thermalised ionised plasma.
It then fires out the plasma using an electric charge to achieve thrust. An air breathing thruster could keep a satellite operational for extended periods of time if it only uses the air around it for fuel instead of propellants.
This Air-Breathing Electric Thruster (ABET) does not operate in complete vacuum, but works in low Earth orbit (LEO) – altitude of 2,000 km or less– notes the ESA.
At LEO, the air is scarce, but not entirely absent. In fact, there is enough air to cause a drag on spaceships and satellites. This is why there are on-board engines installed on satellites to correct course every time it moves out of position.
SOURCE – THE HINDU.