Why in news? European Space Agency (ESA) plans to survey billions of galaxies using the Euclid Space Telescope, which to be launched from Cape Canaveral in Florida

What is Lissajous orbit ?

• It is a quasi-periodic orbital trajectory that an object can follow around a Lagrangian point of a three-body system without requiring any propulsion.

What is Korsch telescope ?

• Korsch telescope or three-mirror anastigmat is an anastigmat telescope built with three curved mirrors, enabling it to minimize all three main optical aberrations – spherical aberration, coma, and astigmatism.
• This is primarily used to enable wide fields of view, much larger than possible with telescopes with just one or two curved surfaces.