Return to the audio for How to Science Episode 7, with astronomer Jon Miller.
Jon Miller: My name is Jon Miller, and I’m an astrophysicist at the University of Michigan. I’m an X-ray astronomer. X-rays don’t go through the atmosphere, so if we want to look at the universe through X-rays, we have to use satellites. When you use satellites, that means they go up in rockets, and you’re in the space environment, and there’s a lot of risk and reward with this.
To put something in space takes years of planning, and it’s not like you can buy things off the shelf and use a MacBook and have it work in orbit, because you need electronics that are radiation hardened and can handle really cold temperatures and really extreme environments, so there’s a lot of prep that goes into these things—many, many years.
I was a part of a mission called ASTRO-H. This was a joint venture of JAXA, which is the Japanese equivalent of NASA; the European Space Agency; and I came in through NASA’s partnership. And we’d been working on this mission for many years. I think I was involved for about eight, and this was really highly anticipated because it flew a new kind of detector that was going to change our view on how X-rays interact with matter and how we can see black holes and clusters of galaxies, and it was going to improve our knowledge by an order of magnitude, or maybe more. We had been anticipating this for quite along time. So when ASTRO-H launched in February 2016, it was 16 years of waiting since the first effort to do science with this new generation of detectors that was going to revolutionize things.
The mission launched in February 2016. I remember sitting at the kitchen table. The launch happens in one of the southernmost points of Japan, so it’s like three A.M. The rest of the family were asleep, and they wanted a report as soon as they got up, but they couldn’t quite make it to the three-A.M. launch window. So I’m online and texting with friends who were involved in the mission, and we were all as nervous as can possibly be about this, and everything goes off without a hitch. It’s a completely beautiful launch, and the rocket makes it up, and you can see it really high into the air, and they are following it from the ground and showing you sort of an animation of what’s happening next.
There were moments where we were very nervous, because the cowling—sort of the shell of the rocket—comes off once it’s high up, because you don’t really need the shielding from the atmosphere at one point. And that made everybody nervous, but that’s what’s supposed to happen, and it got into the right orbit, and everybody cheered. Everybody that I was chatting with online was delighted, and you could see cheers in the control room, and everything was just perfect. Several days passed, and everything was going according to schedule, and it looked great, and we kept getting positive reports from the Japanese team and NASA team.
It wasn’t until later that there were any indications of problems. And when the mission was lost, it was a complete surprise. It was a beautiful launch and a beautiful telescope, as well.
Nine times out of ten, it works perfectly.
In late March, I was awaken by a call from a colleague. She directs another X-ray observatory in orbit. She said, “Jon, the government called me, and they say that where your satellite was, there are now five things floating around. Do you know anything about that?”
I said, “No. Thank you for the call. How about I get back to you?”
So I hung up, made a few calls to other people in the mission, and you know—in these situations, people try very hard not to panic. Possibly just a door on the side of this spacecraft has come off. The military can trace things that are only a few centimeters in size, so maybe it isn’t a full disaster yet.
But the character of the responses, that they weren’t denying the worst case scenario to me when I asked, caused me to realize that there was a very major problem. So I had to call my friend back and say, “Yes, I’m afraid that it looks like a it could be a complete loss of mission. I hope none of this impacts your telescope.”
In the next several weeks, there were many efforts to try to recover the mission, and they ultimately proved unsuccessful. But you know, a large team of people worked very hard to try to get this thing back.
My friends who are surgeons are made to read books about how disasters happen, and it’s never just one thing. I think the lesson of those situations and this one is that it’s never just one thing.
There were three or four things in a chain that caused this problem; it was combination of things that led to the loss of the telescope.
One of them was very likely an incorrect mass model. So where the weight of the—we use “weight” colloquially—where the mass of the spacecraft is, some parts of the spacecraft are heavier than others. In our case, there was a boom that came off, sort of like the arm of an construction crane. Once you extend that boom, the center of mass of the spacecraft moves a little bit farther out from that boom. When you write the code that describes how you should turn the spacecraft, you know that you have to change the center of mass once that boom is deployed. If you call that axis an x-axis, you could do your code so that shifting in one direction is a positive or negative motion.
And I’m afraid the code had the wrong sign. So that caused part of the problem.
It was also the case that it didn’t lock onto positions correctly because of the star trackers. Also, had someone been sitting there every second of those initial weeks, this error might have also been caught. But people need to take breaks after many days of nearly continuous effort. So it’s not just one thing; it’s many things.
On one particular day, the star trackers weren’t working, and the mass model had been wrong, and it wasn’t being watched.
And it got itself confused, and it tried to correct for its confusion about where it was pointing, and because the mass model was wrong, it thrusted the wrong way, and it started spinning. And once you get a spacecraft to spin past a certain rate, you don’t recover. So it spun fast enough that the solar panels flew off, and part of the spacecraft broke off. And that’s a loss of mission. When you can no longer power the mission through the solar panels, there’s nothing to be done.
Many people were very broken up about this.
In April, after the disaster in March, there was a national meeting for people who do X-ray astronomy in Naples, Florida. And everybody was quite sad and broken up, and we were kind of having a “wake” for the mission in the hotel. You could actually go out onto the beach in Naples, Florida and watch the spacecraft tumble across the sky. You could actually see it flicker as it tumbled past. And at this meeting, where we were all expecting that we could tell you all of these amazing things that we had just discovered—instead, we were able to go out with binoculars and see the tumble of the spacecraft from the beach.
We all raised a glass of really good whiskey to ASTRO-H and said farewell. But actually, I think the good part of that wake was that it helped you to realize that part of what’s great about doing these things is the people you’re working with. It’s not just the hardware. As long as you still have these colleagues, the work will go on. The inquiry will go on.
And I think partly in that moment, the idea that we can’t let this be the end, we have to charge forward—it kind of crystallized in that moment.
These things are tough. But when you do space missions, and when you do astronomy that depends on space missions, you have to accept some of this risk. I lost some time and some science this way.
But I think the most important thing about this is that this was one really interesting mission, and there are lots of other missions that also provide critical information about the universe, and they are operated by NASA or Japan or the European Space Agency, either alone or in coordination, and there’s lots of plans to continue doing these things, and especially this particular mission: ASTRO-H.
The critical elements of it will be assembled. The designs are finished. We expect to refly this in 2021. So we have a few years to wait and a few years to work really hard and think about the things that we can do well and the things that we can do better. Ultimately, this science will get done. That’s partly because NASA and JAXA and ESA are committed to this kind of thing, and everybody involved in the project is really, really grateful for that.
Monica Dus: Do you feel that the way you've handle risk versus reward has changed throughout your career?
JM: I don’t think that I did! I think that I like what I do so much that I just plowed ahead almost unchanged by these experiences.
The brilliant thing about X-ray astronomy is that it’s still a discovery space. It’s much younger than traditional ground-based optical astronomy. You can go download the data from a NASA public archive—literally anybody can do this; it’s public data in our field—and in the course of an afternoon, you could find something that nobody knew before. It’s that fast. The barriers to entry are really low, and the chance to add something to the field that was not known before—there’s a daily chance of doing that. Once you get used to that kind of ability, it’s very hard to sort of throttle back and say, "Well, maybe I should be a little more cautious." And I’m afraid that I haven’t. I really like X-ray astrophysics.
As a scientist, this is really fascinating to me—thinking about this idea of the potentiality of our experiments, versus its actualization. Can you tell me a little about how you think about potentiality versus actualization, and how that frame of mind helps you maybe get through some of those setbacks or a longer wait?
JM: It’s interesting—I know exactly what you mean. When you’re setting something up, there’s that anticipation, and you know that there’s tremendous potential, and what you get sometimes lives up to that potential.
For me, I think there’s many aspects to this. One of the important things you have to do to be scientifically honest is know when your results have not lived up and report them truthfully. And when they do live up, that’s terrific. You can play it up, you can send it to Nature, you can make a great big deal about it.
In terms of how you structure your research, I personally know that I do some things that make clear steady progress, and I do some things that are a big reach and have risks and rewards. I try very hard not to put all of my effort into just the high-risk things. So making sure to just spread your effort into things that are all going to make some amount of progress and not putting all of your effort into one thing that could suddenly disappear, I think is important.
So would you say that’s a way that you psychologically balance risk and reward in your experiments or projects?
JM: I think that’s part of it. I wonder if you feel the same. I think that most scientists are very optimistic people. I mean, hoping to sort of peel back what’s underneath and push what’s possible for humans to understand forward—I think it’s a very optimistic process.
That’s interesting. I never thought about that in that way, because I always feel that I’m very pessimistic. But you’re right by the sheer thought that you can understand something that’s actually very complex. That is very optimistic.
JM: Well, I find that it’s easy to be skeptical about my own work, and I bet you’re the same. Because you don’t want to make a mistake, and you want to report it the right way. So it’s sensible to be skeptical about your own work day to day.
But I think in the broad scheme, the whole enterprise is really very optimistic. This particular telescope happened to fail, but we have many things that work really well and afford us a lot of opportunities that I think about. You know, I think one of the nice things about my field is maybe the way you steel yourself against these events—you hope, and you might sort of take the view of let’s see these things happen a few times. I think it’s hope that allows you to put more investment in and into marching forward and making new preparations and planning the next thing.
As we design and think about that one, we keep saying to ourselves, “Let’s prepare to be surprised.” We’ll make a certain number of discoveries, or some that we can anticipate, but also build in the capability to be surprised by things we haven’t even guessed at yet. So, oddly, I think hope helps to steel you against strange events like this.
Another thing I found fascinating when you were talking is that there’s also risk and reward working with groups of scientists, different countries, and all this really complicated engineering and expertise. How do you deal with that aspect of risky endeavors that’s just dealing with a large group of people and having to rely on them? You can’t control all aspects of the mission, right? Is it just essentially hope and faith in many aspects, and the idea that we’re all scientists, and we’re all excited, and we’re all in this together?
JM: There are teams that build the spacecraft software, and build spacecraft hardware, and focus on making sure that it knows where it points, and that it knows where it is, and that it knows how to ingest the data, and telometers it to the ground, and on and on—it’s so complex. Overall, there were 200 or more people involved in all of this, and nobody was underemployed. I remember there were teams that worked seven days a week for two years to get to their particular endpoint, and you do have to put your faith in other teams doing the right thing.
But I guess the way that we tried to mitigate the risk that you’re talking about is in these meetings of the whole collaboration. We come together and presented our progress and development as honestly as possible, giving people the opportunity to say, “You know, I think that’s actually a problem.” Sometimes the really different outside perspective is the one that really helps, so in that way, you try to mitigate the risk, but there is some risk. It is, at some level, a leap of faith.
What kind advice would you give early-career scientists that are entering this field or dealing with projects where they have to balance risk and reward in their research?
JM: I think what I would say is that your chances of success are highest when you really believe in what you do and when you’re really passionate about it. When you’re willing to go all in. I think if you start from that point of view and go all in on it, you have a higher chance of success than if you hedge your bets or decide to pursue a field that might be a little safer, but your heart’s not in it. You never know when having your heart in something makes all the difference, so I would say that if you’re lucky enough to have a passion for one field, then even if there’s some risks, I think you should go in with everything on that.