Development of the James Webb Space Telescope (JWST) stretches all the way back to the mid-90s. No one at the time could have anticipated how long it would take to get the monstrously complex instrument built, but we’re in the home stretch now. Engineers at Northrop Grumman’s facilities in Redondo Beach, California have assembled the two halves of the telescope for the first time. It’s not quite ready for launch yet, but it’s finally starting to look like the renders we’ve seen for years.
The James Webb Space Telescope is NASA’s successor to Hubble, which is still working after more than a quarter-century. However, that telescope hasn’t had a service mission since the Space Shuttle was retired, and some of its components are starting to fail. The JWST won’t just replace Hubble; it will massively expand our ability to observe distant objects. It’s also a much more complex piece of technology. It uses a larger multi-segment beryllium mirror, and the high infrared sensitivity means it needs a deployable sunshield to protect the instruments.
Engineers constructed the telescope in two halves out of necessity. There’s the Webb telescope itself with the mirrors and scientific instruments, and then the spacecraft frame with the sunshield and communication equipment. Northrop Grumman temporarily connected the two halves last year to make sure they could communicate with each other, but now they’re physically connected in their final conformation. The team carefully moved the telescope over top of the spacecraft with a crane, and then lowered it into place, allowing engineers could link it with the frame. Northrop is now working to connect the electronics to get the two halves fully integrated.
The next step is for engineers to test the five-layer sunshield. After launch, the JWST will head near the Earth-Sun L2 Lagrange point almost a million miles away (1.5 million kilometers). If the sunshield doesn’t deploy properly, the telescope could be inoperative with no way to fix it. So, it’s absolutely vital the team makes sure it works before packing it up in the Ariane 5 rocket.
The current timeline, which has been delayed repeatedly, calls for the James Webb Space Telescope to launch in March 2021. It’s designed to operate for at least five years, but the team hopes for 10 or more. We can only hope it’s as successful as Hubble, which is nearing its thirtieth anniversary.