How engineers got NASA’s James Webb Space Telescope to take their first images

How engineers got NASA’s James Webb Space Telescope to take their first images

Over the past six months, Scott Friedman and a team of about 160 scientists and engineers have been working through a very difficult list throughout science. Almost every day, they leave everything at 1:30 PM ET to see and find how close they are to their goal: to get NASA’s James Webb Space Telescope, the most powerful space observer in history, completely Active.

During each session, they reviewed all the work they had done with the observer in the past 24 hours, which is currently zooming into space at a depth of about 1 million miles from Earth. Sometimes their testing and measurement had improved the day before, and they would face the next task. There will be hiccups at other times.

“We’ll have our schedule there too and say, ‘Well, it hasn’t worked, so it has to be reorganized. Let’s get it on schedule as soon as possible so we can continue,'” Friedman. Says the leading web scientist for the James Webb Space Telescope at the Space Telescope Science Institute or STScI. ورج. “And it was a difficult business.”

It has always been an important task to carry the James Webb Space Telescope, or JWST, up and running. Equipped with the largest image we have ever sent into space, observers are fundamentally changing astronomy because we know that by capturing light from stars and galaxies the universe was in its infancy. But, before JWST can begin collecting images of all these children of the cosmos, NASA and STScI, which oversees telescope operations and science, need to understand that all of JWST’s modern equipment and hardware can Really work together. Get the job done.

Now, the commission team is completing its work, successfully completing all its tasks just a few weeks after the summer date. For a telescope that is already a decade behind schedule, the team had a significant time constraint – all things considered. Thanks to their efforts, JWST is on the verge of launching its first year of modern science observations. This period of astronomical transformation will begin on July 12 with the release of the first full-color images taken by the observer. NASA has not yet said what these images will actually be, but we do know that they will include a detailed view of the atmosphere of a planet outside our solar system and “the deepest image of our universe ever taken.” . ” To NASA Director Bill Nelson.

“What I’ve seen only motivates me,” said Pam Miller, NASA’s deputy director, during a press conference before the image was released, as a scientist, engineer and human being.

Properly configured

JWST was in extreme Odyssey. The watchdog, which has made nearly two and a half decades and about 10 10 billion, must first survive the intensity of its launch on Christmas Day last year. Then, once it reached space, it underwent a very complex process to get in the right order to see the cosmos. (JWST was too big to launch in its final form, so it had to launch itself like a Swiss Army knife that is tightly packaged.)

Disclosure was a two-week-long nerve-racking process involving hundreds of moving parts and more than 300 events known as single-point failures: procedures that Had Working or they can jeopardize the whole mission. But, miraculously – or perhaps thanks to years of engineering and testing – the lighting went exactly as planned, the mission team set out on New Year’s Eve to replace some of JWST’s most important hardware at night. Well done.

Launch of the James Webb Space Telescope

JWST launched the Ariana 5 rocket into space from French Guiana in South America.
Photo by Bill Engels / NASA via Getty Images

But, almost as soon as it appeared, the engineering team began to focus on the JWST photo. The famous spy gold image, which is more than 21 feet wide, is actually made up of parts of 18 hexagonal images that must be precisely aligned to make them work as if they were a single image. And they had nowhere near to do it. To get started, engineers must first remove each part of the device known as the “snubbers”: equipment that keeps the photos in the proper condition for space travel. “We started them in a position that is safe for launch, but it doesn’t necessarily allow you to move the images back and forth to adjust them,” said Lee Feinberg, a visionary for JWST at NASA. Says the camera element manager. ورج.

The process took less than a week, with each section moving half an inch from their launch location. Still, it was just the beginning. “It wasn’t even an adjustment,” Feinberg says. “It just got to the point where we could really start.” The team then waits for JWST’s original infrared camera, NIRCam, to cool down enough that they can start using the tool to collect images. Once NIRCam was nice and cool, they used photos to take their first photo with JWST, highlighting all parts of the photo in a bright star. The result: 18 different versions of the same star.

That’s what the team expected. ” The sections are all marked in slightly different directions. Thus began the painful process of moving parts of each image that moved so little that these 18 pieces eventually behaved like one. To fix the position of a glass, the team must move the movement behind the part, slowly adjusting it with a small amount. The editing team will then use the JWST tool and take photos of their progress, sending those photos to Earth. A series of algorithms will analyze the work and determine how to make further adjustments. Then the whole process will be repeated. Step up and repeat.

Photo sections in JWST before launch.
Photo by Northrop Grumman

Things move quickly, because every move has to be done in order. And the team has to be very careful when they move to each section, verifying the exact location of each section when they are done so that the photos don’t accidentally move towards each other. But in the end, after three months of hard work, JWST’s photos came to the fore.

“When the photos started to come together, they moved from one to the other by millimeters,” Feinberg says. “And by the time we were done, they were compatible with the nanometer – so a progress factor of one million in sequence.”

Calibration

While the photo sequence was underway, the rest of the commission team shifted their focus to JWST’s four main tools. In addition to NIRCam, there are NIRSpec, MIRI, and FGS / NIRISS. All have four spectrographs, which break down light into a spectrum that allows scientists to learn more about distant objects. They also have three cameras (NIRSpec is a weird one). Just as the guitar strings must be properly aligned before use, so too do the most complex instruments in JWST. The task of the commission team was to calculate each of the tools to make sure they were ready and functioning properly when the first year of supervisory science began.

The JWST devices booted up and first checked when the photos were still being organized because the team needed a camera and other tools to help organize the photo component. Still, the most powerful work of calibration could not begin until the photos were fully arranged, which took about four months.

Now, over the past two months, the team has gone through a long list of time-consuming measurements, putting the tools through their pace. “Sometimes they were fast, but sometimes they were 12-hour observation times with a lot of observations attached to them,” Friedman says.

Some of this work is simply observing standard stars using instruments, measuring their light and position in the sky. The team then measured these stars based on decades of research with what they measured in order to find the adjustments that should be needed. Each camera, even the JWST NIRCam, has some built-in distortion in its images. By measuring these distortions, teams can adjust for them in the future, according to Friedman.

Some calibrations are forced to show JWST capabilities. Supervisors may have only four main tools, but each tool has different operating modes that offer different capabilities, and the commission team must test and verify each condition. Observers as a whole also have different operating modes that need to be accounted for. For example, JWST would be able to track relatively fast moving objects such as steroids and the outer planet’s moon in our solar system, so the commission team practiced this ability by shutting down test steroids, according to the reference. As using “guide” stars. The sky to prove to be a celestial star. It’s all a complex task that hasn’t been tested in space before. “It’s one thing to write it on a piece of paper and test everything you can on the ground, but it’s not like flying,” Friedman says. “We have to show these things.”

For the most part, Friedman says the whole process of integrating and commissioning went very smoothly, although there were a few obstacles along the way. JWST goes through half a dozen “safe haven” incidents when the spacecraft discovers something it doesn’t like and goes into safe operation to maintain its equipment and power. In total, the incident, most of which involved behavior control, lasted only four days, and the JWST team says such moments are “normal” for a new spacecraft.

“Every spacecraft has a unique personality when it goes into orbit,” Bill Ochs, JWST project manager at NASA, told a news conference. “There are certain things about it that no matter how many ground tests you do, you don’t learn until you’re really in orbit, and we had that experience.”

Adding to this pressure, one of JWST’s 18 photo sections was enlarged by the expected micrometroid in May, leaving a small dimple. While NASA says observers can still perform extraordinary science designed for it, the image portion must be adjusted somewhat to correct for damage.

An image captured by the JWST Advanced Guide sensor before the big disclosure was taken over a period of eight days.
Photo: NASA, CSA, and FGS team

But despite these minor setbacks, the commission’s team was able to complete all of its to-do’s work within two weeks of its scheduled six-month period. For them, it was nothing short of a miracle. “If you asked me before launch, ‘Do you really think you’ll complete it in six months, or in a few days?’ I would say, ‘Well, I hope so. But man, there are a million things that can go wrong,’ says Friedman. ‘And you know what? None of these millions of things were wrong. They are all right. ”

Now, the commission team is entering a new phase. Soon, JWST will enter its first year of science observations – what is known as Cycle 1 Science – which is filled with plans to target exoplanets, galaxies, outer stars, and more. Those who work with JWST tools go into a support role for astronomers who have time with an observer in their first year. These scientists will inevitably have questions about how to use this powerful new observer or explain their results, and instrument teams at NASA and STScI will be on hand to provide answers. “Surveillance will be used in ways we have not yet fully experienced,” Friedman says. “So we’ll look at it carefully.”

While the work is not done yet, it is a bitter time for the people who work in the team. The Commission’s daily summary is over, and many who spend long hours to get to JWST for their first year of science. This is not necessarily a bad thing for some.

“For me personally, I just want to sit back and enjoy it now,” says Feinberg, who has been working on JWST’s development for the past 20 years. “You know, let the scientists have their day and do great things. I’m just looking at pictures with the rest of the planet and enjoying the discovery of the universe.

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