The James Webb Space Telescope (JWST) is an infrared telescope in space orbiting the Sun about 1.5 million kilometres from Earth. James Webb was launched by NASA from ESA’s spaceport in French, Guyana, on 25 December 2021 at 7:20 am EST, and from there began its journey to help mankind look deeper into the history of the universe.
The space telescope was previously known as the Next Generation Space Telescope (NGST) but was later renamed to James Webb Space Telescope in September 2002 after the former NASA chief from 1961 to 1968, James Webb. James Webb Space Telescope is the largest and most powerful space telescope ever made.
James Webb Space Telescope will be Earth’s premier space observatory for the years to come and will study the history of our universe, starting from the first signs of light after the Big Bang to the formation of galaxies and planets such as our own.
JWST was developed in collaboration between NASA, the Canadian Space Agency (CSA), and the European Space Agency (ESA).
JWST includes a primary mirror that is made up of 18 separate segments, a five-layer sunshield as big as a tennis court that attenuates heat from the Sun over a million times, a programmable microshutter that enables observations of up to 100 objects at the same time, a cryocooler that can cool up to 7K, and many other impressive instruments.
The early history of the James Webb Space Telescope
Discussions around what would come after the Hubble Space Telescope started in the 1980s, but serious planning didn’t take place until the early 1990s. The birth of JWST was given a major push after the correction of flawed optics of the Hubble Space Telescope (HST) in its first years.
While preparing for the Astronomy and Astrophysics Decadal Survey of 2000, NASA needed to include future developments of the Hubble scientific program that eventually came to be known as the Next Generation Space Telescope (NGST).
In 2002, the project was renamed to James Webb Space Telescope after NASA’s second admin James E. Webb who was in charge of NASA from 1961 to 1968. James Webb was the leading member of NASA’s Apollo program.
In 2003, NASA awarded the contract for JWST to TRW Inc., an American corp involved in aerospace among many other businesses, for $824 million. By 2011, JWST was in its final design and fabrication phase.
The hexagonal segments of the primary mirror of JWST were assembled from November 2015 to 3 February 2016 through a robotic arm. The installation of the secondary mirror was completed on 3 March 2016. A few months later, extensive testing of the James Webb Space Telescope began after its final construction in November 2016.
The challenges JWST faced
After the telescope’s sunshield ripped during a practice deployment and the sunshield’s cables didn’t tighten sufficiently in March 2018, James Webb’s launch was delayed by another two years to May 2020.
In June 2018, James Webb’s launch was delayed by an additional ten months to March 2021 based on an independent review that concluded that the JWST’s launch and deployment had 344 single-point failures that had to succeed for the James Webb Space Telescope to work as these tasks had no alternative or means of recovery if unsuccessful.
The mechanical integration of the James Webb Space Telescope was completed in August 2019. Following this, the telescope underwent final tests at a Northrop Grumman factory in California. On 26 September 2021, a ship carrying the JWST left California and arrived in French Guiana on 12 October 2021.
On 11 July 2022, all the 17 observatory scientific instrument modes of the James Webb Space Telescope had been fully vetted, and the telescope was ready to begin its epic space mission, as announced by NASA. According to ESA, the nominal duration of the JWST is five years, but the goal is ten years.
The first scientific images taken by JWST were released by NASA on 12 July 2022.
The rise of the James Webb Space Telescope (JWST)
JWST is the largest and most powerful space telescope ever made by Humans. It is made in collaboration between NASA, the Canadian Space Agency (CSA), and the European Space Agency (ESA). The construction of JWST involved over 300 universities, organisations, and companies across 29 U.S. states and 14 countries, according to NASA.
The ultra-powerful telescope will take breathtaking pictures of celestial objects just like the Hubble Space Telescope (HST). James Webb Space Telescope will also be used to look at previously identified exoplanets and follow up on real-time observations from the ground.
After its launch on 25 December 2021, the JWST deployed and tested an important antenna on 26 December, in a process that took about one hour. This antenna is responsible for sending the data collected by JWST back to Earth two times a day. A day later, the telescope flew beyond the orbit of the Moon.
On 31 December 2021, the James Webb Space Telescope unfurled its massive sunshield successfully. On 3 January 2022, the tensioning of the sunshield’s five layers began and then ended the next day. Afterwards, on 5 January 2022, the telescope’s secondary mirror was deployed and latched on successfully.
On 8 January 2022, the JWST unfolded its huge primary mirror successfully and was now fully deployed.
JWST took about 30 days to travel nearly 1.5 million kilometres to its permanent resting place called Lagrange Point 2, which is a gravitationally stable location in space. The telescope arrived at L2 on 24 January 2022.
L2 is a popular spot for other telescopes such as Planck Space Observatory and Herschel Space Telescope as well. This is because since L2 is a spot near the Earth that lies opposite to the Sun, the orbit from this point allows the telescopes to stay in line with the Earth as they orbit the Sun.
The $10 billion space telescope will keep an eye on the cosmos to uncover the biggest mysteries of the Universe, from the Big Bang to the formation of exoplanets and much more. It is humanity’s big eyes looking back at the origins of the Universe.
Future plans of the JWST
JWST is planned to focus mainly on the following four areas:
Planets and the origins of life
The last ten years have seen the discovery of a large number of exoplanets, many of them through the eyes of NASA’s planet-seeking Kepler Space Telescope. James Webb Space Telescope’s much more powerful sensors will be able to look at these planets with more depth and might even be able to image their atmosphere. Better data on the formation conditions of planets and their atmosphere will be very useful for scientists to better predict if a planet is habitable or not.
First light in the Universe
First light refers to the early stages of the Universe just after the Big Bang. In the aftermath of the Big Bang, the Universe was a sea of particles such as neutrons, electrons, and protons, and until the Universe cooled down enough for these to combine, light wasn’t visible. JWST will also study the effects of the formation of the first stars. This era is called the “epoch of reionization” as it refers to the time when neutral Hydrogen was reionized by radiating from these stars.
The birth of stars and protoplanetary systems
Stars start their life in the form of clouds of gas, and as they glow, the radiation pressure they exert blows away the surrounding gas. But it is difficult to look at these stars as they are surrounded by gas. JWST’s infrared capabilities will enable it to look at the stars that are being born inside clouds of gases. The Eagle Nebula’s Pillars of Creation are famous birthplaces for stars.
Assembly of galaxies in the early Universe
Examining galaxies is an interesting way to understand how matter is organised on a big scale, which also helps us understand how the Universe came to be as it is today. The different elliptical and spiral galaxies that we see today evolved in their current form over billions of years. JWST will look back at the galaxies of the past to understand their evolution in a better way and help scientists on Earth figure out the ways in which galaxies form and assemble.
Achievements of the JWST so far
The first scientific images from the James Webb Space Telescope came from NASA during a live event on 12 July 2022. The images included Stephan’s Quintet, the Southern Ring Nebula, the Cosmi Cliffs in the Carina Nebula, and an atmospheric composition analysis of the hot gas giant exoplanet WASP-96 b.
On 11 July, the first science-quality image captured by JWST was released. The image showed the most detailed infrared view of the Universe to date and was created using only one of JWST’s four instruments in just 12.5 hours of observing time.
Prior to these official image releases, JWST had already impressed us with several images during its instrument check.
On 11 February, JWST captured its first images of starlight. It was of a star called HD84406. Light from HD84406 was captured by JWST’s primary mirror’s 18 mirror segments. The image was a mosaic of 18 scattered bright dots that’d become a single star over the next months as the telescope aligns and focuses itself.
A week later, NASA released a new image of HD84406, bringing the 18 unfocused copies into a deliberate hexagonal formation. The final image will be formed by putting these 18 images on top of each other once the JWST successfully aligns the segments of the primary mirror and begins the image-stacking process.
Eventually, on 28 April 2022, NASA announced that JWST had successfully finished its alignment phase. The space telescope successfully demonstrated that it could take crisp and well-focused images with all of its scientific instruments.
JWST has also taken a rather cute picture of itself, a selfie, using a special camera inside its NIRCam instrument. In the selfie below, one mirror segment is shining brighter than others because, at the time when this picture was taken, that was the only mirror segment that was successfully aligned and pointing at a star.
The James Webb Space Telescope vs The Hubble Space Telescope (JWST vs HST)
The James Webb Space Telescope (JWST) and the Hubble Space Telescope (HST) are two space-based telescopes that are used to study the Universe. While both telescopes are important tools for astronomers, they are designed to observe the Universe in different ways. James Webb vs Hubble has been an important question among the general public these days.
The JWST is an infrared telescope, which means it is sensitive to light in the infrared part of the spectrum. This allows it to observe objects that are very distant and/or very cold, such as the first stars and galaxies that formed in the early Universe. It is also designed to study the atmospheres of exoplanets (planets outside our solar system), which could potentially be habitable.
The HST, on the other hand, is a visible and ultraviolet light telescope. This means it is sensitive to light in the part of the spectrum that is visible to the human eye, as well as ultraviolet light.
It is used to study a wide range of astronomical objects, including galaxies, stars, and planets within our own galaxy, the Milky Way. The HST has also been used to study the atmospheres of exoplanets and has made important discoveries about the Universe, including the existence of dark energy.
In terms of size and capabilities, the JWST is larger and more powerful than the HST.
The JWST has a primary mirror that is made up of 18 separate segments, while the HST has a single primary mirror. The JWST also has a number of other instruments and capabilities that the HST does not have, such as a programmable microshutter that enables observations of up to 100 objects at the same time and a cryocooler that can cool down to 7 kelvin.
However, the HST has the advantage of being in orbit around Earth for over 30 years, which has allowed it to make many important observations and discoveries.
Another major difference between the two is that the JWST orbits the Sun while the HST orbits the Earth. JWST can’t be serviced as it is extremely far away from Earth, unlike Hubble, which was serviced by space shuttle missions.
The question of James Webb vs Hubble doesn’t carry much weight as both the telescopes are important tools for astronomers and are meant for different purposes. James Webb and Hubble will continue to make important contributions to our understanding of the Universe.
Drawbacks of the James Webb Space Telescope (JWST)
As with any complex space mission, there are several potential drawbacks or challenges associated with the James Webb Space Telescope.
The main disadvantage of an infrared telescope such as the JWST is that it needs to stay extremely cold. It needs to get colder with an increase in wavelength otherwise the background heat of the telescope itself will overwhelm the detectors and render them blind.
NASA overcame this hurdle by designing the space telescope carefully and placing it in a dewar with an extremely cold substance such as liquid helium. Liquid helium limits the lifetime of the James Webb Space Telescope as the coolant will slowly vaporise, and when it does, the telescope will no longer work.
The James Webb Space Telescope is designed to operate for at least five years, but it is not clear how long it will actually be able to function in space. The harsh environment of space can be hard on the telescope, and there is always the risk of something going wrong that could shorten the telescope’s lifespan, and since it is so far away, it can’t be fixed if anything goes wrong with it.
The James Webb Space Telescope (JWST) is designed to help us better understand the Universe by providing unprecedented capabilities for observing distant galaxies, exoplanets, and other phenomena.
The telescope’s large mirror and advanced infrared instruments will allow it to observe distant objects in greater detail than any previous space telescope. This will enable scientists to study the formation and evolution of galaxies, the atmospheres of exoplanets, and the structure of the early Universe.
By providing new insights into these and other mysteries of the cosmos, the JWST will help advance our understanding of the Universe and our place in it.
JWST is expected to make many exciting discoveries. Scientists are eagerly anticipating the new insights that the telescope will provide into a wide range of astronomical phenomena, from the atmospheres of exoplanets to the structure of the early Universe.
James Webb Space Telescope’s capabilities for observing distant objects in unprecedented detail will enable new and important research on topics such as the search for extraterrestrial life and the origins of the Universe. As such, there is a great deal of excitement and anticipation among scientists and the general public for the discoveries that the JWST will make.