The year was 1996. The mission which repaired the Hubble Space Telescope (HST) had been just three years earlier, but NASA was already looking ahead to their next big space project. In conjunction with the Space Telescope Science Institute, engineers were discussing plans for a new telescope that would specifically focus on collecting infrared light. It was this idea that would eventually grow to become the James Webb Space Telescope (JWST), the most powerful — and precarious — in-orbit observatory the world has ever seen.
Hubble’s Big Brother
The JWST is an improvement over the HST in a few key ways. One of the primary ones is its specialization in infrared (IR) observation (Hubble collects some infrared data, but works mostly in the visible and ultraviolet spectrums of light). By working in IR, the JWST will be able to see farther than previous telescopes and produce more detailed photographs and spectroscopies of objects in space.
The challenge of this switch comes along with one of the more common names we give to light in the IR spectrum: heat. Because IR manifests as heat, the JWST needed to be insulated from all nearby sources of IR radiation and kept at temperatures far below freezing for it to accurately observe distant objects without interference. This challenge becomes even more daunting when you consider the fact that the telescope will be operating in orbit around the sun, which is renowned for being fairly hot. In addition to protection from the sun’s heat, the scientific instruments on board also need to be kept cold enough to prevent them from emitting their own data-polluting IR radiation.
The solution to this issue was a slew of new and updated technologies. An ultra-thin sun shield the size of a tennis court will ensure IR light from the sun, Earth, and other nearby emitters doesn’t reach the instruments onboard. With this shield, the observatory can be cooled to temperatures as low as 50 kelvin (-370°F, or -223°C). Because of this, however, other technologies present on the craft had to be designed to work at these super-cooled temperatures.
One such example is the arrays of microshutters that will be used to perform spectroscopies of distant celestial bodies. These are grids of tiny shutters, each measuring only 100 by 200 microns, which can be individually opened and closed and will allow the telescope to focus on multiple subjects at once. They had to be designed to withstand the extreme temperatures that they’ll be operating in, ensuring that they will be reliable and durable throughout the lifespan of the observatory.
The JWST may be more powerful than the HST in innovative ways, but its improvements include intuitive upgrades, too. The primary mirror is almost three times the size of Hubble’s—6.5 meters compared to Hubble’s humble 2.4. In addition, it will take up residence farther away in space, orbiting the sun instead of the Earth, as its predecessor currently does. These factors together will contribute to the JWST being significantly more capable than the HST. Unfortunately, they have also contributed to the project being more delicate and — perhaps even more detrimental — more expensive.
A Comedy of Errors
Originally, the JWST was projected to cost $500 million and launch sometime in 2007. In actuality, it did neither of these things.
In fact, the JWST became almost infamous for its near-comedic lifetime of budget overages and launch delays. In contrast to earlier, more optimistic goals, the project was not approved to begin construction until 2008, and didn’t pass a Critical Design Review until the summer of 2010. At that point, the expected budget had ballooned from an early estimate of $1.6 billion to about $6.5 billion, and the prospective launch date had been pushed to somewhere between 2015 and 2016. It was amidst these growing challenges that congress officially cancelled the project in 2011, citing a failure of the team to remain within their budget. The decision was eventually reversed to allow development to continue, but the funding was strictly limited to $8 billion. The team would then fail to remain within the new budget.
The Very Expensive House of Cards Takes Flight
All told, the telescope was not launched until Christmas day, 2021, and ended up costing the US government approximately $9.7 billion. Worse still, even after all that investment, making it to launch day in no way meant that the pressure on the observatory’s team was off. Once in the air, the telescope still had to unfold, deploying its 6.5-meter primary mirror and a massive sunshield, which both had to be condensed in order to fit the telescope in the launch vehicle.
Between these and other setup procedures, the craft had over 300 possible points of failure, any one of which could have had catastrophic consequences on the launch and deployment. Making matters even more tense, the JWST’s more distant orbit makes repairs once the craft is deployed impractically expensive; if it breaks, it’s broken, and it becomes the most expensive orbital-paperweight we have ever built.
Despite these factors and against all odds, the JWST completed unfolding its primary mirror on January 8th, 2022, marking it as fully deployed. The next step is to calibrate the telescope’s 18 hexagonal mirrors, which NASA expects will take around 120 days. This, however, is a low-risk step, and it seems that after nearly $10 billion and 3 decades, the telescope may finally be about to start gathering images which will shed even more light on our universe. And, whether it’s in spite or because of the massive waits and costs, NASA promises that it will be breathtaking.
References
https://git.uwaterloo.ca/arts-computing-office/ofas3/-/issues/92
https://www.stsci.edu/jwst/about-jwst/history
https://www.space.com/21925-james-webb-space-telescope-jwst.html
https://webb.nasa.gov/content/about/innovations/microshutters.html
