The James Webb Space Telescope’s Progress

The James Webb Telescope proves unprecedented in its ability to capture accurate, detailed photographs of astronomical objects as it advances toward beginning its mission.

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As time progresses, the James Webb Space Telescope (JWST) continues to prove its prodigious technology as seen through NASA’s test images. After a series of tests, the telescope was launched on December 25, 2021. Since then, NASA has been providing updates on the condition of the telescope as it advances toward complete functionality.

A description of the telescope’s infrastructure is necessary to understand the complexities of the preparation required before the telescope is fully functioning. The three major parts are the Optical Telescope Element (OTE), the Integrated Science Instrument Module (ISIM), and the Spacecraft Element. The OTE includes the mirrors and backplane. The JWST is the first telescope to use folded primary mirrors, mainly to allow it to fit in a rocket fairing. The primary mirror, made of 18-hexagonal segments, first captures faint infrared light. The light is reflected into the smaller secondary mirror, from which it is reflected into the telescope’s four instruments. This includes the Near Infrared Spectrograph (NIRSpec), the Mid-Infrared Instrument (MIRI), the Near-Infrared Camera (NIRCam), and the Fine Guidance System (FGS)/Near-InfraRed Imager and Slitless Spectrograph, all of which are housed in the ISIM. Together, the instruments work to accurately detect and photograph astronomical objects. The Spacecraft Element comprises the sunshield subsystem and the Spacecraft bus. Hence its name, the sunshield system protects the OTE and the ISIM from the sun-facing side of the telescope because these elements need to be kept at deep space temperatures. The Spacecraft Bus, which is on the sun-facing side, contains the systems that operate the spacecraft.

In February of this year, the Webb team released the first photos taken using the JWST. The objects pictured include the star HD 84406 and a “selfie” of the primary mirror. Because the mirror segments are not yet fully unfolded, the images are blurry.

NASA announced that the telescope completed “fine phasing,” meaning the segments have successfully unfolded to form a single aligned mirror, on March 11. NASA released an image of the star 2MASS J17554042+6551277 as evidence that the mirrors are able to reflect light into one spot of the NIRCam, but the same process had to be done with the NIRSpec, MIRI, and FGS.

Recently, the team held a news conference on May 9 during which they announced that the telescope is in its final tweaking stage as the mirrors have finished cooling to the near absolute-zero temperature required for infrared observations. They also revealed an image taken of the Large Magellanic Cloud that demonstrates the MIRI’s stellar performance in clearly capturing material that would be obscured if seen at visible wavelengths.

The Large Magellanic Cloud, a satellite galaxy of the Milky Way, was the release target for the James Webb Space Telescope because it had already been studied by other observatories, such as the Hubble Space Telescope and the Spitzer Space Telescope. The photo captured by the JWST clearly depicts hundreds of stars adjacent to a background of interstellar clouds, whereas the photo captured by the Spitzer juxtaposes a few stars as brighter circles with a blurred background full of dull smaller specks. The prior knowledge of the galaxy includes the locations of its stars, which is significant because they can be inputted for astrometric calibrations that are used to reassure each instrument’s proper function. There are various pieces of astrometric data to be collected before the team can proceed with its exploration.

A scientist for the Webb team, Michael McElwain, says we are currently in the “homestretch” before the mission commences as they finish assessing the telescope’s instruments and collecting data. The telescope’s ability to already capture such great detail accurately proves it will succeed in its mission of showing astronomers the formation process of stars and protoplanetary systems. According to Klaus Pontoppidan, a scientist on the Webb project, the first official scientific images of the “early Universe, to galaxies over time, to the life cycle of stars, and to other worlds,” are expected this upcoming July. These photos will revolutionize our understanding of the universe as scientists expect to see the very first formations of stars and galaxies, otherwise known as the Big Bang.