A conversation with Alan Rhodes, instrument development manager for the Stratospheric Observatory for Infrared Astronomy at NASA’s Ames Research Center in Silicon Valley, and Harvey Moseley a senior astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
Transcript
Abby Tabor: Welcome to NASA in Silicon Valley episode 94. This week we have two guests, Alan Rhodes and Harvey Moseley. They’re here to talk to us about SOFIA, our flying telescope that studies the universe from 45,000 feet. They also explain their work creating new instruments for SOFIA, including ones that will help us understand how water vapor, ice and oxygen combine with dust to form the mass that may one day become a planet. Alan is the instrument development manager for SOFIA and is with us in the studio. Harvey is a senior astrophysicist at NASA’s Goddard Space Flight Center and is joining us from the studio there.
So, let’s get right to our conversation with Alan Rhodes and Harvey Moseley.
Music
Host (Matthew Buffington): Typically when we do these, we have just a one-on-one thing in the studio. A little bit more fun because we have Harvey sitting over at Goddard through the magic of –
Kassandra Bell: Technology.
Host: Technology.
Alan Rhodes: This internet thing that might catch on.
Host: Exactly. I hear it’s doing a lot of good stuff. Yeah, so we have Harvey sitting over at Goddard. You have Alan sitting in the studio with us. And you’ll hear Kassandra’s voice.
Kassandra Bell: Hello.
Host: Most people will be familiar with Kassandra, some of the reads that we’ve done on the podcast. So, Kassandra’s just one of the science communicators that works over in the communications and public affairs and over here with us. But we always start this off the same way. I’ll start off with Alan because you’re closest to me. Tell us a little bit about yourself. How’d you get to NASA? How’d you end up in Silicon Valley?
Alan Rhodes:It’s a crazy story. I don’t believe it, and I lived it. But it’s still one of those things where I’ve literally have bounced around the planet for a while. Started off in the swamps of North Florida. It was one of those things where it had been my dream since I was two. Being the brilliant person I am, I’m like, “I want to go into space. What’s the best way to do that? I’ll start with submarines.” But actually, wound up working out. I made a bunch of great friends that actually wound up helping.
When I finally got the call, I was actually in New Zealand at the time and got a call from the Johnson Space Center saying, “Hey, you want to come help us get to the Moon?” Like, absolutely. But have bounced around, done a lot of really fun things. I was lucky enough to find a way back into the NASA family in the 2015-2016 timeframe. The folks called me up and said, “Hey, we bought us a 747, cut a garage door out the side and stuck a telescope in the hole.” I went, “Well, of course you did.”
And it’s just been nonstop fun, just because of the fact that it’s not just the observations that we get to do, and it’s not just the fact that we literally are the point of the spear on so many different technologies. It’s this idea of you get to go hang out with people that have things in outer space named for them, and they’re just down the hall. It’s like, “Oh, hey. I just heard about you because we’re going to stare at something you named.” That’s cool.
Host:That’s quiet a space pedigree, like mix of Florida, some Texas, and now over here in California.
Alan Rhodes:It’s been fun.
Host:How about you, Harvey? Tell us a little bit about yourself. How did you end up in NASA and how did you end up landing over in Goddard?
Harvey Moseley:It’s been a pretty long and strange journey as well. I grew up way out in the country in Southern Virginia. Went away to college and then to grad school. Went to University of Chicago. And I got involved with a program that was doing observations from a Learjet. I couldn’t believe it. They were flying a small telescope in a Learjet and doing infrared measurements. Soon that turned into a C-141, the Kuiper Airborne Observatory. We ended up being the first generation of people doing airborne far-infrared astronomy.
When I finished my degree at Chicago, I heard that at Goddard that there was a group that was putting together a project to look at the leftover radiation from the Big Bang. It was called a Cosmic Background Explorer. And I said, “You know, that sounds like a pretty neat thing to get involved with.” And you say, “What does that have to do with flying airplanes or whatever?” But it turned out that the instruments and the technology that we had developed for that were pretty much the same. So, I ended up coming to Goddard. That was 30… My gosh, let’s see. 37 years ago. No, no, 38 years ago. So, it’s been a while. But it’s been fun.
It’s been a pretty wide-ranging kind of experience here going from the Cosmic Background Explorer, which actually came out pretty well. The two leaders of that, John Mather and George Smoot won the Nobel Prize in physics in 2006 for the discoveries that were made with COBE. And then since that, I’ve done a number of – have been involved in a number of really interesting things. I developed a new way to do X-ray spectroscopy called the X-ray microcalorimeter, which has been now the spectrometer of choice for space X-ray astronomy. And so watching the development of that has been fun.
More recently, I was involved with the James Webb Space Telescope. We developed a new micromechanical device that would allow – rather that looking at one distant galaxy at the time, we can actually simultaneously observe as many as a hundred. This was something that we developed to basically enhance the capability to enable science programs on that that just would’ve been impossible otherwise.
Unless it had such an impact, I’m sure that they would have never decided to do such a speculative development in the course of an actual development, but they did, because they thought it was worth doing. We were able to deliver that, but it was sort of scary. For a number of years, I felt like – in the old cartoons, you had the little guy running and looking back over his shoulder at the locomotive coming.
Host:Nice.
Harvey Moseley:We did that for a decade. Now for the last bit, I’ve been working on the HIRMESinstrument, an instrument for SOFIA, that’s going to explore systems such as the one protoplanetary disk systems, cloud systems, that will become solar systems much like our own. So, there you go.
Alan Rhodes:That’s my life. When I pick up the phone and he picks up on the other end, it’s like you pick up and there’s a hall-of-famer that’s always on the other end. You start to get used to the fact, well of course everybody else I’ve talked to has a Nobel and I don’t. The idea of living up to that sort of thing is just daunting to say the least.
Kassandra Bell: Alan, can you tell us a little bit about SOFIA? Harvey just talked about one of the really cool instruments and you talked about cutting the hole in the side of the plane. But just for our listeners who might not have heard about SOFIA?
Alan Rhodes:Absolutely. When you see it, that’s when it really sets in, for me. Imagine a 747. The wild thing to me is, because I’ve flown on it a number of times, otherwise I wouldn’t be able to say it works. But we actually did this. We did all the work necessary to cut what looks like a garage door out of the backside of a 747, did the work necessary to stick a telescope that we can move around while the plane is flying. It looks like a 747 just with a huge hole out of the side of it.
What this does is it allows us to move this telescope around wherever we need it to go. Do we need it to go to 45,000 feet and get above the water vapor in the Earth’s atmosphere? Done. Do we need to go fly it somewhere over the middle of the Pacific Ocean and observe one planet getting in between us and a star? Done. We can do that. It’s this flexibility of – it’s taking those constants. What is the constant of a telescope? It’s stuck to the ground. Not anymore. NASA can fix that. We’ll get a 747 and cut a hole out of the side.
I can tell you, you sit there in the cockpit with the pilots. The first time I was there, the copilot turned around. He said, “Did you feel anything?” and I said, “What are you talking about?” He said, “We just opened the door.” We just opened the door to a gaping hole in the side of a plane and you do not feel a thing at 45,000 feet. It is amazing.
Host:That’s the crazy thing from chatting with people about this. You have the land-based telescopes, you have the space-based telescopes, and they’re all gathering information. But SOFIA fits in this unique thing where it’s mobile. But it’s not only just like you can move all over the world and fly, but it’s also you get to land and people can upkeep it and switch out instruments.
Kassandra Bell: Yeah, that’s one of the really special things about SOFIA, and I think people would like to know more – In space, we have instruments on our space telescopes. But SOFIA has instruments and we can change those out.
Alan Rhodes:That’s a great point. That’s one of the fun things about the program is when you start the work to do a space-based system, you have to at some point say, “Okay, we have to lock down the development.” We have to make a decision and say, “We’re flying this. We’re not going to change this anymore.” SOFIA fits in this cool area where we’re able to say, “Okay, we have been flying this. But there’s this guy named Harvey Moseley, and he’s got this really cool idea. Why don’t we go talk to Harvey and the team and see what they can do, that they can make something new for us?”
We have a set of instruments. We can switch them out. We can go fly whatever we want to observe. You want to observe in this part of the spectrum, we got it, no problem. You want to go observe this way. Sure, we can do that too. But I think one of the real strengths of SOFIA is, as technology changes, we’re not limited by the fact that we’ve going to have to launch something that we can’t go maintain. We can land, we can take this new technology, we can take all the developments that we’re making and actually make brand new instruments.
I just got to tell you, the magic of this instrument making – it’s so close to magic. We’re at minus 459 degrees Fahrenheit. I don’t know how to describe cold other than, without any exaggeration, we are millidegrees from breaking the universe. That’s where Harvey and the team works. And so, this idea that not only are they bridging the gaps in technology, not only are they bringing new capabilities to SOFIA, but they’re doing so in such a manner that it is saying the word, this is “difficult,” just belittles the word “difficult” beyond my imagination.
What Harvey and the teams do actually take technology that we have never dreamed of, turn it into realty, and then put it on a plane for us to go make those next great leaps in discovery, and it is just amazing to be a part of this team.
Kassandra Bell: Harvey, the instrument is called HIRMES, and it’s going to study how water, ice, and oxygen combined to form planetary systems, is that right?
Harvey Moseley:Yeah, we’re interested in looking at planetary systems just when they’re coming together and forming. The gas that’s left over from the formation of the star can produce a disc around it that orbits around in a plane. At some point, the density gets high enough so that you’ll start forming solid materials. And very, very quickly you can start to generate, you can start to create planets. So, we’re very interested in looking at these systems like this and finding out where the water in these systems lives, because water makes a huge difference. The Earth wouldn’t be what it is without the water. So how did the water get on the Earth? Is this something that’s going to be universal among planetary systems?
And then farther out in the dust cloud, the water will be in solid form in the form of ice. That’s believed to be a major component of the giant planets – Jupiter, Saturn, Uranus, and Neptune in our solar system. We want to look at these solar systems-in-training, if you will, and find out if the history that made our solar system – is this typical or is it unique? And so we are building an instrument that will let us answer a number of questions about that.
Alan Rhodes:I think Harvey brings up one of the fascinating points that I had not considered until getting the chance to sit with Harvey and the team. It’s a question that seems so fundamental we don’t even ask, “How did the water get here?” It’s so fundamental to what it means to be human, what it means to have life, but we don’t truly know the answer.
And so, HIRMES and Harvey and the team, they’re actually looking to make insights into without water, to the best of our knowledge, we don’t have life, and to answer that question how did it get here. I love the fact that you’re able to look at questions that you may not even consider and think, “Wow, we don’t know the answer to that. Let’s go find out.”
Kassandra Bell: And so, you’re building HIRMES out at Goddard, but SOFIA flies out of Armstrong in California, so at some point we have to bring that out. Can you tell us how that’s going to work?
Harvey Moseley:Yeah, we will build an instrument here. We’ll put it together, and we’ll test it. When it looks like it’s meeting all the performance requirements that it has to do, we get it all working, then we’ll ship it out to Palmdale where SOFIA lives. We will install it on the plane, and we’ll do a number of test flights with the instrument where we will take it through its paces. We hope we’ll actually get some good scientific results in that period as well. But we’ll work with the team out there to get it working. They will learn how to operate it. At some point when it’s all working, then we will turn it over to SOFIA and they will operate it and it’ll be generally available to the world astronomical community. They can think up questions that can be answered with it. And they’ll put in competitive proposals and find out if they get selected. And if so, they’ll go and do those measurements with SOFIA.
Kassandra Bell: Very cool.
Host:That’s one of the things it’s always interesting to keep perspective on. This is the cool thing about my job when I get to hang out and talk with people about this stuff – is you have this insane engineering that comes around to building these instruments, all of this information to gather it in. But when it comes down to it, it’s all about the science. You’re not doing it just for fun. It’s all about better understanding the universe.
It’s not just here at NASA or even at the different centers, it’s the entire international community and sharing that information. I would imagine that even after the instrument has passed its end of life, there’s still people that could use that data to write papers and come up with stuff. It’s like it lives on.
Alan Rhodes:To me, I’ve always looked at it as, it’s a giant puzzle. We’re not sure how many pieces there are, but we’ve got some pieces in front of us and we’re starting to put those together. As we put them together, we get different shapes of things that we’re missing. Then we go and try and find that puzzle. It’s this idea of this information about how water got here.
And then you can take that, share that with the international community, and maybe one of the teams with, let’s say, one of the telescopes in Chile, they go, “Hey, we got another piece. Let’s put these two things together.” And if we go off and study this, then we understand even further. It’s this idea, as Harvey said, this international community that has a set of knowledge.
If we start making these different connections, if we start providing new insights to things that we had never thought of, that’s where we’re going to start to go, “You know what we really ought to do? We really ought to go look at this.” Because in the end we can’t look at everything. We’d love to, but if we can start to say, “These are places of significant interest, these are targets we really ought to go look at,” then we can start to do things: newer instruments on SOFIA, newer in-space missions.
Where are we going to go next? This is where, to me, all these fundamental questions feed into what’s next. I think that by having a team not just here but throughout, as we say, the international community, that’s going to be where we start to get these new answers.
Kassandra Bell: Building on where we’re going next, what’s that next after HIRMES? Do we have another new instrument?
Alan Rhodes:To me, this is a truly fascinating time. One of the things that we’ve tried to work with the team in SOFIA, the team at NASA headquarters, and to really say, “Okay, what’s the best way to ask a very fundamental question?” Is it to go to a community and say, “We think we want this piece of technology,” or “We think we want this kind of instrument?”
We had a lot of discussions. I think for the first time one of the things that we’re really doing is saying, “Maybe we’ve been asking the question wrong.” What if we go forward with just what sounds like a kind of a simplistic question, but to me it gets at – Matt, what we were talking about a little bit earlier – where it’s, “What is the fundamental nature of what we want to do?” and that’s science.
And so, instead of what we’ve done in the past where we may have had an idea, or we may have had a timeline, or we may have had a preconceived idea, we’re actually going to the community, and we’re going to everyone we can get a hold of and saying, “Just tell us the science that we can go complete together.” Let’s not talk about necessarily all the details of the instrumentation or how we’re going to get it on a plane, or what we’re going to do.
Just say, “We’ve got a two-and-a-half meter flying telescope. We’ve got the only one in the world. We want to work together. We’ve got this capability. You’ve got the science in your minds.”
And we’re going to every university group and institution we can think of to ask them just a question of, “What is the science we can complete together?” We’re already starting to hear some stunningly fascinating answers.
Kassandra, to answer your question, “What is next?” We are in the search for that right now. As I say to the universities I’m lucky enough to have visited yet. If we haven’t visited you yet, we will visit you soon, so stay tuned. We are trying to make sure that we visit everyone we possibly can.
But to me, the fascinating and super exciting part is we are changing the fundamental question. We’re simply going forward and saying, “Tell us the great science that we can complete together with this one-of-a-kind observatory that gives us an insight into the astronomical world that we don’t have anywhere else.”
Host:HIRMES, this is a new instrument that’s in the process of being built. Right?
Alan Rhodes:Right.
Host:Harvey, is this the first instrument that you’ve worked on, or how many instruments are there? Kind of go through some of that process. And I’d imagine for years to come they’ll still be new ones. But give people an idea of what they’re looking at here.
Harvey Moseley:It isn’t my first instrument. Well, it’s my first SOFIA instrument, although I did work on the HAWC instrument that’s flying on SOFIA, but as a minor contributor. However, from the time I started with the Learjet in the mid-1970s until now, the work that we’ve done has involved building large numbers of increasingly complicated and increasingly capable instruments. So, the answer is yes, I’ve built lots of instruments for airborne astronomy in the 1970s, 80s, and 90s.
We built the Cosmic Background Explorer satellite. I was an instrument scientist for one of the instruments on the Spitzer Space Telescope. I’m a co-investigator on X-ray microcalorimeter, being built with the Japanese. With JWST, I’m a member of the European instrument team on that for the near-infrared spectrometer. And now I’m building SOFIA. So, the answer is this is the end of a pretty long road of development.
Host:This is not your first rodeo.
Harvey Moseley:Yeah.
Alan Rhodes:I get to talk to him on the phone. It’s crazy.
Kassandra Bell: Alan, you’re an instrument manager at SOFIA. It’s not just HIRMES and HAWC. We have other instruments. Right?
Alan Rhodes:Yeah, yeah, absolutely. Just to go to Harvey. I mean it is just so much fun to be able to be on the phone calls with you and go, “Yeah, yeah. Look what he’s done.” That’s pretty amazing.
Yeah, with regards to the instrumentation that SOFIA has, we do have about seven instruments right now. But one of the things that we’re doing, just like you do with your laptop or your TV or things, as the technology changes, we retire the instruments that were developed with some of the older technologies and we work with teams like Harvey to find the new technologies, to find the new methods, and we make new instruments with the new technology as we go. It’s just with regards to something that you have to launch into orbit, you don’t have that opportunity.
I think it’s one of the biggest strengths that SOFIA has to say, okay, as the technology changes, just like you would with your phone, we have the opportunity to take that new technology, bring it into our instrumentation suite, and then go from something like – some of our instruments had as little as one pixel, one single pixel. And now we’re talking those instruments and moving them into hundreds. So, it is a significant increase in the technology. But that only comes from having that ability to swap out instruments when you land and to develop new instruments as the technology grows.
Harvey Moseley:Yeah, and I think one thing that’s really important to understand is that when you want to put new sensors into these instruments, it’s not like you go down to the sensor store and buy a new one.
Host:Exactly.
Harvey Moseley:These are things typically that are very specialized, and we typically have to build these from scratch. So that ends up being a significant part of the development of the instrument. Some of the instruments on SOFIA have detectors that are at least specialized commercial devices, but many of them are only produced by the research groups that do this kind of work. And so, my group actually has done a lot of this sort of work for many years.
Kassandra Bell: So, Alan can you describe SOFIA briefly to us?
Alan Rhodes:Yeah, absolutely. SOFIA, the question there was, “How do we find a window into an astronomical world that we can’t see from the ground?” To see into the infrared, one of the things that we need to do is get above the water vapor. The water vapor exists all the way up to about 40,000 feet in the Earth’s atmosphere. So, you either have to get something into orbit, but that comes with some decisions you have to make, or can you do something with an existing airplane that would allow us to get high enough where we’re above the water vapor.
That was kind of the birth of the SOFIA idea. It actually comes, even as Harvey has mentioned, the Kuiper Airborne Observatory and even the Learjets before that, is, “What can we do to open a window into the infrared universe that we can’t see from the ground?” So, what we did with SOFIA is, jokingly I say, that we bought a 747 and cut a garage door out the whole of it – but that’s what we did. It is a 747 with a large portion of the fuselage near the tail that has been cut away so that we can put a telescope in that hole.
We’re able to take the plane. We generally fly it out of the Los Angeles area. But we can take the plane and fly it wherever we need to go. We’re able to get up to that 40,000-45,000-foot range, well above where commercial airliners are, so that we can have an open window into the infrared world, and we can see things that you cannot see from the ground.
One of the most amazing pictures you’ll see, there’s really famous constellation called Orion. In the winter it’s in the south. But many people will know it because of the belt, the three stars in a line. If you do a search for an infrared picture of the Orion constellation, what we see at night we see three stars. We see a little belt. If you look at Orion in the infrared, just a nudge different in the spectrum from visible – so we’re really close to visible but we’re just a nudge off – giant fireballs of light. It looks nothing like what Orion looks in the visible.
And we’re right next to that, but we can’t see any of that from Earth. You have to get up above the water vapor so that we can see into this brand-new world where we can make discoveries that are literally impossible from the ground because we can’t see through the water. You take a famous constellation like that and say, “If Orion is this different, what does the rest of the infrared universe look like?”
I can tell you when we’re lucky enough to get to the Southern Hemisphere and fly out of New Zealand – which, another awesome thing that the plane can do – it changes significantly. To be able to look into the galactic core, to be able to see what that universe looks like in the infrared, it allows us to fit those pieces of the puzzle together one by one by one so that we can move into new discoveries using some of the greatest tools we have such as the SOFIA Observatory.
Kassandra Bell: And SOFIA is not the first airborne. You talked about the Learjet and the Kuiper.
Host:Yeah, and Harvey has talked about that. Yeah.
Kassandra Bell: Can you just tell us a little bit about the history of airborne astronomy, the Learjet, the Kuiper, and then now on to SOFIA, sort of how that progressed?
Harvey Moseley:Yeah, back in the late ’60s, Frank Low, who was one of the fathers of infrared astronomy, realized that if we could get above the water vapor in the atmosphere it would be possible to open this far-infrared spectral region where the atmosphere is opaque primarily because of water vapor in our atmosphere. And by going up to 45,000 feet, you get above almost all of that, more than 99 percent of it. So, he went to NASA and they had a Learjet. They said, “Maybe we could use it.” So, I think the first telescope they built was a little 12-inch diameter telescope. I think they might have temporarily mounted it in an emergency exit.
Kassandra Bell: I think I’ve seen pictures of that. Yes.
Harvey Moseley:Yeah. And so, that was flown for a couple of years. And then they did a permanent modification to the Learjet, and that was the configuration it was in when I was flying it around 1974. But we could fly that plane with two people. We’d have somebody running the telescope and somebody running the control electronics. We did a whole lot of the very early measurements, early far-infrared measurements, of brightnesses of the planets in the solar system. Basically, everything we looked at was new. There was no knowledge whatever of the far-infrared sky at that point.
Then in 1974, NASA had developed the Kuiper Airborne Observatory that had a roughly 36-inch diameter telescope, much bigger than the Learjet telescope. And so, immediately my group at the University of Chicago led by Al Harper, who was one of Frank Low’s students, we started building instruments to take advantage of this observatory. And it was, again, amazing because everything we’d looked at was new.
We discovered internal heat sources in Uranus and Neptune. We realized that they were emitting more energy than they received from the Sun. We found that many galaxies had extremely bright infrared sources in their center and were emitting much, much more power in the infrared part of the spectrum than in the optical light that we could familiarly see. So, it was basically all new at that point. And so, there wasn’t a whole lot of specialization. We were basically like kids in the candy store trying to understand what the sky looked like.
Since that time, with some long-lived space observatories, we have a better idea of what the sky is like. Right now, SOFIA is a larger telescope, and it allows us to build some very sophisticated specialized instruments that can follow up and do the kinds of measurements on the objects in the sky that just can’t be done from any existing spaceborne instruments. An example of that is the HIRMES instrument that we’re building.
One of the capabilities that hasn’t really existed since the days of the Kuiper is the ability to look in the part of the infrared spectrum where there’s a strong feature due to water ice. And so, we are going to be able to look at that and be able to determine how much solid water, how much water ice, there is in these protoplanetary clouds so that we can understand how the water is distributed and get some idea about how it might be transported in the process of planet formation. We have the opportunity to build these capabilities to ask more and more specialized questions about the objects that have been found in some of the large surveys from the space missions.
Host:I’ll throw it on over to Kassandra. For folks who are listening who want to learn more about SOFIA, want to know how they can get in contact –
Kassandra Bell: Yeah. NASA.gov/SOFIA is kind of our homepage, but we’re also all over social media. Find us @SOFIAtelescope.
Host:Nice. And we’re @NASAAmes. But yeah, so if anybody has got questions for Alan or for Harvey, just send them on in over on the comments and we’ll get back to you guys.
Alan Rhodes:Absolutely.
Host:Thank you so much, Harvey, and Alan, and Kassandra. Thank you so much for coming on over. This has been way fun.
Alan Rhodes:Yeah, a lot of fun. Thank you all very much.
Harvey Moseley:Yeah, thanks a lot.
Kassandra Bell: Thank you.
Host:You have been listening to the NASA in Silicon Valley podcast. Remember we are a NASA podcast, but we are not the only NASA podcast, so don’t forget to check out our friends at “Houston We Have a Podcast.” There’s also “Gravity Assist,” there’s ” This Week at NASA,” and if you’re a music fan, don’t forget to check out “Third Rock Radio.” The best way to capture all of the content is to subscribe to our omnibus RSS feed called “NASAcasts” or visit the NASA app on iOS, Android or anywhere you find your apps.
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