HUNTSVILLE, Ala. (WHNT) – The James Webb Space Telescope is an example of how scientists can take an idea and make it a reality.
James Webb is making its way to its final destination a million miles away from Earth after launching into space on Christmas Day. Over two weeks from that launch and the 21-foot-primary mirror has completely unfolded, the final stage of the spacecraft major deployments.
Building on what was learned from the Hubble Space Telescope, James Webb was made with the goal of seeing infrared light from the first galaxies formed after the Big Bang and planets outside of our solar system. It’s also the largest space telescope ever built.
“It’s also probably the most complicated thing that we, NASA, have ever built,” Marshall Space Flight Center’s Senior Optical Physicist Dr. Philip Stahl told News 19. He added NASA’s North Alabama facility had a crucial role in what some refer to as “developing the technology to transform belief into knowledge”.
The idea for James Webb began decades ago but first scientists had to invent the technology to make it possible.
Dr. Stahl would know, “I was hired in 1999 to lead the effort to develop the technology, actually to invent the technology, to manufacture and test the Webb mirrors.”
How much detail a telescope can see is related to the size of its mirror, which gathers light from the objects it’s observing. According to NASA, James Webb’s mirror, made of 18 hexagonal segments, is about six times larger than Hubble’s.
“We had a list, there was a list of 10 things we didn’t know how to do. It was called the 10 technologies that needed to be invented. The one that I was responsible for was for the mirror technology,” Dr. Stahl explained. “We invested about $40 million in building that technology. We built 113 different prototype mirrors over the course of about four years. We tested those mirrors in order to develop the process to make the mirror substrate, to machine it, to grind and polish it, to test it, to design the pattern to mount it.”
The mirror is aligned into focus by mechanisms called actuators. The team at Marshall also tested the mirror and its actuators to ensure it would work in the frigid temperatures in space.
“They were brought here to Marshall and put into our X-ray and Cryogenic Testing Facility, they were taken down to temperature and not only did we test them to make sure they had the right shape at temperature but then we moved them over a complete range of motion with the actuators to prove that we could put the mirrors at any position that we needed to in order to align the telescope and make it work,” Dr. Stahl said.
He also said his work on the telescope concluded several years ago but he eagerly watched the Christmas launch. While he is proud of Marshall’s work on James Webb he emphasized that creating it was a global effort and that every single person’s contribution is important.
According to NASA, it took more than 40 million hours to build the James Webb telescope with the work of thousands of scientists, engineers and technicians from 14 countries and 29 states.
16 days after launch, James Webb is over 700,000 miles from Earth and about two weeks from its final home at the second Lagrange point (L2). To keep track of where the telescope is visit NASA’s Where is Webb? website for real-time data.