NASA's James Webb Space Telescope unfolded the second "wing" of its massive primary mirror today (Jan. 8), marking the end of its complex deployment.

The James Webb Space Telescope's 21.3-foot (6.5 meter) diameter primary mirror. (Image credit: NASA/C. Gunn) Aside from its hexagonal shape and enormous size, Webb's most distinctive feature is ...

The primary mirror of NASA's next generation James Webb Space Telescope (JWST) opened for the last time on Earth before the expected launch of the observatory on October 31, 2021.