Skip to main content

How engineers are getting James Webb’s NIRSpec instrument ready for science

While engineers for the James Webb Space Telescope continue the long and delicate process of aligning its mirrors in order to get the telescope ready for science operations this summer, other teams are working on preparing the telescope’s four science instruments for operations. One of the instruments, the Near-Infrared Spectrograph (NIRSpec), recently hit a milestone when it completed initial check-outs for three of its mechanisms. Now, members of NASA and the European Space Agency (ESA) have shared more information about NIRSpec and how it is being prepared to investigate targets including some of the oldest galaxies in the universe.

There are three mechanisms crucial to the operation of NIRSpec: A Filter Wheel Assembly (FWA), a Grating Wheel Assembly (GWA), and a Refocus Mechanism Assembly (RMA). These work together to allow the operation of the spectrograph, which splits light into a color spectrum. By looking at the spectrum of light from distant objects, scientists can tell what those objects are made of, as different elements absorb light in different wavelengths.

Recommended Videos

To make sure only light within the wavelengths being investigated gets to the instrument, NIRSpec uses filters to block out unwanted wavelengths, and these filters are controlled by the FWA. To focus the light, the instrument uses the RMA. And the light is separated into a spectrum using gratings, a prism, and a mirror in the GWA.

The engineers described how they checked each of these components: “We operated the Filter Wheel Assembly first, cycling it through all eight of its positions in both forward and reverse directions… At each position, we recorded a set of reference data. This data showed us how well the wheel was moving and how accurately it settled into each position… The data showed that the wheel moved very well even in the first attempt.”

The operation of the GWA was similarly successful. “We then used a very similar procedure for the Grating Wheel Assembly, which also performed excellently the first time,” they wrote. And finally, the RMA mechanism, which will help to focus the instrument, was moved through a few hundred steps to check it could be positioned correctly. These tests went well too, with the team writing, “successful completion of this test showed us that the RMA is a well-behaved and healthy mechanism.”

Everything is looking good for NIRSpec, so now the instrument can continue being tested and calibrated ahead of its first science data collection in a few months. “In the coming months, the NIRSpec team will continue their commissioning efforts,” the team wrote. “The whole team is very much looking forward to the start of science observations this summer!”

Georgina Torbet
Georgina has been the space writer at Digital Trends space writer for six years, covering human space exploration, planetary…
James Webb captures gorgeous image of a Cosmic Tornado
The NASA/ESA/CSA James Webb Space Telescope observed Herbig-Haro 49/50, an outflow from a nearby still-forming star, in high-resolution near- and mid-infrared light with the NIRCam and MIRI instruments. The intricate features of the outflow, represented in reddish-orange color, provide detailed clues about how young stars form and how their jet activity affects the environment around them. A chance alignment in this direction of the sky provides a beautiful juxtaposition of this nearby Herbig-Haro object (located within our Milky Way) with a more distant, face-on spiral galaxy in the background.

The James Webb Space Telescope has captured another stunning image of space, this time showing the dramatic scenes around a baby star. Very young stars can throw off powerful jets of hot gas as they form, and when these jets collide with nearby dust and gas they form striking structures called Herbig-Haro objects.

This new image shows Herbig-Haro 49/50, located nearby to Earth at just 630 light-years away in the constellation Chamaeleon. Scientists have observed this object before, using the Spitzer Space Telescope, and they named the object the "Cosmic Tornado" because of its cone-like shape. To show the impressive powers of James Webb to capture objects like this one in exquisite detail, you can compare the Spitzer image from 2006 and the new James Webb image.

Read more
NASA’s Webb telescope peers straight at Saturn-like planets 130 light-years away
Saturn captured by the James Webb Space Telescope.

The James Webb Space Telescope is NASA's most precise and technically proficient equipment for observing the wonders of the universe. Astronomers rely on it to unravel the deepest secrets by peaking at distant solar systems and capturing planets like those in ours.

Much recently, the Webb Telescope was able to capture its first direct image of exoplanets nearly 130 light-years away from the Earth. The observatory seized images of four "giant" planets in the solar system of a distant star called HR 8799. This is a fairly young system formed roughly 30 million years ago, a timeline that dwarfs in comparison to our solar system's 4.6 billion years of age.

Read more
James Webb captures a stunning view of the dreamy Flame Nebula
Webb's image of the Flame Nebula

Our universe is host to many beautiful and fascinating objects, and we're lucky enough to be able to view many of them using high tech instruments like the James Webb Space Telescope. A new Webb image shows a new view of the gorgeous Flame Nebula, an emission nebula located in the constellation of Orion.

This nebula is a busy stellar nursery, with many new stars being formed there. But it isn't stars which researchers were interested in when they looked to the nebula -- in this case, they were studying objects called brown dwarfs. Bigger than most planets but smaller than a star, brown dwarfs are too small to sustain fusion in their cores, so they are often referred to as failed stars.

Read more