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Return To Flight

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2006 Preflight Interview: Piers Sellers
+ Read 2005 interview

Q: You have a job that millions of people just dream about having. Is being an astronaut, flying in space, is that what you always wanted to do with your life?

JSC2005-E-29749 -- STS-121 Mission Specialist Piers Sellers Image to right: STS-121 Mission Specialist Piers Sellers is attired in a training version of the shuttle launch and entry suit. Credit: NASA

A: Pretty much. I remember really learning about people going into space almost as it happened, with Gagarin ... a bit of a gap, because I was only 6 at the time, a bit of a gap after that but then I followed the whole Gemini program and then Apollo landing on the moon which just completely captivated me. And from then on there was always the hope that I would get to do this, or, if not, watch very closely. I found it almost as good to watch it. Fabulous.

Do you have a, a sense of what it was about, what you were seeing that got you so excited?

A couple of things. It was completely new; it was something of our generation, our time in history that was brand new and exciting. I loved the technology. I’ve always been drawn to aviation and science, and this was pretty much the sharp end of both of those things, so very, very exciting.

Your interest in aviation goes way back into your childhood, too.

Right. I was fortunate enough as a kid growing up in United Kingdom that I got involved in all these Royal Air Force cadet programs. They teach you to fly gliders when you’re very irresponsible, a 16-year-old—it’s a lot of fun—and then went on to do powered flying at 17, 18. And so, I was flying aeroplanes around at the government’s expense, and having a wonderful time, before anyone would let me drive their car.

Tell me, in terms of your education and, and your career, give me the “Reader’s Digest” version of how you moved through those things and became somebody who was qualified to be an astronaut.

There’s a saying that to be an astronaut you have to be something else first. I was a scientist first. I got drawn into science when I was pretty much a teenager at school. I had wonderful teachers. My two big loves were physics and biology, and I realized I had to do math to do physics well. The more I learnt the, the more interested I got. And so science became a passion for me which has lasted my whole life. And, beautifully the science and the aviation combined with space exploration. So I don’t know if I’m particularly qualified, but I’m certainly interested.

Just recite for us then your college career and your job career.

OK. I was brought up in Britain so my educational path is a little bit different from most people over here, but the equivalent of high school over there I did biology, math, physics, and chemistry; so, straight science. Then I did ecological science for a first degree, and then for a Ph.D., I got interested in global climate modeling, particularly how the biosphere, all living things on the planet, interact with the climate system to create the climate. That was my Ph.D. Then I got an opportunity to work at NASA Goddard Space Flight Center working Earth system science, and that was sort of more of the same–-climate modeling, using satellites to try and figure out how the climate is doing, how the planet is doing. Fascinating stuff -- I enjoyed all of it, kind of a zigzag career through Earth science, but a, a lot of fun.

Piers Sellers, the young boy—who was your hero or, or your inspiration, when you were growing up?

Well, it moved around, I guess I’d have to say that as a kid -- aviation and space, you know -- Gagarin and Glenn and Armstrong, of course, all these guys. I knew who they all were. I could recite all the mission names, so astronauts were definitely among my heroes, they really were. As I got older, other people became heroes; Gandhi, one of my heroes ... still.

Do you still get, get the chance to go back to your hometown in the United Kingdom and talk to the people there who were part of making you who you grew up to be?

Yes. In fact, recently I went back to my high school in England, and I was very surprised to see most of my teachers—who looked terrific, by the way, if anyone’s watching. It was wonderful. These people put so much effort and time into teaching us kids something at an age when you have the attention span of an ant. They tried to get us interested in this stuff, and they were very successful. That the interest has stayed with me at least, so I was really glad to be able to go back and properly thank them for their efforts.

The job that you have today requires a lot of time, and even more so now that you’re assigned to a crew and training for an actual, specific mission. It’s time that you could be spending on whatever your other interests or hobbies are. Why, what is it for you that provides the motivation to make this choice?

I think pretty much anything worthwhile requires a degree of dedication and some sacrifice. You can’t do it all. You can’t be a master athlete and be an astronaut and a tightrope walker, or all these different things. So you, you have to direct your efforts a little. The motivation, of course, is that, you know, you’re participating in something that’s right at the, the leading edge of human exploration and human experience. So the motivation is huge.

As an astronaut, though, you know better than the rest of us just how dangerous what you’re doing is. But here you are, ready to go do it again. So, tell me why. What is it that you, that you see as getting or learning from what you’re going to do that makes it worth taking the risk?

There’s a risk; and the risk is not huge. You know the risk is there, but it’s not huge, but it’s definitely present. The benefits, I think, are enormous. We’re in this ... process of stepping off the planet and going somewhere else. Our generation of astronauts and engineers and scientists who are working at NASA now are pretty much laying stepping-stones. We’re not part of the next leap forward, but we’re preparing a lot of the groundwork for the next leap. It’s a thoroughly worthwhile, a completely worthwhile, activity. I find it personally very rewarding just to be part of it.

That’s how you accept the risk; how does your family accept and deal with the risk that comes with the job you do?

I think most of the time, like most of the families, they don’t think about it. You know, every morning everyone scatters to school, work, college, or whatever they’re doing, and so most of the days go by and you can almost pretend you’re doing a normal job. My wife says that whenever there is a launch, anybody’s launch, she starts to, to worry a bit -- not obsessively, but she starts to worry.

It’s been more than three years now since Columbia and its crew were lost. What was it like for you to learn that an accident had taken the lives of seven colleagues and friends?

It was a terrible, terrible day, at every level. It was terrible for the families; it was terrible for everybody who knew them; and it was terrible for NASA, the agency, the whole group. It was a black day.

It, the accident, was investigated; the Columbia Accident Investigation Board pinpointed some physical causes behind the loss of the orbiter and its crew. Assess the improvements that we’ve made to this point to eliminate hazardous debris and to detect and repair damage on the orbiter.

The story is mixed. Inspection: I think we’ve got a pretty good armory of instruments to basically inspect the skin of the orbiter and see the state of the heat shield after a launch. We’re in pretty good shape there, so I think that’s a, pretty much an unqualified success. Stopping debris falling off the tank: It’s a mixed story. [STS-]114, to everyone’s surprise, we had a large piece of foam liberated off the tank. We’re taking steps to deal with that next time around. However, I think it would be unrealistic to expect that no foam will fall off the tank in subsequent launches. It’s really a question of trying to limit the debris shedding to an acceptable amount. With repair: Again it’s a mixed story: We’re still in the process of developing techniques and in fact on our flight we’ll be testing a repair technique, but it’s an ongoing story with repair.

You’re the second Return to Flight flight; what did we learn in the first one, from STS-114, already that’s being rolled over into the preparations for your mission?

Well, from 114, of course, they’ve learned that we need to fix the tank some more, so they’re doing that for our flight and subsequent flights. We learned that, by and large, the inspection assets that we have in place are very capable; that’s good news. The repair, we haven’t learnt that much from 114, and so we need to do more work on the next flight and on the ground to develop that further.

In all those things that you’re talking about there are thousands of people at work around the country who’ve been involved for three years trying to make a safe Return to Flight possible. What are your thoughts about the contributions that are made by those members of this team?

Well, profoundly grateful at a personal level. But I, I think it’s been interesting to watch the whole agency try and regroup itself, focus, you know, on these problems and fix them so that we can fly again. It’s tough, because, day-to-day it’s not terribly rewarding for most of these people. It’s trying to solve very difficult problems, and sometimes the solutions are not obviously forthcoming. So for a lot of the engineers I know, it’s been a, a long, hard slog and progress has been sometimes very slow.

What has it meant for you when you’ve had the opportunity to go to different centers and meet and talk to those people who are involved in this effort?

JSC2005-E-40279 -- STS-121 Mission Specialists Piers  Sellers and Stephanie Wilson Image to left: STS-121 Mission Specialists Piers Sellers (right) and Stephanie Wilson participate in an exercise in the systems engineering simulator at the Johnson Space Center, Houston. Credit: NASA

I think we both like it, the visitors and the people we’re visiting, because, we get to see the people who are doing the work and really get firsthand explanations of what they’re doing and get a close idea of their involvement. And, they like to see who’s in the machine. They like to see the people who are actually going to benefit from their work, so it’s good for both of us.

Now, we’ve been talking about work on hardware that was involved in the loss of Columbia, but the CAIB pointed out some organizational and human factors inside NASA that also bear some responsibility for the loss of that shuttle. Tell me what do you see so far in the efforts that have been made to improve the management and, and the safety culture.

Well, a lot has been done, and there have been improvements, but I think that all of us recognize there’s a considerable distance to go. It’s impossible to change the way an organization functions, a very large organization, overnight. It can’t be done. The problems you have are, a very large organization tends to fragment a little bit. Communications are hard to maintain across and up and down within an organization. Things take time to change. I think everyone recognizes the need. It’s a question of sticking at it until we succeed. It’ll take time. We’re in the middle of it.

This mission is called station assembly mission ULF-1.1. What does that mean, and can you summarize the goals of STS-121?

Yes, what is the meaning behind the acronym, Utility Logistics Flight 1.1. What it really is is a few prioritized goals -- that’s really the essence of the mission. The first thing is, it’s a test flight. It’s the second test flight after Columbia. So, we’re going to actually test the whole shuttle system’s ability to get up without any problems, without any anomalies, get up into orbit. As part of that we’re going to be doing very detailed inspection of every square inch, pretty much, of the exterior of the shuttle after we launch. So, test flight—testing of the system—that’s the first thing. The second thing we’re going to do is, work on improving our repair capability. We’re going to test this big boom that, you know, we’re going to take out of the shuttle payload bay and test our ability to put a guy on the end of it and see if we can move him around and put him in a position to repair a damaged part of the shuttle. So, repair, that’s the second thing. And the third thing is to try and get station back to a level of functionality and capability so that the next flight after ours, and all subsequent flights, can pick up with the assembly sequence without any bumps. So we’re going to try to re-baseline the station and fix things that need to be fixed so the assembly sequence can proceed, without problems.

You’re delivering a lot of new stuff to the station, too. What, what sort of supplies are you carrying up in that, cargo module in the payload bay?

Well, tons — literally tons — of supplies for the crew, scientific equipment, a lot of spares for things that are either worn out or we expect to wear out or have run out of lifetime … just a huge inventory of things that, basically, need refurbishing after such a long gap between missions. This will be the second mission in three years, pretty much, so it’s time for us to deliver something.

As you mentioned a moment ago, you’re the second Return to Flight test flight, checking to see if some of the improvements that have been made, how they’re working. That gets started in the very first hours of your flight, when you try to confirm some aspects of the redesign of the external tank. Talk a bit about the new sensors in the wings and, and all the cameras, and what you folks have to do in order to get the data from those back down to the ground.

Now, people watching should, should bear in mind that, as we take off there’s just a raft of activities on the ground: radar, optical telescopes, airborne telescopes, tracking us on the way up. So as the people are watching us all the way, pretty much, up through the ascent profile, up through launch, to see if anything comes off, anything happens. However, on board, like you asked about, we have this suite of instruments and cameras to try and figure out what’s going on. There are two really big efforts that could provide useful information. One is a set of cameras. As the external tank drops away one camera will automatically snap a whole series of pictures of it. You should get very good coverage of the tank when that happens. In fact, 114’s camera, those views from this belly camera on the shuttle provided the best information, pretty much, about the foam departure. We also have a TV camera on the exterior of the tank that will be looking down the tank during launch, as on 114. And the other thing is that as the tank comes off the shuttle will move to be in a position to take photographs of it as it tumbles away. Hopefully we’ll get pictures all the way around it so we’ll be able to see all of its surface. And the last thing is we have, like you said, these wing leading-edge sensors embedded on the inside of the wings so that if there’s a strike of any kind on the wing we should be able to pick up the vibration of that and record the event. Now all of this stuff, the belly camera information and the wing leading edge sensors, we have to slurp that data out of wherever it’s hiding, in its recorders into a computer and then downlink it to Mission Control probably within a couple of hours of launch.

The point being that you want to get that down so that folks on the ground can start studying it.

That’s right. They get a lot within the first couple of hours, and most of the useful stuff they probably get within 12 hours, so it’s a pretty rapid-fire operation.

As a crew, you’re going to be the second to inspect the exterior of the orbiter using this new Orbiter Boom Sensor System. Give me the thumbnail sketch on how that’s designed to help an astronaut crew understand about the condition of their shuttle’s exterior.

Well, it provides you with a really long extension to the shuttle arm, with cameras and a laser on the end. So using this boom and the arm you can look all the way underneath the shuttle — and the nose cap — and you can examine almost the entire exterior surface. It’s got a little laser scanner on it so that you can not only take images with this laser but you can see depths. So if there are cracks you could actually get an idea of how deep the cracks are and what shape the damage was. A high-resolution digital camera is on there, a very fancy science-type camera, and of course TV ... all mounted, crouching on the end of the boom here and racking along the wing leading edge and underneath the surface to inspect the damage.

The STS-114 crew used this system. How did it work for them, and did they have any tips for you guys about how to use it?

It worked very well for them, as did the photos that were taken by station of 114 as it approached the space station. They did that RPM maneuver where they did a complete loop and the guys on station snapped photos. It’s a lot of work to inspect the exterior of the shuttle using this system. It’s a lot of hard work which I’m not directly involved in. I’m one of the few crewmembers, in fact I am one of two crewmembers, not involved directly in the work, but I’ve watched them do it. It’s a very painstaking, long, careful task.

You referred to this — there are most inspections of the shuttle that take place during the last phases of the rendezvous. Talk about what is going to happen in that pitch maneuver that Steve Lindsey is going to have to fly.

Well, normally what happens if you have the space station here, the shuttle comes up underneath it and just kind of slides up and docks like that. This time it’s going to come up here and I can’t move my arm through the whole 360 [degrees of a circle], but it’s going to do a complete loop all the way around so that its nose and belly will be exposed to space station. And the guys on space station will be looking through a hole in the floor and snapping away with very high-resolution cameras. They could see objects well below a quarter of an inch in size using analysis of these images that these guys got. That’s how we saw the gap fillers on 114. So it’s an important part of the whole inspection process — proven.

The rendezvous and the docking are completed, and within the first couple of hours you’re scheduled to have transferred over to the station one of the biggest, pieces of the cargo that you’re bringing: Thomas Reiter.

That’s right.

What are your thoughts about being there as you get the ISS back to operating with a crew of three, and in this case a, a crew that’s not all American or Russian?

It’s good. This is super at every level. It’s good because we’re getting back to a capability for doing more science rather than just keeping the station going. With two people on station you can operate the station safely and have a little bit of margin to do a little bit of science. With three, that extra person on board, or person’s worth, if you like, on board — it could be split up among the three of them — can get a lot more science done. So that’s, that’s really good. The other thing is that, of course, like you point out, he’s a European. So, it’s fine to have a representative of one of the other international participants go up there for a while. I think it provides a benefit to a wider group of people.

The day after the docking is when you’re scheduled to deliver the Multi-Purpose Logistics Module to its docking port. Can you give me an overview of what that operation is like that day?

It’s very involved. There’s quite a ballet involving the station arm, in picking up the MPLM, rotating it through several maneuvers, and then plugging it into the bottom of the station. And once it’s in place we have to drive all these little electric bolts to hold it tight, equalize the pressure, open all the hatches, and get in and start on unloading. It sounds simple, but it’s really not; it’s quite involved.

And, transfers of supplies, and in fact in both directions are going to go on throughout the remaining several days of the mission, while you’re going to be also occupied, conducting three spacewalks that are on the schedule. You’ve spacewalked on the space station before. What’s it like?

It is similar to training in the pool in that the physical object you’re crawling around looks something like the training device in the pool. However the environment that you find yourself in is mind-shatteringly different. You are out there climbing around on the outside of this little white space station which is hurtling through the cosmos, Earth ripping by you at five miles a second below, so it’s easy to be distracted in your first few minutes going out. It really is an extraordinary place to be. You can crawl all over the outside of space station, just like a, an ant climbing on the outside of a tree — you can go up this branch or that branch, upside down, on the top, sideways — it’s a totally extraordinary sensation to do one of these spacewalks.

Is there a difference in the sense of either speed or altitude for someone who’s outside the station than there is for someone who’s inside?

Yes; very much so. You find that if you lean forward into your helmet, looking out the visor, you can’t see the edges of your helmet and it’s just like being in an environment: you are watching. You are personally hovering above the planet which is moving below you quite fast. And you can see the curve of the Earth this way and the curve of the Earth that way, and you are flying around this gigantic blue ball, and you’re out there in the sunshine. It’s extraordinary.

As I said, there are three spacewalks scheduled for this mission, and I want to ask you to take us out there with you and talk us through the plan. The first spacewalk, another component of the Return to Flight effort to improve safety, in this case involves demonstrating the use of robotics systems as a possible work platform. What’s EVA 1?

On EVA 1 we’re going to test the OBSS, or “the boom” as it’s affectionately known, as a possible work platform for repairing the shuttle. Now, the shuttle arm is 50 feet long. It’s going to grab this boom that’s stowed on the opposite sill of the, the shuttle payload bay, which is a 50-foot-long stick, basically, with all these camera groups and lasers on the end. So it’s going to grab this boom, and we’re going to have us — crew guys — standing on the end of the boom. So in total about a hundred foot’s worth of long, spindly structure is sticking out from the shuttle. The idea is that we’re going to test the suitability of this system for something to stand on and work from while doing a repair on a shuttle. We’re going to put this whole system through a series of tests to see how well it works as a stable platform.

Which involves you and Mike Fossum standing on it, jumping on it ...

Well, pretty much. The engineering team has sweated for months and months over how to do this, and we’ve decided to do a gradual buildup of tests, some of which we can mimic on Earth using virtual reality or frictionless, air-bearing floors. But, you, you can’t test the whole system until you’re in space. So we’re going to build up. First of all we’re going to have one of us on the boom, doing fairly, moderate maneuvers in a configuration where the arm and the boom are like this and they’re pretty rigid. And then we extend the whole system: We stick the boom out there, all the way to a hundred feet — and now it’s a lot more floppy — and try another series of more vigorous maneuvers. If that all goes well — and we have every confidence it will — we'll bring it back to the sill, Mike will jump on, there’ll now be two of us on there, and we’ll go through a, another buildup of maneuvers. The culmination will be we steer the whole thing so that Mike can touch the space station, one end of the truss; and he will pretend that that end of the truss is an injured bit of shuttle and he will do a whole lot of interactions — hitting, wiping, scraping, bolting interactions — with the truss to simulate repairing a shuttle while standing on this boom and while having me hanging on to a tool stanchion, pretending to hand him tools. I think once we’ve done all that, we’ll know how good the system is for repairing the shuttle over quite a large range of locations on the underside of the shuttle. We’ll know that.

In its life the arm has carried loads far heavier than you and Mike Fossum put together. So I take it it’s not just a, a matter of the weight, or the mass.

No, it’s not just the weight. It’s because the boom is a 50-foot-long spindly object. And if you look at the arm — which is only this much around, and so is the boom, and it’s made out of composite material...bendy. What you have is a, a 100-foot-long system of bendy stick with two big, fat, heavy guys standing on the end. So it’ll sway; it’ll move. What we’ve seen is that, if you put a, a big bounce into it or something, this thing will start swaying, and it’ll take about eight seconds to go forward and back, almost like a, being on the deck of a ship. You’ll just sway slowly back and forth. So you try not to do that, you try not to put in that kind of input so that the boom will respond that way. The real thing we’re trying to figure out is, is the floppiness going to be a hindrance to using it as a repair platform.

The second spacewalk on your mission got a, almost a complete changeover late last year when one of the station’s Trailing Umbilical System cables became severed. Give me an overview for what is now planned for EVA 2 on your flight.

It has changed significantly, but the theme of EVA 2 is fix the station. The first part of the EVA, we’re going to transfer a gigantic pump module — this thing’s about the size of two industrial freezers, about 1,400 pounds. We're going to move that from the shuttle payload bay and plunk it onto the station in a stowage location so it’s ready as a hot spare. The pump modules on station, which drive all the cooling around the cooling systems, haven’t failed. They’re fine, but we’re pre-positioning this heavy spare in case we need it. So that’s one. Two is the Trailing Umbilical System you referred to. This is a kind of a long system that reels out a cable to allow the Mobile Transporter to move up and down the station. It pays out a cable to keep, keep itself supplied with power and video. It’s broken. To repair that, which is a 330-pound device with numerous connections, is going to involve, I think, about 4½ hours’ work outside using the big station arm to detach and bring back the old unit from station, and then bring the new one out of the payload bay, put it in there, make up all the connections, mate it up and get it going again.

And then, the third spacewalk, we’re back, if you will, to testing, in this case, testing techniques for possible repairs to the shuttle’s thermal protection system. Float us through EVA 3.

EVA 3 is pretty much focused on looking at techniques for repairing the reinforced carbon-carbon. That’s the black composite material that makes up the nose cone and the wing leading edge. Imagine the scenario that something’s hit and cracked one of the wing leading edge panels. We have a black material called NOAX, which is non-oxidizing, non-oxidative adhesive experiment; we’re going to apply this over a series of deliberately damaged RCC samples under a range of conditions. These are going to be brought home and they’re going to be tested to see how well they would have stood up to an entry. We’re hopeful that we will have, you know, helped develop a technique that could be used to repair a shuttle wing leading edge in space; that’s the goal.

And there are, as I think you said, a range of different samples to test and, and different ways of applying the material as well …

That’s right. The kind of samples that we’re looking at is, I think, a damage called a spall, where you hit something hard and the impact knocks material off the back side as well as making a crack and knocking material off the front side. There are straight cracks, which is like mechanical damage, which you’re trying to fill in; and there’s coating loss, where the thin layer of glass over the top of the RCC has been eroded off. So we’re going to try applying this material in different ways to repair all these different kinds of damage. Now, the different conditions part is that this material doesn’t seem to work very well when it’s very, very cold, and likewise when it’s very hot it behaves badly. So we’re going to try and catch it under the optimal conditions between extreme heat and extreme cold when the surface is cooling, and how well we do. And of course, it being the nature of these things, there will be times when we’ll be putting it on under less-than-optimal conditions, so it’ll be interesting to see how the repair works out. We expect to get a few samples — four, five, six samples — repaired.

That’s quite a list of things to do. Three spacewalks, transferring tons of supplies and whatnot. By the time you close the doors and start heading home, what will you have had to have done, so that you can consider that this mission was a success and set the stage for the next shuttle missions to come?

Two levels of success, I think. One is, was the test flight a success? Is the shuttle system in good enough shape for us to continue with confidence, with more flights? That’s the whole “test flight” criteria, if you like, that we need to look at. And along with that goes the whole business of have we demonstrated that we can do a repair — has our repair technology proven out to be useful — that’s the boom and the samples. So that’s one set of success criteria. The other set is, have we put station in a posture where we can now continue with the assembly flights without more adjustments for the long gap between supply flights? Have we re-baselined ourselves so that the assembly sequence can just proceed? And that involves, did we get all the resupply done, did we fix their TUS, did we drop off the Pump Module, did we deal with any other odd jobs of fixing around the station that needed doing? There’s quite a lot involved in that. I’d like to think that if we came away from that and the whole system, shuttle and station, was ready to re-continue with the interrupted assembly sequence, that would be success.

Your mission is bringing the space shuttle back to flight and resuming station assembly just as it moves into its final few years of operations. Tell me about the space shuttle’s contribution to the space station.

Well, they’re twins, you know: The space station was designed around the shuttle’s capabilities and limitations. Pretty much all the modules that the U.S. side is taking up were sized completely for shuttle. So their fates and their development are linked; very much so. This will be a high-water mark for the technology of the 20th century in space exploration — this is the limit of what we could have done with this technology. So, we’re looking forward to the step after this, as well as celebrating what we’ve done.

Exactly. As critical as the shuttle has been to building the space station, the space station itself isn’t really the final goal. It’s a step toward a goal. Tell me, from your perspective, how you would evaluate the contribution of the space station to the future of human space exploration.

I think it’s going to be invaluable. Looking back, it will be seen as an invaluable tool, I think, towards getting us out into the rest of the solar system. There’s the obvious things, you know. We will have developed techniques for long-duration human spaceflight. We will have looked at technologies that can support people and machines over long flights. Neither of these things is trivial. They’re hard to do. Another thing that people can often overlook is that it, it was the first time that many of the countries of the world joined together to try and do something like this — something very difficult, something of purely peaceful value, purely to do with science and exploration — and that’s a first, and that’s something else that we can build on. So I think that it’s an important point in the development of space exploration. It’s tough to see that right now, when we’re mired in fixing the Trailing Umbilical System and repairing all the widgets and gadgets on station. But I think when we look back at it from the perspective of 20 years we’ll see it as a vital stepping-stone.