NASA - National Aeronautics and Space Administration

Q: Commander Mark Polansky, can you tell me a little bit about when you decided that you wanted to become an astronaut and what made you want to shoot for that goal?

Image to right: Astronaut Mark L. Polansky, STS-116 commander. Image credit: NASA

A: When I was growing up it was way back in the 60s, it was the beginning of human spaceflight, and I got pretty excited. Back then when I was in school and there would be a launch, they would stop classes, roll in a little black-and-white TV, and you’d get to watch everything live. The networks covered it completely. So you had a lot of exposure back then. And like any kid, you say, “Hey, I want to be an astronaut when I grow up!” I sort of just never outgrew that. But one of the defining moments for me was that I happened to go by chance to Purdue University, which, boasts the first and last men to walk on the moon, Neil Armstrong and Gene Cernan, as alums. When I was a freshman I got to meet Gene Cernan during a visit back in the dorm I was at, and it got me thinking, “You know, this is something that a guy could do.” And then, I got to thinking about the background of the astronauts. I eventually started to pursue Air Force ROTC and a career in the Air Force, and eventually wound up here.

You mentioned some of your professional path to get there, academically and educational. What kinds of steps did you take there?

I actually started out as a physics major in college. But after about a year and a half, I decided that while I liked physics, it didn’t like me. So I switched and discovered aeronautical engineering, which was a field that I very much enjoyed, aeronautical and astronautical engineering. I got my degree there. As I said, I was going through Air Force ROTC at the time. So, when I graduated with my bachelor’s degree, I had about a nine-month wait before I could go into pilot training. And I had enough credits that if I stayed an extra summer and fall semester, I could get a master’s. And so I was able to go ahead and do that, and get both the bachelor’s and a master’s before I left Purdue and then went into the Air Force and made it from there.

Okay. This is your second spaceflight.

Yes.

How has preparing for this flight, as a commander this time, been different from your first spaceflight?

It’s really a lot different. Certainly when I was on my first flight, part of the process was just trying to figure out the things that a person needs to be prepared to do when you’ve never flown in space before. I had a lot of veterans around me. I was the only first-time flyer on STS-98, so I was very much able to just concentrate on my role. Yes, I was aware of the other things that were going on, but it wasn’t my main concern. Now as the commander, I feel exactly the opposite. I really need to know the big picture, what’s going on with the entire crew, be looking out for the rest of my crew with regards to their timelines, their tasks, making sure that people aren’t getting over-utilized in certain areas, as well as concentrating on the things that in particular I’ll be performing on the flight. So, it’s sort of like being both a player and a coach at the same time.

OK. That’s a good analogy. What do you remember from a personal standpoint about your first spaceflight? ISS was in its infancy. What do you remember most?

There’s not one thing. But, certainly the first thing I remember was my first look back at the planet. I don’t think there’s an astronaut around that won’t tell you that it was just an emotional, inspiring moment to actually get a chance to look out the window and glance down at the home planet for the first time while you’re orbiting up there in a weightless environment. I got to do that just after I got out of my suit, when I was coming back upstairs, for about five minutes. And that was pretty awesome. And then, the rest of it was just everything that you did up there you were doing for the first time. So, you’d sit there and say, “Wow! This is the first time I went ahead and did a rendezvous. This is the first time that I saw the Lab get out of the payload bay. This is the first time that we connected the Lab. This is the first time we went inside.” So, every experience was brand new. And, I just remember a great sense of both pride and relief at the fact that we were able to deliver at the time what was billed as one of the most critical pieces of the space station, the Destiny Laboratory.

Tell me a little bit about the place that you consider your hometown and what it was like living and growing up there.

Sure. I’m a Jersey boy; grew up in New Jersey, was born there, and the main town that I grew up in was Edison. We moved there from another town called Perth Amboy; I lived there when I was about 3 years old until through the end of the fourth grade. Then, my parents moved us to, a town, Edison, which is what we call central Jersey. It’s probably about a 40-minute train ride to Manhattan from where I lived. My mom still lives there. It’s, just a sprawling suburban town, fairly large, and our house still borders on a county park. It was just a great town to grow up in. I still have a lot of great friends from back in my hometown and back in New Jersey. It was the kind of place where, in those days, especially when school wasn’t in, you would just, go outside the house after breakfast and show up around dinnertime and just run around and ride your bikes and doing anything that you wanted, which is a lot different from it is now with kids these days.

What were your favorite hobbies or sports growing up and why?

Sports, for the most part was a was a favorite hobby. I loved to play baseball. And so we did a lot of pick-up baseball. Right in the park, we had a nice ball field. A lot of baseball, as well as football, hockey, things like that. So, I just really enjoyed that.

Let’s move on and talk about the mission a little bit. Could you summarize the main goals of STS-116 and give a brief description? You’ve already touched on what your responsibilities are as a commander. But just kind of summarize what the main goals of the mission are.

Well, let’s see. We have several things going on, on STS-116. We’re going to take up a part of the truss structure, called, P5. And we call it a spacer; and, in essence, it goes at the end of P4, which is another truss structure which has a pair of solar arrays. Eventually there will be another piece, P6, which has been in orbit for a long time now but in a temporary location. It eventually will go way out on the portside of the station. P5 is the connecting piece between P4 and P6. So, that’s an important piece that needs to get installed. Once we get up there, we’re going to reconfigure the electrical system. Right now we have again sort of a preliminary, temporary electrical system set up. It does a great job providing power, but it’s not as robust as we need it to be in the future. Once P5 is installed, we will be doing a lot of the rewiring of the space station to get the primary electrical system working. That’s going to be a very critical thing for the station. One of the other main things we’re doing is taking up Suni Williams, who is, going to round out the Increment 14 crew. She’ll be that, third crew member on that flight. We’ll bring back Thomas Reiter, who launched with STS-121. We’ll bring him back home.

You mentioned the crew rotation. As an American space professional, how does it feel to be involved with getting that back on track?

I think it’s really great! I really look forward to it. On STS-121 we did a half rotation. We took Thomas Reiter up but didn’t return anybody, because we were on a two-person station crew at the time and we augmented it back to three. So, this is the first mission where we’re going up and down. I think it’s really exciting to do that. What makes this unique is, since it’s not a full-crew rotation, a lot of times the folks that are training for their increment are so busy that they don’t have much time to interact with the shuttle crews. And in our case it’s different. Mike L.A. and Misha have already gone to Russia and have been there for some time now getting ready to launch. Suni’s back here with us. Even though she has her own training, some of it overlaps with our training, and we share an office. So, we feel very much that she’s a part of our crew and our family. And when we take her up there, it’ll be bittersweet. We’ll be happy for her, but sad to leave her behind. On the other hand, we had the pleasure of getting to know Thomas Reiter before he launched in STS-121, and we had a few social activities. So, we’re very much looking forward to getting up there, greeting an old friend, Thomas, and then bringing him back home to his family. I just have really good feelings about doing those things.

You talked about the reconfiguration. There will be some power-downs involved to make the reconfigurations possible. That poses some risk to hardware and systems. Can you tell us about any kind of procedures that have been put in place to mitigate those risks?

Sure. The main thing that goes on is during our second EVA, the second spacewalk, Beamer and Christer, the two EVA gents outside, will be getting ready to basically do rewiring. Like I said, we have a temporary electrical system in place. Just like you don’t want to take equipment that’s running and just unplug it at the outlet and then plug it in when it’s already turned on, you want to shut things down properly before you move the wires around. So we need to do the same thing on orbit. Mission Control is going to issue commands to power down the parts of the station in order to allow Beamer and Christer to move electrical lines around outside. Once that’s complete, then they will repower those lines, which will now be running through the main electrical system, a lot of the electrical boxes that go through the S0 truss that launched a while back. They will do half of the power reconfiguration on EVA 2. On EVA 3, by Beamer and Suni, they will do the other half, and it will be again a power-down and a power-up. That’s the plan if everything goes well. The Mission Control team has run countless simulations thinking about what could go wrong during these power-downs. What if the ground commands don’t work properly? What if certain, boxes don’t power up as advertised? And so we have a series of fallback plans, depending upon what might go wrong. The course of the EVA could change, could go maybe two, three, even four different directions based on what’s going on. We’ve tried to plan it so that we’re very aware of the most likely chain of events that could happen. Number one, we need to make certain decisions by certain times during the spacewalk in order to go ahead and get the station to safe config and protect the people that are outside from being outside too long.

You mentioned Suni Williams is going to take an active part outside the station in EVA 3. That’s a change from the original mission plan. What’s the rationale behind that change?

One of the thoughts is that Suni’s a first-time flyer. She’s also going to be doing some spacewalks while she’s on the increment. The best time to get somebody experienced is in a fairly controlled environment. Here you have the chance, with a few changes to our training load, to have Suni train for a spacewalk with the person that she’ll be doing it with up until the time we launch. Right now, she’s scheduled to do spacewalks with Mike L.A. I don’t remember the last time she would have done one with Mike, but it certainly has been at least a month. By the time that she actually does her spacewalk with Mike, they’ll have not trained together in probably five, maybe six months. So, the upside here is she can train with Beamer up until the time she launches, like any other shuttle crew would. She’ll have a very set timeline, get up on orbit, get the experience necessary to go ahead and do the spacewalks, and then if there was any contingencies later on, where maybe we slipped and she wasn’t able to do the spacewalk with, with Mike, she’ll already have one under her belt before she would have to go out for the first time as the prime EV1 spacewalker.

What’s the integrated cargo carrier, and what’s its purpose?

Image to left: While seated at the commander's station, astronaut Mark Polansky participates in a training session in the crew compartment trainer in the Space Vehicle Mockup Facility at Johnson Space Center, Houston. Image credit: NASA

We call it the ICC; and in a nutshell, it’s just a place to put things on. It rests way in the aft of the shuttle payload bay. On it we will have what we call the SMDPs, excuse me, service module debris panels. It’s to protect from micrometeorites and orbital debris. It’s shielding, in a nutshell. There will be three different sets of these panels and a carrier. During the third spacewalk, Suni will be taking these three bundles of panels and putting them on the carrier, which will then look similar to a Christmas tree, so we call it a Christmas tree. At that point, Nick Patrick will be working the shuttle robot arm, and he will then fly Suni, holding this set of debris panels, up to PMA-3, which is sticking out of the bottom of Node 1. Up there will be a temporary stowage location where we’ll put this. That’s on the ICC. There are also several payloads which will be deployed, once we undock from the space station. And it looks like almost a giant, fat-looking telescope. And it will be resting on the back of the ICC as well.

On flight day three, some time after docking, operations will get under way to get the P5 out of the payload bay and into the hands of ISS. Can you walk us through the procedure for that?

Flight day three is a very challenging day. Well, they’re all challenging days. But, flight day three … right after we dock, we immediately have to do the preps to get the hatches open, go inside. There’ll obviously be some time to meet and greet everybody, and say “Hi” and get a safety briefing. But unlike other missions where you sort of get to enjoy life a little bit, we immediately need to get to work. Part of it is robotics; part of it is EVA prep. For the robotics portion, Nick Patrick on the shuttle side will immediately, with the shuttle arm, grapple P5, which is in our payload bay. He will take it up out of the payload bay, move it way out to the port side of the shuttle, and then start moving it forward relative to the nose of the space shuttle, and eventually farther out to port towards where the station arm will already be in position. Once he gets it there, Suni Williams and Joan Higginbotham, working the big arm on the space station, will grapple the P5, at which point Nick will un-grapple with the shuttle arm and move the arm out of the way to a viewing position. We will have camera views that will be utilized the following day when the P5 install is complete. All of that’s done on flight day three. While that’s going on robotically, Christer, Billy O and Beamer will be getting all the EVA preps done, because we’re going to be doing an EVA the very next day. That means getting all the suits across, getting all the equipment across, making sure it’s all set up, and then doing a procedure called campout. Beamer and Christer will spend the night in the space station airlock at a reduced pressure to help flush out a lot of the excess nitrogen, which they’ll want to do in prep for their spacewalk the next day. So a lot of activities are going on at once.

Another key activity having to do with crew rotation is the transfer of the individual equipment liner kit for Suni Williams. Why is that so important?

Well, two reasons: number one, you need a very exact understanding of who’s a shuttle crew member and who’s a station crew member. If there was an emergency, people need to know where they’re supposed to go. For shuttle crew members it’s very easy. If we have an emergency, we go back to the shuttle. To the station crew, it’s really easy; they normally go towards the Soyuz. But for somebody like Suni and Thomas, well, who’s on the shuttle and who’s on the station? So the official handoff is done with seat liners. As soon as Suni’s seat liner is installed and aboard, she is officially a part of the station crew and Thomas is officially a part of the shuttle crew. Job-wise, what’s going on up there doesn’t matter. But in a case of an emergency, it matters a lot. The seat liner has an actual function. In the Soyuz, which is a much more cramped compartment to reside in, you want the liner for your seat to fit your body. So, those are molded to match the torso or the contour of each individual. Thomas has his, and as soon as Suni’s is in place, then she will more easily fit in the Soyuz.

Let’s move on to EVA 1. Again one of the key goals is to install P5. Can you walk us through how that’s going to happen and touch on what your key duties are for that EVA?

My key duties are to worry, and just try and provide whatever assistance I can. It’s the beauty of being a commander: everybody does most of the work, and you get to kind of sit back and watch, and offer some advice once in a while. I’ve got a great crew in there, and they’re going to do a super job. But the P5 truss will already be on the big arm, on the station arm. Joanie and Suni will be working from the station side, and they will maneuver the P5 truss to a preinstall position way out on the port side of station, all lined up and ready to come in. In the meantime, Beamer and Christer will be coming out the hatch, doing their things and getting out to that worksite at the end of P4. Bill Oefelein -- we call him Billy O. -- is the pilot and he’s also the IV crew member; the choreographer from the inside. The three of them will be working this EVA. Beamer and Christer will move to the end of P4, and they will help provide verbal cues to Suni and Joanie to bring P5 into position. There are some very tight clearances coming in with some other equipment that’s off on the end of P4, and, as you know, or just in case folks don’t know, the robotics on the station is unique because you don’t have actual out-the-window views. Everything you have is by camera. So for very tight clearances, it’s really great to have somebody’s set of eyeballs on the equipment; kind of like you’re trying to get in a real tight parking spot, and you’d send somebody outside to say, “OK, come on back; you’ve got about this much more clearance.” And, that’s what they’ll be doing verbally, telling them what their clearance is and telling them, “OK, I think you need to come a little bit zenith or nadir or port or starboard,” or whatever direction that they need. So, they’ll be doing that as well as some preps to the truss itself. And then Suni and Joanie will fly P5 into position. Once it’s there, Beamer and Christer with the power grip tool, the PGT, they’ll go ahead and start driving the bolts down and putting it in place. Once that’s done, then they’ll start making some connections and outfitting it. That’s primarily how P5 will get installed on P4.

There’s also, an ailing camera on a part of the ISS that’s going to be replaced. What’s wrong with that camera, and how’s that process going to go?

To tell you the truth, I really don’t know what exactly the problem is with the camera, other than that they’re going to be swapping it out. They have sort of the camera assembly, and it’s kind of like a kid’s toy -- some assembly required. We will, in fact, be doing part of the assembly on flight day two, when we’re up on orbit, in the middeck of the shuttle and getting it ready to go. We’ll put it together as best we can, and the rest of the assembly can’t be complete until it’s transferred all the way to station because it wouldn’t fit. So, on flight day three, the rest of the assembly gets done. It will be in the airlock with the EVA crew members for EVA 1. They’ll take it out with them and then be in a position that they can remove the old one and replace it with a new one.

On flight day five, although there’s no EVA planned, there are a couple of key events that are going to happen. One of the solar arrays on P6 is going to be retracted. Why is that being done?

That’s part of this whole reconfiguration of the electrical power system and is a critical thing that needs to be done because on the previous mission, STS-115/12A, they will have delivered the P3 and P4 truss. It sticks out on the port side, and it has a pair of solar arrays very similar to the ones that are up on orbit right now. It also has a piece of equipment called the solar alpha rotary joint (the SARJ, we call it). That allows the thing to rotate, end over end, with the array sticking out. Right now the arrays like this can gimbal about the beta angle. But to rotate it, we have the entire structure that rotates so that they could just rotate like this around the alpha angle. Well, P6, one of its arrays sticks right out this way. So if you were to rotate around the alpha, it would hit it. So, that’s the side that you want to retract that array, and once that’s done, then you can move the alpha joint or the alpha angle. And, why is that important? Because you want to be able to track the sun as much as possible with these solar arrays. You would, in a perfect world, always have the arrays perpendicular to the sun to get the maximum energy off of the sun on the solar arrays for electricity. And so you need to be able to not just gimbal the arrays off of one angle, but to do two at the same time to get the best angles. And so that’s what retracting one of the arrays on P6 will allow us to do.

What can you tell us about the external thermal control system? Loop B is going to be activated that day, I presume from the ground. What’s the crew part in that? Is there any part of it from the crew?

No, actually the crew has no part in any of this other than, I mean, retraction for the array. But, for the thermal system, it’s all ground commanded. What’s critical about these things is that all of the arrays, when they’re in their final place, such as where P3 and P4 will be and eventually where P6 will be, the arrays themselves are outside of the SARJ, this big piece of the truss that can rotate. Because it’s a moving piece, you can’t run a lot of cooling lines through the area that’s going to rotate. So it needs to have its own totally self-contained cooling system. That’s why it will be very important to activate these cooling units outside of P3/P4 to handle all of the arrays out in that area. Otherwise you won’t be able to dissipate the heat that the electronic boxes are going to build up.

On to EVA 2. Can you walk us through, give us an overview of that EVA?

The very big picture is that Beamer and Christer will be outside, and they will very methodically start undoing wiring cables that were done a long time ago and start hooking up other cables, basically rewiring the space station so that it is able to transform from a very early temporary electrical path to the permanent electrical path for the things that are already going to be installed on orbit. Over the course of the EVA, they also will also take two of these CETA carts, which are these big carts that you could put huge boxes and tow along a set of rail tracks. The mobile transporter, which has the big station arm, can move sort of like a little car on a set of tracks. The CETA carts are not going to be in a location that we want them to be. They’re on the wrong side of the mobile transport. We’re going to relocate them to a side that we would need them for later use. And especially if we should have any contingencies that pop up because of problems during EVA 2, we definitely want those CETA carts to be in a particular location; so that’s also a prime task that we’ll be doing.

And for EVA 3, much the same? Or is there much difference?

Very similar, with the exception of the CETA carts won’t be done, but there will be what we call the service module debris panels (the SMDPs) that they will be in the aft of the payload bay, and there’s some assembly required while you’re outside, and then a relocation with Nick Patrick flying Suni Williams, who will be on the end of the shuttle arm holding these SMDPs, and Nick will fly her to a location where she will then stow them.

You mentioned the ICC with the deployables. You're going to shoot those off into space some time after undocking. Can you tell us a little bit about what those deployables are?

They’re DoD payloads, Department of Defense, for various, tracking exercises and scientific investigations. We’re going to deploy two of them on the day that we undock, later in that day. The third one will come some time during the next day. Our job is to get them out of the payload bay, to document how they come out to make sure it all works properly, take good photographic verification of how the deploy went. From there we have absolutely no interface with them at all. It's all done by, the payload folks that, that own them.

Image to right: STS-116 Commander Mark Polansky simulates a parachute drop into water during an emergency bailout training session at the Neutral Buoyancy Laboratory near the Johnson Space Center. Image credit: NASA

I want to talk, if we can, a little bit more about the electrical power system. Could you give an overview basically of how the ISS’s electrical power system works, maybe in a "neck bone connected to the collar bone" fashion kind of a deal?

I guess the simplest way to think about this is the fact that we don’t generate electricity on orbit chemically. We do it through solar power only. So the solar arrays obviously collect the sun’s energy. Then from there we have something called the direct current switching unit (the DCSU). It needs to figure out, “What do I do?” based on whether it’s daytime or nighttime. If it’s daytime, I’m collecting a lot of energy from the sun; I’m going to take that power and part of it I’m going to use to charge the batteries that are just hanging up out there. From there, that power’s going to work its way down to what we call the main bus switching unit. It is going to take this load at a power voltage of roughly 160 volts, something totally unusable. It is going to shift that power to what we call the secondary power system. That is going to take the power and move it in a direction that’s more user friendly. It goes to these boxes called DC-to-DC converter units (DDCUs). And those boxes will step down the power to 124 volts, which is what, on the U.S. segment, we use as the working voltage for our electrical system. It all sort of flows downhill from the arrays. That’s how the system is designed to work. When we have, a night cycle, the only difference is that we’re not getting any energy directly from the arrays. So at this point, the power is still flowing down, but it’s flowing from the batteries to the MBSUs, to the DDCUs, to the ultimate place that it needs to show up. And we have a system in place so that we shouldn’t drain the batteries all the way down during a night cycle. And,when the sun comes back up, the batteries stop draining, they start charging, the power flows again, and so it’s back and forth. It’s always charging, discharging, charging, discharging, but never at a rate at which you’ve discharged more than you charge up.

Before 12A.1, the path of the power is different from what it’s going to be afterwards. How do those compare and contrast?

Right now we have a very simple electrical wiring schematic. We have the P6 arrays, which are not on the port side where they should be but on what we call the zenith, or the top, of the space station. They’re generating electricity just like we talked about, and they’re charging the batteries just like we talked about. The difference is that, once it comes down from there, it goes straight to the DDCUs for conversion and off to where it needs to go. For what we’re capable of doing right now power-wise, it does a fine job. The problem is it’s not very elegant. If you were to have problems it’s very difficult to have power backup schematics and to do cross strapping, where you could have one unit or one box pick up the load for another one that fails very easily. It’s a lot of work to do that. So the main design has these boxes called the MBSUs, the main bus switching units. They are in the S0 truss, and they have never been used. They won’t be used until we’ve rewired during EVA 2. That’s the first time we’re going to wake those boxes up. Now all the power goes through those boxes. Those main boxes have the capability of having primary power with backup power and cross strapping so that, if you’re having a problem getting power from one set of arrays through the right channels then the MBSU has a backup channel; it can talk to another MBSU, and just very simply swap different power channels around. So, that’s what’s going to make this, a fairly unique setup. This is the final, permanent configuration that the electrical power system is supposed to take.

So the MBSUs provide more versatility. What about grounding? I understand there’s one common method that most of us may be aware of, but then there’s another way where the ISS is actually grounded to the space environment.

Right. That’s called the plasma contact unit. If you think about it, electricity in space isn’t that much different from electricity on the Earth. We build up a lot of static electricity, potential electricity, if you will, just from running things through structure. It's the same as if you’re running around the house in the wintertime with your socks on, on the carpet. You kind of build up a static potential in your body. Then if you touch something metal, all that potential energy goes through you to the metal to the ground, which is usually the Earth, and you get a little shock. When we do it at home, it’s not a big deal. When you do it in space, it can be a very big deal. You could get arcing between the structures. You could also, if there’s a spacewalker outside, hurt the spacewalker potentially or damage equipment. So how do we take care of that? One of the ways is we ground all of these units to each other so that you have a very large space station to somewhat dissipate the electric potential and have an even static or potential throughout the entire station. You can still have an excess relative to the environment and have the ability to discharge that way. So there’s a unit called plasma contact unit. It takes a xenon gas and releases it into the space environment. In effect it uses that and space as the ground the same way that we do using the Earth. It’s just a way to reduce electric potential from the station structure.