Artist's impression of the James Webb Space Telescope

The James Webb Space Telescope (Webb) will be the largest, most powerful telescope ever launched into space. It follows in the footsteps of the Hubble Space Telescope as the next great space science observatory, designed to answer outstanding questions about the Universe and to make breakthrough discoveries in all fields of astronomy.

Webb will reveal the hidden Universe to our eyes: stars shrouded in clouds of dust, molecules in the atmospheres of other worlds, and light from the first stars and galaxies. With its suite of state-of-the-art instruments, Webb will push the frontiers of our knowledge of the Solar System, of how stars and planets form, and of galaxy formation and evolution, in new ways.

The telescope will launch on an Ariane 5 rocket from Europe’s Spaceport in French Guiana. From there it embarks on a month-long journey to its destination orbit around the second Lagrange point (L2), about one and a half million kilometres from Earth. In the first three weeks after launch, Webb will unfold its sunshield, which is the size of a tennis court, and then deploy its 6.5-metre primary mirror that can detect the faint light of distant stars and galaxies with a sensitivity a hundred times greater than that of Hubble.

Webb is an international programme led by NASA with its partners, the European Space Agency (ESA) and the Canadian Space Agency (CSA).