In a triumphant technological feat, a coffee table-sized camera built in the Bay Area sends home snapshots of our nascent universe from the James Webb Space Telescope, ushering in a new era of astronomical exploration. .
As the world waited in suspense on Tuesday morning, his photos emerged – luminous 150 million pixel images from a time long before we existed, when stars and galaxies first emerged from the primordial fog there. about 14 billion years old.
On a video screen in a dark room at Lockheed Martin’s Palo Alto Advanced Technology Center, scientists and engineers erupted in applause. It was their first look at an image portfolio designed two decades ago, with no guarantee of success.
“There’s a mix of emotions,” said Lockheed Martin’s Malcolm Ferry, program manager for the camera project, who joined the ambitious effort when his son, now a married adult, was only ‘a boy.
“There is joy. Joy. Relief that everything is working, creating images is just beautiful,” said Ferry of Emerald Hills. “And maybe I’m a little sad, knowing that part of the journey is over.”
One of their photos – a stunning image of a distant star cluster called SMACS 0723, in the southern hemisphere constellation of Volans – was selected for President Biden’s preview and released worldwide on Monday. . Other images show the Southern Ring Nebula, the Carina Nebula, and “Stephan’s Quintet,” a cluster of five galaxies in the constellation Pegasus.
The near-infrared camera, or NIRCam, travels millions of miles from its birthplace in a leafy Stanford-based research park.
And there’s no way to fix it if it breaks; It is too far.
Four hundred years after Galileo Galilei used a fancy spyglass to look at the moon, this camera can detect special wavelengths of light to, in essence, travel back to very ancient times – 100 million years later the Big Bang. Our previous images, taken by the Hubble telescope, date from 400 million years after the Big Bang.
The Webb telescope cannot show us the moment of our birth, when the universe emerged from nothing about 14 billion years ago. For many years after that Big Bang, the cosmos was just a dense cloud, a dark, messy place.
But it does reveal the remarkable first steps in the self-assembly of the universe, when it spawned galaxies, stars, planets – and ultimately a creature with a brain big enough to wonder, “Where did it come from? are we coming? What was that like?”
To the delight of the team, the camera survived the stress and fatigue of an explosive launch into space from French Guiana last December.
It must now operate with the utmost precision and stability in extremely cold temperatures aboard Webb, the largest and most powerful space telescope ever built.
A second duplicate camera is also on board, as a backup.
The other NIRCam and Webb teams were conceived in 2002, when George W. Bush was president, the United States had just invaded Afghanistan, and iPods had just been released. The Lockheed Martin team partnered with lead researcher Marcia Rieke of the University of Arizona for the project.
“It took time. To see it all come together – and to see the results – is very, very inspiring,” said Nelson Pedreiro, vice president of Lockheed Martin’s Advanced Technology Center, where the camera was designed and assembled. .
Webb’s 18-pane mirror collects light from the sky and directs it to four instruments, including NIRCam, the main source of its images. Another instrument studies the composition of space matter; a third guides and points the spacecraft.
Webb has a larger mirror than Hubble, so camera images have higher resolution. While Hubble’s images were a little blurry, Tuesday’s photos were breathtakingly clear and detailed.
Webb’s mirrors are coated with a microscopic layer of gold that reflects infrared light better than almost any other metal. They are 98% reflective, so they can capture almost all incoming photons of light.
“It was very challenging, from a technology and engineering perspective,” said Pedreiro, who lives in Menlo Park.
NIRCam can detect infrared light ranging from 0.6 to 5 microns, well beyond the part of the spectrum visible by the lens of its predecessor, the Hubble telescope. This makes it possible to see much older objects. As the universe expands, wavelengths change. Because the oldest light is long and red, it cannot be seen by human eyes and conventional telescopes.
It differs from a conventional camera in other ways, with special coatings, filters and more refined optics, splitting light into two paths to capture different infrared wavelengths.
“If the surfaces aren’t perfect — and they never are — they end up distorting the light,” Pedreiro said.
There were several major challenges, Ferry said.
One was to find a way to protect the very fragile glass from shattering during sudden temperature changes and the violent launch of the spacecraft. The Lockheed Martin team therefore designed a special device to hold the lens, using flexible mounts. They also developed a new bonding technique, bonding the lens to the frame.
Another was building a camera that would still work despite shrinking in extreme cold. In space, Webb operates at minus-447 degrees Fahrenheit. Its design therefore had to anticipate a change in shape and size. Scientists feared that such stress would shatter the glass.
“We’re human beings who have to put this thing together, at room temperature,” Ferry said. “Once up there, everything changes. But still it is necessary to align. »
In 2014, the camera was carefully retrieved from Palo Alto by FedEx’s “white glove” task force, then shipped to Goddard Space Flight Center in Maryland, where it was integrated with the other instruments. From there it went to Johnson Space Center in Florida for testing, then to Northrop Grumman in Redondo Beach to be placed in the spacecraft. Finally, the entire project was flown to South America for launch.
“We built an instrument that no one had ever built before, with requirements that had never been imposed before,” Ferry said.
“It was the first time,” he said, “for all of this.”