After Years Of Delays, NASA’s James Webb Space Telescope To Launch In December : Short Wave – NPR

September 24, 2021 News Editor

MADDIE SOFIA, BYLINE: You’re listening to SHORT WAVE from NPR.

RHITU CHATTERJEE, HOST:

Hello, SHORT WAVErs. This is Rhitu Chatterjee here. And joining me today is science correspondent Nell Greenfieldboyce with some exciting astronomy news. Hi, Nell.

NELL GREENFIELDBOYCE, BYLINE: Hey there, Rhitu. So today, we’re going to talk about NASA’s next big space telescope…

CHATTERJEE: Mmm hmm.

GREENFIELDBOYCE: …The James Webb Space Telescope. This is a behemoth that is sometimes called the successor of Hubble. And it will be the biggest, most powerful telescope ever put into space.

CHATTERJEE: And I hear we finally have a launch date. It’s been a long time coming.

GREENFIELDBOYCE: Indeed, indeed, it has, and now it’s supposed to launch on December 18.

CHATTERJEE: Hasn’t this telescope been in the works for over 20 years?

GREENFIELDBOYCE: Yeah, yeah. I first reported on it for NPR back in 2007.

CHATTERJEE: Mmm hmm.

GREENFIELDBOYCE: That’s when they built this giant life-sized model of the thing and were bringing it around the country. I went to see it when it was set up here in D.C. down by the White House and all the monuments. And to me, it looked like this big ray gun that was about to zap the dome off the Capitol Building.

CHATTERJEE: (Laughter) I love that description. And that’s an unusual look for a telescope, right? I mean, usually space telescopes look like metal tubes but not this one.

GREENFIELDBOYCE: Nothing like this has been put out into space before – nothing.

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CHATTERJEE: So today, we’re going to look at what this powerful new instrument is going to be able to do, like see the earliest galaxies and search for the first hints of life beyond our solar system. Plus, we’ll talk about why building it took two decades and $10 billion.

GREENFIELDBOYCE: This is SHORT WAVE, the daily science podcast from NPR.

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CHATTERJEE: So, Nell, let’s start with the name – James Webb. Who was he?

GREENFIELDBOYCE: James Webb was a NASA administrator. Usually, telescopes get named after famous scientists – like Hubble, for example. But that was not James Webb. He did, however, help establish the Apollo program that put people on the moon, and he worked in some form at the agency for a long time, so he was important to NASA.

CHATTERJEE: And how did he become the namesake for this space telescope?

GREENFIELDBOYCE: Another NASA administrator sort of unilaterally made the decision to name it after him years ago. Recently, though, some researchers have raised questions about this. They believe James Webb went along with discrimination against gay and lesbian people inside the government in the 1950s and 1960s – you know, the so-called Lavender Scare.

CHATTERJEE: Yeah, so the Lavender Scare was when people in the gay and lesbian community were let go from government jobs because they were thought to be a moral and national security threat, right?

GREENFIELDBOYCE: Right, right. So that’s why these researchers are objecting to naming this telescope after James Webb. They want it renamed to something without all this baggage, and…

CHATTERJEE: Mmm hmm.

GREENFIELDBOYCE: …I asked NASA about this, and they sent me a statement saying, quote, “NASA is aware of concerns that have arisen about James E. Webb, and we are working with historians to examine his role in government,” unquote. So they’re doing this kind of internal investigation, but they wouldn’t tell me the status of it or when it might be done or what was going to happen.

CHATTERJEE: Well, moving on to the instrument itself – whatever its name ends up being – I mean, this is a huge telescope that has to be launched into space and travel a million miles.

GREENFIELDBOYCE: Exactly. It’s going really far away. And the other thing about it that is unique is that this is a telescope that is folded up inside the rocket. So it’s a foldable telescope.

I talked with Jane Rigby at NASA. She’s part of the James Webb team.

JANE RIGBY: What we’re doing is going to be hard. We are unfurling a telescope that is bigger than its rocket. And that’s not an easy thing to do.

GREENFIELDBOYCE: She says the whole telescope basically gets crammed inside the rocket. And then, once it’s out in space, it unfolds itself.

RIGBY: So it’s either a Transformer or it’s origami.

GREENFIELDBOYCE: And hopefully that whole process works because here’s the thing – there will be no way to repair it.

CHATTERJEE: Right, because of what you said – it will be a million miles away in space. I mean, its predecessor, Hubble, was closer to Earth and got repaired repeatedly by astronauts, right?

GREENFIELDBOYCE: Right, and remember, Hubble didn’t even work at first because of a flaw in its mirror that no one had detected or anticipated. So, you know, they’ve tested James Webb extensively on the ground, but it’s really an unprecedented telescope, so you know.

CHATTERJEE: Yeah.

GREENFIELDBOYCE: (Laughter).

CHATTERJEE: So I’m looking at a photo of it now on the ground unfolded, and the most prominent feature is this big, gold hexagon – looks like a giant yellow honeycomb.

GREENFIELDBOYCE: That is the telescope’s light-collecting mirror, and it’s made, you can see, of separate smaller hexagons. There’s 18 in all. And they’re arranged in that, you know, honeycomb pattern.

CHATTERJEE: Right. And they’re in segments so that it can fold up.

GREENFIELDBOYCE: Yep. Out in space, the segments will actually act like one giant mirror. And for that to happen, their positions need to be aligned precisely, like to within one-ten thousandth of the thickness of a human hair.

CHATTERJEE: Wow.

GREENFIELDBOYCE: So, you know, it’s got to be precise, and these segments are literally covered in gold, real gold.

CHATTERJEE: Huh.

GREENFIELDBOYCE: And that improves the reflection of infrared light, but, you know, it is a microscopically thin layer of gold. The total amount of gold on the whole telescope is like the mass of a golf ball. So, you know, this isn’t super (laughter) – it’s not like we’re sending a treasure into space.

All in all, the mirror is 21 feet across.

CHATTERJEE: Twenty-one feet across – wow. That’s big. And how does that size compare to the mirror in the Hubble Space Telescope?

GREENFIELDBOYCE: So the mirror, you know, is the key part of the telescope, the light-catching mirror. And this one is substantially bigger than Hubble’s, so James Webb has more than six times the light-collecting area. And so that means it’ll be able to catch much more light from faint distant objects.

Jane Rigby told me Webb is so much more sensitive than Hubble, you know, when we look up at the night sky with our eyes just looking up at the sky, we see places that look to us like just blank sky, just black nothingness. But when Hubble looks at those same spots in the sky, it can see thousands of galaxies.

RIGBY: When Webb looks at it, there will be still far more galaxies that just were too faint or too red for Hubble to see. They’re just going to pop out.

CHATTERJEE: Wow, that just sounds incredible. OK, going back to this funky telescope, it has this big golden mirror – right? – and it seems to be sitting on what looks sort of like a silver trampoline. What is that, Nell?

GREENFIELDBOYCE: That’s the sun shield. It’s the size of a tennis court, and it has actually five layers to it.

CHATTERJEE: Huh.

GREENFIELDBOYCE: And the sun shield is so that the telescope will stay in the shade and stay cold. Scientists want the telescope to be colder than negative 370 degrees Fahrenheit.

CHATTERJEE: Negative 370 degrees – that is cold. Why does it have to be so cold?

GREENFIELDBOYCE: That’s so it can better detect infrared light. Infrared is the kind of energy that we feel as heat.

CHATTERJEE: Mmm hmm.

GREENFIELDBOYCE: And you don’t want an infrared telescope to be warm because that would mean all the infrared light it wants to capture from interesting stuff out in space would be swamped out by the telescope’s own warm glow.

CHATTERJEE: OK, so all of this delicate equipment designed to be crammed into a rocket and then unfurled and operate at these super-low temperatures and be perfectly aligned, et cetera, et cetera, – it all sounds pretty technologically complicated, and I think I’m starting to guess why it cost billions of dollars.

GREENFIELDBOYCE: Yeah, yeah. So when the telescope was first conceived, some of its necessary technologies hadn’t even been invented yet. And the entire history of James Webb is one of cost overruns and delays. A report from the Government Accountability Office earlier this year noted that since its costs were sort of baselined in 2009, the launch date has been delayed by over seven years, and the costs have increased by 95%.

CHATTERJEE: Wow. I mean, it’s common for big science projects to go over budget but still.

GREENFIELDBOYCE: Some astronomers have been resentful of how much NASA’s science budget has gone into this. And some people, like in Congress, have tried to kill it over the years. But now James Webb is a done deal, and everyone’s just counting down the days to the launch. And I would say the astronomy community is just crossing their fingers and hoping it doesn’t blow up on the launchpad when the rocket tries to take off.

CHATTERJEE: Seriously. I mean, are astronomers truly worried that it will fail?

GREENFIELDBOYCE: It’s definitely a concern for the whole astronomy community. I mean, their credibility is on the line, and this is a huge investment for their field.

Here’s how astronomer Lisa Storrie-Lombardi put it to me.

LISA STORRIE-LOMBARDI: It is a worry, I’m sure, for every astronomer in the world who’s paying attention.

GREENFIELDBOYCE: She isn’t even part of the James Webb team. She directs a big ground-based telescope.

CHATTERJEE: So if it gets up there as planned and is perfect, what kind of interesting stuff will this telescope be able to see? I mean, what’s the big payoff that is worth all this money and time and risk?

GREENFIELDBOYCE: One of its primary goals has always been to see the earliest galaxies to form after the Big Bang. So remember, light takes time to travel.

CHATTERJEE: Mmm hmm.

GREENFIELDBOYCE: And here’s how Jane Rigby describes this.

RIGBY: Because the speed of light is not all that fast and the telescope is super sensitive, and we’re looking back so far out into space that we’re seeing galaxies where the light’s been travelling for almost all of the history of the universe – right? – that you’re seeing – Webb will be able to see galaxies as they looked a couple hundred million years after the Big Bang.

GREENFIELDBOYCE: So that’s the cool thing about telescopes – right? – like, because light takes time to travel, you basically, you know, end up with sort of a time machine that’s looking back into the past.

CHATTERJEE: Wow. So that’s like looking back at sort of – and getting pictures of a baby universe, right? It’s mind-blowing to think about. What else will the telescope be able to do?

GREENFIELDBOYCE: Another major activity is going to be studying the atmospheres of planets in other solar systems, so, you know, planets orbiting distant stars. James Webb is not going to be able to take, like, photographs of small rocky planets around other stars – it’s not that powerful – but what it can do is study starlight. And what happens as a planet passes in front of its star is that some of the starlight gets filtered through the planet’s atmosphere, if the planet has an atmosphere. And so there’s a change in the starlight that can be detected, and it can be analyzed to understand what gases are in the air around the planet.

CHATTERJEE: So will this telescope be able to find evidence of life outside our solar system if it’s out there?

GREENFIELDBOYCE: Some people think so, if we get really lucky. Nikole Lewis is an astronomer at Cornell University.

NIKOLE LEWIS: The James Webb Space Telescope does have the capability to measure those key biosignatures that are sort of held by scientists, as we want to see this mix of things to prove that life exists on a planet.

GREENFIELDBOYCE: Other researchers, though, aren’t so sure. Laura Kreidberg studies planets outside our solar system. She works at the Max Planck Institute for Astronomy in Germany.

LAURA KREIDBERG: I personally do not think we will detect biosignatures with James Webb.

GREENFIELDBOYCE: She says she thinks the telescope will do a great job at identifying the basic building blocks of atmospheres, like what dominates the atmosphere, if it’s dominated by methane or water or carbon dioxide.

KREIDBERG: But when you start talking about combinations of different gases, particularly those that have very low abundance or not very strong spectral features, it’s a really big challenge.

CHATTERJEE: So it’s probably a sure bet that whatever is seen in the air of distant planets will get argued about endlessly by scientists – right? – I mean, because to say something like, you’ve detected a mix of gases that indicates life on another planet, another world – that would be a huge claim.

GREENFIELDBOYCE: For sure, for sure. But even just being able to have those arguments about individual planets out there would be transformational for the field. There’s this one particular solar system that James Webb will look at called the TRAPPIST-1 system. So this is a solar system about 40 light-years away, and, you know, it’s a sort of small, cool star that’s orbited by seven small planets – you know, small, like, potentially rocky planets, and three of them are in the so-called habitable zone around the star. That’s where temperatures are mild enough for there to be, you know, maybe liquid water and maybe life. So as you can imagine, this one solar system is like a perfect little laboratory – a bunch of small planets in one solar system that James Webb can start to study and compare.

CHATTERJEE: OK, so more information about that solar system is definitely something to look forward to. Nell, you said the telescope is supposed to launch in December. I’m curious, when will the first images start coming back?

GREENFIELDBOYCE: It takes about six months to get the telescope to cool down and adjust all the mirrors and check out all the instruments, and so it’s about half a year before they can really start doing science. And the James Webb team already has a top-secret plan to take certain pictures that are designed to be both visually and scientifically jaw-dropping, so those will be released to the public first to sort of show off the new telescope and what it can do. All the other stuff about rocky planets and their atmospheres – that kind of stuff is going to take some time to get, but hopefully, like Hubble, this telescope will be operating out there for years and years to come.

CHATTERJEE: Assuming, of course, it gets up in space OK and unfolds and works smoothly.

GREENFIELDBOYCE: Fingers crossed. That’s all they can do once it lifts off.

CHATTERJEE: Right. Well, Nell Greenfieldboyce, always lovely to talk to you, and thank you once again for stopping by with this fascinating tale of this telescope.

GREENFIELDBOYCE: Thanks for having me here.

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CHATTERJEE: This episode was edited by Gisele Grayson, produced by Thomas Lu and fact-checked by Berly McCoy. You’re listening to SHORT WAVE from NPR.

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