The James Webb Telescope — A Look Into the Very Beginning The Spectator / Science / Issue 10
Issue 10, Volume 112
A peer into the very first light in the cosmos or perhaps a peek into the origins of the most ancient stars—these breakthrough images will be captured by NASA’s most powerful telescope yet, the James Webb Space Telescope (JWST), which launched the morning of December 25, 2021. Around 100 times stronger than the Hubble—the renowned Earth-orbiting space telescope launched in 1990—the Webb has begun its journey to photograph some of the most crucial pictures ever to be taken in, quite literally, the history of the universe.
Named after James E. Webb, who led the Apollo moon program, the long-envisioned telescope became a reality as construction began in 2004 with contributions from the European and Canadian Space Agencies. The intricate parts and design came together over two decades, costing nearly $10 billion despite the original $500 million budget. Successfully launched in the Arian 5 rocket from French Guiana, the telescope reached L2 on January 24, a month later from its launch date. L2 is a Lagrange point, a position in space where the gravitational forces of objects are balanced. JWST’s arrival at its permanent home for the next 20 years is a crucial milestone which allowed engineers to take a short breath despite there remain several nail-biting steps to achieve.
In contrast to the Hubble Space telescope, whose job was to gather light from astronomical objects to help us better comprehend the universe around us, JWST will collect light from the very beginnings of the Universe. It’s only possible we’re able to capture light as ancient as time itself because light has a speed. We’re able to see light as it was, relative to the distance we are from it. Essentially, something that is one light-year away can be seen as it was one year ago. The distance the light has traveled to reach the relative standpoint, in this case JWST, determines its age.
To be able to see this light, we need a tremendous telescope. The only thing is, the universe has been expanding at an incomprehensible rate since the moment it began and light has been red-shifted. Red-shifting, or infrared light, is the wavelength of light extending into the infrared section of the spectrum. This led to Webb not only being enormous but being able to see into the infrared. Since Earth’s atmosphere absorbs all infrared light, JWST is located in L2, a gravitationally stable spot where excess fuel isn’t wasted. Being in space would mean absorbing heat, which would lead to glowing in the infrared and disrupting the infrared light it’s trying to receive. Such a feat would require cryogenic, or extremely low temperatures, as well as a gigantic mirror that cannot be accommodated by the rocket, meaning it would need to unfold in space. These constraints ultimately led to the Webb's extraordinarily intricate design.
The telescope consists of a gold-plated mirror seven yards in width. Composed of 18 adjustable hexagonal segments, this golden mirror allows the telescope to see infrared light. Any heat would interfere with the required conditions, so a huge sunshield and refrigeration system block the sun’s rays while keeping the telescope cool. Unfortunately, these parts are huge and can’t fit inside Ariane 5, meaning the unfolding process, as well as the telescope alignment and instrument turn-on, will take a nerve-wracking month.
A variety of benefactions were provided by other agencies involved in this immense project. Canada’s largest contribution is the Near-Infrared Imager and Slitless Spectrograph which enables the capture of exoplanets and relatively distant galaxies. While NASA provided JWST’s primary camera, the Near Infrared Camera, the European Space Agency supplied the Near Infrared Spectrograph, which will be used to transfer the light captured into a spectrum.
It is crucial that these multiplex parts function accordingly because, unlike the Hubble, the James Webb telescope will be orbiting the Sun instead of the Earth. At L2, it is inaccessible for service or repair, meaning a single malfunction would ruin the mission. If it is successful, the mission is planned to be five years long, though it is prepared for a 10-year goal with enough fuel and backup instruments. Webb is similar to Hubble in the sense that the Hubble’s primary mission to capture the most imperceptible reaches of the universe ended 15 years earlier and has continued to orbit the Earth for another 15 years. The Webb will also continue to be in service after its initial mission is completed.
The first images from Webb are scheduled to arrive in about 6 months, but we may receive images earlier. The pictures, retrieved via radio antennas, will be studied at the Webb Science and Operation Center at the Space Telescope Science Institute in Baltimore, Maryland. Webb will also send images of exoplanets and perhaps offer clues about alien existence.
Once we’ve collected all these photos, there will be a lot to be uncovered. Though we have a decent amount of evidence of the Big Bang, there remain many unanswered questions. How exactly did particles form to create stars that would form galaxies? How did everything line up, by chance it seems, that life originated on Earth? Now secured in its final destination, Webb will be able to look back even further than the Hubble and hopefully answer some of astronomy’s most burning questions once and for all.