The James Webb Space Telescope (IMAGE) University of Copenhagen Caption The James Webb Space Telescope, whose primary mirror has a diameter of 6.5 meters, will be launched in 2021. It is the designated successor of the Hubble Space Telescope. Credit NASA / ESA / MPIA Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.