Preflight Interview: Michael Foale

Why did you want to be an astronaut? Where is it in your life that the dream came to be an explorer, to fly in space?

Well, I think the first time I became aware of traveling and going somewhere new was when I was flying as a child of about four years of age, maybe three, to Cyprus from Great Britain in a commercial airliner where my father had recently been posted to command a Royal Air Force squadron. I grew up with the sound of jets, and I lived in exotic places, and I developed a taste, I think, for not so much adventure but just new vistas, new places, new things. Because aviation was in my upbringing from the beginning, I quickly decided that I wanted to fly, and it was then, when I visited the United States when I was about six or so - I should tell you that my mother's American -we would visit her family every two or three years in Minneapolis/St. Paul, in Minnesota. We were at the state fair there, and I saw John Glenn's capsule, all burned and charred and black, pretty small, too, even to me, and I was pint-sized. I said, I understood, that this was about going into space, and about that time I think the X-15 was flying, which was a very sleek-looking experimental test airplane that was being used at the time, rocket plane, and I put all that together and said, "I want to be an astronaut." I knew when I saw John Glenn's capsule that that was not the way that I was going to go into space-I was going to space in style, you know, with wings on, and the shuttle turned out to make that come true. I also then became aware of astronomy through my American grandma…she showed me books on space as a result of that interest. It all sort of led from there. Here I am now as an astronaut.

You've mentioned a couple of people; are there others - special people in your life who you credit with helping form the desire for you knowing what it is you wanted to do?

Well, my father didn't discourage in any means my interest in being a pilot or astronaut; I'm not sure he credited very realistic my dreams and aspirations there especially since Britain did not have, and still does not have, a human spaceflight program. However, nonetheless there was quiet support, and my mother certainly-I think because she was American and she had no kind of patriotic reservations about me joining United States services, be it the Air Force, the Navy or becoming a NASA astronaut-she actively encouraged me with books on space and it continued. I should also say that before this episode, I wanted to be a train driver.

From the desire to be a train driver-what steps brought you to the point today where you do get to fly in space?

Well, I followed a path which is quite common to most of those in my group, the 1987 class of astronauts. I grew up watching the Apollo moon landings absolutely enthralled and excited by them, wanted to do the same thing myself; saw that test pilots were being involved in those missions and so I did focus most of my energies in terms of career thinking on becoming a pilot. To be a military pilot was my plan and a test pilot would be fine, too. Then something changed. When I was about sixteen, my applications to join to become a pilot were delayed because I was misdiagnosed with a vision issue, and as a result what happened was I shifted my emphasis on becoming a scientist, and I put all my energy into becoming a physicist and an astronomer, and I did a Ph.D. in astrophysics at Cambridge. Then, lo and behold, when I thought maybe I should find out if I could still be a pilot, I found out that my eyesight was perfectly fine to become a military pilot. I then said: "Oh, well, the game's changed in terms of spaceflight. Do you really want to go to the services at this point, with a Ph.D., or do you want to just go and attack it as a Mission Specialist?" I decided to attack it as a Mission Specialist, be a specialist as a physicist, astrophysicist, and work at the Johnson Space Center first, and then apply to the astronaut selection program.

Did you work at JSC as a scientist first?

Yes…not as a scientist, but as a payload officer, the person who controls the cargo, the payloads that we carry up on the shuttle and put out into space or bring back, or service in the case of Hubble Space Telescope. I was the responsible officer in the Mission Control Center who had to know all about those payloads and make the decisions along with the rest of the flight control team and the crew as to what we were going to do in the event of unforeseen problems. I should add that Steve Smith, on this crew for the STS-103 mission, is also an ex-payload officer, so we kind of come from the same club.

Your flight together on STS-103 is coming just about two years since you returned to Earth from your last spaceflight, a four-and-a-half month long mission on the Mir space station. How was your readjustment to life on Earth after having spent so much time in the absence of gravity? How'd it compare to the recovery you went through from your previous spaceflights?

Well it's notably different primarily because I'm getting used to my family again and they're getting used to me. The absence is certainly quite long to be away from small children, from your wife, and I had very limited communications with my family while I was on the Mir space station. As a result, I intended, and NASA permitted me, to spend quite a lot of time at home for a month or two right after the flight. I did most of my physical rehabilitation, which is the other thing that I had to do that was different, at home. My son Ian, who was at the time three when I landed, had been starting to talk while I was in space, and so I really got to enjoy and interact with him and see the development of his language, and of course, re-establish a strong bond with my daughter Jenna, who was six at the time. She's seven now. So the difference was that I had all this effort and interest and desire to put into my family compared to the previous flights. Then on the physical level, I was weaker after this flight than I was after my shuttle flights, and I had lost a fairly substantial amount of muscle mass in my calf and a little bit of bone mass from my hip and spine. I had to go through a weight program, lifting weights, and gentle running and swimming-that brought up both my bone density and also my muscle mass to my preflight levels. I recovered most of the muscle strength back in about six months, and most of the bone mass, within a percent or so, has come back over a year since the landing of that flight. Right now I feel like I'm in tip-top shape. I've been training for six months roughly, geared towards the Hubble flight and the EVA that we have to do, and so physically I feel about as good as I have been in the past.

In the time that you've been back, it would seem that you've had time to reflect on the Mir experience, from the training that you went through and to flying the mission that, in your case, featured some quite harrowing times, including an on orbit collision and a depressurization of the station. What're your thoughts about all of that now? Apparently, your Mir tour was not enough to make you look for another career, but has it made you a better astronaut? A better man?

You should always remember the Mir flight resulted from training in Russia and learning Russian and living with my family in Russia for a year-and-a-half, and that experience, truly, is the one that changed my life and my family's dramatically to the extent that we were enriched in learning another culture. We have totally different friends now as a result of that travel over to Russia and living there. The actual time on board the Mir with the two crews-the Mir-23 crew which was Vasily Tsibliev and Sasha Lazutkin, and then they were replaced by Anatoly Solovyev and Pavel Vinogradov-those two crews I got very close to, and I developed a physical bond, basically, an emotional bond. We'd kind of hug each other if things went well, and we'd be there if things were going badly. They weren't speaking my language, I was always speaking Russian to them. I developed this whole new way of relating to people in another language and so this was quite different for me, quite special. It lets me understand Russians especially, and I think Europeans overall, better than other Americans, and as a result it's been extremely valuable to me now as we carry on working with our international partners to build the International Space Station. I feel that I "click" faster, I understand where their problem is, like the Kosovo bombardment. I could see the other point of view, as far as the Russians reacting to this, as much as I could see ours. I think that's valuable to us, and to me.

One more before we go to STS-103. As the first of the seven Americans who went to the Mir to have another spaceflight, do you see any ways in which your Mir experience is being put to use as you prepare for a space shuttle flight now?

Yes, I mean, there's one very obvious and direct parallel, and that was the whole issue of safety tethering when we're doing a spacewalk. We've discussed carefully as a crew, the EVA crew, what would we do to prevent ourselves falling off the space shuttle, that is, not tethering properly and slipping and letting go, or, much more likely, letting go of some tool or piece of equipment. The hazard here is that one, you could be lost in space, which is very bad, but two, more important, you could lose something very expensive, some equipment that's very critical to the Hubble. It's essential that we don't do that. On Mir, because you're on a vehicle that can't follow you, can't jump after you, the whole approach to tethering and moving around outside the Mir space station-and I did an EVA on the Mir space station to investigate the damage as a result of that collision you mentioned-there you hang on much more seriously, I would say, with two tethers all the time, and you move more ponderously. Because we realized, as a crew for STS-103 servicing Hubble, that, truly, it's very bad if the shuttle has to break free from Hubble to come and get you, we have to take our tethering very seriously also. So some of those parallels of double tethering we've carried over and I've carried over to the crew on STS-103. One of the more, I would say, personal characteristics that I brought from the Russian training to the shuttle for training is that I have more of a laissez-faire attitude. If things get difficult, I know things will get better; if things get kind of hard, I know it will be easier. I kind of take the rough with the smooth much more easily now as a result of that training on Mir, so things don't bother me so much in any of the shuttle training. One area which is significantly different between a space station flight-nothing to do with the Russians in this case-and a shuttle flight is the detail to which you have to plan your activity. Because we really must go up there, get to work right away, and come home within ten days having done maybe four or five EVAs--four are planned--we have to have the whole thing worked out perfectly, and Claude Nicollier, who's the other EVA crewmember with whom I'm working while changing out the computer of the telescope and changing out a Fine Guidance Sensor, we've had to work out what we call our tether ballet-it's where we map out exactly, minute by minute, what we're going to do during these spacewalks. We're adaptable, we can handle changes; but in the process of all that we know which tether, which lanyard we're going to use to hold something, which hand I'm going to use to get it from Claude, which hand I'm going to use to hold on with. That's the extent to which we've planned our flight for the Hubble. On the space station you would never go to that level of detail because you're going to be there for six months maybe, and you'll have long since forgotten the details. You have to be much more, kind of rough-and-ready, and accept that this might take a little longer to carry out your tasks. On a space station you have time to plan what to do the next day or the next week; on the Hubble mission you don't, and so we have to be perfect on the Hubble spaceflight mission right up front because we can't afford to waste a day.

You're training to take off on a space shuttle mission that's been pulled together on relatively short notice, comparatively speaking for shuttle missions, for an early servicing mission to the Hubble Space Telescope. Can you summarize for us what your role will be on the mission and what it's like for you to be a part of this flight after the flights that you've had?

I think the Hubble Space Telescope is like the gem payload of NASA. I think it's produced some of the most startling visual images ever since the Apollo moon landings that NASA's ever put out. Of course the Voyager spacecraft and the Galileo and others have done similar jobs, but I think the telescope is continuing to do that-it's putting out these fantastically high quality images that captivate the rest of the world, I think, when they see them, knowing that they're from the heavens. Given that, I have also always known as an astronaut that this telescope is high compared to where we normally go in the space shuttle; it's about twice the altitude that the space shuttle normally flies at and the altitude of the telescope is, of the order of 310 nautical miles or about roughly 350 statute miles. I know that the Earth will look a bit more round, it'll look a bit more like the ball that the Apollo astronauts showed us that captivated me when I was a boy. I want to go high, I want to see the Earth high, and I've always wanted to be on a Hubble flight because it goes high, it goes about as high as a shuttle can go. The other thing that the Hubble mission means for those of you that are chosen to do spacewalks is the EVA, the extravehicular activity. Spacewalking, I'm afraid, I became addicted to on STS-63, on a shuttle flight, when I did an EVA with Bernard Harris. We practiced moving a satellite called Spartan around, that weighed about one-and-a-half tons, and we had to do mass handling, see how it moved: such a heavy mass, no weight, but lots of mass, and we would practice moving that around. We also tested our current U.S. spacesuit in temperature extremes, extreme cold in that case. That experience was so positive for me and so beautiful that I said, "I want to do an EVA again, I want to do another EVA." I was lucky I did: I did it on the Mir and I did it in the Russian suit and the Russian language and it's quite a different experience, actually, from the shuttle EVA. In spite of the Mir and the Russian experience, I had identified to my bosses that I had always been interested in Hubble even before I went to Russia, and certainly when I came back from Russia. I said, "Hey, is there a chance for me doing that?" and they said yes. So I'm realizing a dream, a desire to go and visit the Hubble Space Telescope and do the EVA, see the telescope in all its glory, and also see the Earth from very high up.

When you were first assigned to this mission, more than a year ago, you were expecting to have two years to prepare for a mission that was going to include six spacewalks; earlier this year you found out that you were going early and you'd be performing an altered schedule on the repairs. How did you get the news? How has it made a difference for you as you prepared for the mission?

I have to tell you, my nature is one of rough-and-ready, so I'm pretty quick to say "Yeah, we can do it" and go off and do it. I'll generally have to iterate it two or three times to make it polished, but I'll get the job done one way or the other. When I heard the Hubble had to be serviced a year early and we had to change the plan a little bit, that didn't bother me in the slightest. I was pleased because it moved up the next flight and got me into training again. I just took it as a great bonus. In terms of training, we had already been, as an EVA crew, practicing these tasks for almost six months before that announcement and so it was a no-brainer-I mean, this was easy and it was a gift. The crew, I don't think, had to really adapt much to handle this-initially we had to adjust to the loss of two days of EVA; we initially were planning a six day EVA on the original mission and now we were at a three day EVA in the planning for this mission, but it's since extended to four days. So that was a slight disappointment more for Claude than for me because we were going to, us as a pair, were only going to get one EVA, initially, in the plan, but I said to Claude, "Don't worry, it'll expand, we'll always find more work to do up there", and sure enough, that's happened in the plan.

You made reference to the two spacewalks that you've made, one on the shuttle and one from the Mir space station. Can you tell me how that experience contributes to your preparation for this mission, and if you can, highlight a couple of the differences-you referred to the great difference between doing a Russian spacewalk, Russian spacesuit, etc.-between doing that and doing a shuttle spacewalk?

Well, I've touched on that already. I think the big difference is the way we tether ourselves and the way we move. The Hubble Space Telescope servicing plan is perfect for the space shuttle. The space shuttle and the telescope were designed for each other; it's a marriage, and that's because the shuttle has a robotic arm-built in Canada, the RMS we call it, remote manipulator system-and that arm allows us to take one crewmember and move him or her around and take boxes out of the thing and put boxes back in, while the other crewmember can be tethered to the arm or to him and loosely moving around, or independently moving from the shuttle's cargo bay up to the work site. This harmony, this choreography between the operator of the arm, who's on the shuttle flight deck, and the two crewmembers out there can really achieve an enormous amount of physical labor reconfiguration work very quickly. It's like having a cherry picker at home when you're trying to fix your roof and having painters at the same time coming in from the side. It's a good deal. For the space station, space station Mir especially, there is no internal operator of the arm. I used an arm, in fact, I was the arm operator on the Mir station, but I was operating these very simple handles and waving this big sixty-foot crane around with Anatoly on the other end and we achieved less work in terms of reconfiguring modules, putting up structure, than we could've done on the shuttle using the RMS system. That's quite different. The suits are also different. The Russian suit has a pressure that's about 50% higher than the American suit; this has advantages for the Russians. It means that you don't have to reduce the pressure of the cabin before you go and do a spacewalk, or you don't have to spend a long time in the suit prebreathing, getting nitrogen out to your body, before you go down to the working pressure of the suit, and so it's something that we are operationally struggling with now as we get ready for our space station, for the International Space Station. However, it has one disadvantage: it makes the suit stiffer and the gloves stiffer. The U.S. suit is, as I say, operates at a pressure that's 50%, well it's down from the Russian suit 4.3 pounds per square inch, and our suit's more dexterous because of the lower pressure; you see the difference immediately when you jump from one suit to the other, and so you can move your fingers more easily. You can go longer in the swimming pool in your training, and presumably you can do a longer EVA in space in the U.S. suit. However, we have to reduce the whole cabin pressure down to the altitude of about 10,000 feet and then stay there for twenty-four hours before we go and do our EVA, and this has negative effects, if we had experiments on board-we don't-but it has other drawbacks. However, it does mean when we reduce the pressure we can go on outside only after spending forty-five minutes in the suit prebreathing.

To help set the stage of understanding what you and your crewmates are going to do when you get to Hubble, talk about the mission of the telescope itself. What is it that the Hubble Space Telescope can do that other telescopes on the ground, or other ones on orbit, can't do?

Well, what's the big problem with astronomy? It's clouds, you know, it's daylight. You can't see the stars if you have clouds, haze, or lots of light, and what's so special about the Hubble Space Telescope is that it gets way up above the Earth's atmosphere, away from all the effects of the Earth that would otherwise diminish very good images. You could always argue, why don't we just build a huge mirror on the Earth, much, much bigger than Hubble could carry, and just point that at the heavens? We can, in fact, we have. It's been done in Hawaii on the top of Mauna Kea there at 14,000 feet. There're some pretty good seeing conditions, even on the Earth with big mirrors. However, there's always a problem and that is the atmosphere itself causes twinkling of starlight. The molecules of the air actually interact with the light coming from the star and blur out the image slightly. There are some very clever techniques being done today, in this decade, to actually get rid of those and make the big telescope on Earth do as well as Hubble, but it's with great difficulty, and nonetheless, those molecules of the atmosphere absorb some of the light, like ultraviolet, like infrared. So in the ultraviolet and the infrared parts of our light spectrum, the Hubble telescope is unique. It's not masked at all and can look at the star formation regions in the infrared, for example, it can look at supernovas in the ultraviolet. That's astronomy you can't do on the Earth at all.

Can you characterize, for the layman, the value of the data and the images that Hubble has already gotten and could continue to bring to us?

It's interesting. Astronomy is one of the very few subjects that almost everyone agrees should be done even if it has no reward in terms of economic benefit. I'm not even going to try and say that there is economic reward from astronomy, per se. I do believe the knowledge that we gain in terms of science, and physics especially, does possibly, many years down the road, filter back into our economy. You only have to be a father and son, father and daughter, and going out and looking at the stars and you get what it's about, to talk about astronomy, and it's always captured people all over the world for centuries-for many, many thousands of years. The Druids, you know, and others in England started this thousands of years ago, and in South America. So I am not going to attempt to justify, economically, astronomy. I think it's something that human beings will always hanker towards, and there it is. We're doing it and doing it well.

The Hubble is the first of four components of NASA's Great Observatories program. It's been followed to orbit already by the Compton Gamma Ray Observatory and the Chandra X-ray Observatory, with an infrared telescope still to come. What is the value, or in fact, the necessity, of having telescopes that are designed to investigate different parts of the spectrum of light?

Well, it all goes back to my cloud analogy. You have to be able to see, and what you're seeing with is the wavelength, the color of the light that you've picked out. In the visible, we could use a red filter and use red sunglasses and look at the red light, or we could look at the blue light, and that tells us different things about the temperature of the object that we're looking at: hot things are bluer, cold things are redder. If we're looking at planets being formed from rocks clumping together around stars that are just forming, they're cool, basically, and so there you're looking at light that is much more red, or in fact infrared, below red, and so there you need a telescope-if you're going to see that stuff going on-that looks at the infrared. On the other hand, if you're looking at explosions, huge supernovas, or you're looking at stars that are burning fast and hot, then you need to look in the cold blue. I say "cold," but it's not, it's very very hot, actually, but it looks cool blue. You look in the blue part of the spectrum, in the violet, and then into the ultraviolet. The thing is, when you look in the red, dust clouds in space-and there are many, many of them and they're light years long-can obstruct visible light making it look black, for example, the center of the galaxy, which is extraordinarily beautiful from space, this big bulge almost covered up, it's matte black, there's nothing in it, and you think why; what's there? You know there's a whole, burning millions of suns behind it. It's because there are dust clouds there. If you look in the infrared or in the radio part of the spectrum, you can see all those stars; if you look in the visible you can't. Gamma Ray Observatory, this is very, very energetic radiation that comes from radioactive processes in general, but more important in space it comes from the annihilation of electrons and positrons, the antimatter of electrons. That telescope is telling us about processes that are going on on the surfaces of stars, or around neutron stars, or near black holes-very, very, very exotic phenomena, happening actually on a small scale compared to the size of a solar system, millions of light years away, but nonetheless because the energy of these light rays-we call them photons-reaching us can be detected by the Gamma Ray Observatory, we learn a lot about what's going there. That's more of the physics side of astronomy than the visual impact side of it, I would say.

For Hubble to continue to do its part of the job of all of these telescopes, it's about to receive on-orbit servicing, although a little earlier than was originally planned because of the failure of some of its gyroscopes. What do these gyroscopes do? Why has their failure prompted NASA to take the step of flying this mission ahead of the original schedule?

The Hubble Space Telescope has been running for many, many years on orbit unmanned, unserviced most of the time. It's like a ship at sea: periodically it needs some repair and refurbishment. Part of the system that steers the telescope to point towards that star or that one over there consists of big wheels that are spinning and cause, like an ice skater spinning on the ice, cause the telescope to spin in the opposite direction as the wheels spin one way. They actually help to orient the telescope. Then there are small wheels that just act as gyroscopes, sensing this rotation of the telescope, and those gyroscopes are critical to let the telescope know when to start and when to stop its movement, and to remain pointed steadily. As a result, the designers of the telescope were smart and they put on board-you need three to do this job correctly because there are three different directions in space-and there are six gyroscopes on board. So at any one time you can have three of them turned off and three working and you'd be pointing just fine. Well, we've been using up the spares, and we're now at the point where we have just three gyroscopes running on the telescope, and it's time to put some new boxes in with two each so we'll have a total of six gyroscopes once more after this mission.

To begin to do these servicing tasks, on Flight Day 3 of this mission you and your crewmates are going to approach this telescope and snatch it out of orbit and secure it to a rotating table in Discovery's payload bay. Talk us through the procedures of rendezvous, grappling, and berthing of the Hubble, and point out what it is that you will be doing as you, or as a part of the crew, goes through this process.

My designation on this flight is Mission Specialist No. 4 and I'm the EVA crewmember number 3. What that means is that I'm one of two EVA teams who've been training primarily to perform a total of four EVAs to change out a number of systems on the Hubble. The first priority, though, are the gyroscopes we've talked about. However, we have to get to the telescope first. My role initially on the flight is to participate, after we're on orbit-I'll ride on the middeck during ascent-and after the eight minutes and thirty seconds that the main engines run-we lost the solid boosters two minutes into the flight-and we've had main engine cutoff, I will get out of my seat, the MS3 seat by the hatch, and I will help the other crewmembers get out of their suits and rapidly configure the middeck to be a livable, habitable place where we can then conduct the rest of the mission. I'm also the medical officer on the flight, along with the Pilot, Scott Kelly. After the first day, the second day my other main responsibility is for all of the photo and TV recording and picture-taking that we have to do for the different mission phases: approach to the telescope, the grappling of the telescope with the arm that Jean-François Clervoy will do, and then the surveys we'll do of the exterior of the telescope looking for meteorite damage to the skin of the telescope. I'm prime to make sure all of that is working well. There are other crewmembers who will have to do some of that when I'm outside, especially during EVAs. Steve Smith is the lead Payload Commander for the flight. His job is to make sure the whole EVA picture is coming together, that we have the right tools, that we're properly trained in concert with the Commander, Curt Brown. Steve Smith and I are responsible for making sure the tools that we take out with us-and we have three-hundred tools on board, different tools-that the selection of tools that we choose to take out on that day of the EVA we put together correctly, in the right places, according to my ballet that I've worked out, on where they go on the stanchion or on the handrail. We put those together, we check them out, make sure the batteries for the power tools are charged up, etc., and gather those together in the airlock. Finally, when we either get ourselves into our suits-Claude and I, and go outside, we then continue and actually do our spacewalk, that's the easiest part of it, that's the thing we trained the most-or we work to get the other pair, Steve Smith and John Grunsfeld, into their spacesuits, and get them together, button them up, make sure the tools are with them, and close the hatch, and then help them depress the airlock and put them out into the payload bay. When I am not doing a spacewalk, I will be what's called the IV crewman, that's the intravehicular crewman, and I'm responsible for all the activity on the flight deck that directs the EVA. I am the choreographer during the other pair's EVA. I tell Steve and John what's next on the checklist, what we're going to do next, and if we have problems, I'm the interface to Houston to work them out and then tell the EVA crew that's out there what to do next. In turn, when Claude and I go out on the second day and on the fourth day and we do our EVAs, Steve Smith will work as the IV crewman directing us. I should tell you that on EVA Day 2 with Claude Nicollier our prime task, the very first thing we do, is to change out the brains of the Hubble Space Telescope. It still has a 286 computer-with co-processor-that runs all of the systems and equipment on board the telescope. It's obviously a little out of date. A 486 by most people's standards is out of date, but this is a pretty special 486: it's able to withstand all of the radiation, and there's very strong radiation, up at the high altitude the Hubble flies without causing the program to crash. This 486 computer we'll replace in the first half of the EVA on Day 2, and Claude will be assisting me. I will be changing out roughly nine or ten connectors with about a hundred pins each, and I mustn't bend the pins, otherwise that would be bad for the telescope. This computer's about the size of a chair, it's a big box, although I'm sure the chip is just a small piece of it. The connectors are large, they're large enough for me with my EVA spacesuit gloves on to detach the connectors from the old computer, remove the computer, having undone six bolts with a power tool, and pass that to Claude. Then I take some adapters that go onto the seven cables that go on the side of this box so that I can put them on without bending the pins, and then I receive the new computer, put that in, bolt it in with six bolts, and put these cables on one by one, being very careful to make sure all the pins line up, these hundred pins I talk about, per connector. Once I've completed that function, we close the bay up and move on to the next task of the first EVA, which is to install… it's like a scientific instrument but it is not: it's actually just a simple visual telescope instrument called the Fine Guidance Sensor. It's a fancy title, but all it's doing is looking at stars, and stars that the telescope knows and recognizes, looks at them continuously to make sure the telescope doesn't move while the other instruments of the telescope are doing the actual scientific observations that the astronomers on the ground require. This equipment called the Fine Guidance Sensor is the size of a baby grand piano and actually is a telescope detector. We have to-Claude now is the prime on this-and Claude will be on the end of the arm, will open up the doors with my assistance, he will take it out, I will be giving him "back a bit, left a bit, right a bit," but he'll be doing the motion, pull it out and then he will take it down to the side of the shuttle payload bay sill where we will leave it temporarily stowed. Then we'll go and get a new one out of the cargo bay, that we've taken up with us, bring that up, I'll take a cover off the mirror-it has a mirror on it that picks off light from the main tube of the telescope-and then he'll install that back into the telescope and we'll close up the doors. That's our first EVA, which is Day 2 EVA.

Before you talk about the second one, let me back you up for just a moment. The first part of the EVA and the replacement of the computer that you've described, I take it you will be on the end of the arm.

That's correct, yes.

How difficult or easy, just relatively, is it to coordinate that work with the person inside who's running the arm?

It's very, very simple. The difficulty is only if you don't talk to the arm operator beforehand and agree on a convention about left a bit, in a bit, right a bit:, what does "in" mean? What does "up" mean? In space there's no up or down, so you have to make sure each of you understands what you're talking about when you ask for it. We have conventions about how to move depending on whether we're above the payload bay or whether we're close towards the telescope and we change our frame of reference accordingly, and we tell each other what frame of reference we're using. As a result it's almost invisible to me, it's almost like it's an extension, you just say "in a bit, left a bit," and it all happens, it's almost instantaneous, it's as if you were moving yourself. So there is very little difficulty in coordination, as far as the motion of the EVA crewmember goes. What is difficult and what is one of our biggest concerns is maintaining the rest of the arm's clearance, especially its elbow, away from the telescope's solar arrays. The great challenge for us is to move in towards a tight spot on the telescope, do our work, and the arm may be kind of cocked, and not have the arm touch the solar arrays. Sometimes the places we go into Jean-François Clervoy, the arm operator who's prime, will have trouble seeing us on the end, and so he has to rely on our call, looking around in the helmet while we're doing our task, to make sure that he is clear and isn't going to bump something with us on the end. That's the area where we have to pay a lot of attention.

Let's go back then. You were about to tell us you and Claude Nicollier will make the second of two planned spacewalks scheduled on Flight Day 7. Talk us through that timeline again and what the jobs are that the two of you will be trying to accomplish.

All right. Well after our first EVA, which is the second EVA of the mission, Claude and I will take a rest. We'll work as the choreographers for Steve and John who are doing their second EVA, and then finally our shot will come again on the fourth day of EVA when Claude and I will pick up all of those tasks that we didn't achieve, as a crew, in the previous three days of EVA. Having completed those prime tasks, and they have priority any that were missed, we expect to actually get ahead during the EVAs, I should add, but if we had difficulty anywhere along the line, we do any one of those things that either Steve and John didn't get done or we didn't get done on our EVAs. We would then move into our planned activity which is to install space insulation blankets along the length of the tube of the telescope. I need to explain a little bit about what I'm talking about. Over many, many years, eight years the telescope has taken a number of hits from meteorites. In addition, the very hard ultraviolet light that comes from the telescope has reacted with the mylar and foil and coverings of the telescope to make it brittle. In addition, the paint pigment that's on the handrails-and that's generally a yellow pigment-has lost its gloss because of atomic oxygen. It's a very, very rarified atmosphere up there. There's only a few molecules, but even so it's a very reactive chemical, this atomic oxygen, that's high up in space there, as well as the radiation, have caused degradation to the handrails, and to the mylar film of the insulation. So as a result we are expecting to see some blankets in fairly tatty condition: peeling or cracking, coming off. We have covers to put on the handrails that we're taking up with us, and Claude and I can install those just as Steve and John can at any moment in our EVAs; but more important, we are planning to put sheets-literally like wallpaper-down the length of the barrel of the telescope to cover up the whole side that's been generally-most, we expect-degraded because it's been pointed towards the sun the most. We will-it's the side opposite from where all the star trackers are and the gyros, and it's basically a half a cylinder's width-and we will run all the way from the top of the telescope, which is like sixty feet up above the payload bay-the arm can't reach that high so Claude's going to be holding my feet while I go the last six feet to put up this blanket to the top-and then we start running it down, literally rolling it down, and it's about five feet wide, this wallpaper roll, and bring it all the way to the base of the equipment bay about midway down the telescope. We put these blankets on basically with simple lanyard wires, thin wires, and clips that you could buy in a boat or hardware store. We have nice little schemes and plans to tell us where the clips go to on the telescope and what to hook them on to, handrails-we use all kinds of things that are on the telescope, never planned for, but now serving the purpose: we're going to handrail stanchions, we're going to trunnions that we used to take the telescope up in the very first place, on its maiden voyage, and we do this a total of seven times. Actually, we have four large ones to do from the top to the midsection, and then we have three smaller ones around the midsection that we install. This insulation will not only make the telescope look better, but that's not the purpose; it will enable the equipment inside the telescope to remain cool, or within the temperature range that it works well at. As you probably know, computer equipment, watches, radios, it only works in a certain range of temperature. If it's too cold, it'll quit working; too hot, quit working. The extremes in space can go all the way from absolute zero, or three degrees above absolute zero, all the way up to many, many thousands of degrees Celsius or Kelvin. So that, the mid-range that we choose-which is about room temperature actually because the equipment's designed on Earth-has to be maintained at that temperature and we do it with insulation generally. The telescope also has some heaters inside that keep things warm. Overall, the problem in space is to keep warm, not to keep cold.

With all the spacewalks concluded and planned improvements to Hubble concluded, it'll be time to put the telescope back out to continue its mission. Tell us about the plan for your crew for concluding your operations with this satellite.

After the last EVA we'll have gathered up all our stuff, tidied up, left the telescope, I hope, in good shape for another three or four years, if we don't get to visit it again in that time. The following day we will deploy the telescope, and its configuration will be one of instant readiness to do science. I think it will only take a day or two to have that telescope once again looking at the targets that the astronomers have picked. As we put these boxes in during the EVAs, and they're pretty serious boxes-I mean it's like the brains of the computer is what I'm replacing-as soon as I've done it, before I've even closed the door, I stand back and I say, "OK, Houston", and they then say "OK, Goddard Space Flight Center, you have a "go" to test the box", and as soon we've installed a box there is a functional test, we call it an "aliveness" test, to make sure the wires, at least, that I connected up are connected. They don't go through all the programs, that can take a lot of time, but they at least do that functional test of the connections we've made to check that everything's sort of OK before we leave the telescope. Once we go to bed during the night, they will be testing the boxes that the EVA crew installed during the day, and doing a full functional test, to make sure we don't need to go back and replace it with the old one, or a spare. We do have a spare computer on the flight, for example, so we will have left it in a pretty new, refurbished condition, ready to do observations for two or three years, and I'm sure we will be pleased, I hope, and also sad, to say good-bye to such a great observatory, but knowing it's going off to do some more work.

Discovery will then head home having completed another important upgrade to the Hubble and, as well, demonstrating that shuttle missions can be planned and prepared and executed in a relatively short period of time.

I was going to say, I don't want to bring too much attention to the short period of time. It's more a matter of announcement that gives the impression of short time. The mission being moved up a year, that changed when we launched the mission, but the team, there's about a hundred or so engineers that are always thinking about the next refurbishing of Hubble and they're working continuously-it's a career for them, they're always ready to go do something. So for them, it's just a matter of choosing what they're going to do and that's what's happened, I think, on this mission. So as I say again, it appears if you're not involved in the project, that there was a decision made to go and do a mission to Hubble with six months to go, but actually the team was continuously working. As I say, we've been training on it for six months beforehand, we already sort of knew what was to be done, we just chose what to do.

With that in mind, and perhaps on behalf of those hundreds of engineers who've been involved, when you're asked, how do you explain how this mission, the mission that you and your crewmates and the people who don't get to fly with you, all of those people, how do you explain how this mission helps further the objectives of space exploration?

Well, it's always a good idea to look out and see it the best you can before you go there yourself. You know when Lewis and Clark went west they always used an eyeglass, I'm sure, to see what was out there before they walked that way, to choose the best path. In a very simple way I think astronomy, for one thing, satiates our curiosity, but second shows us what's worth going to. Mars or Venus? Choose Mars. Should we go to the moon? Where on the moon? Do we go to the highlands or to the lowlands? That was done with astronomy, with telescopes. Astronomy is the first inkling that humans have of what there is to go to. Then follows the question, do we want to go there? I mean, when you look at the burning surface of a sun, no, you don't want to go there, but you're going to learn about it. Do you want to go to a planet, if you see one someday, and I think fairly soon, we're going to see-and maybe with Hubble, maybe with a follow-on-we're going to see another Earth around a solar system, with oxygen in its atmosphere, and that's going to open up our eyes, we're going to say, "Wow, we can go there and actually live there." Of course, what we'll do, if there's oxygen in the atmosphere that also tells us something, according to our science, that there's already life there, so what we're going to do is we'll start listening with our radio telescopes, we're going to start trying to find out, we're going to try to communicate, maybe, with that planet. Pretty soon that's going to happen, we're going to see planets like that, and that's in the future of astronomy. Then we have to face the difficult decision of, do we want to go there? When do we want to go there? Can we afford it? What will we get out of it? Are we going to trample this new world?