Beginning no earlier than 9 a.m. EST, NASA will air live coverage of the final hours of Webb’s major deployments. After the live broadcast concludes, at approximately 1:30 p.m. [EST], NASA will hold a media briefing. Both the broadcast and media briefing will air live on NASA TV, the NASA app, and the agency’s website.
As the final step in the observatory’s major deployments, the Webb team plans to unfold the second of two primary mirror wings. When this step is complete, Webb will have finished its unprecedented process of unfolding in space to prepare for science operations….
Consisting of 18 hexagonal, gold-plated segments, the mirror is one of the telescope’s most visually striking components. The primary mirror needs to be large as this is directly related to how much light the telescope can detect, which makes it more accurate (via NASA). James Webb’s mirror is 6.5 meters (21ft) across, which is the largest ever launched into space. Compared to the 2.4-meter (7.8ft) mirror used on James Webb’s predecessor, the Hubble Space Telescope, this big mirror will help the telescope to see out further into space.
Engineers couldn’t just build a 6.5-meter (21ft) mirror like Hubble’s, though, because it would be too large and too heavy to launch. Instead, they built the James Webb mirror in segments made from beryllium, which is both lightweight and strong. These segments fold in on themselves to fit into the rocket, and now it is time for them to unfold into their final configuration.
“Once fully operational, Webb will explore every phase of cosmic history,” NASA announced, “from within the solar system to the most distant observable galaxies in the early universe, and everything in between. Webb will reveal new and unexpected discoveries and help humanity understand the origins of the universe and our place in it.”
SlashGear adds that “Having left Earth’s atmosphere and traveled over 250,000 miles away from our planet, it is now more than 70% of its way to its final orbit around the sun…”