This Monday, NASA rewrote astronomy’s history by releasing the first full-colour image from its massive James Webb Space Telescope, after a White House briefing led by President Joe Biden.
As the highest-resolution infrared image ever captured by humankind, NASA’s first teaser of what the James Webb telescope is capable of is what astronomers call a ‘deep field’ image — a long-exposure infrared capture of a certain region of the sky, designed to allow researchers to peer far into the universe, both across distance and time.
The galaxy cluster observed in the above image is SMACS 0723, a group so large that viewers can observe a ‘gravitation lensing’ effect, clearly observable in the middle of the image.
If you held a grain of sand at arm’s length, that would represent the speck of universe you see in this image, NASA Administrator Bill Nelson told Biden in the briefing. Nelson added that the image is just the first. “We’re going back to about 13 and a half billion years. Since we know the universe is 13.8 billion years old, we’re going back almost to the beginning,” he explained.
Biden responded with a note on the cultural significance of the image. “These images are going to remind the world that America can do big things and remind the American people, especially our children, that there’s nothing beyond our capacity. We can see possibilities no one has ever seen before. We can go places no one has ever gone before,” the President said.
As the most powerful telescope ever launched into space, The James Webb Space Telescope, or JWST, is a major upgrade over the Hubble Space Telescope, which celebrated its 30th year of operation back in April 2020.
Back when Hubble made it into orbit in the 1990s, NASA had already begun discussing plans for a successor, primarily aiming to outdo existing infrared resolution tech and view deeper into the universe.
Much of the early development of the JWST can be credited to NASA’s Hubble teams, which sent space shuttle missions to retrofit and maintain the older telescope. These missions provided valuable data and insights, as well as strengthened the bonds between NASA and other organisations such as the European Space Agency (ESA) and the Canadian Space Agency (CSA).
By 2005, the project was formally put into place by NASA’s Goddard Space Flight centre in Maryland, with Nobel Prize laureate John Cromwell Mather as the lead project scientist. At this time, the project was expected to cost $4.5 billion across the telescope’s total lifespan, with two years spent on intense research and development of the technologies that would come together to form the JWST.
Large-scale, high cost projects such as these require something called a ‘Non-Advocate Review’ — a high-level report that deemed the tech mature enough to retire significant risks in the project. By 2011, the project reached its final ‘design and fabrication’ phase, described by NASA as a point of no-return for the project. Back when Hubble launched, the engineers at work did not know if such a large and complex telescope was even possible to build. Over 20 years later, they saw such a marvel form before their very eyes.
Despite the progress on ground, NASA’s spreadsheets were looking alarming by this point, especially to the US Government.
In July 2011, the United States House of Representatives’ appropriations committee on Commerce, Justice, and Science moved to cancel the project after it had spent over a decade in conception and development, slashing NASA’s budget by nearly $2 billion. This was a major play, considering that $3 billion was already spent on JWST, and that the telescope ate up a hefty 25% of NASA’s entire wallet.
While the proposal was initially passed — adding insult to injury by claiming that the over-budgeting was a direct result of ‘poor management’ — a growing movement amongst scientists, journalists, and even Maryland Senator Barbara Mikulski drew international pressure in favour of JWST. Less than a year later, Congress back-pedalled and capped the project’s funding at $8 billion.
To no one’s surprise, the $8 billion mark was quickly overshot, and the project is now estimated to cost over $10 billion. That’s about as much as it costs for SpaceX to launch a staggering 161 space missions, making the JWST one of the most expensive passion projects ever undertaken by the human race.
Perhaps the biggest nailbiter about the JWST’s operational plan wasn’t getting the photos done; it was simply putting it in the right place to begin with.
The first step to establishing a space telescope is, unsurprisingly, getting it into space. This involved a long, complex deployment sequence — a phase described by scientists and engineers as ‘terrifying’. Designed ‘Ariane flight VA256’, the telescope was launched into space on Christmas Day, December 2021.
Fortunately, the launch was near-flawless, circumventing over 350 possible mishaps that NASA was hoping to avoid. Across the next few days, the JWST would maneuverer itself into place, slowly unfurling tennis-court-sized sunshields that protected its delicate instruments from space’s harsh conditions.
A month later, on 24th January 2022, the JWST was finally placed in what’s called a ‘halo orbit’, traveling around the Sun while loosely keeping pace with the Earth. You can actually track the current location of JWST on this website.
Once in place, the JWST began its job of calibrating and testing a wide variety of high-sensitivity instruments. The main purpose of the telescope is to use a massive 6.6m diameter mirror to focus infrared signals of light into a smaller ‘secondary’ mirror. This then reflects those signals into the JWST’s sensors, which record and eventually transmit data back to Earth.
Space telescopes largely use infrared sensors as infrared light can easily pass through dust particles, allowing us to see far further than normal light would allow.
Since the telescope aims to pick up light sources for over 13 billion light years away, it operates with very high degrees of sensitivity, making other light sources such as the sun a major issue. It resolves this by utilising a set of sun shields, where the temperature difference is so great that the ‘hot’ side of the JWST can reach around 85ºC, while the ‘cold’ side plummets to -233ºC.
Apart from pulling off some record-breaking astrophotography, the JWST also contains a ‘spectrometer,’ an instrument capable of studying the atmospheres of distant exoplanets. Mather aims to find one with water out in the distant universe. As he puts it, “a wet little planet out there that might be a little bit like home.”
For Mather, much of the telescope’s appeal lies in deep philosophical questions that have eluded scientists and thinkers for thousands of years.
“We’re going to look at everything there is in the universe that we can see. We want to know: how did we get here from the Big Bang, how did that work? So, we’ll look,” Mather said.
NASA will continue to release further images through the weeks and months ahead.
(Featured Image Credits: NASA, Goddard Space Centre)