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The James Webb Space Telescope Has Reached Its Final Form


To the world, the new telescope that NASA recently launched to space is one of the most ambitious scientific endeavors in history. It is the next Hubble, designed to observe nearly everything from here to the most distant edges of the cosmos, to the very first galaxies.

To Jane Rigby’s son, it’s “mama’s telescope.”

Rigby, an astrophysicist, used to bring her young son to the NASA center in Maryland to watch the James Webb Space Telescope being assembled. They would stand together on an observation deck overlooking a giant, glass-walled room and watch the technicians, dressed head-to-toe in protective garments to prevent contamination, do their work. Over the years, they saw the observatory’s 18 mirrors—tiles of a lightweight metal called beryllium, coated in brilliant gold—installed, one by one, then the science instruments bolted into place. “It took him a while to figure out that not everybody has a telescope at work,” Rigby told me. “I remember him asking my wife, ‘So where’s your telescope at work?’”

Rigby’s son, now 8 years old, watched Webb’s historic launch on a livestream on Christmas morning. Webb, a NASA-led international mission, left Earth from a European spaceport in French Guiana, in South America. After the telescope made it into space, controllers in the United States took over. Engineers had carefully crumpled the massive observatory, folding up its pieces of hardware, so that it could fit on top of a rocket. Now, in space, it was time for Webb to unfurl.

NASA had never attempted such a complicated deployment before, and there were hundreds of ways that the process could go wrong. If an important part became stuck—really, truly stuck—NASA would have to face the painful reality of abandoning its brand-new, $10 billion mission. Over the past two weeks, Webb’s stewards have worked nearly nonstop, trading 12-hour shifts, checking and rechecking data as hundreds of little mechanisms clicked into action.

And this afternoon, one final piece slid into place. The deployment, the scariest part of the mission—the one that astronomers and engineers have dreaded for years—is over. Rigby was in the mission-operations room at the Space Telescope Science Institute, in Baltimore, when they called it. Webb, once compact and curled up, has finally become a real space telescope.

The Webb telescope, named after a former NASA administrator, left Earth in a thundering launch from a rain-forest-ringed spaceport. The mood in town in the days before launch was cheery optimism, with an undercurrent of low-grade panic. When I asked the engineers and scientists there about the launch, they would make a bit of a nervous face before returning to a confident expression. The launch wasn’t the scary bit; Webb was riding on one of the most reliable rockets in the industry. The deployment sequence was another story. When I asked them about that, their face would turn into a perfect imitation of the grimace emoji. Astronauts managed to build the International Space Station in orbit, yes, and to repair the Hubble Space Telescope when it needed fixing. But they wouldn’t be able to help Webb after it launched. The mission is a very complicated series of “this has to work” moments. If something had jammed during deployment and couldn’t get unstuck, the next Hubble would have become a new piece of space junk.

The first “this has to work” moment came just a half hour after Webb launched. The observatory released its solar panel, stretching it like an insect arching a wing toward the sun. Now the observatory could power itself and could move on with ever more complex steps on the checklist that has consumed the scientists until today.

From there, the deployment sequence reminded me of The Great British Bake Off, a cosmic version of the Showstopper Challenge. Like the bakers, engineers had presented the world with a picture of what their beautiful space telescope would look like in the end, and now they had to make it happen. Astronomers around the world, eager to use Webb’s data in their research, braced themselves for some kind of catastrophe to topple the effort. They ran into a couple of issues, but managed to adjust; when some motors became a little overbaked by the sun, for example, engineers shifted the observatory slightly away to reduce the heat. Some employees tested positive for the coronavirus and isolated themselves at home, where they continued working remotely.

The release of Webb’s diamond-shaped sun shield, the cover that will protect the observatory’s mirrors and instruments from our star’s glare, was undoubtedly the most stressful part. The five-tiered shield is the size of a tennis court, and each layer is made of material as thin as a human hair. Engineers had warned, in the days before launch, that this sun shield, floppy and unpredictable, could snag and potentially doom the whole mission. But earlier this week, each layer snapped into its final position, just as engineers had imagined. “We’ve nailed it,” Alphonso Stewart, Webb’s deployment systems lead, told reporters after it happened. And then this morning, engineers completed the last big “has to work” moment, moving the telescope’s mirrors into their final honeycomb shape.

Perhaps few are more surprised at this outcome than some of the people who work on the mission itself. Engineers had tested and retested every bit of the observatory on the ground, and determined that they had done their best. But Webb, a project 25 years in the making, is extremely complex, and experienced some nerve-wracking technical problems during development. NASA raised the specter of failure so often that I began to wonder whether everyone was part of a mass delusion about Webb’s chances, fueled by the agency’s mantra of “failure is not an option.” Before the launch, I spoke with Mike Menzel, the mission’s lead systems engineer at NASA, about the high-stakes deployment. “You convince yourself that, Hey, you know, I’ve done everything humanly possible,” he said. “Sure, there’s bad things that can happen. There’s a lot of bad things that can happen.” But those bad things haven’t happened, at least not yet.

Webb still faces other important milestones ahead. Some adjustments to those gold-plated mirrors; one more burst from the observatory’s thrusters to propel it deeper into space. It will be weeks before Webb’s science instruments switch on and start operating, and several months before the public sees the first glorious images—before the mission can be truly deemed a success. Webb is still making its way to an orbit 1 million miles from Earth, where the telescope will have an unobscured view of the universe. A few days ago, an amateur astronomer caught a glimpse of it in the night sky: a faint, silver splinter—the sun shield, coated in aluminum—cutting through the darkness. The light of distant galaxies has already reached Webb’s shiny mirrors and still-slumbering science instruments. Soon, the rest of the telescope will waken and start to make sense of it.




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