The Wait Was Worth It

After more than 25 years of development and delays, the James Webb Space Telescope has left Earth.

The James Webb Space Telescope
JM Guillon / ESA

KOUROU, French Guiana—More than 25 years ago, the Next Generation Space Telescope was mostly a dream, an idea for a complex instrument meant to see farther than Hubble ever could, which no one had ever attempted to build. A few years ago, the dream was ready to be assembled into a real observatory—gold-covered mirrors, sensitive instruments, a sophisticated sun shield. A couple of months ago, that telescope sailed on a ship to a spaceport here in South America, and two days ago, tucked safely inside the tip of a rocket, it was pulled to the launchpad, its final stop on Earth.

And then this morning, the space telescope was airborne. The observatory, now known as the James Webb Space Telescope, named after a NASA administrator from the Apollo era, throttled into the sky on Christmas Day, trading the humid air of the French Guyanese jungle for the cold darkness of outer space. The observatory left Earth folded up and must now carefully unfurl itself in a dramatic, unprecedented deployment on the way to its orbit 1 million miles away. Webb carries the hopes of countless scientists into the expanse, and, if the process works, it will have a deliciously unobscured view of the cosmos.

The mission, an international project led by NASA, is designed to look deep into the universe to reveal the faint light of the first stars and galaxies, which helped give rise to everything else. As much as any nonhuman cargo can be, the Webb telescope is precious. No other instrument has done what Webb can do. It also cost $10 billion.

The engineers responsible for assembling Webb and getting it off the ground are now exhaling. Their moment in this long effort is over. But the engineers in charge of deploying the observatory, as well as the scientists eager to use it, are taking a deep breath, ready for their own big moment—and the one after that, and the one after that. “There are some people whose jobs ended years ago on the telescope,” Elaine Stewart, an aerospace engineer at NASA, told me before launch, as we stood looking at the Ariane 5 rocket that launched Webb. “And there are some people whose job is just about to begin.”

Some of Webb’s next steps will be more stressful than a rocket launch. If everything works, if every new juncture—and there are a lot of them—ends with a sigh of relief, Webb’s instruments will switch on, and its radiant, gold-coated mirrors will begin the work of searching the darkness to show us more of everything. If it doesn’t work, well, no one wants to think about that just yet.


Telescopes are, in a sense, an extension of human perception. The technology has moved our eyes beyond Earth’s boundaries to other planets and moons, asteroids and comets, distant stars and galaxies. The Webb telescope will study these and many other astronomical phenomena, but its founding purpose is to stretch our view into the cosmos even farther.

Webb will observe the universe in infrared, the perfect wavelength for catching ancient light from early stars and galaxies. The more distant a galaxy is from Earth, the faster it’s moving away from us, tugged along by the expansion of the universe, which has been whirring since the Big Bang. By the time the well-traveled light from those early galaxies reaches us, the cosmos has stretched it so much that we can no longer detect it as visible light, which is Hubble’s specialty. Hubble has managed to capture galaxies as they were about 500 million years after the Big Bang, but Webb should reveal an even older landscape, giving humanity a firmer grasp on how it all began.

NASA and its partners in the mission, the European Space Agency and the Canadian Space Agency, began working on Webb in 1996, some years after astronomers first floated the idea of building an infrared telescope. In 2002, the NASA administrator at the time decided to rebrand the Next Generation Space Telescope as the James Webb, a choice that surprised the international community of scientists working on the project, many of whom bristled at the idea of naming a mission after a government administrator, even one who had overseen NASA as the agency developed the Apollo moon missions. Earlier this year, a group of prominent scientists organized a petition demanding that NASA rename the project, pointing to James Webb’s connection to government policies in the 1940s and ’50s that discriminated against LGBTQ people. In October, after an internal review of Webb’s public record, NASA’s current administrator said that historians had not found sufficient evidence to warrant changing the name.

That same month, the telescope arrived in Kourou, a small coastal town in French Guiana, on the northeastern coast of South America. The European Space Agency oversaw launch services for the mission, and Arianespace, a European company, launches those rockets only from here, a few hundred miles from the equator, where departing missions can take a swig of momentum from Earth’s spin. Stewart had her big moment in Webb’s preparations during the weeks just before liftoff. She and her team traveled to Kourou to make sure the telescope was absolutely spotless. Small particles, even certain molecules, can hinder operations, so Stewart and her colleagues inspected every bit of hardware for contaminants, especially on the mirrors. Imagine looking at your reflection in a mirror spotted with grease or dust. Enough contaminants could smudge Webb’s view in a similar way, she said, and “we would not be able to see as much.”

The next six months will involve a series of careful maneuvers for Webb—some automated, others manual—that will test the nerves of everyone involved. NASA is accustomed to deploying rigid pieces of hardware, not floppy contraptions like Webb’s sun shield, which must fully expand so the telescope can cool down to very frigid temperatures. The observatory’s instruments don’t stand a chance without the sun shield, but they can also snag the cover as it opens. Engineers have spent years developing all kinds of contingency plans, including shimmying the observatory around if something gets stuck and needs a jolt. “You convince yourself that Hey, I’ve done everything humanly possible,” Mike Menzel, the Webb mission’s lead systems engineer at NASA, told me earlier this month. “There’s a lot of bad things that can happen. But all the things that I could plan for, I have planned for.” If one of those bad things does happen and it can’t be fixed, even with the perfect shimmy, years of work could be undone in an instant.

Unlike Hubble, Webb wasn’t designed with future repair missions in mind. Astronauts can’t fly to Webb to make any fixes, as they’ve done on four occasions for the other telescope. When the observatory runs out of fuel more than 10 years from now, its watch over the universe will end. Future robotic spacecraft could, in theory, sidle up to Webb, open its gas cap, and refuel it. Thomas Zurbuchen, NASA’s associate administrator for science missions, declared publicly for the first time yesterday that if Webb works, the agency will devote resources to achieving that future. “I’m going to put all the effort toward developing that technology,” Zurbuchen said. But “I am not going to start putting money into it before we’re there,” he told me.

Webb has been one of the most expensive, most delayed missions in space history. Some elements of the observatory have been finished for a decade now. A project this massive is full of people with their own expertise, their contributions clicking into place over time. Who feels the most nervous about the mission right now? Is it the astronomer who has waited more than 25 years to use Webb for his research, or the astronomer who was born 25 years ago and is now staking her career on it? The person who built an instrument a decade ago, or the last technician to add a final touch to the observatory before launch? All of the above, probably.

The people whose job it was to launch Webb today are certainly relieved, and they can continue their tradition of celebrating the big moments. There’s a room at the spaceport with shelves lined with dozens of champagne corks from every successful launch, interspersed occasionally with water-bottle caps—the mark of a failed launch that means it’s time to get back to work, Julio Aprea, a European Space Agency engineer who works on Ariane rockets, told me.

A couple of days before launch, Mark McCaughrean, who joined the project 23 years ago and traveled to Kourou from the Netherlands, was almost in disbelief that the telescope was finally ready to go. “I think at some point, you almost don’t expect it to happen,” McCaughrean, a senior adviser at the European Space Agency, told me earlier this week, when we met at the spaceport. The astronomy community must now adjust to a strange new reality in which Webb isn’t stuck on Earth but exists in space at last. With every successful step, every exhale after a smooth deployment, scientists get closer to actually using this powerful tool. “We’ve always known that this project would be a risky endeavor,” NASA Administrator Bill Nelson told reporters earlier this week. “But of course, when you want a big reward, you have to usually take a big risk.” We may learn a little bit of everything through Webb’s view of the cosmos—or nothing at all.

Marina Koren is a staff writer at The Atlantic.