2 Weeks after Launch, Webb is Fully Unfolded

Credit: NASA

2 Weeks after Launch on an Arianespace Ariane 5 rocket, the James Webb Space Telescope is now fully unfolded! Commissioning Operations began as soon as Webb separated from the Ariane 5 upper stage after launch on December 25, 2021. The James Webb Space Telescope is so large that it had to be folded to fit into the payload fairing of the Ariane 5 ECA rocket. After early deployments that started soon after separation, the sunshield, the large silver "base" of Webb that keeps it dark and extremely cold (below -300 degrees Farenheit!), unfolded between L+3 and 10 days after launch. After that, sunshield tensioning began, which means the sunshield expanded like a concertina. That was completed about 10 days after launch. With the sunshield fully deployed, the teams at the Space Telescope Science Institute at Baltimore, Maryland could start deploying the two mirrors. The Secondary Mirror, which is just in front of the Primary Mirror, is used for directing light to the Primary Mirror. It was deployed 11 days after launch. Then 13 days after launch, the teams unfolded the starboard (or right) mirror segment of the Primary Mirror. The same thing happened to the port (or left) mirror segment at L+14 days (January 8). Even though the JWST Primary Mirror is fully deployed, commissioning operations are not over. Teams will now direct light into the primary mirror. They also will unfold 18 smaller mirror segments until L+26 days. At L+29 days Webb will be inserted into its L2 orbit, a million miles away from Earth. L2 is a Langrange point, which are points in Earth's orbital path. L2 is about one-fourth behind Earth in its orbit around the Sun. Webb is planned to observe light coming from the beginnings of the universe. It will observe our Solar System, distant stars, blach holes, and distant exoplanets (planets beyond our Solar System).