Set to join the pantheon of great observational instruments, the James Webb Space Telescope will launch this December and with it bring a new era of insight into the universe. Let’s wind back to the clock to examine how the telescope came to be, and how it will change science forever.
Fig. 1: The James Webb Space Telescope (JWST) at a NASA facility. (Chris Gunn/NASA)
History
When NASA was still in its infancy, James E. Webb guided it as an administrator for over half a decade. With the philosophy that NASA was more than just a political instrument, Webb was known to strive towards a balance between scientific endeavour and human exploration. As told on NASA’s official webpage, ‘‘Webb believed that NASA had to strike a balance between human space flight and science because such a combination would serve as a catalyst for strengthening the nation’s universities and aerospace industry.’’ (NASA)
However, there have been calls to rename the telescope, after information regarding Webb’s conduct as a government official has come to light. He was undersecretary during what was called the ‘’Lavender Scare’’ when LGBTQ+ employees were forced out of roles in government. NASA has said that, after an investigation, the telescope did not need to be renamed. Many scientists and other concerned parties have expressed anger for the lack of action.
The Next Hubble
Many pondered what would come after the Hubble, the iconic space telescope that captured the world’s imagination. Hubble’s pictures would come to change the way we viewed space and our place in it. So, it was only natural that people start thinking about what would come next. In 1981, the STSci director Ricardo Giaccono challenged the institute with the following question, ‘‘Think about the next major mission beyond Hubble.’’ This small sentence would lay the foundation for the Next Generation Space Telescope, which would later be renamed the James Webb Space Telescope (JWST). A myriad of workshops, papers and proposals, which would carry over for decades, would form the scientific basis for the amazing capabilities of the JWST.
How it Works
Flying aboard a modified Ariane 5 rocket, the JWST is in good hands. The Ariane 5 has had a stellar record since 1996, having launched instruments such as the Rosetta and the BepiColombo. Webb stands at 10,66 meters and has a 4.5-meter width when folded. However, fully expanded, its 5 layered sun shield is 21.2 x 14.2 meters.
The telescope will lift off from a European spaceport located in Fench Guiana. But, before it ever gets off the ground, it has to undergo much preparation for launch. The telescope will have to be tested and then sent to Pariacabo harbour, where the Ariane 5 rocket will have to be positioned on the launch table. Then placed and encapsulated in the fairing, Webb will be brought to the launch pad.
Fig. 2: Concept art for the JWST launch on the Ariane 5 rocket (ESA/D, Ducros)
Chosen for its history of space flight since 1968, the French Guiana spaceport harbours a strong team of skilled workers and a null risk of natural disasters. The launchpad is also surrounded by a dense jungle with 690 km2 of land. Its position at the equator also gives an extra kick to the Ariane 5 after it launches.
After 2 minutes of acceleration, its boosters will detach and a few minutes later the main stage will separate before the spacecraft does the same. The telescope is aiming to orbit what scientists call the Second Lagrange Point, which stands at about 1.5 million kilometres from Earth. After half a year of space travel, the JWST will start observing the cosmos. But before it can elucidate the mysteries of the universe, Webb has to unfold in one of the most expensive origamis ever made. To be able to fit in Ariane 5’s fairing it has to be folded. But once floating in space, it has to undergo a complex unfolding process to start collecting data. The month-long process starts with the sun shield insulation layers, the secondary mirror support structures, and finally the mirror’s lateral wings. Compared to the Hubble, Webb’s mirror is gargantuan (Hubble’s 2.4 m to Webb’s 6.5). Not only that, but Webb is over two thousand times as for from Earth as Hubble. However, this renders Webb incapable to be serviced by astronauts from the International Space Station (ISS). If something breaks, it can’t be fixed. Nevertheless, the reward might make the risk worth it. This is because Webb is using near and mid-infrared light.
Fig. 3: Brief overview of infrared astronomy (A. Field/NASA)
Near-infrared light is used to pierce the mist of cosmic dust to observe the formation of newborn stars and planets. On the other hand, mid-infrared is used to observe how black holes and stars influence their surrounding space. Webb will also be able to observe molecules in the atmospheres of exoplanets, collect information from the first galaxies and stars, use spectroscopy mapping and also measure temperature mass and chemical composition of astrophysical objects. Another important scientific element of the JWST is the use of the NirSpec to obtain the spectra of 200 astrophysical objects in unison. In astronomy, spectrography is an important tool. The capture of wavelengths helps give characteristics from its emitter, such as atomic composition. Being the largest space telescope ever, Webb has 100 times the sensitivity of Hubble and can peer further back in time to see how stars form, how black holes work, and how dark matter’s omnipresence can be elucidated. Webb has also spearheaded international collaboration between the CSA (Canadian Space Agency), ESA (European Space Agency) and NASA.
Conclusion
With the upcoming launches of the Artemis Program, the rise of private space companies and international pressure for space law to be revised for a new age, space is getting more crowded than ever. Amidst this, the James Webb Space Telescope stands as a beacon of collaboration and exploration, for the good of all mankind.
You can catch the launch Saturday, December 25th!
Bibliography
[1] Griffin, Andrew. (2021). ‘’NASA says James Webb Space Telescope will not be renamed despite controversy.’’ Independent. https://www.independent.co.uk/life-style/gadgets-and-tech/nasa-james-webb-space-telescope-name-b1930856.html
[2] (N/A). (N/A). ‘’Who is James Webb?’’ Goddard Space Flight Center. https://www.jwst.nasa.gov/content/about/faqs/whoIsJamesWebb.html
[3] (N/A). (N/A). ‘’Webb Launch.’’ Goddard Space Flight Center. https://www.jwst.nasa.gov/content/about/launch.html
[4] Gleim, Sarah & Gerbis, Nicholas. (2021). ‘’How the James Webb Space Telescope works.’’ HowStuffWorks. https://science.howstuffworks.com/james-webb-space-telescope.htm
[5] ESA. (2021). ‘’Webb Launch Kit.’’ European Space Agency. https://esamultimedia.esa.int/docs/science/Webb-LaunchKit_EN.pdf
[6] WEBB Space Telescope. ‘’Infrared Astronomy.’’ STScI. https://webbtelescope.org/webb-science/the-observatory/infrared-astronomy
[7] Clark, Stephen. (2021). ‘’Ariane 5 fairing cleared for Webb launch after ‘perfect’ performance on last flight.’’ Spaceflight Now. https://spaceflightnow.com/2021/11/07/ariane-5-rocket-fairing-cleared-for-webb-launch-after-perfect-performance-on-last-flight/
Very informative and well written.
Very interesting and easy to understand even for a lay person.