Preflight Interview: Steve Lindsey

The STS-104 Crew Interviews with Steve Lindsey, Commander.

Q: Steve, I'd like to start by getting you to take us back to your beginnings. Tell me why it is that you wanted to become an astronaut.

A: Why did I want to become an astronaut? Well, when I was a young child, about eight years old, I remember being in the living room, I think in the middle of the night watching Neil Armstrong take the first steps on the moon with my dad on our little black-and-white television, and like most kids that age at that time, we all wanted to be astronauts, and that was probably my first time I really thought about doing it. Over the years after that I kind of faded away and I went off and did other things. When I got into high school, though, I wanted to pursue a career, I had two real interests: I wanted to be an engineer like my father was, I was very influenced by him; but I also wanted to fly airplanes. And so I chose to go to the Air Force Academy, or I was fortunate enough to get selected to go there where I could do both, and I got an engineering degree and then afterwards I started flying airplanes. And then later on in my career I kind of looked at that and I said, you know, I really want a job where I can combine engineering and flying, and what best to do that. And then I went off and was selected to be a test pilot where you do get to combine engineering and flying, and so my two things I've always been interested in I got to do as a test pilot. And then after several years I hadn't really thought about being an astronaut for many years, and I found myself, as a test pilot, now qualified for the program, so I decided, well, what the heck, I'll give it a shot, and so I applied, and again was fortunate enough to be selected, and so here I am now doing this job where, again, I get to combine flying and engineering.

You mentioned that your father was an influence in your life. Talk about your father and whomever else you think either were or are the biggest influences in you getting to where you have gotten.

Well I can't count the number of teachers that obviously have been a big influence in my life primarily in the math and science field that got me interested in math and science, which I think is absolutely critical to our future as a nation. But they influenced me and encouraged me to go where I ended up going. My father and mom, big influences on me: they both grew up during the Depression on small farms, and my dad became an engineer kind of out of the blue -- went on the GI Bill after being in the Korean War, and had that opportunity and took it -- and watching them has probably been my biggest motivation to…they taught me the values and the importance of hard work and really working for what you want to do. So they were probably the biggest influences in my life so far.

Sometimes when people tell the story about what they've done and how I was selected to the Air Force Academy and I became a test pilot, it sounds easy -- is it, was it easy for you?

No, it wasn't easy for me. It's like anything else and I really believe this, that if you, if you're willing to work for something, you can achieve it. But quite frankly, all those things were a lot of hard work; they were something I really wanted to do, I kind of set the goal, and I worked for the goal. But it's also important to note that I tried not to focus my whole life around that goal, like I-want-to-be-a-pilot, I-want-to-be-a-pilot; instead, what I tried to do is focus on the journey a little bit and enjoy that along the way. But it was a lot of hard work; I feel very fortunate and lucky, quite frankly, to be where I am today.

STS-104 is your third shuttle flight, but it is your first as the Commander.

Yes.

How has it been for you, taking the responsibility for leading this group in preparing for this mission?

Well, it's…you know, my first two flights, I flew as a Pilot, and I initially thought, well, when you jump to the left seat as Commander, I knew what the Commander roles were, they're different than the Pilot, but some of them are very much the same in the actual operation of the vehicle. So I kind of thought I knew what I was getting into, but I don't think now, looking back, I knew as much as I needed to know. But being in the left seat's quite a bit different -- the responsibilities are quite a bit different. Having said that it's been a real pleasure and a privilege to lead this crew. I've got an exceptional crew of folks that I can ask to do just about anything and they can do anything; they're capable of any job on the vehicle. And now my job is to kind of keep the big picture in mind, but primarily, just to enable them to do their jobs, because if I just lay the groundwork and enable them to do their jobs, I know we can complete the mission and do it successfully.

Earlier on in your astronaut career, you worked on the development of an upgrade to the shuttle's flight deck instrumentation that's known colloquially as the "glass cockpit"…

Yes.

…it's already installed on the orbiter that you're going to be flying for this mission. Could you briefly describe what this new system is, and tell me what it's like for you to get a chance to "test drive" this system that you worked to develop?

Well, the glass cockpit, I believe this will be the fourth flight of it, on our flight on Atlantis. What it did was, we had a lot of electromechanical flight instruments similar to airplane gauges in the front of the cockpit, and those were wearing out, so several years ago NASA embarked on a project to upgrade all those and replaced all those mechanical gauges with essentially eleven glass cathode ray tube displays or television screens, essentially, to replace all those. So it's turned it all into what we call the "glass cockpit" and took all those gauges and put them on. We've had the additions of or the advantages of, when you do that we can add color and things like that to enhance those displays, so it's real exciting for me to get a chance to fly something that I participated a little bit in. The project, however, I've been working on the last couple of years prior to getting assigned to this flight is now going to replace the computers behind that glass. And that's a project scheduled to fly in about the year 2005, and in that project what we're going to do is, we're going to change actually what's displayed on those pieces of glass into something that's more intuitive for the Pilot and Commander and the flight crew to look at. For example, today when we…when you think of main engines you think of big engine bells and fire coming out of the bells, but what you want to put on these displays in the future are not what the engines look like but how the Pilot and the Commander and the Mission Specialists think of the engines, and I think of the engines as these devices that are hooked up with electrical controls and hydraulic controls and hydrogen and oxygen. You want to display how the Pilot thinks about the machine. And, that's going to be in place, hopefully, in 2005, and maybe I'll get lucky enough to get a chance to test fly that one as well.

Let's talk about the mission that you are about to fly. Summarize the goals of STS-104 for us. Tell us, what is this mission designed to do?

Well, this mission is the last assembly flight in Phase 2, as we call it, of the International Space Station, which is essentially the first assembly phase. And our primary objective on STS-104 is to deliver install, activate, check out, and then finally perform the first space walk out of a new Joint Airlock that's going to enable space walks in both Russian and American suits on this International Space Station.

Before we get into the detail of the mission itself, let's talk a little more detail about this hardware. Describe this Joint Airlock, what its major components are, where it's going to go on the station.

Well, the Joint Airlock is a pressurized compartment, essentially it has two compartments in it: it has something called an equipment lock, and a crew lock. The crew lock is the smaller section, and that's where the two space walking astronauts actually go inside, close the hatch and depressurize down to vacuum, and then open up another hatch and do their space walk on the International Space Station. On the other side of that crew lock is something called the equipment lock, and the equipment lock houses the, kind of the meat of the airlock, all of the systems: it has systems that charge all the batteries that are used on the EMUs, the suits, the spacesuits the astronauts wear; it also includes water for recharge of those spacesuits; it has an entire atmospheric control system that scrubs the carbon dioxide out of the atmosphere and provides nitrogen and oxygen for pressurization and breathing air for the astronauts; it also has computer systems and allows you to work this entire airlock system. One thing that's very unique about the airlock as opposed to how we do space walks today, is that the airlock actually has a depressurization pump. In the shuttle, when you do a space walk out of the shuttle, when you vent the airlock out so the astronauts can go down to vacuum, you actually vent all that gas out to space and you lose the nitrogen and oxygen, so you have to replenish it from inside. With the airlock there's a pump that will actually pump this atmosphere back into the space station, pump it down, and then we open up the hatches, and, when they come back in we open the valves and it repressurizes. But the advantage of that is it doesn't use very much gas, so we save all that gas so we don't have to continually replenish gas whenever you [do] a space walk. If you're docked where we are on the space station and you're looking aft to the space station, the airlock will be located on the Node; if you're looking down the space station, it's on the left side of the Node and just aft of the U.S. Lab.

It's on the left if you're looking from the shuttle…

Yes.

…it's the station's…

Station's starboard, or the right side, yes.

Another component of this whole package has to do with the repressurization and the gas that you referred to. It's a set of High Pressure Gas Tanks. Explain the role that they play.

Well, we have two nitrogen and two oxygen high pressure, about three-thousand pounds per square inch, gas tanks, and these gas tanks will be installed on the outside of the airlock-we're also carrying those up with us. The purpose of those is to replenish atmosphere, because we do lose maybe 10% of what we normally would lose on a normal space walk, so we do have to replenish that. Additionally the oxygen provides breathing oxygen for the rest of the space station if they have to go on a portable masks or something like that, if there's some contamination or something like that, so it provides emergency oxygen. And the nitrogen and oxygen can also be used to just pressurize the space station, so there's several roles of this gas. Additionally, these four tanks can actually be recharged from the space shuttle, so when future space shuttles dock with the space station we can connect some lines and use shuttle oxygen and nitrogen to repressurize those tanks.

These are pretty large apparatus, aren't they?

Yes. They're quite large; if you imagine your, and we call them, in fact we call them doghouses--if you imagine your typical doghouse, that's about the size they are, of a large dog. They weigh about fifteen-hundred pounds each.

Now, if we can compare using the airlock on the space shuttle, what are some of the differences that we would notice in the use of this new airlock on the space station?

Well, one of my, I've already mentioned before, and that is that it has a depressurization pump that allows us to save the gases as we depress it down to a vacuum versus the shuttle today, where we actually have to open hatches. So that's one of the differences. The other, one of the other major differences for assembly operations and for docked operations is that the shuttle airlock is in the direct translation path between the shuttle and the space station, so right now when we do space walks out of the shuttle onto space station we actually have to close hatches between the two vehicles, and when we do the space walk the hatches are closed so that the station crew and the shuttle crew cannot interact directly during these space walks. But with the airlock we'll essentially close the airlock off on the space station, we'll leave the hatches open between the shuttle and the station, and for assembly operations it's going to make things simpler in the future for us to do.

So, we won't see this opening and closing, and opening and closing, of the hatches throughout a docked phase?

Typically…in some cases we may see that but primarily the intent is, once this thing is installed and it's working properly all of the docked space walks will be done out of the station airlock, so the hatches will stay open. And that will be a big operational advantage for us.

I'm going to get, ask you to take us through this several days here to, and the first step, in order for you to deliver your cargo is to bring the shuttle and the station together on orbit. Talk us through the plans for the shuttle's rendezvous and docking, and describe particularly what you will be doing.

OK. Well on the third flight day, the third day up there, we're going to do what's called a rendezvous. And we will launch into plane with the space station and over the first couple of days, we'll be several miles away and we'll do what's called phasing burns to get us closer to the space station. On the rendezvous day we'll start at a point about 48,000 feet behind the space station, we'll do a burn to allow us to intercept with the space station; after that burn we'll do a series of small correction burns and essentially get the shuttle into a position of about two-thousand feet below the space station directly below it. At that point as Commander, my job, besides doing those burns and working with the Pilot on those burns, is to do the manual flying of the vehicle to docking. So when we get underneath the vehicle, underneath the space station, about two-thousand feet, then I'll take over manually, and we'll fly, staying underneath the space station, to a point about six-hundred feet or so underneath the space station. At that point we'll do a 90° flyaround to the front of the station, and when we get up to the front of the station we'll be about four-hundred feet in front of it, and from then we'll just drive straight in, in front of the station, and come in to a docking. And the whole process will probably take us four or five hours from the time we start to the time we finish. So, my job on the flight during the rendezvous phase is, again, to do the manual burns with the Pilot and then when we get to the docking phase then I step into the aft station and fly the vehicle from the aft station with the Pilot and the Mission Specialists assisting from the front of the vehicle, and drive it into a docking.

For a pilot, is that a highlight of this mission?

Oh, there's no question it's a big highlight of the mission -- it's something that I've always looked forward to doing, I've always wanted to do, to have the opportunity to do a docking, and now it looks like it's going to happen. So it should be fun.

As you've described it, you're going to fly up in front of the station, in its direction of travel; does that mean that you, in essence, once you get out there, that you just slow down and let the station come to you, or do you fly back toward it?

Actually what happens is…it's kind of hard to explain, but what we do is, we put a rotation rate on the vehicle which makes the vehicle want to rotate so that it's pointing in front of the station. Then I do some translational pulses to put it up there. And once we get in front of it, if I didn't do anything, it would probably just hang there in front of the vehicle at about four-hundred feet or so, so we actually pulse in a little bit, get a little bit of speed, and move it slowly toward the space station. It's a very, very slow closure rate, about two-tenths of a foot per second, and we want to be very, very slow coming in to docking…when you're putting two hundred-plus-ton vehicles together, you don't want them to hit too hard, so you have to control that rate of closure all the way in.

The day of docking, after you've completed this task, you and your crew and the space station crew are all going to be quite busy in those first few hours. You've got an item on the timeline that's called a "dry run" of the airlock installation. Can you tell us what's on tap for this? Why is, I mean, you've practiced it here on the ground -- what is it that you're going to do differently once you arrive on the station to practice?

Well, one of the unique challenges of this flight in particular is -- and we'll probably get into it a little later -- but every crewmember, both on the station and the shuttle, has a critical role in all of these space walks in assembling this airlock. This will be the first flight where we're actually using the space station newly installed robotic arm to install the airlock, because the shuttle arm can't actually reach that position. So, and the other unique thing is that the Expedition 2 [crew], who we'll be working with, is already on orbit and they'll have been on orbit about three or four months before we ever get there, so our last opportunity to train with them was last February, or actually, January, prior to their launch. We trained as much as we could with them, but they won't have seen the tasks in about four months, and we won't have trained together for about four months, and they will have never flown the space station robotic arm in the positions we're going to be in with the shuttle attached and the airlock there. So it's real important for us, and we agreed early on that we really wanted to do a dry run, and during the dry run what we're going to do is, we're going to be on the shuttle side, they're going to be on the station side; they're going to pull the space station arm out, and they're going to practice the motions down to the airlock and back up to the install position. The other critical part of this is not only are we depending on them for the space station arm but they depend on our camera views because they only have a couple of cameras up there, and they're going to use some of the cameras in our payload bay. So we have to ship those camera views across these closed hatches that we talked about before, so we're going to practice that coordination as well. So there's a tremendous amount of coordination between the crews, and by doing this dry run it enables us to essentially practice and do one last training session the day before the space walk.

The first of those space walks is scheduled for the day after you arrive. First off, tell us who's going to be doing what, both on the shuttle and on the station.

OK. Well, I'll start on the space station. Yury's obviously the Commander of that mission, and he'll [have] overall responsibility on the station side with all their activities that day. Susan Helms is going to be the space station robotic arm operator, so her primary job is to fly the robotic arm; she'll be unberthing the airlock, maneuvering it into position, and then berthing it onto the space station. Jim Voss will be assisting Susan in that and also working the cameras and he'll also be working something called the Common Berthing Mechanism, which is the device that attaches the airlock to the Node, the berthing mechanism, and he'll be working that as well. On the space shuttle side Mike Gernhardt and Jim Reilly are our two space walkers, and they'll be out the door; during the first couple of hours of the space walk they'll be doing some preparations in the payload bay to get the airlock ready for unberthing. They're going to be doing things like removing some covers off the berthing mechanism, disconnecting some heater cables, and doing some preparation work so that they can reach in, grab the airlock, and pull it out of the bay. Charlie Hobaugh, my Pilot, is the IV crewmember, so he's the IV, and the backup space walker in case something happens to one of our guys and they can't go out and he'll be choreographing or orchestrating the entire space walk, and you'll hear his voice on the radio quite a bit as he talks to them, making sure they're getting their tasks done and keeping track of the timeline and the choreography of the space walk. Janet Kavandi is our primary robotic arm operator on the shuttle side, and during the first part of the space walk she'll be maneuvering Jim Reilly on that arm as he goes about and does his tasks around the payload bay. After that point, when Susan pulls the airlock out, Janet will be using the space shuttle RMS to provide views for Susan both during the unberth and also provide something called a Space Vision System solution when she goes to berth the airlock. Something else unique about our flight is there is no direct view cameras when we go to attach the airlock to the space station, so we're using a Space Vision System, which essentially uses photography to determine the relative position of the two -- the airlock and the station -- and we'll be shipping that solution across to them to assist them in berthing the airlock.

Because they won't be able to see it either?

They won't be able to see it either: they have also their version of Space Vision System that they'll be using, but we're going to, it'll be the first time, again, that that's ever been tried so by having two solutions available, if one of them doesn't work, maybe the other one will, or we can compare the two. And if both of those fail, then in the last part of the space walk Jim and Mike will climb up the stack to the airlock and actually give a verbal guidance to Susan as she brings it in, telling her which way to move the arm and how it looks. So we have several methods for getting this airlock berthed.

Now, you omitted mentioning what you were going to be doing -- you do have a particular role to play during the space walk.

Basically my job during the space walk is to pick up everything that everybody else doesn't have time to do. I'll be doing all of the camera manipulation back and forth with space station crew, I'll be picking up anything going on the shuttle that is not directly related to the space walk but again, as I said before, what I try to do, during all these tasks, is stay out of everybody else's way and enable them to do their job. And my primary job as Commander is to try to keep the big picture in what's going on, so I do as much as I can to stay out of any of the specific roles. Now, I am the backup robotics arm operator and I may do some of the arm flying, but Janet's going to do the majority of that.

You touched on a couple of the steps in the process during this first EVA; take us through the rest of the way. What are the big milestones that we'll see?

On the space walk, the big milestones [are], again Jim and Mike will come out of the airlock, our airlock, they'll go into the payload bay. Mike's going to go back and remove something called the "shower cap," and it's a big cover on the berthing mechanism, and the seals around the berthing mechanism -- we have to make a pressure seal with the space station, we have to keep that very pristine -- so he has to pull off those covers that have been on there since launch. So he will gather all that up, he will also disconnect some heater cables -- because the airlock has water and uses water cooling we also have heaters that are powered by the orbiter to keep those lines from freezing and so he's going to disconnect those and has to disconnect those before Susan can unberth the airlock. Meanwhile, Jim's going to be on the robotic arm, Janet will be flying him around, and he's going to be installing some equipment on the airlock that will enable us to put on the High Pressure Gas Tanks later on, and basically just doing some prep work around that airlock. When they get that done, and all that should take about two hours, we think they're going to both move forward to put some of this equipment away, and once we get the shuttle arm out of the way and then forward far enough, then you'll hear a call that the space station crew is "go" for unberth. And at that point Susan's going to bring the space station robotic arm in for a grapple. Meanwhile, because it's such a lengthy space walk, or planned lengthy space walk, Jim and Mike will actually go back in the airlock and go back on external hardline power and oxygen to preserve some of their battery while Susan unberths the airlock. So Susan will unberth the airlock with the space station arm, and she'll move the airlock up to the pre-install position on the space station, just on the other side of the Node, get it into position there. So we'll all, so you, at that point or in that phase of the EVA you'll hear all radio calls between the two robotics operators because we'll have two arms in motion at the same time and there's a lot of coordination involved in that, a lot of collision avoidance we have to watch out for, and one of the bigger challenges is sharing the camera views between both the shuttle arm and the station arm. Once she gets in position and we have a good solution with our systems, and we think we're good, then she'll bring it in to berth. And once she's got it berthed and attached to the space station, then our two space walkers will go back up the stack and hook up another set of heater cables, again to keep the airlock from freezing. And that's the gist of the EVA; right now it's timelined at about seven hours and fifteen minutes, and…

So they've got to unplug it from the payload bay and then plug it back…

Plug it back in, yes.

…in on the side. The heavy lifting of this operation is being done by the station's new robotic arm. Talk about how the unique characteristics of this new Canadarm are being employed in this task.

Well, the Canadian arm is unique: different than the shuttle arm; similar in some ways and different in a lot of ways. It has multiple, more degrees of freedom, if you will, than the shuttle arm, which means it can maneuver over a wider variety of positions than the shuttle arm. It also is unique in that it can reach the location we're going to, whereas the space shuttle can't. Again, this will be the first true operational use of this new arm again with a space station crew, so it's going to get quite a workout.

For the two days after the airlock is installed on the side of Unity, you all are scheduled for a lot of work inside the shuttle/station complex. Without any specifics tied to times or which one of the days, but what is the job to be done here? What sort of activities have to be done, and how does it fit in to the overall plan?

Well, once we get the airlock installed and get a hard, we call it a "hard mate," so you have a pressure seal with it, one of the first things that's going to happen is we're going to open the area called the vestibule, which is the area between the Node and the airlock, with the hatch still closed, and in there we're going to connect a whole bunch of jumpers: electrical jumpers to provide power to it, water lines to provide cooling and heating to the vehicle, computer lines, things like that to make it functional. While we're doing this we're also going to be doing leak checks to make sure that we don't have any leaks, that we have good seals all the way around, and the hatches are sealed. Once we have a good leak check complete we'll go ahead and open the hatch and go into the equipment lock, which is the larger section, and we'll start setting up computers in there to run the systems; we'll be turning on systems, we'll be installing things like smoke detectors, installing other umbilicals to give us some redundant heating capability, and just hooking up everything inside there. At some point during there we're also going to move a hatch. We have a hatch on the equipment lock, on the outside, that we're actually going to move in between the equipment and the crew lock, which will provide us the two separate compartments to use during the space walks. And then we'll do a whole bunch of more pressure checks with that just checking it out, and obviously the eventual goal of this is to get this airlock fully functional so that we can do space walks out of it. It'll be a very busy couple of days.

After that busy couple of days you're scheduled for a second space walk: your two crewmates, Gernhardt and Reilly, out of the shuttle, the shuttle's airlock, again with the station's arm playing a big part in what goes on. Talk us through what is supposed to happen on this space walk, outside the station as well inside.

Well, on the second space walk what we're going to do is we're going to install the first two of those high pressure nitrogen and oxygen gas tanks. So what will happen there, again, this will be another coordinated EVA with the hatches closed…roles are very similar with Susan Helms on the space station robotic arm, and Jim Voss working with her, and the same roles that I described previously for Mike and Jim and Janet on the arm, but the space walk itself is a little bit different. In this one they'll come out of the payload bay and the first thing that'll happen is, Jim Reilly will start climbing up the stack, up to the airlock, in prep, and get the airlock prepared to receive the first tank. Meanwhile, Mike's going to go back to one of the tanks and he's going to prepare that for release, and Susan's going to bring the space station arm RMS and grapple this tank. And once he's released the tank then Susan's going to maneuver this tank up to the airlock. Meanwhile, once the tank is released, Mike is going to go over to the side of the payload bay, he's going to hop on the space shuttle arm and Janet's going to fly him up to the Node so he doesn't have to climb up and down the stack. So we'll be using the space shuttle arm just like an elevator in this case. We'll take him up to the Node, he'll drop off there, he'll go over to the airlock, and then Jim and Mike will get in position to receive the tank. And what Susan'll do is, Susan will maneuver the tank to a position just above their heads, and then they're going to talk her down, do what's called a GCA -- we call, we use the word GCA, or ground control approach -- but essentially it is, they will guide Susan in, tell her to bring the tank down, and left, and right, and rotate it, and then at some point they're both going to reach up and grab this tank, and then they'll give Susan the command to release the tank; she'll release the tank off the arm, and they're actually going to physically take the tank down and latch it into place…a fifteen-hundred-pound tank. Once we get that tank done, then Mike will ride the elevator, or the arm, back down, get the second tank, Jim will stay up there and prepare the next site, and they'll get the second tank up. And so that's the goal of the second EVA.

Then you've got another day's worth of work inside…similar to what happened before the second EVA?

Yes, in between the, yes, the day after the second EVA we'll be doing a lot of nitrogen and oxygen tank hookup and checkouts, making sure the flows work, making sure the tanks are hooked up properly, and primarily preparing the airlock itself for the third and final space walk, which we're actually going to use the space station airlock to go out of. So, we'll be transferring spacesuits across -- Jim and Mike will be transferring their suits across, checking their suits out in the airlock, and getting prepared for that third and final EVA.

What is the reasoning behind having the shuttle crewmembers conduct the space walk from the station airlock? Is it simply to give it a test?

Primarily the reason we're doing the third space walk out of the ISS Joint Airlock is, it's kind of the graduation exercise, if you will, for the airlock. We have all this installation checkout to do, and to fully check it out in the end what we'd really like to do is to be able to do that space walk out of there because if we can successfully do a space walk out of the airlock, then we'll not only know that it works and it's ready for Expedition crews to use and other shuttle crews, but also, if there are any problems, we can identify them as we go through this process. Having said that the way we're going to run this mission is, we have a specific plan for activating this airlock and checking it out; if we get behind on our timeline or if we run into any problems at all, we are protecting enough nitrogen and oxygen on the shuttle to do this third space walk out of the shuttle. So what we're not going to do is rush things to ensure we get the third space walk out of the airlock: if there's any question in our mind at all, we will go out of the shuttle and do the third one out of the shuttle.

And what are the tasks that are planned for the third space walk?

Well, on the third space walk we're going, the plan is to deliver those last two nitrogen and oxygen tanks. And essentially the way we're going to do it is the same way we did the first two, except this time we're starting from the space station instead of starting from the shuttle. So, for Jim, it makes things easier for him because he's already on the airlock and he'll just stay there and prepare the third and the fourth sites for the tank; for Mike, he's got to jump on the elevator at the space station, ride it down to the shuttle and back. So, other than that, it's basically the same thing.

Are there any other significant differences about how you conduct the space walk by virtue of the fact from which airlock it comes from?

Yes, there is. One of the big advantages I mentioned earlier is that the hatches are open now so for the third space walk our hatches will be open. What I didn't mention before is, previously, the reason we go "hatches closed" for the space walks is not only because we vent our airlock into space, and that's in the translation path, but also we do something called a 10.2 depress, which is the equivalent of taking the cabin pressure up to about nine-thousand feet elevation. And we do that about twelve to twenty-four hours prior to each space walk, and the reason we do that is just like when you're doing deep-sea diving and when you come up too fast, you risk decompression sickness or "the bends;" we have the same risk when our guys go out and space walk in spacesuits, because they're the equivalent of being at 35,000 feet altitude on 100% oxygen. So what we need to do is get all the nitrogen out of their system, or as much as we can, prior to them getting into the suits. So we've always closed the hatches, go down to 10.2 psi, and then go out for that purpose. One of the unique things about this new Joint Airlock is that we're working on a new protocol, and it's called a two-hour prebreathe protocol, and it's been developed by Mike Gernhardt, who's one of my crewmembers and…interesting thing about Mike is, he is a former deep-sea diver, he's got thousands of dives, and he's one of the world experts in this area. And he's assembled a team and been working for the last three or four years on this, what's called a prebreathe protocol, and the idea behind it is, how can we get away from having to do essentially a campout, or a twelve- or twenty-four-hour campout, at a depressed atmosphere, and is there another way we can get nitrogen out of the system faster and do these space walks -- well, his team has been working on something called a two-hour prebreathe, where they go into the ISS airlock, they close the hatch, they depress it to 10.2 psi, just like we do on the shuttle, but instead of being in there for twelve to twenty-four hours, locked in or camped out they do just two hours in there. And what they do is they add some exercise and they breathe some 100% oxygen, and instead of taking twenty-four hours they take two hours; then they get in their suits, put the suits on, and we can open it back up. So we hope to use that on this flight and test out that method, and he's done a lot of research with a lot of universities around the country; the data we have so far shows that this is one of the safest protocols ever developed. So we're optimistic and we really hope we get to do that on this flight.

With all that work completed, you're scheduled to conclude a solid week's worth of docked operations. Once the hatches are closed for a final time, describe what happens as the shuttle departs from the station and flies around it.

Well, once we close hatches for the final time what we're going to do is prepare to undock. And in this case, the roles are reversed: my Pilot, Charlie Hobaugh, will be flying in the aft station, he'll be doing the manual flying, and I'll essentially be doing his role in the front, which is monitoring the vehicle systems and kind of coaching him, just like he coached me on the rendezvous and docking phase. So Janet and Mike Gernhardt are our primary docking system operators, they'll be actually doing the physical undocking from the station; once we're separate then Charlie's going to back the vehicle back to about 450 feet or so away from the station, and he's going to start a flyaround and just do a big circle around the space station -- probably one or two laps, depending on how much propellant we have -- and then when he's done with that then he'll do a couple of separation burns and we'll separate away from the station. So it's his first opportunity to fly the vehicle.

The rationale for flying around the station, rather than unhooking and just leaving…

There's a couple of reasons why we want to do a flyaround around the station… we do a lot of photo-documentation of it each time we build to note the changes to the station; engineers and scientists can get a lot of information on how the station is doing just by doing the pictures as we fly around. On our flight we're also carrying a IMAX 3-D camera out in the payload bay -- several flights have been carrying it -- and we're doing it for, eventually they're going to do a movie on space station assembly, so we'll be doing a lot of documentation with that camera as well. The other thing it provides for Charlie in particular, is a chance for a Pilot to fly the vehicle. And which is why I would like him to do that. So he gets a chance to feel what the vehicle flies like. For myself, I've never had an opportunity to fly the vehicle on my previous two flights, so when I go to do the manual phase of rendezvous, it'll be my first time flying the vehicle. But by giving him this opportunity, eventually he'll probably be sitting in my shoes as a Commander someday -- it gives him experience and confidence in flying the vehicle as well.

The completion of your mission, as you mentioned earlier, marks the completion of Phase 2 of the International Space Station program, the "some assembly still required" phase, and it'll be the start of the scientific research phase. Finally, tell me how the science that is to be conducted on board ISS is going to contribute to our lives on Earth and to our future exploration beyond Earth -- and tell me how you feel about being a part of making this happen.

Well, first of all, it's a real privilege to be a part of this; I was really surprised and pleased when I found out I was going to get assigned to one of the initial assembly missions so it's really, these are really, really exciting times here at NASA. We're doing stuff we've never done before, and these assembly missions are very, very challenging and complex, and it's just a privilege to be a part of it. But, on my last flight, we were up for about nine or ten days, and we were a science mission, and we had probably eighty-five experiments on board, and we got all kinds of science. But we had to come home after nine or ten days: now, we couldn't stay up any longer, we didn't have any power left, and we didn't have any oxygen left, we had run out of food, we had to come back. The unique part about the space station is, imagine you could take those eighty-five experiments -- and many of our experiments were things like osteoporosis studying how bones grow and how bones decay as you get older, a lot of cancer-treatment drugs, AIDS-treatment drugs, things like that -- and you can get some information after nine days but not as much as you really want, but imagine taking all those experiments and being able to run them for months at a time. So in terms of benefit on Earth, the science benefits are going to be tremendous. You know, you can try, the other thing about, when we go up and we do research in space or research at a university, you may try a thousand different things, and 999 of those may fail. But the one success is going to make it all worth it. And I don't know what that success is going to be, but we're going to have it. And that's what it's all about, and it's about making life better here on Earth. For the long-term exploration aspect, we're going to learn a lot more about what it's like to live in space for long durations. We're going to learn things about, do we need an artificial gravity if we go long duration, up to Mars or some other planet? How do we live in space? What's the psychology of living in space? How do you, how do three people or six people get along for four months in space in a very alien environment with, you know, no 7-Eleven to go to or anything like that. So there's a tremendous amount of gain to doing that. And finally the exploration aspect, that's part of our human nature: we want to explore, we want to experience new things. We're all in this business because we like that, we all believe in the mission, and the benefits to that, in terms of inspiring young people, I hope we can do…and old people, and everybody, you know, around the world, in the international cooperation aspects of this. I think the benefits of that are difficult to measure quantitatively, but I'll think they'll be there.