The immense sound of the Ariane 5 rocket will rumble across Europe’s spaceport in French Guiana. This will signal the end of a journey that took decades to make. Atop of the Ariane 5 rocket, the James Webb Space Telescope will glitter. The James Webb Space Telescope is one of the most sophisticated and complex observatories ever made. A 6.5-meter enormous mirror which consists 18 gold-plated segments will be unfolded delicately to fit within the nose cone.
The precious cargo holds the dreams and hopes of thousands of engineers and scientists who have worked hard to make this observatory a reality.
If everything goes well, we will be able to see a whole different view of the cosmos. It will surpass everything that have gone to space before it. The telescope will show us territories that have been previously hidden from us by being too distant, too cold or too faint for the Hubble Space Telescope to discover them.
The light from the earliest stars has been expanded of the universe over 13 billion years. Scientists needed an instrument that can work in infrared light which we feel as heat, and peer into the mysterious epoch of cosmic history. JWST is very sensitive and it can detect the heat of a bumblebee from the distance of the moon.
We all are at the edge of discovering the origins of our universe and our place within it. These insights will fix the information in our textbook pages.
Before that discovery, we have to go through an agonising period of wait. It is during the launch of the US$10 billion JWST and also during the tense months of deployment as well. Then for the preparation of the “first light” of a facility which is the “most expensive astronomical gamble in history.”
JWST is the first observatory that has been subjected to so many tests and scrutiny. JWST had cancellations, design changes and many technical mistakes. JWST had faced budgetary woes and natural disasters like Hurricane Harvey and a pandemic. It had also faced the threat of piracy in its journey from California to French Guiana through the Panama Canal.
An international team of with a worldwide partnership led by Nasa, the European Space Agency and the Canadian Space Agency have developed the telescope with the help of hundreds of other institutions around the globe.
The launch of JWST
The eyes of all the scientists will be fixed on the rocket as it clears the tower at the spaceport. This will be just the beginning of JWST’s perilous journey. After some weeks, an array of mechanisms and sequential deployments will start to work perfectly which will add risk to the process.
After the faring separates from the telescope, the observatory will deploy its communications devices and solar arrays. Then it will start its 29-day journey towards the “Lagrange point” . In this point, the gravitational forces of the sun, Earth, and orbital motions of a spacecraft interact to create a stable location which is nearly 1.5 million kilometres from our planet. Ariane will send the telescope directly to this location without orbiting Earth.
When travelling to its destination, it will execute a delicate unfolding. The whole observatory should remain cold to not to be blinded by its own infrared warmth and to tease out the faint infrared light from both distant stars and galaxies. The observatory will do it by keeping its back to the sun and using an enormous parasol which is a tennis-court-sized sunshield made of five layers of thin plastic coated in reflective aluminum and doped-silicon. This sunshield is durable to withstand strikes by swarms of tiny meteorites. The sunshield will deploy first, after a week of launch.
After this, the petals of the primary mirror will unfurl itself. The eighteen segments need to be aligned in space and need to adjust and focus to work together as one giant mirror. The total deployment will have 344 steps.
Scientists have given months of testing, calibrating, aligning and more testing to the telescope as it cools to 40K. The MIRI instrument needs to go cooler to 7K. This will be possible by thermally isolating it from the rest of the observatory on long legs and special helium refrigerator will be used.
Astrological bounty waits
After six months, JWST will open its eyes to the cosmos. The telescope will peer back in time such as looking back at few million years after the Big Bang to witness the end of the dark ages. It is the time when the matters coalesced to form simple stars of hydrogen and helium. This era was the stage for the origins of galaxies which shaped our cosmos and seed the universe with complex elements.
It will also investigate the atmospheres of planets around other stars in order to understand their origins and potential habitability. JWST will also look at the worlds of our Solar System to explore the rocky and icy remnants from the origin of planets.
University of Leicester scientists have worked on the MIRI instrument. This instrument has been built by a transatlantic partnership of ten European countries also US was also included in this. The team of the scientists were led by Professor Gillian Wright at STFC’s UK Astronomy Technology Centre in Edinburgh and Professor George Rieke at the University of Arizona.
MIRI is the only mid-infrared instrument in JWST’s toolkit. This will provide images and spectroscopy which is a technique that breaks down light into specific wavelengths. This will enable to tease out the chemical signatures of JWST’s astronomical targets.