The alignment of NASA’s James Webb Space Telescope has begun
The James Webb . Space Telescope continues to make great strides towards becoming an active observatory.
Mission team members have begun the three-month process of tweaking the $10 billion Webb, Released on December 25th, NASA officials announced today (February 3).
About a day ago, for the first time ever, photons from distant stars passed through the entire telescope and were detected by Webb’s Near Infrared Camera (NIRCam) instrument, NASA officials said. NASA official said. This was a huge moment in itself, and it laid the groundwork for alignment, based on data collected by NIRCam.
“This milestone marks the first of many steps in capturing out-of-focus images and using them to slowly adjust the telescope,” said NASA officials. wrote in an update today. “This is the beginning of the process, but so far the initial results are in line with expectations and simulations.”
Related: How the James Webb Space Telescope works in pictures
Webb .’s 21.3 feet (6.5 meters) wide main mirror consists of 18 hexagonal segments, launched in a compact configuration and unfolded after the telescope’s launch into space. The alignment process will make all 18 act as a single light-collecting surface, which is by no means a feat.
“To work together as a single mirror, the telescope’s 18 main mirror segments need to fit together into a fraction of the wavelength of light – about 50 nanometers,” NASA officials wrote. “To make this clear, if Webb’s primary mirror were the size of the US, each segment would be the size of Texas, and the team would need to align the heights of those Texas-sized segments together to Accuracy about 1.5 inches [3.8 centimeters]. “
There are seven stages in the alignment process, which will be based primarily on Webb snapshots of the bright star HD 84406. The mission team will take a picture of the star with each of the 18 mirror segments, then use that information to move the segments into their proper positions.
Today’s update goes into considerable depth about the seven stages and how each will work; you can read the details here.
NASA considers Webb to be its iconic successor Hubble Space Telescope, has been orbiting Earth since April 1990. However, while Hubble observes the universe primarily in visible and ultraviolet light, the newly launched scope will focus on infrared. – the wavelength that we feel as heat.
Webb’s optics and four scientific instruments must be very cold to do this; Even the smallest amount of heat can be carried away by the faint signals that the observatory is designed to study. So Webb fitted a giant, five-layer sunshade to block and scatter solar radiation and was installed at Earth-sun’s Lagrange Point 2, a gravitationally stable point 930,000 miles (1.5 million km) from our planet would allow Webb to use that shield effectively at all times.
Alignment is not the final step in Webb’s journey to a working state; The mission team will also need to operate the telescope’s four scientific instruments. That work is expected to be completed by late June or early July, team members said, at which point Webb will begin his much-anticipated science mission. During that mission, the observatory will study the universe’s first stars and galaxies, scrutinize the atmospheres of nearby alien planets for intriguing chemicals, and perform a variety of tasks. other high-impact research.
Mike Wall is the author of “Out there“(Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow them on Twitter @Spacedotcom or above Facebook.
https://www.space.com/james-webb-space-telescope-alignment-begins The alignment of NASA’s James Webb Space Telescope has begun