ESA) Euclid mission is designed for launch in 2020 to study some of the least understood aspects of our universe. Dark Energy and Dark Matter comprise 95% of the universe that we live in, yet very little is known about either one of these things. Dark Energy makes of about 70% of the universe and is thought to be the major reason that all space everywhere is pushing all the rest of the space away from it, causing an expanding universe. Dark Matter, totaling about 25% of the universe is thought to be key to understanding why galaxies form and move the way that they do and how galaxy clusters plus even larger filaments formed after the big bang are able to keep their formations. Now NASA wants to join in on this mission to explore the universe by contributing about 20 special detectors that are to be used on the Euclid satellite. NASA will also be adding 40 new members to the Euclid team in addition to the 14 scientists already supporting the mission by developing instruments, managing operations and going over the collected data.
Lagrange point L2. This is the location in space where gravitational forces from the Earth and the Sun balance out, allowing the Euclid spacecraft to maintain a position 1.5 million kilometers directly ‘behind’ the Earth as viewed from the Sun. The location will allow the spacecraft to keep this position relative to the Sun and the Earth without having to expend fuel and allowing it to be far enough from the Earth so that there is no interference with the observations. There is also no orbiting of the Earth or the Moon, so that the spacecraft will not heat up and cool down from passing through the shadows of either the Earth or the Moon. These shadows can cause the spacecraft to heat up and cool down, which directly affects the distortion of the view.