Webb Space Telescope completes risky deployment but faces more hurdles

The National Aeronautics and Space Administration declared deployment complete at 1:17 p.m. ET Saturday, when the starboard right wing of the $10 billion space observatory’s 21.5-foot primary mirror was replaced. The announcement, which brought applause at the Mission Operations Center in Baltimore, marked the completion of the final process in a process that included 50 major steps and 178 different release mechanisms.

“How does it feel to make history?” Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate, told members of the mission team after the announcement.

The successful deployment means the most powerful telescope ever launched into space is on track to begin its decade-long mission of observing stars and galaxies later this year as they long after the big bang. did not appear.

It also provided a respite of sorts for mission controllers, who supervised the deployment of the truck-shaped telescope and conducted breathless surveillance, thanks to the dimensions of which fold-up, origami-style launches into the Ariane 5 rocket’s nose cone. fell. ,

“It’s definitely been a roller coaster,” Keith Parrish, Webb’s observatory manager at NASA Goddard Space Flight Center, said of his shifting feelings during the deployment process. “It’s excitement. And then immediately, my mind goes to the next thing.”

Some agency insiders expected the deployment to be completed soon enough.

“If you had asked someone two months ago, even a month ago, ‘Hey, we’re going to be on January 8,’ I would have said that to assume that’s widely optimistic and frankly. was unreal.” Dr. Zurbuchen said at a news conference on Saturday ahead of the announcement.

Deployment began shortly after launch on December 25, when Webb’s solar array opened up so that the telescope could begin generating electricity. Other steps in this process include expanding the communications antenna assembly and positioning Webb’s secondary mirrors and a radiator designed to dissipate excess heat.

The most difficult challenge for mission controllers was the extension of the telescope’s five-layer, tennis-court-size sunshield, which is designed to keep Webb’s instruments at their extremely low operating temperatures. According to NASA, that move, which involved 70 hinges, 90 cables and 400 pulleys, was completed on Tuesday.

Webb has 344 single-point failure components—pieces of equipment that, if any of them fail to operate as designed, will thwart the entire mission. According to Webb’s Sunshield Manager James Cooper, about 266 of those items were removed with the deployment of sunscreen. “More important to my mind is that we have retired the people who were most likely to be,” he said.

According to Dr. Parrish, the completion of Webb’s deployment meant that an additional 29 single-point failures were retired.

Dr Cooper said the deployment of the sunshield posed the biggest threat to the mission’s success because the motor and cable used to raise the shield were difficult to predict and control because the thin layers of hair are so fragile. Difficulties were encountered during tests of the system in 2018—the layers of the sunshield frayed and torn. It took two more years to complete the final series of deployments and tense tests.

“After all the setbacks this team went through during Sunshield development, it’s really nice to end the story like this,” said Dr. Cooper.

The motors were operating at an unexpectedly high temperature last week, but NASA said mission controllers had resolved the problem by commanding the firing of thrusters that replace the telescope to keep the motors in shadow.

Webb is now nearly halfway through with its 29-day journey to a destination called L2 or the second LaGrange point, about 1 million miles from Earth. Once it reaches this perch in orbit around the Sun, Webb will spend about five months cooling down while mission scientists align its mirrors and calibrate its cameras and other instruments.

If all goes well, Webb will release its first images to the public in June.

But Webb still faces obstacles in the coming weeks, including activating and individually adjusting the 18 hexagonal, gold-plated segments that make up the primary mirror—and ensuring that Let the telescope cool down to its minus 388 degrees Fahrenheit operating temperature.

“Until we reach those temperatures, we’re not going to breathe a sigh of relief at our cooling architecture,” Dr Parrish said.

“There is no individual thing that keeps us going,” he said in reference to the remaining challenges, before beginning his comments on Webb. “I think it’s an overwhelming number of activities that we still have to get through.

NASA maintains a webpage that shows Webb’s current speed and location in space and another displays the telescope’s operational status as it completes the later stages of deployment.