|Preflight Interview: Robert Curbeam||
This is the STS-116 crew interview with Mission Specialist Robert Curbeam. First of all, can you tell me a little bit about why it was you decided to become an astronaut? And if you can recall, around the time when you decided that.
Image to right: STS-116 Mission Specialist Robert Curbeam. Image credit: NASA
I was always interested in spacecraft and aircraft, thought I’d be a spacecraft or an aircraft designer. I grew up being a big fan of Wernher von Braun’s and reading a lot about his work and about the V1s and V2s and Saturn Vs, things like that. But never really thought I’d be an operator. I thought I’d be a design kind of guy, an engineer, basically designing and building aircraft and spacecraft for other people to use. But then decided to go into the Navy and started flying in the Navy. When I was going through test pilot school we actually took a field trip down here to Johnson Space Center. We got to see what the astronauts did and how they did it and had lunch with Kathy Thornton, who was an astronaut at the time. I’ll tell you: After having lunch with her and talking to her, I decided I wanted to do what she did! So here I am. I was fortunate enough to be selected on my first try to get into the Office.
Can you give us a thumbnail sketch of the academic and professional path that you took to get here?
I am in the Navy. I’m still active duty. I flew F-14s as a radar intercept officer for a few years in the fleet then went to graduate school, got a few degrees there, and then went to test pilot school when this, when I came down here.
I actually came and took this trip down to Johnson Space Center while I was in test pilot school. I did flight test work at Patuxent River for about three years with the F 14, and then taught at the Naval Academy for about six months before showing up here. I’ve been here for about 11 years. So, that’s my professional path and education path. I started all that at the Naval Academy; that’s where my naval career started.
Looking back on it, obviously it’s not the easiest thing to do. What does it take to get here, just from a personal standpoint? Fortitude or what?
I think it’s actually kind of funny, because I started out on this journey not with the goal of being an astronaut, but with the goal of learning enough about airplanes so I could go and help design better ones. It just so happened that when I did meet an astronaut and speak with her at length, it sounded interesting to me. It sounded like something that I wanted to do. And I was fortunate enough to have pursued education through enough of my life that I had the qualifications necessary to be competitive. So I think it’s kind of funny. The destination is not exactly the one that I had planned, but because the Navy had given me many opportunities to go to school and I took all of them, I was eligible or competitive, as I said, in this regime without even planning it that way.
Tell me a little bit about your first spaceflight. What that was like?
My first spaceflight was STS-85; back in 1997. It was a science mission. We did all sorts of science; just about any kind of science that you can think of we did some of it: Everything from oceanography to upper-atmospheric science to meteorology, robotics, colon cancer research. We did a little bit of everything, which was fantastic. But I think the biggest impression that I left with from that flight, although we did a lot of work in the sciences, was just the view. It’s absolutely incredible! And when you’re up in space, all you want is for all your friends to be with you. Because everywhere you look, there’s something that reminds you of people. When I go over the Philippines, it reminds me of when I was there and the friends of mine from the Naval Academy that were with me. When I go over to Japan, same kinds of things. When I fly over the Mediterranean, the different people that served in the Navy with me then. Or when I cross over Baltimore, friends of mine from high school. That’s probably the first impression you get. I’d say the second one is one of conservation. I always tell my friends, “If you leave this world not a conservationist you’ll come back as one.” And when you see the view how beautiful this planet is, another thing that you take in is how limited our resources are. Our resources are definitely finite. When you come to that realization in space, you come back deciding you want to make sure that those resources are left for generations to come.
So do you think if everybody were to be able to take a trip to space and see what you’ve seen, to see the planet from the perspective that you’ve seen it, that some of the world’s conflicts might be a little less ...
Oh, yes. One thing that you do notice is that your problems, although they seem large to you, are very, very small in scope. That is something that you realize, just how insignificant you are in the big scheme of things when you go up into space and look back on the Earth. At least that was the feeling that I got. I think you’re right. I welcome the day when more people get to experience some of the things that I’ve experienced in looking back to the Earth. I think that you’ll see people probably a lot easier. I just think that they’ll get along a lot better. I think that we even get some of that within our crews. If you’ve had little arguments or spats -- we’re people, too. You know -- I think all that goes away after the solid rocket boosters light.
Okay. And your most recent spaceflight was to ISS in its infancy. There have been a lot of changes since then. What changes are you most looking forward to seeing when you get up there on this flight?
The space station really didn’t look lived in when I went there. Don’t get me wrong. When we got up there, the Expedition 1 guys had been up for about four months, three months, something like that. But you could tell there was a lot of work to be done before it was going to go from just an outpost where people were living to a world-class laboratory. I look forward to seeing it in that state, where they can actually do some great work up there. They’ve added a couple of more rooms since I’ve been up there; well, one, the airlock. And the truss is there; the truss wasn’t there at all. So it’s going to be a larger station. I’m just looking forward to the changes in general. I don’t think there’s any one specific change that is going to be, you know, more significant for me than the others. Just I just want to see the changes in general.
Tell me about the place that you consider your hometown and what it was like for you growing up there.
Oh, I’m from Baltimore. I’m a Baltimorean through and through, born and raised. I love the East Coast. I’m an East Coast guy. Granted, I have a lot of pride in Baltimore. I love my Orioles. Still love the Colts, even though they left us. But you know the Ravens are there now. So I love them. I think that’s pretty typical of most East Coast guys. You just love the city that you were brought up in. That’s not to say I won’t visit Philly or D.C. or New York or Boston. But it’s not Baltimore!
Do you like blue crabs?
Oh, my goodness! Maryland crabs and Maryland crab cakes! Gosh! I try to have one Maryland crab cake every time I got back. I enjoy it. I really do.
Did you have a favorite sport or hobby growing up? What was it?
I played lacrosse for a long time. I played a lot of sports growing up, football, tennis, baseball, wrestling. I wrestled in high school as well. But I played lacrosse in junior high, high school, a little bit in college. Two and a half years in college. I love it. I’m also glad to see that the sport’s growing here in Houston, because I love lacrosse. I just think it’s a great sport. It’s a great balance between a very physical sport and a lot of finesse. I really did enjoy playing lacrosse. So that’s probably something that I miss being down here, that it’s a little harder to see competitive lacrosse. But it’s possible.
What do you do now in what little spare time you probably have as far as an activity or hobby?
I watch my son play sports. I try to stay involved with both of the kids. I have a daughter going to college, a son in middle school, so that takes up a lot of time. But I would say if I do have spare time, a thing I enjoy is going to the gym. I love to lift weights. It’s something that to me is a tremendous stress reliever. And it’s a healthy vice, if a vice can be healthy!
Let’s get on to talking about some general things about the mission. If you would, could you summarize the main goals of 12A.1, and give us a brief description of what your main responsibilities are?
Our primary goals are to: one, get Suni Williams up to space station and bring Thomas Reiter back. Also we want to install the P5 truss element, which is a small spacer that goes between the two, large solar array trusses on the portside. We’re going to reconfigure the power system. Basically what we’re going to do is set up the space station so it can go to its permanent power supply system.
You mentioned, with the reconfiguration of the EPS (electrical power system), it’s going to go from temporary to permanent. How is the temporary different from the permanent?
The big thing is how the power is supplied or where it comes from really. Space station was designed around a truss, what we call a main power truss, which spans space station and has solar array wings on the end of it. Right now one of those solar array wings is actually situated on top of space station in a temporary place. We’re basically going to unplug space station from that truss and plug it into this main truss, which goes span-wise across the station. And then, several flights later, they’ll take that truss that is sitting on top of the station and put it in its permanent place outboard of the small spacer that we’re going to put in. So that whole port truss will have four solar array wings, and all be providing power through that main truss to the U.S. lab and the U.S. operating segment, and eventually, through power conversion, to the Russian segment, too.
Let’s talk a little bit about some of the key components of the electrical power system. Two specific ones are going to be activated for the first time on your flight: the, solar alpha rotary joint is going to actually move. And you mentioned you’re going to connect them permanently into this new spot at the main bus switching units. Tell me a little bit about those two components and what they do.
Image to left: Astronaut Robert Curbeam, STS-116 mission specialist, gets help with final touches on the training version of his Extravehicular Mobility Unit spacesuit. Image credit: NASA
Well, basically the main bus switching units distribute what we call primary power, 160 volt, 160 or 151 volts, depending on whether you’re in sunlight or not in sunlight, to all the different elements in the power truss. And the solar alpha joint, the SARJ (I usually remember all these things by their acronyms) allows the solar array wings to rotate and to track the sun so they can stay normal to the rays of the sun and receive and produce as much power as possible. So that’s why we have basically all of our solar array wings gimbaled. And you have an alpha gimbal to alpha joint and a beta gimbal to beta joint as well. And through using those two joints we can always point our solar arrays to the sun when we’re on the sunny side of the Earth outside the shade to produce as much power as possible.
If the cells gather sunlight while the ISS is in the sunny part of the orbit and that provides power, how is power provided when the ISS is not exposed to sun?
Basically, we have a bunch of batteries, rechargeable batteries. They charge up while the station is on the sunny side of the Earth in direct sunlight. And the solar array wings can produce enough power so they can charge those batteries and run the systems on board the station at the same time. So we’re charging the batteries, running the systems on the station, and then, when we go into eclipse (or the dark side of the Earth), we can draw power from those batteries. And it takes about 90 minutes to go around the Earth. So in general, and of course this varies depending on the angle that the orbit makes with the sun, we have about 45 minutes of daylight, 45 minutes of darkness.
During the two EVAs, the power reconfigurations are going to happen. About half of the ISS power will be shut down for each of those EVAs. What risk does that pose for systems and hardware?
Well, it is actually quite risky. You’re right. But probably the biggest risk is starting up the items that have never been operated on the station. We have all these power units, all these electrical supply units and direct current-to-direct current conversion units, main bus switching units, remote bus, distribution systems, all in this truss that have not been used yet. So the scary part about all of this, if I can use that word, is that these are being started up for the first time. For anybody who’s operated electronics, you know that usually you get the most failures either right at the beginning of the life of your electrical components or when they’re very, very old. So our big worry is we’re going to tell all these different systems, the cooling system and the power distribution system, to start up and something won’t start up, or something won’t operate as we designed it to operate. That’s when we start doing different spacewalk contingency procedures to either replace boxes, fix boxes, whatever we need to do to get that system up and running. So that’s probably the biggest risk we have right now, as far as the spacewalks go, that we unplug two channels from P6, the vertical array, plug it into the main power truss, and you know, nothing happens! For lack of a better word. And of course, we don’t expect everything to crumple on us like that. But you just don’t know.
I guess, like you said, there’s a graduated level of contingency options if stuff doesn’t power back up.
The great thing about our situation is we have an absolutely awesome team on the ground. This is one of the few missions where they probably play a larger part in the choreography than we do up in space. It is very, very important that they power those things up in an orderly fashion so that they know if they do have a failure, exactly where the failure occurred. They also have a thermal clock like we were talking about. It’s very, very important that we regulate the temperature of all of this, all these things, and nothing stays too cold for too long or too hot for too long. So Mission Control-Houston has a huge job as far as making sure all of this stuff powers up in an orderly fashion, not only because we want to know where a failure occurred (if a failure occurs). It's also so that we don’t bust any of those operating limits for any of the equipment up there. It is absolutely impressive to see those guys work, because they know the system and the sequence backwards and forwards now. It’s going to be a pretty exciting day.
You mentioned that part of the mission is to deliver Suni Williams and return with Thomas Reiter. It’s the first shuttle-based partial ISS crew exchange, since before Columbia. What significance does it have for the American space program?
I think probably the most significant thing for us to exchange Thomas Reiter for Suni Williams is that we’re back in business. This is how we intended to do business. Granted, it’s a small step; it’s one person this time rather than the three we thought we’d be exchanging at this period. But it’s a step back to use Wilson’s words, normalcy. You know, this is what we had planned to do. This is how we had planned to operate. This is one step in that direction to getting back to operating the way we wanted to and the way we had planned to. That’s the real significance, to prove to ourselves that we can do this; that we can get back to a situation where we can reliably deliver people to the international space station using the space shuttle.
Back to the EPS. I was reading about, the grounding scheme, that it has, all electrical things need a ground in some way. It’s grounded to the ISS infrastructure itself, but it’s also grounded to the space environment in a way. Can you tell us about how that is accomplished?
Because the space station is moving through the upper atmosphere at such a high rate of speed, it produces a small electrical charge on the outside of the spacecraft, which could potentially be dangerous to spacewalkers going out there. So we use a plasma contacting unit. It uses xenon gas to basically neutralize that charge on the outside of the spacecraft so that we don’t have to worry about arcing at all between us and the space station or different parts of the space station or the suit and the space station, things like that, which would be bad.
You mentioned the P5 placement and what it’s going to do. It looks like it’s a relatively small piece of equipment compared to the rest of the truss. But it’s also a very vital one. Why is it so important to ISS?
What the short spacer does is just that. It’s a, just a very small piece of the truss. But it fits over the beta gimbal assemblies of the inboard solar array wing. Because the beta gimbal assemblies, which are the second set of gimbals which allow us to point the solar array wings to the sun all the time during the period of what we call insolation, or the daylight periods going around the Earth; because those have to rotate, they have to be in an area free from obstruction. This truss that we’re bringing up, the P5 truss, is almost like a spider. It hooks into the rest of the truss over these beta gimbal assemblies, allowing them to rotate freely and not touch anything, and then it allows us to take another truss piece, another solar array wing truss and place it outboard of those inboard solar array wings. So that’s why it’s important. It allows us to take the P6 truss, which has been up there for several years now, temporarily mounted on top of the station, and put it in its rightful place, if you will.
Let’s move on to some flight day-specific activities. Can you give us an overview of what’s going to happen on flight day 3, the day that you dock? Just give us an overview of how P5 is going to get out of the payload bay and into the hands of the ISS, so to speak.
Well, flight day 3 is going to be a busy day. We all know that. It’s rendezvous and docking day; and rendezvous and docking takes a very, very huge portion of the day. But we also know that once we dock, which is, like I said, almost a day-long job, we have a lot of work to do; and one of those things is to hand off P5. Nick and Mark, Polansky will be on board shuttle. They will grab P5, the P5 truss segment, which will be sitting in the payload bay, with the RMS, the robotic manipulator system on shuttle, pull it out of the payload bay, and basically move it to a position where the station robotic manipulator system, the station RMS, can grab it. And then, they’ll put it into an overnight park position. The next morning when we go out to do the spacewalk, they’ll actually take that P5 truss and move it outboard to the location where it’s going to be attached. Christer and I will connect it to the rest of space station.
While those robotic ops are going on, you and Christer will be preparing yourselves for the EVA the next day. What tasks do you have for that day?
Actually, that’s a pretty busy time because not only do we have to do the normal meet-and-greet with the station crew and also transfer a few items for their use, we have to get the station airlock ready for us to spend the night there, to get ourselves ready for the spacewalk the next day. To prevent decompression sickness we go into the airlock and depress the airlock to 10.2 psi, about a quarter to a third less than the normal atmosphere of the spacecraft, to reduce the chance of getting decompression sickness when we go on the spacewalk the next day. So we have to move all of our gear, our spacesuits, the equipment that we’re going to need for the spacewalk, some food, our sleeping bags, all of that kind of stuff, our hygiene items over to space station and stage it in the airlock so that we can close off the airlock later that day and depress it so we can sleep over there. Christer and I will be very, very busy moving items from space shuttle to space station that night.
Let’s move to the next day for EVA-1. Can you walk me through what you and Christer will do on that EVA?
Christer and I will go outboard as far as the port truss goes, and that’s where P5’s going to get installed. So when they bring P5, which we affectionately call “puny,” (S5 is “stubby"; it’s the same truss, but on the other side), so they’ll bring “puny” out and put it on there. We’ll drive the bolts that connect it to P4, the truss just inboard of it. Once we get all that done, we’ll start making the electrical connections and make sure that the latch assembly that’s going to allow them to connect the next piece of the truss that’s outboard of that works. We’ll move what we call the photovoltaic radiator grapple fixture off of the front of P5 and move it to a location where it’s out of the way of all the CETA carts and things like that that will be rolling up there. We’ll move that out of the way. Then, after we’ve basically configured the small spacer for all the operations that will have to be done out there later on to continue construction of space station, we’ll come back in and replace a camera that’s broken on the outside, the starboard side, of the truss for space station. And that’s pretty much all the EVA-1.
Can you touch on a couple of other tasks in that EVA early on, while the truss is being moved closer to hard dock. You and Christer will provide some guidance; you’ll be giving clearances to the robot, robotic arm person?
We will basically be the eyes of the robotics operators, and that’s Suni and Joanie. They’ll be inside actually moving the truss into position, and we’ll be giving them different clearances so that they don’t hit any structure as they’re placing P5 in the proper location. That’s our first job once we get out there, just to talk them in. They’ll come in to about 20 centimeters from contact. We’ll remove launch locks, which are just items that protect the bolts that are going to permanently attach these two pieces of truss together. And then, once we remove those launch locks, they’ll bring it all the way in and we’ll drive those bolts to connect the two pieces of truss.
Is there a particular order that the bolts have to be tightened, or can it be in any order?
Oh, no, no, no. The bolts are numbered, each corner, one through four. And they have to be tightened that way, too. We’ll tighten them; we’ll do what we can an initial torque using our cordless drills that we bring up there. And then, after that, we’ll use a torque wrench to get the final and exact torque for each corner.
The next day, flight day 5, no EVAs are planned but there are a couple of key activities scheduled. One is retraction of one of the P6 solar arrays. Why is that happening?
Image to right: Astronaut Robert Curbeam, STS-116 mission specialist, attired in a training version of the Extravehicular Mobility Unit spacesuit. Image credit: NASA
The solar array on P6, the one that’s on the portside, has to be retracted because if it isn’t and you start to rotate the solar array rotary joint on the portside, the solar array wings from P3/4, the inboard solar array wings will actually contact the solar array wing on the portside of the vertical truss. So we have to roll that in before we can fully activate the portside of the truss. So that’s why we’re rolling that in. And we also would like to retract those arrays on P6, before we move it out to its permanent location. So this is just a kind of a get-ahead for that, but it’s definitely so that we can start rotating the alpha joint.
What happens if that array doesn’t retract per the nominal plan? What kind of contingencies are we looking at?
The great thing about it is we’ve had some experience in fixing solar array wings. To answer your question: if it doesn’t retract fully, we’ll see how much it has retracted, if it’s retracted enough so that we can start rotating the alpha joint. If not, we’ll go up there and we’ll manually retract it. A lot of the systems on space station's exterior have a lot of what we call EVA contingency hardware on them. We can actually retract it using our cordless drills -- we can retract it. We can latch it.
How long of a process is it to do it with the drill?
Doing the retraction with the cordless drill, that’s a good question. I used to have that number. And it’s on the order of several minutes to make it happen. I want to say it’s 10 or 15, but please don’t quote me on that.
Flight day 6 is the second EVA. What’s the key goal for that one?
The second EVA is the first power reconfiguration. We’ll unplug power channels 2 and 3 from P6 and we’ll plug it in to the main truss. That’s the primary goal of that spacewalk.
Can you walk me through that spacewalk, kind of highlighting the key areas that you, that, where the connections will be, where the demates and mates will happen?
I could walk you through each mate and demate, but I’m all up and down the truss on the portside. And, actually, Christer is actually on the back side of the truss, a little bit, and he is also all over Z1 doing mates and demates. So it’s over that entire half of the space station. So it really would be a little difficult to do that. We’re also moving two of the CETA carts, which are just carts that connect to the small trolley that the robotic arm is on space station. And we move two of those during that spacewalk as well.
Okay. And what’s the reason for the CETA carts being moved?
Most of the moves that we do with the CETA carts are just to have room either to move the mobile base, which the robotic arm rides on or is connected to, farther to the starboard side if they need to, or to get them out of the way so we can get into the truss, where they may be at that time. So most of your CETA cart moves from side to side are for that purpose.
Also on that EVA there’s a plan to install some additional thermal insulation on portions of the space station robotic arm. Can you tell us why that’s happening?
There’s a force moment sensor on each, what we call latching end effector, of the arm. The robotic arm on space station is kind of like an arm with a hand at each end. So it can go off and can grab a part of the station. And if that station part, and it’s usually called a power and data grapple fixture, can supply power and data to the arm, then it can let go at what was the shoulder and then that last hand becomes the shoulder and the old shoulder becomes the hand now. So it can kind of inchworm its way around space station, which is kind of interesting. They have what’s called a force moment sensor on each of these hands, and the temperature, the thermal environment, is a little different from what we had planned. They’re getting a little colder than we expected. So we’re going to take a blanket and put it around those areas to basically regulate that temperature. A lot of people don’t realize that the temperature swings can be on the order of hundreds of degrees Fahrenheit, as you go from darkness into sun and then back into darkness. And most equipment, especially electrical equipment doesn’t like that. So in this case we’re using a passive system to try to regulate the temperature of the force moment sensor.
Okay. Let me step back to the first EVA for a question. You mentioned the relocation of the grapple fixture on P5. Why is that necessary?
That’s necessary to get that grapple fixture out of the way, basically. It would interfere with some of our later assembly ops if it stayed in that location. By putting it down on what we call the keel of P5, it’s totally out of the way. It won’t interfere with the translation of any items or any other rotation of the joint. So that’s why we move that.
For flight day 8, EVA-3, is it much the same as EVA-2, just different areas? Or is it another power reconfig?
Exactly. It’s the same thing, except now I’ll be mostly on the starboard side of the truss. This time Suni will be out there with me, and she’ll do the same types of worksites on the back side of the truss and on the Z1 truss to, basically like I said before, unplug things from P6 power supplies and plug them in to the main truss supplies. The only difference on this one is at the end of the EVA, instead of moving CETA carts like we will be doing on EVA-2, on EVA-3 we’ll be taking some service module debris panels, which are micrometeorite protection panels, out of the payload bay of the orbiter and we’ll be putting it on space station for a crew to install them on the service module later. Additionally, we’re going to take an adjustable grapple bar, which is basically a re-locatable grapple fixture, something that a robot arm can grab onto -- we’ll be taking that out of the airlock and attaching it to a part of space station, temporarily stowing it just in case the guys up there need to use it later on to move any very, very large orbital replacement units.
During the reconfig, is it just as simple as just taking a connector, unplugging, and plugging someplace else? Is there more to it?
Usually most of your connections are capped and we are swapping a cap for a plug. So you’ll uncap the connection, which allows it to be powered from the main truss. You’ll take a plug out of one jack, put it into that jack, and then cap the other jack. And that is the majority of at least of my reconfiguration. Suni and Christer are also taking out some circuit interrupt devices, which are big switches basically that we had installed in series with some of these electrical lines for more control of where power went and when it went to that area. They’re EVA-operated switches. Actually I placed most of them in there that they’re taking out, as a matter of fact, on my last flight. So that’s what’s involved with a lot of this stuff as well.
Not looking for an exact number, but just roughly, About how many mates and demates are we talking about total for both EVAs?
Just a general number.
Yeah, probably on the order of, I don’t know, 30, 40 per spacewalk. So 50, 80, something like that, when all’s told.