The James Webb Space Telescope Has Launched: Now Comes the Hard Part

The relief was as deep as the stakes were high. At 7:20 A.M. (ET), the rocket carrying the largest, most ambitious space telescope in history cleared the launchpad in French Guiana, and the members of mission control at the Space Telescope Science Institute in Baltimore roared their relief.

The suspense was not quite over. Half an hour postlaunch, the telescope still needed to decouple from its host rocket, after which had to deploy solar panels to partly power its journey. Only after that first deployment proved successful, said a NASA spokesperson in a statement to Scientific American, would “we know we have a mission.” When the announcement of a successful rocket separation and solar-array deployment finally came, it was almost drowned out by cheers.

Astronomers have more riding on the rocket than the James Webb Space Telescope (JWST). Also at risk is the viability of NASA’s vast space-science portfolio if not the future of astronomy itself. As the successor to the Hubble Space Telescope (HST), JWST is one of those once-in-a-generation scientific projects that can strain the patience of government benefactors as well as the responsible agency’s credibility but also define a field for decades to come—and possibly redefine it forever.

Back to the Beginning

The telescope that would become JWST was already under discussion even before HST launched in April 1990. By orbiting Earth, HST would have a line of sight free of the optical distortions endemic to our planet’s atmosphere. It would therefore be able to see farther across the universe (and, given that the speed of light is finite, farther back in time) than any terrestrial telescope.

Even so, HST would be observing primarily in optical wavelengths—the tiny portion of the electromagnetic spectrum that the human eye can detect. The Next Generation Space Telescope (as the future JWST was then known) would be looking at the universe in infrared, the regime into which cosmic expansion would have stretched, or redshifted, visible light emitted more than 13 billion years ago.

Much of the attention leading up to today’s launch has focused on the ability of JWST to peer farther into the past than HST, which has observed infant galaxies as far back as approximately 400 million years after the big bang. At that point in the universe’s history, however, matter had already undergone several generations of evolution—galaxies merging and shredding, supernovae seeding space with additions to (what sentient beings on Earth would one day call) the periodic table of the elements.

JWST, however, will be able to see as far into the past as 100 million years after the big bang, a period when most matter consisted of only the primordial elements and was just beginning to coalesce into stars and galaxies. From the inception of JWST, the primary goal has been to glimpse these phenomena—the first luminous objects in the universe.

A New Search for Life

The other major scientific frontier that JWST will probe is one that has received less attention but might prove to be just as profound in our understanding of the universe. It is a bonus of sorts, a subject of study those 1980s-era visionaries could have scarcely foreseen: exoplanets.

Evidence for planets orbiting stars other than the sun first emerged in the 1990s (a finding that earned some of its discoverers a share of the 2019 Nobel Prize in Physics). Since then, astronomers have found exoplanets by the thousands, with tens of thousands more sure to overflow their catalogs in coming years. Almost all of these discoveries, however, rely on indirect evidence: the regular brightening and dimming of a star as a planet transits across its face, or the wobble in a star’s axis caused by the gravitational pull of a nearby world.

JWST should offer more direct evidence: observations of the planets themselves, a feat only a few other facilities can manage—though none with the promised clarity of this new space telescope. In visible light, the brightness of a star overwhelms any nearby objects, but by observing in the infrared JWST will reduce the contrast so that the planets can pop out from the background stellar glare as tiny blips of light. That reduction in contrast will further help observers to probe the atmospheres of a handful of worlds for potential biosignatures such as oxygen (produced on Earth by photosynthetic plants) as well as tracers of habitability such as water and carbon dioxide.

In short: JWST offers some chance, however slim, to answer an eternal question: Are we alone?

“That’s where the big discoveries will be,” predicts Nicholas Suntzeff, an astronomer at Texas A&M and former vice president of the American Astronomical Society. “Is there other life in the universe? If so, it would have to be the biggest discovery in science ever.”

Near-Death Experiences

But first JWST will have to, you know, work.

Many of the members of the JWST project were not yet born when HST launched in 1990. But what happened next shadows them, just as it haunts all of NASA. Like some “Ghost of Missions Past,” a grim event from the observatory’s early days drags and rattles its chains along the otherwise pristine corridors of the Space Telescope Science Institute—the operations headquarters for HST and now mission control for JWST. Initial observations from HST were out of focus, and engineers soon realized that its mirror had been improperly polished, leading to a ruinous case of cosmic myopia and widespread public ridicule. Although spacewalking astronauts later repaired the mirror (at tremendous expense), the fiasco was a classic instance of “You had only one job…,” threatening to render HST almost useless and leaving NASA vulnerable to congressional oversight bordering on strangulation.

In the case of JWST, similar significant setbacks—technical, political, sociological—have preceded the launch. The original budget estimate was a hazy $1.5 billion to $3 billion, and its similarly nebulous launch date was, oh, let us say 2010. By that deadline, however, not only had costs risen to $5 billion but much of the telescope was still on the drawing board; the development of JWST’s myriad foundational new technologies was proving more intractable than planners had imagined. Only a year later the budget had ballooned by 60 percent to $8 billion—at which point Congress intervened, establishing a cost cap for JWST: $8 billion, or bust.

Would Congress dare to cancel a scientific mission of such ambition? Yes, it would—and once did. In October 1993, President Bill Clinton signed a bill killing the Superconducting Super Collider, which would have been the world’s most powerful particle accelerator. Never mind that the project had already cost $2 billion ($3.15 billion in 2021 dollars). Never mind that underground boring had already cleared nearly 19 of the projected 51 miles of tunnel. Never mind that the particle accelerator promised transformative scientific breakthroughs. Congress deemed the project’s budget to be out of control. The cancellation blew a hole through the heart of the U.S. particle physics community, which, even three decades later, has yet to fully recover.

By 2018, the JWST project was both flirting with the congressional cap and pushing the launch date farther and farther into the future. Behind the scenes, as a Government Accountability Office investigation would later reveal, technical problems were multiplying: Workers at Northrop Grumman, the primary contractor for JWST, discovered that the application of an inappropriate solvent had damaged the observatory’s propulsion valves. A wiring error destroyed the pressure transducers. And during vibration testing, dozens of bolts flew off the spacecraft.

The budget grew by another $800 million, officially exceeding the congressional cap. And the launch date slipped to 2021.

Even the name of the telescope has been a subject of controversy. In 2002, NASA’s then administrator Sean O’Keefe announced that the Next Generation Space Telescope would thereafter be called the James Webb Space Telescope. The practice of replacing generic names for telescopes and observatories with the names of prominent scientists is routine. O’Keefe, however, violated two norms: His choice of honoree was essentially a unilateral decision, and that honoree was not a scientist but a fellow administrator—indeed, one of O’Keefe’s predecessors. James E. Webb had served as NASA’s chief during its race-to-the-moon heyday, from 1961 to 1968.

In recent years, though, the name of the mission has gained another layer of controversy: who Webb was, at heart. Webb’s tenure as the second in command at the Department of State in the late 1940s and early 1950s and then as the head of NASA coincided with what historians now call “the lavender scare”—a search for and purge of LGBTQ…