James Webb: Our Golden Eye in space | By Nikhil Joshi

On 25 December 2021, an Ariane5 rocket blasted off from the European Space Agency’s (ESA) launch station in French Guiana, carrying aboard one of the most momentous space exploration projects of the 21st century. a collaborative project of the ESA, NASA, and the Canadian Space Agency (CSA/ASC), the James Webb Space Telescope is expected to be 100 times more powerful than the Hubble Space Telescope. During its thirty years of operation, the Hubble Space Telescope has already altered our conception of the cosmos. Its images, crafted carefully by digitally processing the relayed image data, have expanded scientific knowledge of everything from planets in our solar system to dark matter. Hubble was a huge step forward for humanity, and James Webb has the potential to completely transform our understanding of many of the phenomena observed in space, and show us things we have no idea about. Coming as a kind of Christmas gift to scientists all over the world, James Webb truly promises a new era for astronomy.

Named after NASA administrator James Webb, the telescope was originally supposed to be launched back in 2010. However, a series of issues delayed the launch by over a decade and led to the budget skyrocketing from $1 billion to around $10 billion. Adding to these already high stakes, James Webb is expected to be unserviceable by human hands if anything goes wrong because it is to be launched to nearly 1 million miles away from the earth. This is quadruple the distance between the earth and its moon. The scientists and engineers involved in the project are careful to note that there are still a lot of things that could go catastrophically wrong, with over 300 single points of failure observed. An ever so minor error could turn this state-of-the-art telescope into an aimlessly floating hunk of metal. However, for what it promises, a look into the earliest stars and galaxies, this steep price still seems to be worth it.

A Marvel of Design and Innovation

Just a glance at models of James Webb is enough to make anyone’s jaw drop. The telescope with its gold-coloured primary mirror made up of 18 hexagonal gold-plated beryllium segments is aesthetically stunning. The mission scientists also designed it innovatively so that it folded to fit the 8-foot-wide, 56-foot-high narrow nose cone of Ariane 5. At 6.5 metres across, it is the largest space telescope sent to space. While its predecessor, Hubble has been able to observe light from 400 million years after the Big Bang, James Webb promises to be able to see light from just 250 million years after the Big Bang. Glimpses of this “Cosmic Dawn”, when the first starlight shone through the universe have the potential to alter our understanding of the Big Bang, and the initial phase of the formation of our universe. Going beyond this horizon of time is not possible for light-capturing telescopes (such as Hubble and James Webb), as they encounter what scientists call the “cosmic dark ages”, a period with no observable light. Astronomers hope that James Webb will provide answers to how the cosmic dark ages came to an end and the cosmic dawn was ushered in. The current hypothesis is that the starlight from the earliest galaxies caused the fog to dissipate, and dissociate the gas clouds.

Another significant advantage of the Webb telescope is that it primarily collects infrared light, which is what will allow it to see so far back in time. Such infrared light is often very old because as light from distant galaxies travels through space, it gets stretched into longer and longer wavelengths, getting redder and redder. Astronomers, therefore are eager to get the first human look at how black holes in the centres of many galaxies form. James Webb is also capable of detecting some chemicals in the atmospheres of celestial bodies, such as water vapour, Carbon monoxide, Carbon dioxide, and methane. This, some astronomers hope, would allow them to search for another Earth-like planet, as the presence of these is a necessary condition for life. This might allow humankind for the first time to definitively answer the age-old question “Are we alone?”.

To be able to detect infrared light, the telescope has to be kept extremely cold (-220 degrees C) Therefore, it is intended to orbit around what is called a langrage point. This is a point in space where the telescope can stay at the optimum temperature and also stay in line with the Earth as both orbits around the sun. Even after being so far away from the earth, another invention was required to keep Webb cold. This came in the form of a five-layered, tennis court-sized sunshield made of a material called Kapton. This acts as an umbrella and protects the telescope from the heat emitted by celestial bodies, as well as the observatory itself.

Another key feature of the Webb programme is the democratized access to the telescope. Researchers from around the world can apply with a research proposal to use the telescope. All such proposals are subjected to a rigorous peer review, and selection is competitive. In 2020, the Space Telescope Science Institute, at John Hopkins University in Maryland, put out a call for proposals for the first observing run, and just under a quarter of the proposals were accepted. The review process is also dual-anonymous, which means that those who review the proposals have no idea about the identity of the authors of the proposals, thereby eliminating the possibility of bias.

The Way Forward

With advances in the technology of the different types of telescopes and other types of unmanned spacecraft, the incentive for a human flight further afield into space has been reduced. This could eventually lead to human spaceflight becoming more of an adventure sport for the super-rich, as more and more private companies enter into the business of space tourism. There are proposals to set up a radio telescope in a lunar crater on the dark side of our moon, to study the initial period of the formation of our universe after the big bang, thereby overcoming the limits of telescopes like Hubble and James Webb. However, no national space agency/ consortium has expressed interest in actually setting up a telescope on the moon so far. But the idea of a telescope on the moon is exciting, and who knows, might become a reality some years from now.

ISRO’s Grand Plans

On the home front, ISRO has also been showing interest in developing a more advanced telescope, following the success of its first space mission focused on astronomy, called AstroSat, launched in 2015. The data from AstoSat, which had a combination of x-ray and ultraviolet telescopes, was used by scientists around the world and facilitated the publication of several acclaimed research papers by Indian scientists. While originally intended to function only till 2020, AstroSat continues to transmit data. ISRO had proposed a successor mission in 2018, to be called AstroSat 2, however, as of 2021, the agency has decided to set its targets higher and work on a truly next-generation space observatory. While the planning and development may take a few years, AstroSat 2 is certainly a welcome sign for the prospects of India’s astronomy and astrophysics research.

Conclusion

On January 8, 2022, the second wing of the primary mirror was finally deployed, following the deployment of its secondary mirror on January 6. This brought relief to anxious scientists all around the world. On 13 January, it was confirmed that all the actuators, which are tiny motors that move the mirror segments were functional. The Webb telescope reached its target location on 25th January, and will subsequently undergo a phase of final testing and calibration measures for around 5 months.

Once operational, the visions of the cosmos provided by the James Webb Space telescope will serve to remind us that we are but infinitesimal beings riding on a fragile, rocky planet in a vast, dark expanse of space. But when we work together, we can accomplish great things like sending a telescope a million miles out into space to try to see the birth of the first stars.