02 Webb Space Telescope

For delivering the most powerful telescope ever built—and opening up galaxies of possibility

It was a take-your-breath-away moment more than three decades in the making. The Webb Space Telescope had launched from Europe’s Spaceport in French Guiana in late December 2021, then two weeks later unfolded a mirror more than twice as large as that of the legendary Hubble telescope it succeeded. 

“It’s like origami on steroids,” says Webb Space Telescope project manager Bill Ochs, of watching the mirror be folded to fit into its launch vehicle.

After that came the long wait. 

The team held its collective breath for months in anticipation of the first photos from the US$10 billion telescope, until finally, on 12 July, the world saw the clear images of a sparkling galaxy cluster, an exoplanet outside our solar system and a nebula where stars are born. 

“These images, including the deepest infrared view of our universe that has ever been taken, show us how Webb will help to uncover the answers to questions we don’t even yet know to ask; questions that will help us better understand our universe and humanity’s place within it,” said NASA Administrator Bill Nelson.

Uncharted Territory

Webb is the largest telescope ever launched into space, an effort led by NASA with support from the European Space Agency and Canadian Space Agency. And its journey—and the project’s payoff—are just beginning, with the potential to uncover nothing short of the history of the universe. Unlike previous telescopes, including the Hubble, Webb’s enormous 6.5-meter (21.3-foot) mirror is capable of capturing infrared radiation normally invisible to human eyes—meaning it can record the light from stars and galaxies that came into being near the beginning of the universe, around 13.8 billion years ago.

The infrared detectors developed for Webb—which are lower noise, larger format and longer lasting than any predecessors—are just one of the many technological innovations unlocked by the project team. For instance, spectroscopic instruments (capable of measuring the intensity of light at different wavelengths) have flown into space before, but none had the ability to observe up to 100 objects at once in high resolution. So the team set out to develop a device that could—which sometimes meant a whole lot of iteration and experimentation. 

Case in point: Webb’s microshutter device, which consists of 250,000 miniscule shutter windows arrayed in a waffle-like grid, with four of the arrays then joined together, two-by-two. To get there, the team had to conduct extensive material testing before settling on silicon nitride, which can handle extreme cold as well as resist fatigue, as the shutters need to open and close repeatedly and independently. 

“We’ve worked on this design for over six years, opening and closing the tiny shutters tens of thousands of times in order to perfect the technology,” says Murzy Jhabvala, chief engineer of NASA’s Goddard Space Flight Center’s instrument technology and systems division. “To build a telescope that can peer farther than Hubble can, we needed brand-new technology.”

Another item on the team’s to-list was the telescope’s cryocooler, essentially a super-sophisticated refrigerator dedicated to actively cooling its mid-infrared instrument, which must be kept below 6.7 degrees Kelvin (-448 degrees Fahrenheit or -266 Celsius) to operate properly. Past cryocoolers used two stages of pulse-tube cooling, with the precooler and cooling hardware situated very close together. For Webb, engineers were able to distribute its pieces throughout the observatory, resulting in dramatically low temperatures and the near elimination of vibration that can cause blurred images.

Tiny Errors, Big Consequences

Webb’s path from project launch to space pad launch was a lengthy and complex one. Early proposals stretch back to 1989, but NASA didn’t commit to procurement and testing until 2007. And it was soon clear to the engineers and NASA officials working on the project that the cutting-edge technologies they needed to develop simply couldn’t be delivered with the US$3.5 billion budget set in 2002. 

A 2011 NASA review confirmed the early targets as woefully optimistic, so the agency reset the project budget to US$8 billion, targeting 2018 for launch. Still, big, ambitious goals require big, ambitious breakthroughs—and the endless dance of developing, testing, iterating and retesting made for slow progress. In 2017 NASA’s science chief, Thomas Zurbuchen, announced “integration of the various spacecraft elements is taking longer than expected,” and the launch date slid back to 2019. An independent review found that a handful of human errors—such as using the wrong solvent to clean the telescope’s propulsion valves—had contributed some 18 months of delays and accounted for US$600 million of the program’s bloated budget. 

“The stuff they faced was what a lot of space programs face, because everything has to be perfect on a spacecraft like that—you can’t go fix it after launch,” Cristina Chaplain, who led audits of the Webb space telescope at the U.S. Government Accountability Office for roughly a decade, told The New York Times. “It’s very complex and fragile. There’s going to be mistakes, but on a program like that, one little teensy thing can have dramatic consequences.”

One of those little teensy things? In 2019, engineers tested the telescope’s ability to withstand the vigorous vibrations of launch. Screws holding the telescope’s large sun shield popped loose during the test—an error later traced to the fact that engineering drawings hadn’t specified how much torque needed to be applied, leaving it in the hands of the contractor. That oversight pushed the launch date back an additional 10 months and the budget up by another US$800 million. 

NASA appointed a review board to investigate the issue—and to help mitigate the risk of similar goofs happening in the future. The resulting report made 32 recommendations, which NASA’s Gregory Robinson, who took over the Webb project in 2018, says the team followed to the letter.

“People aren’t perfect, and people are going to make mistakes,” says project manager Ochs. “But when you make mistakes, you’ve got to take corrective actions so it doesn’t happen again.” 

In the dozen years he spent working on the project before launch, Ochs never saw a sense of defeat take hold of the team. “I never heard anybody say ‘I give up; I don’t know how to fix this,’” he says. “And I knew that same attitude would be there when we got to orbit. I was always confident that it was going to work.”

3… 2… 1… Liftoff!

After two decades of timeline slips and tumultuous setbacks, Webb was finally ferried from California to French Guiana in October. (The 16-day trek was made in secret, partly out of concerns over piracy.) But the maddening schedule slips didn’t stop there. A lose clamp mount, a glitchy cable and high winds contributed to a trio of launch delays. And then… Webb finally launched 25 December. 

Ultimately, about 20,000 engineers, astronomers, technicians and administrators worked together to help helped Webb take flight. For PMI Future 50 leader Kenneth Harris II, working on the Webb space telescope was “lifechanging” and “very humbling.” 

“I didn’t understand the gravity of the work at the time,” he says. “But looking back on challenges my team overcame, and ultimately the success of the integration, I am truly thankful for the opportunity.”

With an expected lifetime of at least 10 years, it’s still early days for Webb. As it studies the atmospheres of exoplanets that orbit stars beyond our sun, massive black holes and the formation of planets, NASA will make the telescope data available to select groups through its Early Release Science Programs. 

“Scientists are thrilled that Webb is alive and as powerful as we hoped, far beyond Hubble, and that it survived all hazards to be our golden eye in the sky,” says John Mather, Webb senior project scientist at Goddard. “Astronomers see everything twice: first with pictures, and then with imagination and calculation. But there’s something out there that we’ve never imagined, and I will be as amazed as you are when we find it.”