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Preflight Interview: Michael Gernhardt

The STS-104 Crew Interviews with Michael Gernhardt, Mission Specialist.

Q: Mike, tell me why you wanted to become an astronaut.

A. Well, that's a good question -- that goes way back to my early childhood, where my first love was the ocean. I got fascinated with fishing and scuba diving at a very young age, pursued that very intensely throughout my childhood. I guess around 10th grade in high school I started getting interested in physics, and at that time, Skylab was up in space and the underwater habitat project, Tecktite, was going on beneath the ocean. And I kind of put the two things together in my mind at that time and said, you know, living and working under the ocean is very similar to living and working in space, and the first love was the ocean, so I stuck with that, you know; went on to study physics and math and things of that nature to keep my options open as far as eventually becoming an astronaut, but, I pursued a career as a commercial deep-sea diver, was involved in heavy construction all over the world doing deep, helium-oxygen, surface and saturation diving and commercial diving. And, again, my first love was the ocean but I had this long-term goal to be an astronaut, and I actually convinced the Board of Directors of the company that I worked for, Oceaneering, to allow me to start a company called Oceaneering Space Systems to transfer all of this subsea technology that we had developed in terms of how to work and perform a sophisticated task underwater, the life support systems, how to work with robots and divers in a cooperative fashion. And, so, I started this company, Oceaneering Space Systems, and, in the meantime I was continuing in my spare time to finish my Ph.D. degree in biophysics, or bioengineering actually…working on new decompression procedures which I'd worked on my entire career in commercial diving, and I was starting to apply that to astronauts doing space walks. So I finally finished that up and then got selected to be an astronaut.

Do you remember what it was that made your first love the ocean?

Definitely. It started out, my dad was really into fishing, and he took me, I guess I was probably four years old, and we went down to a place called Marco Island, Florida, and I went fishing and, you know, caught these fish and it just…it was fascinating because I think it was the intrigue of really not knowing what you were going to catch and looking down at the ocean and I just had this desire to learn how to dive and to get underneath the sea and learn all that I could about it. And, so that's what got me interested in the ocean and fishing and then diving and then, you know, if you think about diving and the kinds of things we're doing, you know, we're in suits, diving at great depths, dealing with sophisticated life support systems; it's very similar to space flight. And, like I said, some time about high school I put those two things together and set a distant goal.

We'll talk more about it in a moment, but along with your career as a diver, on your first shuttle mission you conducted a space walk. You've said that those are similar -- can you compare, for those of us who do dive, how does that compare to the feeling of walking in space?

Well, I think on one level they're very similar in terms of doing, like, commercial diving, where you're doing a construction project and you have to think about every little task that you're going to do: we had umbilical hoses, astronauts have tethers, you have to keep your umbilical hose and your tether clear, and sort of the thought processes are almost identical. You know, you try to design the task to make it as easy as you can, because it's a difficult environment to work in. Physically they're very much different. In the case of diving, we're exposed to the ambient pressure conditions, typically wearing a wet suit or a hot-water suit, so you've got no delta pressure across the suit so it's much easier to swim and work and so forth. Then again, underwater you're dealing with currents, typically very low visibility when you're working down on the bottom of the ocean, you have mud in your eyes and so forth, so that makes it more challenging. A space walk, first of all, you're working in a pressurized suit, so the suit is pressurized to 4.3 pounds per square inch, which is about the same pressure as a football, so every time you move you're fighting this pressure of this suit, and that makes it very hard, particularly within your hands and wrists and forearms, where actually all your work is going on. The term "space walk" is probably a misnomer because we're actually walking with our fingers, like you do in the Yellow Pages or something, but so that the forces are different. And then everybody says, well, in space, you know, it's microgravity, you don't weigh anything, and that's true, you don't have weight like you do on the Earth but you have mass, and between you and the suit, you weigh about five-hundred pounds. And that inertial mass has to be well controlled. If you start moving fast, you know, you'll go tumbling out of control in a second. And so you have to be very, very light with your touch on your fingertips, and you have to constantly sense what your body's doing. If you feel like you're pitching up with your feet, you need to reach out and touch and null that rate. And every once in a while you find a sweet spot where your forces are all lined up with the center of mass, and you just glide, but it's actually a lot of work to translate, even though you are weightless. And so, between the inertial dynamics and the fact that you're fighting this suit the whole time, it makes it in many ways harder than diving, where you don't have those issues to deal with.

While we're on the subject of the space walk, the space walk that you conducted on STS-69, with Jim Voss, who's circling over our heads…

Sure is, yes. …

as we speak, was part of an ongoing evaluation of tools and techniques that were being developed to use to assemble the station, which you're about to do yourself. What do you feel are the most important things that were learned from the Development Test Flights, and how are they, in fact, being implemented now?

Well, that was a great series of EVAs. I think there [were] at least five, right off the top of my head I don't know exactly, but what we were trying to do is establish all of the basic techniques and building blocks of hardware that we'd use to build the space station. STS-69, we basically had almost every kind of connector that we're using on the space station -- electrical connectors, mechanical fasteners, some fluid connectors, ORU box changeouts -- so many of the things on the subtask level that I'm going to do on this flight I've already done on STS-69. Probably the most significant thing to come out of that was this device called the Body Restraint Tether, which was an idea that I had had for years, before I came to NASA, and then working with a great team of engineers we got it built. And the Body Restraint Tether is this little third arm that comes off your suit, and there's a lot of cleverness in the design but basically it clamps on to a handhold and it provides a force reaction path. And between that and your second hand, it gives your third hand the ability to work with a high level of restraint, and it prevents you from having to use these Portable Foot Restraints. Now, the Portable Foot Restraints, or PFRs, are a lot of overhead -- you have to translate with them, you have to install them in these sockets, you have to set them up right, then you get in them. And a lot of the tasks we have are not that long -- maybe five minutes here, ten minutes there -- whereas it might take fifteen minutes to move this PFR. And with the Body Restraint Tether you can hook it on and work really easily. And Jim Voss and I got to evaluate that -- it worked great in space, it was every bit as good as I ever hoped that it would be. And it's a real pleasure to listen to the crews coming back from these assembly missions, and…I think Mike L.A. was saying, hey, if you've got more than ten seconds' worth of a task to do, go ahead and hook up your BRT, because it's going to make it easier. So that was probably the most significant thing to come out of 69.

You've made a couple of references to it; let me get you to do it more specifically. Talk about the steps in your career that led you to becoming an astronaut -- back to, you were interested in the ocean and became interested in studying physics; how does it get from a kid studying physics to where you are today?

Well, again, I started out in scuba diving, I got interested in physics in high school, still just interested in the ocean, wasn't quite ready to go down, you know, the aerospace path, but in my own mind working undersea was providing me with the background that I thought I would need eventually to become an astronaut. I went off, I taught scuba diving, down in the Virgin Islands in the summers, last summer in high school and through the first couple of summers of college; I got my Coast Guard captain's license and ran a charter boat down there; all the time studying physics and math at Vanderbilt, and then, finally got to the point where I'd done pretty much everything you could do with scuba and I wanted a bigger challenge, and so I applied one summer to work as a commercial diving apprentice out in the Gulf of Mexico, which is not something that… usually you have to go school for a couple of years to do that but I sort of talked my way into a job because I had a lot of diving background. In fact, this company I interviewed with, they said, all right, if you can pass this test we'll hire you, and I did great on the test. So anyhow, I worked, as an apprentice commercial diver, and was fascinated with the challenge of deep diving -- I mean we were doing up to a thousand foot dives in very complicated life support systems and so forth. So, when I actually graduated from undergraduate school I wasn't sure which way I wanted to go: I mean, I knew I wanted to be an astronaut, I knew I wanted to follow a scientific career, but I wasn't ready to commit to a certain graduate school or medical school or whatever, so I went off and spent five years working as a commercial diver…the first job I had on that, after I got out of school was down in Peru; we were rebuilding a series of platforms that were falling over -- they were completely rusting apart and falling over -- and I was the engineer and diver on the job, and we were basically rebuilding them one brace at a time underwater. So I got fascinated with all that, had a lot of good influence, I think, from my mom who kept saying, you need to keep getting your degrees, because she knew I wanted to be an astronaut, so I went back and did my master's degree at University of Pennsylvania, and then came back to work and while I was doing my master's, I was on the compressed course because I had done some graduate courses as an undergrad, so I finished that up in ten months but my advisor at the time was a guy named Dr. Lambertsen, who's sort of the world's foremost authority on all this, both hyper- and hypobaric physiology; he convinced me to stay on for three more months and study to pass my Ph.D. qualifier exam, which normally you'd take after your second year of the program. So I studied real hard, and I aced that test, and then I went back to work, but I had passed what I needed to get my Ph.D. and then, I had an ongoing project with the British government to develop new decompression tables for diving in the North Sea. And I had previously developed this new model of how bubbles grow in your tissues, and so that was an ongoing project that took about six years; we had collaboration with the U.S. Navy, the British Navy, the Canadian Defense and Civil Institute for Environmental Medicine, so I got all this great data and ended up in parallel with that starting the Oceaneering Space Systems company, and then, you know, finally finishing up my Ph.D., and coming on board here at NASA.

By the time STS-104 launches, it'll have been about four years since you and Jim Reilly were assigned as space walkers for assembly mission 7A. Has that long period of time, do you think, helped you or hurt you get prepared?

I think it has helped, ultimately, in the sense that our flight was considered one of the highest-risk assembly flights in the initial assembly sequence because of these high-mass, high-pressure gas tank ORUs, and they had been carrying that as a robotics task for years, and right toward the very end, right before we got assigned, they said, you know, we can't place these things with the robot, and so they threw it over the fence to the EVA community, and Jim and I were fortunate enough to get assigned to this flight. And when I was assigned, they really didn't have any designs, any detailed designs, and that was great because we were able to work very closely with the Boeing engineers right from the outset. And I made the comment then, and I think it still stands now, I told the whole Boeing team, I said, the success of this mission will be made in the next six months -- and that was four years ago -- with how we design these tanks, because they were over two-and-a-half times the mass of the largest ORU they've had on Hubble, and with some very different techniques with how we handle them. And so that was a great relationship; they were very cooperative in terms of taking our design concepts and working with us. We built mock-ups, we got in the NBL, we evaluated them, we worked back and forth, and -- knock on wood -- I think we've got a design that's actually going to work quite well. And, without that time, without that lead time, we might've been stuck with something that would've been an uphill battle.

Let's talk about the mission. Summarize the goals of STS-104: tell me, what's this mission designed to do?

Well, the main objective of STS-104, ISS 7A, is to install the international Joint Airlock on the space station, to install the four High Pressure Gas Tanks -- that would be two oxygen, two nitrogen -- to activate and checkout the airlock, which is no trivial task in itself, and then to make the first space walk from the Joint Airlock, and demonstrate the viability of the whole process and sort of usher [in] the space station era of EVA.

Well that sounds very simple, Mike.

Yes, it is -- we hope!

Let's talk about the hardware. Take them one at a time, start with the Joint Airlock: tell me about what it is, its major components, where it goes on the station…

OK. It's…the term Joint Airlock means that it's applicable to both U.S. suits, the EMU, and to the Russian suit, the Orlan suit. It's different than what we've had on the shuttle in the sense that it consists of two components: there's the equipment lock, in which we have all the servicing functions for both suits…this is all the resupply, the battery chargers, we're actually using a new device called Metal Oxide for removing the carbon dioxide from the suits, and it's a [regenerative] device and there's a special oven in the equipment lock that processes this and allows us to reuse it each time, as opposed to having to carry up, you know, unique consumables, which is a very big consideration, for space operations, on a space station. So that's the equipment lock. And then there's the crew lock, which is the part that actually depresses to vacuum. And that's very much like what we've had on the shuttle -- in fact, it's almost the same size, identically. The other thing that's unique is that we have this reclaim pump: whereas on the shuttle we would actually vent the gas from the crew lock out to the vacuum of space and then lock out, on the international airlock, we have this reclaim pump that will actually pump down the crew lock and recover 90% or more of the gas. And when you look at a space station with limited logistics and limited supplies -- you know, it's not coming home every two weeks like a shuttle mission does -- every bit of that consumable counts. And so we're going to use this reclaim pump to reclaim most of the gas -- we'll actually pump it down to around five psi, maybe a little bit less than that, and then we'll just vent that last bit of gas overboard.

So you're saying most of that gas, instead of being vented overboard, is being, if you will, vented back inside the station?

Right; it's being pumped back into the Node.

In order to keep that portion of the station pressurized and to…

Well, it's really just to recover the consumable. Rather, I mean if every time you did a space walk you had to vent all of that gas overboard you would run out of consumables and your station pressure would stop dropping, or start dropping, and so, what this does is just recover the nitrogen and the oxygen, and within the pressure control system of the space station, it'll keep the station pressure at like 14.7 psi.

The other major component, which you've referred to a couple of times earlier, the High Pressure Gas Tanks…

Right. …

and they play a big part in this pressurizing and venting scenario that you've described.

They do. And they also play a big part, particularly the oxygen, in recharging our spacesuits for doing space walks, and, as well as the Orlan spacesuit. One of the unique things about these tanks, again, is their mass, and, like I said, they're about two, two-and-a-half times the largest mass that we've ever handled in space. Typically, like on the Hubble missions, they would handle an ORU with an astronaut on the robot arm holding it in one place, but because we're going to have to, it's going to take about forty-five minutes to translate these tanks from the bay of the shuttle up to the space station where the airlock is, using the space station RMS, which 6A is going to put on for us, it was felt in the EVA community that that was too long for one person to hold a tank and to control it. And so we developed a new approach where the robot arm is going to bring the tanks up to Jim Reilly and [me], who will be in foot restraints up on the airlock or the equipment lock portion, and then we're going to take a handoff of these tanks and then, ever so carefully, bring them down -- we have to place them within about a quarter-inch accuracy, onto these "towel bar" latches. And one of the things that is going to be very interesting to see how it works, when we first were doing these tests in the Neutral Buoyancy Lab back in, I guess it was 1997 now, with the position that we could put our foot restraints for both me and my partner, Jim Reilly, we couldn't see all four corners of the tank. And so the only way to put these tanks on was to roll them up, do two latches, and then roll them back down, and that worked great in the water -- it was like, hey, no problem. But realizing that nothing is as simple as it looks in the water and that the dynamics in zero-g are different, we went over to the Virtual Reality Lab and the mass simulator, and Joe Tanner, who had just got back from the Hubble mission, and I went and did this task in that simulator. And what we found is that the place that I hold the tank is different with respect to the center of mass than where Joe was holding the tank, and as you go to rotate the tank, you have different moments of inertia and you put different forces on the tank. So as I try to roll it up, I actually pitch it over toward him, and, with his handholds as he tries to roll it up, he actually yaws it, and you end up fighting each other trying to get this tank down. And it was really, you know, like Joe said, hey, you know, this is not pretty. And I came up with an idea that we'd used in deep sea diving, called the guidepost. And we used to put these big oil blowout preventers where you'd have one little post and then you'd have like a funnel, a thing called a bell-guide, and you could line that up and then once you got the bell-guide over the guidepost, then it was, you took out all the rotations except for yaw, and it was fairly easy to drop that thing into place. And so we implemented that on these High Pressure Gas Tanks, and Jim Reilly's actually going to be looking straight down this funnel at the guidepost, so he'll be able to line up on that; I'm looking across from the starboard side, and I can take out any of the rotations that are in the tank, and our plan is, once the arm lets go, we're just going to walk it with our fingertips onto this guidepost, and it should just go right down into place.

Once this new system is installed on the station, give us a comparison, I guess to the shuttle's airlock system, and what are some of the differences that we would notice in the use of this hardware for conducting space walks as opposed to what we're used to seeing?

Well, as I pointed out before, I think the key conceptual difference is that we're recovering the consumables, both with this reclaim pump that takes the nitrogen and oxygen from the crew lock and recovers that to the station, and then the use of the Metal Oxide CO2 removal scrubbers versus lithium hydroxide that we use on the shuttle. The other key difference is that the airlock is developed to interface with both the Russian suit and our suit, and that's the first time that's ever happened, as far as one airlock adapting to two different suits.

Will there be any appreciable difference in, say, prebreathing procedures beforehand?

Yes. Actually, we're working, and we hope to use on this flight, a new prebreathe protocol, and that's a great question. On the shuttle, we typically go down to 10.2 psi, so we depress the whole cabin of the shuttle from 14.7 psi to 10.2 psi with 26½% oxygen. And on the vast majority of the shuttle flights we stay there thirty hours or more -- actually, the average has been forty hours. And that allows us to re-equilibrate at the lower pressure and lose nitrogen. Then, before we go EVA we get into the suits and we breathe another forty minutes of oxygen, to purge the nitrogen so we don't get bubbles that can give us "the bends." Well, on space station we can't drop the whole space station down to 10.2 psi because it wasn't designed to work that way, partially because some of the life science experiments they do they want to have it the same pressure as ground controls, and so for that reason none of the hardware was certified to operate at the lower pressure, and at lower pressures the cooling is not as good and so forth. So the whole station has to stay at 14.7 psi. So the two options that we have are, first, campout, which was the baseline procedure, where would we have to go into the airlock, this Joint Airlock, the night before we did a space walk, depressurize to 10.2 psi, and sleep there. And keep in mind, you're isolated and there's no bathroom or food or anything, you know, none of the things that you would like to have as far as comfort features. So, we would camp out in the airlock, and then in the morning we'd put on these oxygen masks so we didn't interrupt the prebreathe and re-saturate with nitrogen, we'd have to re-compress the airlock, excurt on a long hose to go use the bathroom, and then on the way back grab some food, get back into the airlock, depressurize that to 10.2 psi, eat your breakfast, and then prepare to do your space walk. And there's a lot of overhead in that -- in fact, it really wasn't going to work out that well in the sense that you couldn't do back-to-back EVAs, and still meet our scheduling constraints, because you'd of had to get one crew back in and out and the other crew in to camp out, and so, you know, it was workable but certainly not an [optimal] approach. Back in 1997, we started a project called the Prebreathe Reduction Program, which was based on a lot of enabling research that had gone on here at NASA and at the Air Force, and Duke University over several years looking at how to cut back on the prebreathe while maintaining the same degree of safety. And one of the things we jumped on was the use of exercise during prebreathe to speed up your blood flow and your nitrogen elimination, and that was based on the experiments that the U.S. Air Force had done with Drs. Pilmanis and Webb, some of the basic research done here by Dr. Michael Powell, and some work at Duke. So, I joined that team and actually functioned as the project manager and then Principal Investigator to develop this protocol, that we hope to use on our flight; it's in the final stages of approval now, but it's the two-hour exercise prebreathe protocol. And what we do is we get up and we don't have to campout so we sleep at the station, you know, 14.7 psi, we get up in the morning and we have an hour where we don't have to do anything other than our regular crew, post-sleep activities. And then we put on oxygen masks and we go and we ride the station bicycle against a very specific exercise prescription that's based on our maximum aerobic capacity that we've already had a test on, and we ride the bike for just ten minutes -- there's basically a five-minute warm-up, and then there's five minutes at what's called 75% VO2 peak, which is basically like a nice jog. So we ride the bike and we're pulling on surgical tubes to keep our upper body moving, and what's happening is you're increasing your cardiac output and your blood flow, and the more blood flow you have to the tissues the more nitrogen is carried back to your lungs. And so we do that, and then we do the balance of eighty minutes on the mask, preparing to get in our suits. So at that point, we end up getting in the airlock, we start putting on our liquid cooling garment, our biomed, we do some power-ups and suit checks on the suits; once we arrive at 10.2 psi then we can come off the masks and take our time to get in the suit, and, you know, once we get in the suit it's just like what we do on the shuttle -- we do another forty minutes prebreathe and go out the door. And we worked with a very world-class team of decompression researchers at the Canadian Defense and Civil Institute for Environmental Medicine, Duke University, and Hermann-UT. We did a whole bunch of tests of this trial, or of this protocol -- we actually looked at four different exercise levels, and what we found is that the ten minutes' heavy exercise by itself was not sufficient to provide adequate protection, then we looked at light exercise and light exercise by itself, associated with the EVA prep, wasn't enough; but when we coupled the heavy and the light, we didn't have any decompression sickness. Actually, it's the safest trial that we've had to date, and, like I said, it's going through the final approval process, and we hope to use it for this flight; if not for this flight, then in the very near future.

Let's get you to take us through this flight. To do all that we've been talking about, you've got to bring the shuttle and the station together on orbit. Tell us the plans for the shuttle's rendezvous and docking to the station on this mission, and what your part is going to be as part of the team on board Atlantis.

OK. Well, as you know, the first thing that counts is when you launch, because here's this space station orbiting the Earth in a certain orbit, and we have to catch up to it, and so we have to launch within a very narrow window -- it's about five minutes, I suppose. And then, after we insert into orbit, the next day we start doing phasing burns to actually, eventually rendezvous with the space station. And during the rendezvous itself, during the final stages of the rendezvous, I'm going to be working with Janet Kavandi and be in charge of the docking system, so when we actually do the docking, we'll be actually operating the mechanisms that allow us to dock. I also will be backing up, toward the end of the rendezvous, Steve Lindsey, the Commander, will go to the aft flight deck and be looking out this thing called the COAS at the space station where he'll be actually doing manual flying in the final phases of the approach and docking, and then I'll be sitting in the front seat with Charlie Hobaugh, backing him up on all the procedures that we need to do -- the navigation and adjust burns as we approach the final docking phase. And I'll also be running the IMAX camera for some of the docking and then the flyaround when we actually leave the space station.

Once you're docked, you guys are going to be pretty busy in those first couple of hours, including going through what on the timeline is called a "dry run" of the airlock installation. Tell me what's on tap for this dry run -- is this something significantly different than all the practice, the simulations, that you've done on the ground?

Well, I think one of the big issues on this mission is that it's a joint operation of two robot arms: the station robot arm that Susan Helms will be operating, and then the shuttle robot arm that Janet Kavandi will be operating. And we have not had the typical chance to train for months and months with the station crew -- they've been off in Russia, they've been doing their own thing. In fact we've only had a very limited amount of training sessions with them. And the dry run is to let Susan Helms actually look at, you know, not only the trajectories and the kinematics but the camera views, you know, where the tight points are as far as clearances in the payload bay and then clearances between the two robot arms. And so that'll give her a chance to fly that out, and the other thing that makes it complicated is that the station doesn't have very many cameras…the SSRMS has its own cameras, but in order for this to be successful we have to use the shuttle cameras. And so Steve Lindsey and Janet Kavandi will be, basically, sending different camera views over to Susan in the station. And those will be necessary initially for the unberthing, and then later we're using the Space Vision System to calculate the alignment trajectory for the final mating of the airlock on the space station, and we'll need to use the shuttle arm to give the Space Vision System the appropriate view of the targets. So that's going to be one of the more complicated parts of this whole operation, is that joint operation of both arms.

Let's talk about the first of these space walks; it's scheduled for that next day, on Flight Day 4. First off, who's doing what -- you and Jim Reilly are the space walkers, what does everybody else do?

OK. Well, Jim and I are doing the space walks; like I said, Janet Kavandi will be running the shuttle arm, which Jim Reilly will be on; Steve's backing her up; Charlie Hobaugh, Scorch Hobaugh, is our IV crewmember, so he'll be running the checklist and kind of running the choreography of both Jim and I as we do these tasks in the payload bay. But at the same time the shuttle, or the station, arm is coming down to grapple the airlock, and once we start our EVA, and the big issue here on this first EVA is the time that it takes from when I release this electrical connector that powers the heaters of the airlock in the shuttle bay, until we get it and mate it to the station and I make up another electrical connector to power those heaters. And the big issue -- and this is the first time we've had to deal with this -- is that we've launched the airlock, in quotes, "wet," so the water lines are wet, they're full of water, whereas the other earlier flights launched them dry. And if we don't get it made up within our EVA, then these water lines risk freezing, which would not be a good thing. So, the initial part of the first EVA, Jim and I have to be really, you know, on the mark as far as getting things off the airlock and preparing it for release.

Let's take us through that first EVA…

OK. …

if you will, step-by-step...

All right. I can do that. …

not in the tiniest of minutiae but…

I can do that. No, I have that all in our heads after all this training that we've done. …

but what are the big steps, what are the mileposts that we should look for to see that things are going as they're supposed to?

The big things to look for, first of all, Jim and I get out and we do some setup; we set up the arm with a Portable Foot Restraint so he can get on the arm. And then I'm going down on the starboard side and the first task that I do is actually sort of a minor one where I install one of these PFR sockets that we're going to use later, and the only reason I do that first is it's real easy for me to do, but the major tasks that are in the critical path are pulling off this thermal cover of the airlock -- it's called the "shower cap" -- and it's roughly about ten feet wide, and based on what they learned on 5A it's going to be a little bit of a wrestling match with this thing, it's going to be real stiff. I have to pull that off and get it under control, and out of the way, and then there's a seal that's on the airlock that we're mating to the space station, and that has these seal protectors. There's eight arcs, metal arcs, that cover this seal, so I need to pull those off very carefully, the seal is very, finicky, I guess would be the right word, and if, you know, if I bump the seal or somehow damage it then we're going to have leaks, which might not be a problem in the short term but over the life of station you're going to lose a lot of gas so I have to be very, very meticulous when pulling these seals off, or seal covers off. So I pull off four from the starboard side, then I move over to the port side and pull off four more. In the meantime, Jim Reilly is doing a couple of things. He's staging some thermal covers that we use on the second and third EVAs from the shuttle airlock out to, hang off on the station airlock, just to get [them] on there so we don't have to carry [them] all the way up on the next couple of EVAs. And, then he's installing these fixtures called, "towels bars," which is like a little bar onto which we will clamp the tanks. Now originally that was supposed to be all pre-integrated but it turned out that the airlock was so, was bigger than they thought and you couldn't close the payload bay doors. So Jim's got to put these towel bars on while I'm pulling this shower cap and these seal covers off. And then I go around and when I get the "go" from Scorch, I release this cable, it's called the launch-to-activation cable, and that's what's powering the heaters that are keeping the airlock warm and the water from freezing. So I pull that cable off and coil that up and take it back and integrate it with this shower cap and all this other, all these seals and so forth, and then, Jim comes around on the arm and he's going to pick this thing up, which is going to be, it'll be interesting to watch this because it's going to be a big mass, and, so I help him get it all squared away on the arm, and then he starts heading back to this, what's called the TSA, the starboard TSA, tool storage assembly; if I'm ahead on some time, I have some extra time, I'm going to actually go over to the station airlock and pull these pins that are on this cover, that we have to remove before we can ever do an EVA. So if I've got the extra time to do that I'm going to do that then, and then I meet Jim back at the starboard TSA and take this big old, you know, bag of stuff and put it into the TSA and close the door, and then we go off and wait inside the airlock while Susan Helms and the rest of the crew is installing the airlock itself on the starboard CBM of Node 1.

So, if I can interrupt, you two will be in the shuttle airlock when the station arm comes to pull the station airlock out of the payload bay.

Right. And the reason we're doing that is that we want to preserve our consumables in case this EVA goes long. Right now, it's planned for over seven hours, which is a long time, and of course it always has the threat of going longer, and so, for about, over an hour, about an hour and a half, we're going to be in the shuttle airlock on the umbilicals -- the service and coolant umbilicals -- just preserving our power and oxygen, while they're mating the airlock up there. And if they have problems with the SVS, where they need, you know, they're not getting a clean solution, then Jim and I are trained to go up and give [them] GCA commands as far as guiding this thing in. Once it's installed and they get what's called the "A" bolts, which means that about half the bolts are made up and it's stable enough for us to get on, then I'm doing the main task of the whole thing, which is to get this other cable, which was used on the Lab, I actually have to remove the Lab cable from the Node, and that's what's powering the Lab, and then I have to take this other cable that's on the airlock and bring that down to the Node and establish it, on connector J-612, and then that gives us power to the airlock and we know we can keep the water from freezing. So, once that's done that's the end of the EVA -- while I'm doing that Jim Reilly will be staging Portable Foot Restraints that we'll use on the next EVA to put the High Pressure Gas Tanks on.

We've mentioned the real heavy lifting here is being done by the station's new robotic arm. Are there unique capabilities in the Canadarm that are going to be utilized in this operation?

Well, I'm not the expert on the shuttle or on the station arm, rather -- I'm trained on the shuttle arm and have used that -- but one of the big differences is that it has seven degrees of freedom instead of six degrees of freedom. And with seven degrees of freedom you can get kinematic redundancies where you have different solutions that result in the same endpoint, and so they have to very carefully manage those seven degrees of freedom. And, they would be better to tell you about that than me but I do know from an EVA perspective that we have to wait for a while, right in the middle of the trajectory up, while they do a display reference frame, and then, when we're doing the handoff of the tanks they have to do some special software reconfiguration. And so it's actually more complicated to operate because of those seven degrees of freedom.

For two days after that first space walk, you've got a lot of work scheduled inside the station and the shuttle complex. What are the jobs here? How are these activities fitting into the overall plan?

Well, it's a fairly complicated process where we have to, first of all hook up the, outfit the vestibule, where we provide water lines from the station, power, data, oxygen, nitrogen lines, all those need to be hooked up. We actually have to relocate a hatch…and that's a whole long story but there's a hatch that launched in place on the airlock, and we need to move that hatch, and that's at the interface between the airlock and the Node. There's already a hatch on the Node, so we don't need two hatches at that interface. So we're actually going to have to move this hatch from the first interface over to the equipment lock-to-crew lock interface. And that has to fit just exactly right and so forth, so we've got to do that. But before we do that, we have to change out relief valves. When the station launches it has what's called positive pressure relief valves and negative pressure relief valves, and that's to prevent it from either getting overpressurized because there's some kind of leak where the thermal condition causes it to get overpressurized, and then of course, the negative pressure would be to protect against imploding on entry, which hopefully will not be an issue. At any rate, all these valves need to get changed out, and we have to check that there's no leaks between all the valves and all the hatches, we have to power it up, like I said get the water lines flowing, and then there's all this equipment that we're going to use to do the EVAs and service the suits that has to get powered up and checked out. So there's about two days there where it's just nonstop in terms of, you know, all these different activities to activate and check out the airlock, and we actually have a suit that we'll carry up with us on the shuttle that we will check out and confirm as 100%, A-OK, on the shuttle, and then we take that over to the station airlock and we have to check…we know the suit's good, now we check that out with all the interfaces on the station airlock to make sure that it's good.

For Flight Day 7, you're looking at the second space walk of the mission, again out of the shuttle, and again with the station's robotic arm playing a big part in the plan. Again, talk us through what's going to happen on this space walk, both outside the station, where you're going to be, as well as what's going on inside the shuttle and the station.

OK. Again, a very, integrated activity between the two crews. The main objective is to install two of the four High Pressure Gas Tanks, and the way that's going to work, we go out the door, Jim Reilly heads right up to the space station airlock and starts doing some work site preparations, and I go out and I tether up to the shuttle arm, so I'm going to be tethered to that for the whole space walk, and then at that point, the station arm grapples these High Pressure Gas Tanks down in the payload bay of the shuttle, I float in underneath, hook up my BRT, and release some latches of these tanks and then make sure they're clear, and then it starts the long, slow process of taking this tank up to the space station while Jim Reilly's working away setting up the Portable Foot Restraints and putting in these guideposts and things of this nature. And then I ride the shuttle arm, I use that as my elevator, to get from the shuttle bay up to the work site at the station. And, that's going to be kind of a neat thing to watch, and I know I'm going to enjoy that, where you have both arms moving and there's one place where they sort of get close together and we have to watch that real closely. But, Janet will be using the shuttle arm to take me up, she'll drop me off by the Node, I then translate up, I actually install a handhold that needs to be there for our translation path, and then both Jim and I get into these foot restraints and take a handoff from Susan Helms of these big tanks, and we bring [them] down and lock [them] into place, and then I have to throw a latch to put it into hard dock so it can't get away. At that point Jim is clear to go on and start setting up for the next work site, and then I have to make up these quick disconnects that actually attach the 3,000 psi gas in this tank to the station. And that will be another interesting area in that there's a little bit of a history with these things being problematic and we've worked it real hard, we've got [them] marked, with all these markings and so forth, and I think it's going to go fine. But it's one of those things where, you know, we put a healthy amount of effort into making sure it goes well, and knock on wood again, it will.

At 3,000 psi, it's probably worthwhile.

Yes, absolutely.

Is the procedure essentially repeated for the second tank?

It is. There [are] some slight differences in that the second tank is nitrogen, and it's actually plumbed to two different interfaces so we have to do a slightly different procedure with the manual isolation valve on that. And on the second tank on -- which is tank 4 actually, nitrogen tank 4 -- Jim Reilly's got his foot restraint in a slightly different position because there's a thing called the SASA which is in the way. So the actual ergonomics of putting the tank on will be slightly different on the second one, and neither one of us actually have a good control of the forces on the port, right side of the tank and so we might get into a situation where not all three latches make up, but if we can get two of the three then we can get out of our foot restraints and go get that third one. So, we'll be watching that.

The next day you've got another day of inside activities scheduled; what happens there?

That's just more of the overall checkout that I talked about, in terms of moving hatches and checking, you know, to make sure everything's sealed, that there's no leaks; we actually change out some of these positive pressure relief valves and Jim Voss will be hooking up these oxygen lines -- this is kind of an important thing. Because we're going to use oxygen on every EVA that we do, and we don't want to have to change out these tanks like, you know, two or three times a year because there's a lot of EVA time involved, we actually have a high pressure oxygen pump, and we'll pump oxygen from the shuttle into these tanks on the space station. And so Jim Voss will be hooking up these, what's called gamma fittings, but there's basically hard plumbing that will go all the way back from the airlock to the Node through the Lab through the PMA, and when the shuttle comes up on every other mission we'll hook up a line, and then we activate this high pressure oxygen pump, the ORCA, and it'll take the shuttle's oxygen, which is actually cryogenic, supercritical, and the vent pressure of that is about 850 psi, and it'll take that and, with a two-stage pump, pump it up to like 2,750 psi. So we'll move all the gas from the shuttle and continually recharge the oxygen tanks on the station.

All of that work is leading up to the mission's third space walk, and the first space walk ever to come out of this brand new station airlock. First of all, what do you think about you getting to be one of the first people to make a space walk out of this piece of equipment?

You know, I don't think that much about that; I mean, it's not like, you know, hey, we're going for the record, I mean it's, that's our job, to put this thing on, to check it out, and to do it. And I think, you know, it will be neat to be the first one out of that airlock, but I'm more concerned with just getting it on there and making sure it works, and even if we're not the first ones out [of] it, as long as we're leaving them with a functional airlock, I'll be happy.

What is the rationale here for having two shuttle astronauts make this space walk out of the station airlock?

I don't know that there's any rationale, per se, other than that we're trained to, you know, this is our mission, to put the thing on, and all of the tasks that we do we've been trained for, and, for example, the station crew would not have had time to do all the training that we did on these specific EVA tasks. And it just kind of fell out that way.

All right; but let's talk about what you're going to do then. What are the jobs, then, for you and Jim Reilly on this third EVA?

Well, on the third EVA we'll be putting the remaining two High Pressure Gas Tanks on, and then we'll be installing a fair number of on-orbit-installed handholds, and it looks like we're going to get tasked with covering up all of the grapple fixtures that are on these tanks. We didn't think we were going to have to do that, but it looks like we're going to, and so we'll have to take these other covers out and put covers over the grapple fixtures on the tanks. There's an Orlan antenna cable hookup that we do, and this comes all the way from the Russian segment -- some of the previous flights will have left it for us -- and we actually hook that up into our airlock, and it goes into an antenna that's in the airlock that allows the Russian segment and the Russian ground sites to communicate directly with the Orlan suit.

Does it make any significant difference to the way you conduct this space walk of the fact that it begins from the station airlock as opposed to the shuttle airlock?

Well, it kind of does in the sense that -- the other thing I didn't tell you about is, we talked about the Space Vision System; well, it turns out where we have our High Pressure Gas Tanks is exactly where they need these targets for the Space Vision System to install the airlock. And so, they're on this multilayer insulation that has to be removed, and then the tanks are put on, and that establishes a good thermal contact to keep the tanks warm. So we're going to have three of these pretty bulky covers with these SVS targets and plates on [them], and they'll be right up there on the airlock and so it's much more to our advantage just to bring them into the station airlock than to translate with these big, bulky objects all the way back down to the shuttle bay. So that works out well. And then additionally, these grapple fixture covers are going to be fairly unruly as well, and instead of having to translate all the way from the shuttle with these four grapple fixture covers, we'll have them right there in the station airlock and literally we'll go out the door and start putting them on the tanks, and so, you know, it saves a lot of the overhead. Actually, as we come up from the shuttle to the airlock, we have to do at least two if not three tether swaps, and every time we do a tether swap, I mean, it takes time because you've got to make sure that you're double-tethered, and, you know, there's always a certain risk associated with tether swaps, so we'd rather not have to do those if we don't have to.

In doing a space walk from the station airlock, are you going to be employing these new, preparatory protocols that we were discussing earlier?

We expect to be using the two-hour prebreathe protocol; if we don't, if that's not approved by that time, we will actually do a campout. And then the other thing to keep in mind, though, is that any number of things could cause us from actually being able to do an EVA from this airlock. If the oxygen lines have a little bit of a leak in it, apparently there's some software that needs to get upgraded to, or uplinked to the station that might not make it in time, so there's any number of reasons [that] could prevent us from actually doing the final space walk from the station airlock. If that's the case, we have plans to come out of the shuttle; it'll make it a little bit longer, a little bit more of an overhead, but, we can get the job done. And our main job is to put the airlock on and the four High Pressure Gas Tanks and all these covers, and then ideally we'd get the airlock checked out, and make the space walks, but if we don't then, you know, that's why the station crew is there, they've got plenty of time, and if anything doesn't get done, at least the main objective of our mission is accomplished and we've left the components up there for [them].

You're scheduled to wrap up a solid week's worth of docked operations the following day. Once the hatches are closed, describe what is to happen as the shuttle departs from the station and flies around it, and what you'll be doing during…

Well, as we…you know, there's a fair amount of transfer activity, obviously, to make sure that…we have to transfer some suits over to station to make sure they have the right number of suits and stuff like that, but once all that's done and we close the hatches and undock, we'll be doing a flyaround. And this is normally done just to give an external view of things. Charlie Hobaugh will be doing that. At that point, again, I'll be backing up the flight deck, looking ahead in the rendezvous; I'll actually be running the IMAX camera during that flyaround, and doing some photo documentation as well.

The completion of your mission also marks the completion of Phase 2 of the International Space Station program…the, for lack of a better term, the "some assembly still required" phase, and be ready to start the scientific research phase. Tell me how the science that's going to be conducted on board the International Space Station, in your mind, how that can contribute to our lives here on Earth as well as to future exploration beyond Earth -- and how you feel about being a part of making that happen.

Yes. I think it's a really great thing for life here on Earth and for human destiny. The science will range from growing protein crystals that could result in drugs that could cure diseases here on Earth, and without getting into the fine details of that, I can give you an example and take that forward. On my first flight on the shuttle, we grew this one drug called urokinase that has been determined to cause the spread of breast cancer. And we know the chemical composition of urokinase, but we don't know the three-dimensional structure and that is because when you grow this crystal on Earth, gravity deforms it and makes it so complicated that you can't use X-ray diffraction to determine the three-dimensional shape. Well, when we grow that crystal in space, in the absence of gravity, it forms a more perfect crystal, and, which, with simpler geometry to where you can use X-ray diffraction to understand what the active site would be, where it bonds with the cancer cell. And once we know, we already know the chemical composition, and if we can determine the three-dimensional structure and the active site, then, pharmacists or whatever could design drugs that would bind with that active site and prevent the spread of cancer. And the problem in the shuttle is that we're not up there that long: we're only up there for ten days and then we bring things back home, and they get deformed by gravity. So with space station, you know, that's one of hundreds of drugs that we're working on, and there's no doubt in my mind that eventually, the research we're doing will produce something that will make a big difference to our life here on Earth. Unfortunately, in terms of the, you know, the general public, it takes years for this kind of research to get completed and then the drug trials to get done and so forth, and so you don't see immediate returns but, you know, as a taxpayer this is a great investment in our future in terms of just life here on Earth. Not only the life sciences, but the material sciences, better understanding of material properties and chemical reactions and so forth. And then, of course, as an astronaut I'm interested in the long term as to where we go out, into the universe. And one of the big challenges we have as we look forward to our next, you know, fairly long-term but certainly not ultimate goal, and that's to go to Mars, and one of the big challenges that we have is having people live and work in microgravity for long periods of time. And this space station is the perfect place to do that. And so we'll learn that, we'll be doing all sorts of physiological experiments to better understand, you know, how the adaptation, both to space and back from space, bone loss, looking at, eventually, there'll be a centrifuge on there where we're looking at how to apply gravity dose, and the notion would be, you know, maybe once a day you get up and you get on this centrifuge and you go through a two-g profile, and that keeps your bones remembering what gravity is and it keeps the activities happening, you know, and works as a countermeasure. But, you know, there are various different scenarios that we'll use, but the bottom line is that the station will give us the experience that we need to keep humans healthy and working in space for long periods of time.

Crew Interviews
Image: Michael Gernhardt.
Click on the image to hear Mission Specialist Michael Gernhardt's greeting (WAV file 317 Kb).

Curator: Kim Dismukes | Responsible NASA Official: John Ira Petty | Updated: 04/07/2002
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