The telescope is being built to replace the Hubble, which has long outlived its lifespan. It has longer wavelength coverage than the Hubble and has greatly improved sensitivity, giving it the power to detect light from the first galaxies that formed after the Big Bang. The telescope can also be used to observe the atmospheres of nearby exoplanets to look for signs of habitability.
The James Webb team still has to complete a set of “extremely difficult environmental tests” before the observatory can be shipped to its launch site in Kourou, French Guiana. If everything goes well and the pandemic doesn’t cause additional issues, the telescope will be folded “origami-style” for shipment and will be fitted inside its launch vehicle early next year.