Planetary Radio • Dec 03, 2021

Space Policy Edition: Astronomy goes big, with Heidi Hammel

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Hammel heidi

Heidi Hammel

Vice President, Board of Directors of The Planetary Society; AURA Vice President for Science

Casey dreier tps mars

Casey Dreier

Chief of Space Policy for The Planetary Society

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Mat Kaplan

Senior Communications Adviser and former Host of Planetary Radio for The Planetary Society

The search for biosignatures on hundreds of exoplanets is the top goal for U.S. astronomers. That's the conclusion from the new, once-per-decade report from the National Academy of Sciences: Pathways to Discovery. In it, the field of astrophysics is analyzed and prioritized: establishing the major scientific questions, the tools to answer them, and how to best engage the human talent necessary to enable our continued investigation of the cosmos. Dr. Heidi Hammel, astronomer, Vice-President for Science at the Association of Universities for Research in Astronomy, and Vice President of The Planetary Society joins us to discuss the new results and what it means for the future of astronomy.

LUVOIR Observatory Concept
LUVOIR Observatory Concept Illustration of the Large Ultraviolet Optical Infrared Surveyor (LUVOIR) space telescope.Image: NASA


Mat Kaplan: Hello again, everybody. It is the first Friday in December. Welcome to the last month of the year. This is the Space Policy Edition of Planetary Radio. I'm Mat Kaplan, the host of Planetary Radio, joined, as we are each month, by the Senior Space Policy Advisor and Chief Advocate for The Planetary Society, welcome back, Casey.

Casey Dreier: Hey Mat, always happy to be here.

Mat Kaplan: I just want to tease a terrific conversation with the distinguished, the esteemed Heidi Hammel, a conversation that we recorded a few days ago with Heidi that you'll be talking with her. Well, what will you be talking with her about?

Casey Dreier: Well, we just had a seismic event in the world of astrophysics, which was the release of the National Academies of Sciences, Engineering and Math, the US institution that advised says Congress and the US government on science issues, their Decadal Survey Report. This is a once every 10 year report that sets the direction for various fields in space science, in this case astrophysics, that helps NASA plan for the future, it helps Congress decide what to fund and really represents the consensus approach from the US scientific community about what the big questions are in astrophysics and how best to solve them.

Casey Dreier: This is a very, very, I cannot emphasize this enough, very influential report. It just came out a few weeks ago. Heidi and I dive deep down into it. I also have a corresponding article on you can reference, and it will help you understand what the next 10, actually 20 years of NASA's investments in space-based telescopes are going to be and what we can look forward to coming down the pipeline.

Mat Kaplan: There is your tease for the month, and it also is an introduction to the value delivered to members of The Planetary Society, and hopefully to all of you who might be considering becoming a member. This is a great example of the work that we do to further space science and space exploration. There's so much more that follows this. We hope that you will take a look at and see all the other benefits of becoming a member of the society, but it is, we're a nonprofit, and you know what happens with nonprofits at the end of the year.

Mat Kaplan: It's time to go to all of you and make our year end appeal, which, toward the middle of this show, you'll be hearing about, just for a moment or two, from our boss, the CEO, Bill Nye. We hope that whether you're a member or not, that you will see fit to support the great work that the society is doing, which you can do right now.

Casey Dreier: We do after gift memberships. Unlike a lot of things, there's no supply chain issues backing those up, so you can give those as a great present for the holiday season this year to your fan of space that you know, or potential fan of space that you want to engage. Again, I always like to remind people that this organization, The Planetary Society lives and dies by its membership. We don't have big corporate donors, we don't have government sponsorship. We exist because of you. Mat and I, and all of our colleagues do our jobs because people pay to be members of the society and we cannot be more thankful for that.

Casey Dreier: Because of that, we can do this great work, and because of the gifts and the donations and the support you give us, we will continue to do so in the year.

Mat Kaplan: So, to find out, both how to become a member, specifically there,, and you can go there to join in on our year end appeal as well that you'll be hearing about from the society and certainly on Planetary Radio, right up to the end of 2021, a very momentous year. Casey, bringing up this conversation with Heidi makes me want to mention that I will be having Heidi back on the weekly Planetary Radio. It'll be our December 15 episode, if all goes well, just one week before the scheduled launch of the James Webb Space Telescope.

Mat Kaplan: Joining her will be the JWST observatory scientist, Mike McElwain, and a principal investigator for one of the instruments on that telescope that's going to inaugurate a new era in space-based astronomy, Rene Doyon, a Canadian scientist, who is also very excited about the launch of this new telescope. Casey, as you know, a slight delay in that launch, but few big relief. JWST, we hear, is apparently okay after a little mishap.

Casey Dreier: Yeah. There was a clip that became unclipped unexpectedly and it caused some vibrations to the spacecraft. They've delayed the launch by four days just to check that out, I think absolutely the right call. I mean, we are getting down to the very near moments. It's been so abstract this project for so long. This project really began in the very late 1990s, really got kicked up in the early 2000s. It's a 20 year or so project.

Casey Dreier: And we are down to the last few weeks as we record this before launch and it's multi-week, nail biting, must work deployment procedure that cannot be rescued this time by astronauts the way that the Hubble Space Telescope was. So, it's going to be a very exciting holiday season here for a number of people in the astronomy community and at NASA, and all of us watching nervously and hoping everything works. Top price is about 9.7 billion, just the US portion. The Europeans added on their contributions on the order of 700 million euros.

Casey Dreier: The Canadians added around 200 million Canadian dollars of contributions to this. I wrote this up in an article at that we will link to in the show notes. The cost of this mission is arguably the most expensive single scientific platform ever made at the time of launch. Hubble creeps up there over time because it was upgraded five times over the last 30 years. James Webb won't be, but by the time of launch, this will be about a $10.5 billion project. This is a big deal, if nothing else, through 20 years of development, it has survived multiple attempts of cancellation.

Casey Dreier: Obviously it has blown its original budget profile and original schedule, but it survived. The question is, how did it manage to do that? I think this brings up this idea of the decadal survey process. JWST was the top recommendation of the year 2000 decadal survey. The value of this, again, it shows you the power of these recommendations is that by creating this as this will address some of the top questions in the astrophysics community. In this case, really studying the very, very early universe, the first stars in the universe.

Casey Dreier: The decadal survey is referred to, in this sense, as the sword and the shield behind these types of big projects. The sword in the case that it allows the scientific community to advance forward and coalesce around their big project ideas, and the shield to protect these projects from potential cancellation when they run into trouble. I think there are some really interesting questions about, people will say, "Well, this is a $10 billion project. Maybe we could have gotten more science doing other missions or different types of science. Could done more with this money than James Webb?"

Casey Dreier: I'm not going to sit and defend all the mistakes that happened. There were some serious past mistakes in management, really fundamental engineering mistakes and design issues that happened a long time ago that did make it cost more than in a sense that it "should have." However, at the same time, the way that astronomy works is to answer the questions that we have not yet answered. It kind of, by definition, needs to do something highly technologically complex, or else we would've answered them by now.

Casey Dreier: To push our collecting abilities of these very, very early universe photons, you start with those big questions and work backwards to the design and to the capabilities of projects like JWST. In this case, this mid infrared space telescope that needs, because it's looking at basically the warmth levels, it has to be very cold itself so it doesn't block its own signal. It creates the complexity in a sense. Then you, of course, have to design it to launch in a rocket, so you have to fold it up so it fits.

Casey Dreier: All of these things aren't just done for fun. They're done to answer the fundamental science. Kind of has to cost a lot of money sometimes to answer these really profound questions. This is in a way that astronomy is fundamentally different than planetary science. In planetary science, you make one spacecraft to go to a certain place. You probably haven't been there much, or haven't been there often, or at all. So, just doing anything will get you a lot of new science, even flying by close, just like new horizons at Pluto, flying by close and taking a bunch of pictures and other measurements, revolutionized our understanding of Pluto.

Casey Dreier: In astronomy, you are pushing the boundaries of what you can collect. You're trying to find these new signals to answer these fundamental questions and so you have to create the technology to gather that information, which will then be used by a large community for decades. That just presents that ... Kind of pushes the types of projects that happen in astronomy to these big projects that happen less frequently but then can provide a huge range of scientific return over the years. As a consequence, you get very nail bitty moments of watching the one thing that has to work, launch and deploy and go through this complex sequence.

Casey Dreier: JWST is this fascinating, I think output of what, in a sense, has a very beautiful thing that we do in our societies of starting with these profound and fundamental scientific questions about the state and origin of the universe, working backwards from those questions to say, how do we answer them? And then spending the money and time and effort to then answer them.

Mat Kaplan: And you're going to hear an even deeper exploration of this when Casey begins his conversation with Heidi Hammel, who has been at the forefront of much of what you've just heard Casey talking about as a leader in the field, as a vice president at AURA, as you will hear when Casey introduces her. Casey, before we go to that interview, just maybe a little bit more about what's happening in Congress with coming up with a budget, a FY22 budget for the United States of America. Looks like we're going to see this get pushed off yet again.

Casey Dreier: One way or another, we're going to have something happen by Friday, December 3rd. We are recording this a little earlier than that so we don't know exactly what will happen yet. The current spending authority expires on that day. Either Congress has to extend temporarily the current budget again, which seems, at this point, likely, or reach some final deal on appropriations and pass all of these fiscal year 2022 budget legislation documents that they have not yet, that we can tell, worked out in a compromise between the Senate side and the House side.

Casey Dreier: We are actually asking members and supporters of The Planetary Society, any supporter based in the United States to write their members of Congress and encourage them to pass the 2022 NASA budget to help get this over the finish line to show that people are paying attention, that the people care about this stuff. We've made it really easy for you to do so. We have a form at

Casey Dreier: You can also just go to and you can find our action center there, and it will make it very easy for you to fill out a quick form, a letter, or edit it yourself to make it your own, to send to your member of Congress and your two senators to support NASA's budget for next year. This budget has some very critical developments that will support, particularly for us, the Near-Earth surveyor spacecraft that'll look for potentially hazardous near-earth objects.

Casey Dreier: Obviously very important funding improvements for Artemis to get humans back to the moon, and really important funding development for Mars Sample Return, which really needs to start amping up spending to try to hit this 2026 Sample Return launch goal, which is coming up very rapidly. They need this stuff as soon as possible in order to keep these tight timelines from our sample return Artemis and Near-Earth surveyor. You get that by having a good budget coming through in 2022. The House and Senate versions have a few slight differences.

Casey Dreier: Overall, they're very good. We want them to reach that compromise and pass this budget so NASA can get to work and do the best work the most efficient way possible. If you live in the United States, take a minute and fill out this form at, or keep following us to hear more about what happens next month when we will have some more clarity on the issue. Lots of stuff potentially being decided this week. Again, I think the likely outcome is they have further delay in the 2022 budget process. Not unusual from what we've seen in the last few years. I think the last few years, we've gotten a budget right before Christmas, possible it'll happen again.

Mat Kaplan: We hope you will get involved. Casey, let's go ahead and begin that conversation you had a few days ago with Heidi Hamlin. We'll come out on the other end and close out this month's Space Policy Edition.

Casey Dreier: Heidi, welcome to the Space Policy Edition. Thanks for making time today.

Heidi Hammel: Delighted to be here, Casey.

Casey Dreier: You are a professional astronomer. You are also vice president of The Planetary Society and a vice president at AURA, the Association for Universities for Research and Astronomy. This is something that decadal survey is, is it too small of a phrase to say that it's a big deal? What does this mean? What kind of impact does this report to professional astronomers like you?

Heidi Hammel: It's a big deal, Casey. Every 10 years, our community gets together, assesses the state of the field scientifically, looks at our suite of capability, and assesses where we should be going in the next decade and beyond. And then, when they decide what those science priorities are, they then make recommendations on the kinds of tools and capabilities that we need to accomplish that science. This is information that's published in what we call our Decadal Survey Report.

Heidi Hammel: It guides decision making that goes on at our funding agencies, which are primarily NASA and the National Science Foundation, but also, the department of energy does astronomical research as well. It's a big deal. Over the 60 years that astrophysicists have been doing decadal surveys, our very large programs and missions have arisen because of the consensus we developed during this decadal survey process. Things like the Hubble Space Telescope, the other great observatory, Spitzer and Chandra, the James Webb Space Telescope, all of those were products of prior decadal surveys. So, it's a big deal.

Casey Dreier: You raised a point that I was going to mention too, that astrophysics has been the leader, your field has been the leader in creating this type of consensus report to drive the direction of the field. As you said, it goes back through the 1960s or '70s, way before we've seen similar reports in planetary science or earth science, the other areas at NASA that do these types of re reports. Do you have a sense, is this just because astrophysics is always at the verge of what's possible technologically or that the field, like you build an instrument that lasts for so long? Do you have any insight on why your field needed this type of guidance from the beginning of modern astrophysical observations in the mid 20th century?

Heidi Hammel: Well, obviously I wasn't around in the '60s and '70s [crosstalk 00:16:17] then, so I wasn't party to the discussions on why this happened. But I can share that the field of astronomy and astrophysics, for a long time, was struggling with this dichotomy of most of the telescopes being private, owned by private institutions or private telescopes for specific universities. There was a period of time where there was a great debate going on about whether or not we should have public facilities, public telescopes for the broad community you to use.

Heidi Hammel: I think that, in part, this development of the decadal survey was in response to this debate about whether it was a good thing to have public facilities or not. If we were going to have public facilities, how were we going to decide what they should be? To do that effectively, there needed to be a consensus discussion amongst the astronomical leadership. That has evolved into this more formalized process of, not just astronomical leadership, but all in the astronomical community who believe they have something to contribute, writing white papers and participating in this consensus discussion.

Heidi Hammel: I think it was extraordinarily successful. Because of that success, I think that is why we saw other parts of NASA and other groups start to pick up this structure of doing a decadal survey and making plans this way.

Casey Dreier: You listed through these amazing scientific instruments that we have because of previous decadal surveys, the Hubble, Chandra, Spitzer, James Webb, which is about to launch as we record this. You get a sense for, you realize how this final recommendation really is. You are really directing, or the community is, the next 10 to 20 to 30 years, if not longer, of your field based on what rises to the top out of this, as you say, consensus-driven process.

Casey Dreier: There's a huge committee of people involved in writing this report. There's a steering committee, smaller committees in various scientific topic areas, but then anyone could submit their opinion, right? Whether on science or an approach, or framing. You and I wrote a paper for The Planetary Society, urging the committee to think big, I think was the name of that paper. You were also, I believe I lost count after six, but something like a dozen other papers talking about various aspects of this. Let's look at what came out of this process.

Casey Dreier: This was a multi-year process, obviously delayed because of the COVID pandemic, finally came out November 4th. Let's state right away, what are the biggest headline recommendations from this report that are going to be driving astrophysics in the next couple decades?

Heidi Hammel: Let me take a little bit of a step back and explain what the framing of the report is before we jump to the headlines because people sometimes miss the fact that this report is a comprehensive report, not only of the headline next future, but about the state of our profession and our community. This particular report, which was a beautifully crafted report, I have to say, it laid out a sort of a pathway. They called this Pathways to Discovery. They have a figure that shows the path and the path is based on the foundations, which includes people and research, diversity and equity and sustainability.

Heidi Hammel: It moves through to the frontiers. Then, from the frontiers, the science that emerges from the frontiers. So, they define the science that they want to accomplish. They say, what frontier tools do we need to do that science? And then, how do we sustain our community so that we can take advantage of those frontier tools? I'm going to tell you some headlines, but those headlines are only at one tiny piece of this very large picture of where astronomy and astrophysics stands right in this moment of time.

Heidi Hammel: What are the headlines? The headlines, they come sort of two flavors. One is the space-based activities that we do funded by NASA. And the other is the ground-based activities funded primarily by the National Science Foundation, NSF, and the Department of Energy DoE, to some limited extent. Let's talk about space. What this decadal survey said is that we have three priority science areas for the future. One of those is worlds and sons in context. This is looking at of the thousands of exoplanets that we have now discovered throughout our neighborhood of the galaxy.

Heidi Hammel: They identify a particular case, pathways to habitable worlds, and they say, how do we, in our local neighborhood, assess what worlds are habitable, and to do that, what tools do we need? The science recommendation they make is we need to build a space telescope that is capable enough to assess atmospheres of at least 25 earth sized planets in the habitable zones of sun-like stars. That's the recommendation. So, they don't say, "Build LUVOIR," which was one of a study that NASA did. And they "Don't say don't build HabEx," which was a different study.

Heidi Hammel: They say, "We're not going to tell you what the architecture is, but we're going to tell you what this thing needs to do." Based on the studies that NASA has already done, it's clear that this space telescope will probably have to be at least six meters in aperture. For reference, Hubble is only two meters in aperture. We're talking about a telescope that is much larger than Hubble, and it needs to be operating in the same wavelength regime as Hubble, the UV, optical, infrared. That's important, because of course, James Webb, which is a six meter class telescope, that is operating in the near and mid infrared.

Heidi Hammel: Webb can't do the science that I just outlined looking for habitability on 25 Earth-like planets around sun-like stars. Can't do it. That's why this new telescope is needed. That's the headline. They also say, "Oh, and by the way, this telescope also must be capable of doing terrific revolutionary astrophysics as well." They are very clear what astrophysics they want it to do. Another science theme, in addition to worlds and suns in context, is what they call cosmic ecosystems. This is really talking about trying to understand the context in which galaxies, and from the galaxies stars and planets form out of dust and gas in the universe.

Heidi Hammel: Really looking at the drivers of galaxy growth throughout the universe. How do we get galaxies? And from that, how do we get the stars and planets in our galaxies? To do that, you need the same telescope. You need a very large UV optical infrared telescope. For space, that's the big headline. There are secondary headlines that are equally important to us as a community on the space side. Definitely want to be looking at a line of great observatories. Not just one telescope, but a series of telescopes, preferably a collection of telescopes that operate together in space that are multi-wavelength.

Casey Dreier: Yeah, which is referencing the Great Observatory Program or what NASA already did in the '80s and '90s. Right. So, that's a callback in a sense. It's almost like an upgraded version of the Great Observatories that gave us Hubble, Spitzer, and Chandra.

Heidi Hammel: Yeah. That's exactly right. In fact, we call it like the New Great Observatories. Our Great Observatories have been just absolute fundamental for changing our understanding of the universe. The current Great Observatories, of course, Hubble is like the mainstay.

Casey Dreier: The greatest.

Heidi Hammel: I'm biased. I'm an optical [crosstalk 00:24:57], so of course I'm biased. The Chandra X-ray telescope, it has been the leader in x-ray observatories as well. And Spitzer telescope was a really wonderful infrared telescope. But Spitzer is basically limping along, it can't really do much of its mission anymore. Chandra has been having some health scares. I'm sure people are aware that Hubble itself has been having some health scares recently with communication issues and things like that.

Heidi Hammel: I don't want to forget there's also the Compton Observatory, Gamma Ray Observatory. There are other parts of this Great observatory program. It's time for a new generation. We've been using Hubble for 30 years, and it's still incredibly productive, but we have identified new questions and problems that are just, you can't answer them with Hubble. You need to have a larger telescope.

Casey Dreier: You learn different things about physical characteristics and the natural world by viewing the universe through these different pieces of the electromagnetic spectrum. We just can't emphasize that enough. This is why James Webb is designed to answer a very different set of scientific questions than this super Hubble kind of proposal that they're putting in there. That you're taking these scientific questions, working backwards and saying, how do we answer them using various windows into the electromagnetic spectrum or the size of things, or the number of planets we need to find?

Casey Dreier: That all drives ultimately, why we come to those, right? It's not just like the astrophysics community is saying like, what's the biggest, coolest space telescope we can spend money on? That all falls out of the big questions that we're trying to answer.

Heidi Hammel: Yeah. That's exactly right. That's why I was trying to be very clear that what the decadal said was not build ... They didn't say go build a super giant space telescope bigger than Hubble. They said, here's the science question. We want you to characterize 25 Earth-like planets around sun-like stars. You got to do that many to really be sure that if you're detecting what you think are signs of potential habitability or potential biological activity, you have enough information to make a definitive answer about that. That's what they are recommending. The tool you need is the super Hubble, right?

Casey Dreier: Yeah. Well, and that's also why you can't just build a second Hubble, right? I mean, that's like, when people say, why do we need something as expensive as James Webb as opposed just building another Hubble, for example, well, you build another Hubble, you can still only answer the types of questions Hubble is currently answering. You can just do more of it. Your bandwidth of that expand, but your fundamental limits, your physical limits are the same. This is why we don't just repeat at the physics community, why you just don't repeat what you've done before. You need new tools designed specifically to answer the progress of the science, like to recognize and acknowledge the progress of the scientific theory and observations that have been happening.

Heidi Hammel: Exactly. Let's jump a little bit to the ground-based side. What they said on the ground based side is, following the same scientific themes about new worlds and suns in context, and the pathways to habitable worlds, we know from our work with exoplanets that it's actually easier to find exoplanets around cooler fainter stars, because the star itself is just fainter and so the relative brightness of the planet is better, more amenable for detection.

Heidi Hammel: One of the recommendations is to study a suitable sample of earth-like planets around these cool faint red stars, these red dwarfs M-type stars again, to look for the signs of habitability. These kinds of worlds are a little more challenging because the stars themselves are cooler. That means that the habitable zone where water can be liquid is closer to the star and there's some suggestion that these types of M stars are more active than G stars like our sun.

Heidi Hammel: There's more radiation flares from them and that might pose a problem. But nevertheless, it's a whole nother class of habitable planets that are totally worth exploring. The tool that you need to do that is actually large ground based telescopes, these 30 meter class telescopes that are being explored by different consortia here in the United States. That is their top recommendation is again, to try to study these class of planets around these M-type stars. That's the science recommendation, and the tool that you need is an extremely large telescope, of which we have two in development in the United States.

Heidi Hammel: One is the Giant Magellan Telescope. The other is the 30 meter telescope. My organization, AURA, the organization I am the vice president of science for, we operate what is called the National Optical-Infrared Laboratory for Astronomy, for the National Science Foundation. The short name for that is NOIRLab. NOIRLab has been crafting what we call the US ELT Program, United States Extremely Large Telescope Program. One of these telescopes would be situated in the Southern hemisphere and the other in the Northern hemisphere, which gives us all sky access.

Heidi Hammel: That was the recommendation of the decadal. If we're go going to characterize this type of planet around this type of star, we need this US ELT program to move forward. So, that was the headline for that. It's pretty exciting too.

Casey Dreier: Yeah. Well, I mean, it's just remarkable to me thinking how much of this report is focused on, not just exoplanets, but seeking out, essentially biosignatures. That's ultimately what's driving this on habitable, potentially habitable exoplanets, right?

Heidi Hammel: Yeah.

Casey Dreier: Earth-sized ones. The report points out, it's only been what? 25, 30 years since we had the first confirmation of any exoplanet at all. How rapidly that has come to dominate or grow into the field where we're now setting these science questions that will drive literally tens of billions of dollars of investments over the next 20 years to seek these out, planetary exploration with statistically significant results, like number you can go to. You're not just stuck in a sense with our own solar system. You can survey hundreds to thousands of other solar systems to see what's out there.

Heidi Hammel: Yeah. But I want to be ecumenical about this and point out that the exoplanet case is really robust and it's really exciting, but it isn't the only science case. It's one of the three science cases. There have been other really remarkable discoveries in the [crosstalk 00:32:29].

Casey Dreier: Past, like LIGO. Yeah, gravitational.

Heidi Hammel: Exactly. The second, one of the other science areas is called new messengers and new physics, and that word, messenger, refers to the different ways we can learn about the universe. We talk a lot about light all the time, right? We talk about optical light and infrared light, and even at the extremes, x-rays, or radio at the other end. That's all light though. What the revolution that's occurred in astrophysics in the last decade has been the use of gravitational waves as a whole new type of messenger to explore the universe, to explore black holes and to look at neutron stars and learn about the size distributions of these objects.

Heidi Hammel: We had no way of doing some of this work until LIGO became operational. Another tool that we have is particle physics, things like neutrinos coming from the sun and cosmic rays. These are other are types of messengers that are not light. Pulling all of those new messengers together is really crafting a whole new way of sensing the universe. They had a really lovely example in the decadal survey. They said something like, as human beings, we use all of our senses, whether it is sight or hearing, or taste, or touch with this new messengers of, we are opening up our ways of exploring the universe beyond just light.

Heidi Hammel: We're not just using our eyes anymore. We're using our eyes and our ears and, and touch effectively. And what do you need to really advance that? Well, you need to, of course upgrade the sensitivities of these gravitational wave detectors. You also need to improve your high energy neutrino observatories, these things like kamiokande and IceCube and all these other different kinds of particle detector observatories, but you also need to be able to find the optical counterparts to these things. Like, you've got a gravitational wave from the combination of two black holes, you want to be able to see where that is and see where it is in relation to the other galaxy that it might be a host in.

Heidi Hammel: To do that, these things are typically really faint. So, you know what you need? You need a super giant large space telescope-

Casey Dreier: [crosstalk 00:35:10] of six meters or so. Yeah.

Heidi Hammel: Yeah, exactly. Or you need your US ELT program because you don't know what hemisphere that this gravitational wave is going to be emanating in. All of these new fields, they all point us kind of in the same direction, but it is for a breadth of science. It isn't just exoplanets. It is, what is the nature of dark matter? What is the nature of dark energy? How do we understand how galaxies evolve over the age of the universe? We've answered those questions to the extent possible with the tools that we have, and now we know where we need to move forward.

Casey Dreier: That's what really struck me, and thank you for making that point. When you talk about the idea of senses, of how we're able to sense in our own experience and mapping that onto astronomy, it's not just that we have these senses, it's that we're integrating all of those feeds into one moment of experience to give us a fuller way to interpret the world around us.

Casey Dreier: That was of a thing I was struck with over and over again in this report, is that data processing and dynamic ability to kind of rapidly move and slew into position and look for where things are happening, we're able to create, and if this is followed through, we're creating this multisensory apparatus in a sense. Global apparatus that can integrate across multiple domains of information of multiple messages, you said, to create a more comprehensive picture by looking at life, by looking at gravitational waves, by looking at neutrino and other particle detections, to piece the full physics of what we're seeing altogether.

Casey Dreier: That was just really exciting. I don't often say that reading a 700 page report can be joyous in a sense, but these are, particularly ones that come out like this, and I really recommend chapter two, for those who are interested in reading this, really runs down of here's what we know and here's where the big unknowns are. They're basically defining out these big science questions. There's something still so beautiful and optimistic about that, to me, that ultimately, behind all of our debates about funding and politics and programmatic balance and interest groups kind of buying against each other, at the end of the day, we're really starting from this really beautiful notion of trying to better understand the natural world in which we inhabit it.

Casey Dreier: That we're able to, to a large degree, find some sort of consensus about what are the biggest and most important questions? Not every field or not every activity that we do in space has that to create unification. It's just a really wonderful, it's just really exciting just to be reminded about how much we've learned and how much then we can continue to learn if we have these tools.

Heidi Hammel: You're absolutely right. There's another aspect of this that I think is really exciting. They talk about this a lot in this decadal survey. One of the things that was recommended in the last decadal survey, 10 years ago, was the development of these new types of telescope that are survey telescopes, broad area telescopes. One of them is the Vera Rubin Observatory, which is under construction in Chile, and is just a year or two away from starting its full survey of the Southern sky every three days for 10 years.

Heidi Hammel: It's going to be a remarkable, remarkable new tool for understanding the dynamic nature of our sky. Another outcome from the last decadal survey, it was called WFIRST in that survey, that has now been renamed the Nancy Grace Roman Space Telescope. It is a hub class telescope, except, instead of being a small field of view, it is a Hubble class wide field of view.

Heidi Hammel: It will be working in concert with Rubin. It's in development right now, but it will be launched during our next decade. When Ruben and Roman are working together on sky, we're going to be entering a completely new realm of astronomy. We are going to be doing what we call time domain astronomy, getting tons of data and looking at things that change. Some of those things, we know what they are. For us, at The Planetary Society, we're very excited about the number of near-earth objects that will be discovered through the power of these telescopes.

Heidi Hammel: But there are going to be many things that we find out there in the universe flashing or doing something weird in terms of their brightness and we aren't going to know what they are. Following up on that and understanding this time domain, it's a whole new realm of astronomy. It's not often, in your field, that you know you're on the cusp of a revolution. And we are. This decadal survey recognizes that and gives us a little bit of a warning, all of us who are old school, people like me who are old school astronomers, who've been doing an astronomy for 20, 30 years.

Heidi Hammel: We're not ready for that. We're not ready for the onslaught of data that we're about to have in our field. It's going to be yet another new way of doing business. There's a lot of information in this decadal about data archiving, data management, curation of data, and building tools that allow most astronomers to get in there and work with this new regime of astronomical data. That's a whole new frontier that we don't really ... It's not really a new tool. It's not a new telescope, but it is equally exciting to be this whole new way of thinking about the sky.

Mat Kaplan: Astronomer, Heidi Hammel with my colleague, Casey, Dreier. They'll be right back after this message from the boss.

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Casey Dreier: This time domain approach to observation, which really, in a sense, is a function of the growth of data storage and processing capability, enabling suddenly your capability to collect and retain. We're talking about terabytes of, not petabytes of data coming in.

Heidi Hammel: Petabytes.

Casey Dreier: Petabytes of data. We all exist in the time domain, but so much of our limitations, in terms of scientific observation, are functions of these snapshots of what you're able to see once and then you have to share all this observation time with other people or limitations about how you're able to observe or store that data. Not to mention just the computing. We're seeing real, I think, integration of the computing revolution into observation, like through these big survey programs coming up.

Casey Dreier: You're right. I mean, I think that's what's so fascinating to me, is that we're seeing these consequences being reflected now through policy, and then all the kind of messy aspects of that, of making sure it's not just enough to collect all this data. It's nothing if people don't access it. It's nothing, of course, if you don't have scientists to look through it and analyze the science. That kind of brings me to this, there's this whole other aspect I just want to touch on a little bit, a really nice section talking about, as you brought this up earlier, these foundational important aspects of the field, which is the people who actually the science.

Casey Dreier: We have a section on workforce and diversity and making sure that the people who are astronomers represent and are pulled from all walks of life, essentially, to make sure we have the best minds available through all of humanity, able and capable of participating in these really exciting fields. Is there any kind of reactions or thoughts you had to that aspect and how they framed the workforce and inclusion perspectives?

Heidi Hammel: Yeah, they put a tremendous amount of thought into this aspect of the people who do astronomy. There's so much detail that would take us hours to get through it. For listeners' perspectives, they really leave no stone unturned. They look at the demographics, the current demographics, they look at the trends in the demographics. They compare the demographics of our field with other fields and with the population at large. They're really very frank. At one point, they say basically our diversity is abysmal.

Heidi Hammel: Abysmal was the word. They're very honest about that. We have a lot of work to do in our field. We have made strides in bringing in white women, such as myself, but there are women of color, there are men of color, there are people different genders, all sorts of ... People with disabilities. We have so much work we have to do. They lay out ideas and pathways for some of this to take place. It's not going to be easy, it's not going to turn on a dime, but what I can share is that this is representative our field trying to work on these issues and trying to identify pathways so that we can become a more diverse field, a more inclusive field, and more equitable field. All of those things are important.

Casey Dreier: There's a couple of really fascinating charts. One, I want to absolutely talk about, but one that just, to your point, shows the growth of women participation in PhDs and undergraduates. And it's still not parity, but change can happen. It showed that there has been improvement, which gives ultimately some optimism, that being aware of the problem, and then working to make it draw this talent and to maintain this talent in the field can happen. But it starts with acknowledging the problems. I thought that was a really fascinating and really self reflective.

Casey Dreier: And as you said, a very kind of honest assessment of what the issue was. Then there's all sorts of changes you can start to make. I just want to mention this because this probably struck me as one of the most amazing charts that I've seen in a while in science, not a budget chart. I think the one I may be talking about is the percentage of first time PIs by observing cycle, looking at Hubble data. Or not Hubble data, people proposing time on the Hubble.

Heidi Hammel: People getting time.

Casey Dreier: Getting time. Yeah, proposing and getting time. Winning time on the Hubble Space Telescope, PIs being the principal investigators. And Hubble changed the process for selecting who is a principal investigator, whose proposals get selected for time on the Hubble changed a few years ago. They went to what's called double blind. I'll let you explain it and we can talk about this dramatic change in the types of people getting time on the Hubble.

Heidi Hammel: Yeah. A number of years ago, Hubble has been operational long enough, 30 years, and has enough people proposing every year, thousands of astronomers that we can pull out meaningful statistics. Well, what we noticed is that women just weren't getting as much time as men in proportion to how many proposed, and any single year, it was just barely within the noise. And you would say, oh, it's not statistically significant. But we brought in social scientists and they evaluated the data and said, "When you look at this in the aggregate, this is statistically significant."

Heidi Hammel: So, what can you do to change that? When I say we, I'm using that word to refer to the space Telescope Science Institute, which full disclosure, is managed by AURA, the company that I'm the vice president of science for. So, I was personally involved in a lot of the development of this process. When I use we, I'm using it literally, I was part of this process. How can you change that? Well, we tried many things. The institute first, they said, "Well, we'll go to initials. That way people won't know." You won't know it's Susie or Sam. It's just S.

Heidi Hammel: Well, that didn't work because everybody knows people's last names anyway. Then they said, "Okay, well, we'll do initials and we'll put all the names on the second page, and so it's not on the front page." That didn't work either. We went through many different iterations, none of it worked. And we finally came to believe that we had to go, what we call full dual anonymous. By dual anonymous, it means that the people who were evaluating those proposals do not know at all who is doing the proposing, and so there's no names on the proposals.

Heidi Hammel: They're just like the number. And you might say, well, how, when they read the proposal, they'll be able to figure it out. Because someone will say, "Well, I used my code." No, we had to teach the proposals how to write proposals that were anonymous. So, you didn't refer to my work, or my theory, you would say, X, Y, Z's theory of this or that, even if X, Y, Z was you. That took a lot of preparation, and planning, and training.

Heidi Hammel: The proposals became completely anonymous. It was huge pushback. People did not like this idea at all. They said, "You have to know who the scientist is." We used, as our inspiration, the dual anonymous orchestra options.

Casey Dreier: Right, where they performed behind a curtain or something like that so they don't see ...

Heidi Hammel: At first, they performed behind a curtain and it didn't make any difference. Some clever person realized that the judges could hear the footsteps of the people walking up to behind the curtain. And they could hear when it was a woman's footsteps versus a man's footsteps because women's shoes tend to sound different than men's shoes. High heels have a sort of click clack sound and others don't. So, they carpeted the walkways, that is when it changed. That was our inspiration.

Heidi Hammel: Like I said, it was not well received, but we went anyway and said, "But we're going to do it." We were doing it primarily to try to change the gender dynamics because that was something that was easy to track. But once we went to this full dual anonymous, where people had no idea who was writing these things, you don't know who's reviewing them either, that's why it's dual. There's two sides to it.

Heidi Hammel: What we found, and this is a chart you're referring to that was in the decadal survey, not only did it probably start to change the dynamics of gender. I'm saying probably because there's some murkiness there. What was not murky was the chart you're referring to, where we saw that suddenly unique observers who had never gotten time on Hubble before, suddenly were getting time on Hubble. It's sort of, as if in the past, it was only like, sort of the same groups. Oh, they're from this school, I know they're a good group, give them the time.

Heidi Hammel: I've never heard of these people. Don't give them the time. Suddenly those, I've never heard of peoples, turns out they can write darn good proposals, proposing darn good science. And they were suddenly getting time now. It is diversifying the field of people who are using these tools. It was a really very successful program. We are now broadening it to all of our observatories that we operate on the ground. I know that other observatories around the world have adopted it. NASA is starting to adopt this for some of its programs as well. Because despite astronomers and scientists saying, "You have to know who the scientist is." You know what? It turns out you don't. You really don't.

Casey Dreier: This charts, Figure 313, for anyone keeping track at home, just you see, over the course of three observing cycle proposal cycles, an increase of roughly a factor of six of first time participants getting time on the Hubble space telescope. It's just so dramatic and it just shows you how, whether consciously or not, people were reacting to reputation, which is a very self-reinforcing loop obviously, of people who have good reputation can more easily get time on the Hubble, can publish more papers, can get that high profile science, and it closes off.

Casey Dreier: Time in the Hubble is a fixed quantity, right? You only have so many seconds in the day to observe things. You can see small thoughtful changes like this, though it sounds like not easily implemented, can have huge consequences for this concept of equity, of giving more access based on the ideal of the field, right? That the best ideas should be given credence and opportunity.

Heidi Hammel: I want to be fair to my fellow astronomers. I don't think any of this bias that was creeping in was conscious bias. We've always, in astronomy and in our processes, tried to be as fair as possible. But I think a lot of this is unconscious bias. It's not that people want to be biased, it's that our human brains work in a biased way. We can't turn that off. It's really hard to turn that off because it's ingrained in the way humans make decisions. By taking the biased triggers, just removing them, that's really the only way we can prevent our lizard brains from taking over and introducing these biases that are ingrained in us from just our own cultural upbringing. It's a really important thing to do.

Casey Dreier: We've talked about big picture goals coming up in science. We've talked about some of the ground-based calls that they're recommending, the big areas of interest, the fundamentals of workforce investment in making sure you have the people to do this kind of work. I want to end this discussion by talking a little bit about the timeframe. To me, that was perhaps the most contentious, or should be in a sense, a little bit of a unusual departure, let's say, for the decadal survey.

Casey Dreier: Because, instead of saying in the next 10 years, which is ostensibly what the responsibility of this report is saying, this is what we should do, they say, the next 10 years, we should put in significant, basic investment in studying how to build these future space telescopes. Then, once we feel comfortable, starting in the 2030s, then we start to build them with the goal of launching this six meter-ish super Hubble type of mission in the 2040s. Suddenly, we're on a scale of 2025 years. How do you approach something like that? Is this just the reality of where we are in astrophysics, that things just extend beyond the scope of decadal surveys?

Casey Dreier: Is that fair to the next decadal survey? How do you see this fitting in, in terms of timeline? Because this is extraordinarily long for people to wait for this.

Heidi Hammel: Yeah, you're right about that. I'll share that there has been a lot of discussion over the past 20 years about this very topic. People are like, Webb was delayed, over and over, and over again. I'm like, yeah, and Hubble was too, and just about any large facility that we've wanted to build. You and I have talked about planetary, Mars missions get delayed as well. I think that this decadal survey, more so than some in the past, was really trying to be pragmatic about how long major missions and major facilities truly take to build.

Heidi Hammel: And not have just a fantasy, oh, we can do this in 10 years. Likewise, with the cost, they didn't say something like, we want to build a super hub and we want to do it for $3 billion. It's like, well, you can't do that. I mean, that was sort of the whole issue with Webb when it was first proposed decades ago, the initial price point that was given was known to be fictitious at the time. And we've been dealing with the fallout from that ever since. I think they were trying to be really honest and pragmatic about how long things take.

Heidi Hammel: They do take this long. Does that mean we should only do a decadal survey once every 30 years? I think the answer is no, because things change. I mean, look at the revolution that we were talking about of exoplanets. We wouldn't want to put that off 25 years before we think about the next step. Really, what we are doing now, I think is trying to understand how these things fit together over the multi decadal time scale, and making sure that we're identifying for ourselves now scientific goals that will stand the test of that time.

Heidi Hammel: We did this correctly with Webb. People will fuss about how long it's taking to get web to the launchpad where it is now, literally. But I will share with you, as one of the scientists working on that program, the program I proposed for 20 years ago stands today. I mean, there's no other tool that can do it. Because we said this is the tool we need to do this science. And we didn't just say build a bigger telescope and we'll figure out what to do. It was no, we want to do this science, this is the tool we need. If it takes you 20 years to build it, it does. But that's how long it takes.

Heidi Hammel: It was very pragmatic and I appreciated that. I thought that was realistic. We all always assessed our decadals five years in. They talk about that in this decadal and they had some specific things that they talk that should be happening at the five year mark. Have you made progress on this technology maturation to the point that you're ready to move? Also, if I look at the profiles they give, this is funding as a function of year, it looks to me like they're might be opportunities to try to bring some of this development forward into more current times and maybe get these things off the ground a little sooner.

Heidi Hammel: I would also like to see some of those other telescopes, not just the super Hubble, but also the x-ray telescope and the far infrared telescope, I would love to see them brought forward so that we could fly all these things together because that's where the true power of the science is. It's all funding limited. If we can make case that this is absolutely terrific science, it'll position United States at the forefront of space and ground-based observatory, we hope that we can convince our stakeholders that fund us, that maybe they do want to make these investments and maybe invest robustly to make sure that this science happens in a timely fashion.

Heidi Hammel: I'll tell you, Casey, having worked on web for over 20 years, I know how long these things take. I think that one of the things astronomers are pretty good at doing is recognizing that the tools they are building are not necessarily for them, particularly on the large scale. They're building tools for the next generation, and they've always done that. Back in 1990, when they launched the Hubble Space Telescope, some of the people who were working on it, they were not even around anymore. When I got to use it as a young scientist in 1994, I was like, "This is amazing. This telescope is incredible."

Heidi Hammel: I had nothing to do with building that telescope. It was built for me by the previous generations. Same with Webb. I'm at a stage now where I'm not actually doing much observational astronomy because I'm more managing things, but there's a whole suite of young people who are going to be using Webb when it launches and when we start getting data back next year. We're not building these telescopes for us. We're building them for the next generation. Astronomers are good about thinking that way, that it's like, yeah, it's not for me. Scientific great-grandchildren.

Casey Dreier: You, more than anyone else, maybe a geologist who get cosmic timescale, is built in to astronomy, to your field. You're kind of into it. You're right. I mean, it's interesting, this word pragmatic, and I think that's an important reminder for someone listening to this who's not an astronomer or involved in this, that this report doesn't itself happen in a vacuum, so to speak. They're aware that they're making recommendations to the US like system. And with all of the attendant positives and negatives of that, of uncertainty, and annual funding cycles, and domestic spending limits, and so forth, and so on, there's an awareness by the people making this about what they're making recommendations to.

Casey Dreier: That acknowledgement, I think in a sense, also is just very ... They had a hard hand dealt to them because of the delays of Webb, which then delayed the Roman Space Telescope. Roman is now not scheduled to launch, then plus COVID, until 2027, late in the game of this decadal. There's just no room in the funding line. I think Roman's going to be occupying, give or take, about half a billion dollars a year for the next four years. Just some fundamental acknowledgement that astrophysics is not going to see a tripling of its budget anytime that dramatically, that quickly.

Casey Dreier: They almost had to take like a gap decade realistically before they could really start moving on the next mission. This is not just, I'm making this up. This is recommendation after recommendation, after recommendation of how you build complex space missions. You put your money in early, figuring out where your problems are going to be. So, you're not frantically trying to solve those while you're maintaining this standing army of hundreds or thousands of other highly paid expensive engineers, trying to build the rest of the system at the same time.

Casey Dreier: It does make sense to me that you put in, I think they recommended on the order of 800 million over the next 10 years on technology development basically, or I'd say phase A in that parlance work on this super Hubble. My worry is, in terms of the politics of it is, even though programs like James Webb and Roman have been delayed go over budget, because they're tied to a thing, because they're tied to that single project, ultimately they're able to pull it out. I think, just politically, people latch onto, we were talking about our lizard brains earlier, I think our lizard brains latch onto things and objects and coherent idea, like single entities.

Casey Dreier: I worry that 10 years of technology development without a coherent mission, it's a little iffy on this, but without a real mission at the end of it, is somewhat of a political risk. How do you ensure that that tech money shows up when you need it versus being thrown to the more immediate needs of Roman or Webb or whatever mission at the time that needs it in the midst of its development? That's my concern. I think that's almost the challenge for the community to really be tying this. This isn't just tech development for its own sake. This is really on ramping to this next step of astronomy.

Heidi Hammel: I share your concern and part of what will be happening over the next couple of years is being very thoughtful about technology development funding, and making sure that it is being used in the ways to achieve the goals that we need to advance. This is something that we talk about a lot right now. We're all processing this decadal survey in our heads and trying to understand what its implications are, but this issue that you raise of making sure that the funding is used appropriately in the right time, for the right things to achieve the goal you want, that is a really important aspect of this decadal survey.

Heidi Hammel: This decadal survey, it's a science document, right? The way we deal with this is by focusing on those science goals all the time. When they're going through the trade studies, they're going to be asking, will this help us achieve this science goal? If it does, that's good. If it doesn't, then we let it go. That's the best way to proceed. People who ask, "Why did web take a long? Couldn't you just have made it smaller and less complicated?" The answer is we were trying to devise a tool that could see the first galaxies in the universe.

Heidi Hammel: That was the goal. We had to make the telescope able to do that. And if we made it smaller, we couldn't, or if we made it less sensitive, we couldn't, or if we took off certain instruments, we couldn't achieve that science goal. That's why the decadal lays out this science goal for us. We want to characterize habitability. We want to be able to understand the drivers of galaxy growth. We want to be able to unveil the nature of dark energy and dark matter. Those are the goals, and the tools have to achieve those goals. We put those in front of us and that is what allows us to get through this complex issue of funding and timing, and which trade studies do you do? You just got to keep your eye on the science goal.

Casey Dreier: And that you're right. That's what we talked about right at the beginning of this conversation that you start with the science and you work backwards to define your requirements of the instrument, then you build, as you were just saying. To note real quick here at the end, there were some very rough, I'd say early estimates about what it would cost to build this super Hubble for, that's my nomenclature, and then some of the other two big recommendations in infrared and x-ray. They estimated around 11 billion for the big one and then three to 5 billion for the two other ones.

Casey Dreier: You mentioned James Webb, and the complexity, we're talking about different level of complexity, in some way, for this potential mission. Because it's not in the mid infrared, you don't need to keep it as cold so you don't need that very big sun shield. What actually really excites me, and almost as a benefit of pushing it off into the 2030s, is the potential availability of super heavy lift launch vehicles. Something like Starship with these massive, something like a nine meter fairing, would you even have to fold up a telescope like Webb. That's the big aspects of complexity that made Webb expensive and difficult to work with, folding it up, everything, may not have the same level of constraints in the future.

Heidi Hammel: Maybe. Right.

Casey Dreier: There may be more nuance to these ultimate numbers that, as you said, putting in this tech development now, and then seeing where the world of launch is and reliability is by 2030, you may actually have a lot more options in trade space to build something that can just be big on the ground and then doesn't have to origami itself out in space. And perhaps that keeps things more in line with what's affordable. I think there's this whole other intersection of this developing space field in terms of infrastructure and launch and communications that will play into this in the future as well. That's where this study, I think, also benefits from, of seeing that.

Heidi Hammel: Yeah, that's right. Also, even internal to the astronomy field, the technology continues to develop and things like working with arrays of segmented mirrors now so that we don't have to have a single monolithic mirror like Hubble that can have an array of mirrors and do what we call Wavefront sensing across that, and then have the flexibility to be adjusting things on the fly. I mean, like we will be doing for web, that maybe we don't need to fold it up so maybe it'll be easier to get it working.

Heidi Hammel: All of these things are things that are hot fields right now. People are really very interested in how they're evolving so quickly. Yeah, there's just a lot of promise right now. It's a pretty exciting time to be an astronomer right now. A lot of things are happening. It's a cool time.

Casey Dreier: It really is. I'll end, if you'll forgive me, the indulgence of quoting from the paper you and I wrote together along with colleagues on the board of directors at The Society. I'll let you react to this line that we wrote. Our title of the paper we submitted was Thinking Big. We say that, "The threads of exoplanet discovery advances in understanding of planetary habitability and advances in launch vehicle development have come together and point toward a monumental goal, enabling the search for life at a large scale with discoveries possible in a single generation." That's what we submitted to the survey report. How do you feel that line stands up and what ultimately came out?

Heidi Hammel: I think they heard us. They listened. That word, single generation, is important here. It goes back to what you and I were talking about. It may not be me or you or people our age, but it could very well be some kid right now, in whatever town you pick, Harrisburg, Pennsylvania, Ames, Iowa, Billings, pick your favorite city, it could be some kid there who listens to this podcast who gets excited about this, who goes into the field. They could be the one. There's a kid today, somewhere in the United States, who could be the young person who finds that first spectrum with this telescope 20 years from now, and finds evidence for life elsewhere.

Heidi Hammel: It's real. It's within our grasp. I get almost to the point where I can't verbalize how exciting that is, but that's where we are people. We're at the edge now where we can build the tools that we've dreamed about for a millennia to answer this question, are we alone in the universe? We can do it.

Casey Dreier: That's a great point to end on. Dr. Heidi Hammel, Vice President of Science at AURA and at The Planetary Society, thank you so much for making time for us today. Really enjoyed having you on.

Heidi Hammel: It's been a pleasure, Casey, thank you.

Mat Kaplan: Senior Space Policy Advisor and Chief Advocate for The Planetary Society, Casey Dreier, talking with Heidi Hammel of AURA, a great astronomer in her own right, and someone who's very much looking forward, as you heard, to the launch and deployment and first light for JWST. Casey, great conversation. So many things caught my interest. One of them being something you also addressed as you were opening this month's show. This is an example of working backward from figuring out, okay, here's what we want to know, what kind of instrument is going to deliver the data that's going to help us answer that question?

Casey Dreier: Yeah, I think it's a really subtle, but a really important point, right? This is what is fundamentally different between areas like commercial space flight and human space flight. The scientific questions create a convergence. Eventually, enough scientists will agree on what the major unknowns in the field are and how important they are. That creates this external pressure for people to agree on what the big ideas are. Then that gives you the guidelines of what to do next. Absent those guidelines, absent those restrictions, it's really hard to create consensus about where to invest your money and where to invest your time and resources in the near term.

Casey Dreier: The scientific process, and this is something, again, I think that really has only existed in terms of federal investment in the United States, less than a hundred years. This is still a relatively new idea, and it's just profound and very successful when you think about it. But again, it's what really separates. Commercial space flight works kind of the opposite ways. It's like, what can we do that then is useful to people? Human space flight is, where should we go that we think we can pull off? But space science is the only part of the space activities that we do, where we start with the fundamental goals first.

Casey Dreier: Then from there, use that to define our program. This is why, I think, space science is so successful and has been so successful for so long. Again, it shows you that power of understanding what the questions. I always think of Douglas Adams is ... What's the meaning of life, the universe, and everything? Well, you can get the answer, but defining the question can sometimes-

Mat Kaplan: 42.

Casey Dreier: Yeah, the question can be really hard to figure out first. Once you have the questions, that just gives you then so much. That gives you the pathway to the answer. It's a really important process and I'm glad you picked up on that because it's one of the things that I've realized again, this process that we've created of defining science and promoting science for the sake of science, is this powerful way of building consensus and helping people work together in cooperative and peaceful ways.

Mat Kaplan: By the way, Casey, speaking of life, the universe and everything, the answer, 42, is also the no number of years that Jim Green, the NASA Chief Scientist, will have worked for NASA, the space agency, when he retires early next year. This is all a plug for the Weekly Planetary Radio, our December 1st episode, which featured Jim Green and Mary Voytek, the head of the as biology program at NASA in, what I think, was the best astrobiology discussion ever on Planetary Radio. We'll talk with Jim more about the time he retires early next year.

Mat Kaplan: To close out, of course, we direct you to to learn much more, including the analysis of the JWST budget over the years, all the spending on this grand project that was assembled by my colleague, Casey Dreier, and it is also where you can go to and become one of us, a member of The Planetary Society, or You don't have to be a member to support our work.

Mat Kaplan: If you go to, and just look for The Planetary Fund, that will get you in, on our big end of the year fundraising push, so that we can keep enabling Casey and all of his colleagues, my colleagues to do the good work we do on your behalf as fans of space science and space exploration. With that Casey, unless you have anything to add, we'll close out the December, 2021 Planetary Radio, and I'll just wish you happy holidays and a wonderful new year. And we'll talk on the first Friday in January, I hope

Casey Dreier: I hope so too, Mat. We'll see you next year, and happy holidays and thank you everyone so much for listening this year, and hopefully next year will be better on the upswing, or if it's been a great year for you, it continues to be better.

Mat Kaplan: Here, here. Thank you, Casey. And thank you all of you for joining us once again, here for Space Policy Edition of Planetary Radio, I'm Mat Kaplan. Ad astra.