The Spacecraft Tarot: James Webb Space Telescope
The Star is a beacon of hope.
The stars have called out to humanity for as far back as we can remember. Before we understood exactly what stars were, our ancestors created myths to explain the mysterious arrangement of light that seemed to move around the sky. They identified patterns, named constellations after the heroes and beasts in their stories, and passed the knowledge down for generations.
Now we have a better understanding of what stars are and where they come from. We know that the jewels in the night sky speak of other worlds, distant and alien and strange. The stars continue to stir something in our blood — something that yearns to meet them, to reach into the sky and stretch across the expanse and touch them. For this reason, the Star is a symbol of hope, renewal, and fascination.
Humanity is on the precipice of coming closer of knowing the stars more intimately than ever before, thanks to collaboration between NASA, the European Space Agency, and the Canadian Space Agency. After decades in the making, the world’s most powerful and sophisticated space telescope has successfully launched, deployed, and has begun capturing glimpses of the universe in its infancy. James Webb Space Telescope (JWST) is enhancing our understanding of the cosmos more than ever before.
The big bang is how astronomers hypothesize how our universe began. 13.8 billion years ago, everything in the entire universe was condensed to a single burning, minuscule point. As the universe expanded and cooled, tiny particles formed atoms, and over time atoms formed stars and galaxies. Today our universe is still expanding.
As the universe continues to stretch, so do the wavelengths of light that humans can perceive. This means that many of the wavelengths of light that originate from the beginning of the universe are imperceptible to us, hidden within the infrared spectrum.
Although the speed of light is very fast (about 186,000 miles per second), light from distant stars and galaxies are traveling such great distances in space that we are actually seeing how they existed in the past. Oftentimes, the stars we see in the night sky have already burned out millennia ago. 100 more times powerful than Hubble Space Telescope, JWST can gaze so far into the distance that it can see farther back in time than ever before — going back as far as 13.5 billion years ago, when the very first stars and galaxies formed.
However, JWST experienced a multitude of delays, engineering challenges, and funding difficulties before finally making it to space. For example, in August 2017, when teams at NASA’s Johnson Space Center were testing JWST inside Chamber A. The purpose of this chamber is to simulate the harsh coldness of space, in order to ensure spacecraft hardware will survive once it’s off the planet. The cryogenic testing chamber takes weeks to reach temperatures of almost absolute zero, and then even more weeks to return to a normal temperature. Several weeks into testing, Hurricane Harvey hit Houston, Texas, and the center was hit with flooding and leaking. Thankfully, teams were still able to access the center through a back entrance, and testing continued amidst the chaos.
By this point, JWST was already ten years behind schedule and vastly over budget. But the challenges did not end there — once the space telescope launched from Arianespace’s ELA-3 launch complex at Europe’s Spaceport in French Guiana on December 25, 2021, JWST still faced the most complex deployment ever attempted in space.
The fully deployed telescope includes a gold-coated beryllium primary mirror divided into 18 segments, as well as a massive sunshield comprising five layers of Kapton, a high-performance polyimide film. The mirror segments come together forming a golden honeycomb structure. The entire telescope stands at three stories tall and weighs roughly six tons.
In order to unfold safely and exactly in the harsh environment of space, the telescope relied on a vastly complex series of mechanisms. Every command needed to be executed perfectly, as any flaws in the mirror would have guaranteed faulty data. Of the thousands of steps that JWST needed to complete, 344 of them included single-point failures — failures that would jeopardize the entire system from working.
On January 8, 2022, JWST latched the final mirror wing, successfully deploying the telescope and realizing decades of work. Weeks later, JWST arrived at the second LaGrange point in Earth’s orbit around the Sun, an area where it will balance perfectly between the gravitational forces of the Earth and the Sun, one million miles from the our home planet.
On July 12, 2022, after months of aligning its mirrors and calibrating its scientific instruments to the space environment, the JWST team proudly unveiled the space telescope’s first scientific observations.
With those first images, JWST proved to the scientific community that the telescope’s imagery can reach an unprecedented level of detail. Since then, scientists all over the world have been able to use JWST data to pull back the curtain on the mysteries of our universe.
For example, the telescope’s suite of highly sensitive instruments recently measured the atmospheric ingredients of WASP-39 b, a planet orbiting a star 700 light-years away. JWST’s detection of sulfur dioxide in the exoplanet’s atmosphere marked the first concrete evidence of an exoplanet experiencing photochemistry, or a chemical reaction caused by energetic stellar light. This is how Earth’s ozone layer in the upper atmosphere is created.
Even more recently, JWST data was used to confirm an exoplanet’s existence for the very first time. The telescope’s Near-Infrared Spectrograph (NIRSpec) captured an Earth-sized planet 41 light-years away, after NASA’s Transiting Exoplanet Survey Satellite (TESS) picked out some clues and identified a target of interest. The discovery made clear JWST’s ability to put more exoplanets on the map.
And most notably, scientists are using JWST’s unprecedented level of detail to examine the universe’s early galaxies, like GLASS-z12 — which is believed to date back to 350 million years after big bang. JWST observations of this galaxy suggest that an unusual number of galaxies in the early universe were much brighter than previously thought — perhaps because they were filled low-mass stars, like later galaxies, or because they were filled with fewer but extraordinarily bright stars.
As JWST illuminates the unknown like never before, everyday people are looking up at the sky in awe again. What is our place inside this ever-expanding universe? How did the stars and planets come to be? The future of astrophysics has never looked brighter.
JWST reminds us to find hope and wonder in the starlight.
