No matter how grim the past two years have been, humanity has shown its resolve by not giving up and courageously and desperately holding onto hope, moving forward inch by inch. The parting days of 2021 left us with a similar hope. This hope however comes from science and is the result of the adventurous human mind and its never ending thirst for exploration.
On 25th December 2021, James Webb telescope was launched into space as the whole world watched in awe and excitement. It is one of our most important attempts to understand the initial and formative phases of the universe. The main purpose of the telescope is to get a glimpse into the origins of our mysterious universe by capturing the light from billions of years ago and sending images back home. The telescope - about a hundred times more sensitive than its predecessor, the Hubble telescope - is a technological wonder in every aspect. The existence and making of the telescope itself narrates the beautiful story of human endeavour and curiosity.
The James Webb telescope is named after the NASA administrator who contributed greatly to the historic Apollo missions which were responsible for the Moon landings. Work on the telescope began about 30 years ago at NASA with the help of the European Space Agency (ESA) and the Canadian Space Agency (CSA). This telescope is the fruit of a cumulative effort of decades of work by the scientists and engineers along with millennia of scientific innovation by our ancestors. This daunting project took 10 billion dollars and more than a thousand people’s tireless effort to get completed.
The telescope is set to reach its destination in space called the Lagrange point 2 or L2 within one month from launch. It’s a point in space one million miles beyond the Earth where the forces balance each other so that the telescope can easily stay in a stable position with minimum utilization of energy.
Each small part of the telescope has been meticulously designed and engineered just for the telescope. Every bit of it being a product of latest cutting edge research, JWST is truly a child of the twenty-first century.
JWST is an infrared telescope. We need an infrared telescope to investigate the times and bodies far away from us because the universe is constantly expanding. Expanding universe stretches the light and shifts it towards the longer wavelength side of the spectrum, hence infrared. While infrared light is ideal to understand the expanding universe, detection of IR radiation is a very sensitive process which requires some very specific conditions and technology. The problem is that the space is overflowing with heat radiation from the Sun which can interfere with the IR radiation that the telescope intends to detect.
The observing side of the telescope is the dark side which has the mirrors facing away from the Earth, Sun and Moon into the deep vast space. This dark side requires a temperature of -233 degree Celsius to work which is more than 300 degrees less than that present on the side facing the Sun and the Earth. To block out all excessive sources of heat and maintain this temperature difference, scientists devised a highly specialized heat shield. The heat shield efficiently blocks this heat through its complex engineering of multiple layers coated with materials like silicon and aluminum. The heat shield, stretching the size of one whole tennis court, is one of the most critical and astonishing components of the telescope. It is thinner than a strand of hair and thick enough to create hundreds of degrees of temperature difference across its two sides. Scientists also took special care in making it strong enough to not get ripped apart by the shower of micrometeoroids in space and be resistant to degradation by solar radiation.
What makers of the telescope are most worried and nervous about is its proper unfolding and deployment in space at L2. To fit it into the launch rocket, the heat shield had to be carefully folded and packed inside the spacecraft. The heat shield is very delicate and will have to unfold in a very specific manner and orientation to serve its purpose. Unfortunately, this is just one occasion where things could go wrong. Scientists at NASA say there are 344 such failure points in the proper deployment and functioning of the telescope which could render the entire effort useless. 344 occasions which could make 30 years of hard work and collaboration go to waste. The whole scientific community and all curious minds on the planet are holding their breaths in nervous excitement in hopes that everything will go as expected and we will soon get our first glimpses into the origin of this bewildering universe.
If everything goes according to the plan, the first images from the telescope are expected to arrive by late June but if something goes wrong, scientists have backup plans and considering the stakes of the project, they even have backup plans to the backup plans. The telescope is expected to work for 10 years as it only carries a limited quantity of hydrazine fuel. The telescope is unserviceable and currently we have no way to refuel the telescope so far away into space but rumours suggest that NASA has started investigating other projects and ways to increase the telescope’s life.
The telescope is no doubt a massive step in mankind’s journey, but it is by no means the biggest or the last step. Just as it is meant to capture new and unknown horizons from far across the universe, it also signifies a new horizon in our understanding of the universe and ultimately our place in it.
The extraordinary Hubble telescope was launched in 1990 after years of planning and research. Hubble is much closer to Earth than the James Webb Telescope and is moving at a speed of 5 miles per second. Unlike JWST, Hubble is a serviceable telescope and it started sending jaw-dropping clear images of our beautiful universe in 1993 after astronauts fixed some minor defects in the telescope’s focus.
The Hubble telescope is responsible for all the breathtaking images of faraway galaxies and stars we are so used to seeing. 30 years later Hubble is still serving as our eye in the universe and contributing greatly to our understanding of the cosmos.
Hubble Space Telescope is named after Edwin Powell Hubble, an American astronomer. He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology. A model of the telescope is prominently displayed in his hometown of Marshfield, Missouri.