James Webb: The Future of Space Exploration

Over 1200 scientists, 25 years and 10 billion US dollars, have gone into the creation of the James Webb Space Telescope. A feat of engineering and scientific mastery, James Webb is a space mission like no other, which provides us with a unique opportunity to explore space to a degree we have never been able to before…but what is the James Webb Space Telescope?

The James Webb Space Telescope is a giant observatory that will allow us to capture information about the earliest stages of the universe. It contains a giant mirror, organised in 18 hexagonal segments, which can detect infrared light emitted from the formation of stars and galaxies. The telescope is composed of a plethora of parts working together, some of the most interesting being the mirror, the Nircam (detects infrared light),the Nirspec (analyses the light to determine mass, temperature and chemical composition of objects) and MIRI. These components work together, along with many other features, to create the most advanced and sophisticated telescope we have ever seen.

James Webb is going to allow us to see the formation of the first stars and galaxies. When these stars and galaxies were created, they emitted gamma rays, which is at the end of the electromagnetic spectrum. According to Einstein's theory of relativity, the universe is expanding, meaning that the wavelength of these rays is increasing, leading them to become infrared light. This is what the telescope captures. The light takes time to reach us, and due to James Webb’s advanced equipment, we are going to be able to see images from around 100million years after the big bang. Using the Nircam, the telescope blocks out light that isn’t relevant, and using MIRI, the telescope is able to see images through dust clouds which has previously prevented us from seeing detailed images of stars.

One thing that sets this telescope apart from previous space missions is its position within space. The telescope will be operating at a point known as the second lagrangian point or L2. This is one of the 5 points within space where the orbital motion of an object is in balance with the gravitational force acting upon it, leading to objects being able to remain stationary or ‘hover’. This point is located 1.5 million kilometers away from Earth, which will take 29 days to reach. For reference, the predecessor mission to this was the Hubble Space Telescope, which was located just 547 kilometers away from Earth, in low Earth orbit. Due to the distance the telescope is at, we are unable to reach it once it has left Earth, and therefore we can’t service it. To protect the telescope from space debris and the scorching temperature of the sun, it contains something known as the sun shield. The sun shield is 5 layers of a material called Kapton covered in aluminum. This keeps the telescope at an extremely low temperature of 45° Kelvin, or -288.15°Celsius, which is the ideal temperature for this telescope to operate at. Kapton is extremely strong yet thin. It protects the telescope from any debris that may hit it.

Something that is especially interesting is the possibility of this telescope finding life on other planets and the conditions of exoplanets. The telescope will analyse planets located within the habitable zone from their star, which is the area in which water could exist on a planet. The telescope uses 2 methods to break down the atmosphere of exoplanets; first, using background infrared radiation detected from exo-planets as well as where the light is coming from, scientists can break down the molecules within the atmosphere. Secondly, using a coronagraph, James Webb can block the light coming from the stars around an exo-planet, and zoom into the planet's surface and atmosphere. This could potentially allow us to discover water on other planets and maybe even living organisms.

The James Webb Space telescope provides a completely new outlook on space exploration, and could vastly improve our understanding of not just our solar system, but galaxies we were unable to ever see. This huge project, 25 years in the making, will literally show us new worlds of opportunity, and provide an insight into the universe that we were previously blind to. A culmination of every bit of space exploration done previously, this telescope is about to change the course of history.

By Dia Nanda 11F