Preflight
Interview: James Newman
The
STS-109 Crew Interviews with James Newman, mission specialist.
Why
did you want to become an astronaut? What made you want to become
an astronaut?
Oh, when I
was growing up, it was in the period when people were first going
to the Moon. And, that was a very, very exciting time. I was about
13 when we landed on the Moon. And, I realized, watching those people
work on that project, that it was a very exciting thing to be doing;
Something important, important for the country, something important
individually. And, I really liked that concept of service as well
as an opportunity to challenge oneself. So, I decided that I'd like
to try to do that. And, it's been a long, it was a long time coming;
but it's been quite well worth it.
Can
you briefly outline for us the academic and the career path that
you've taken to achieve your goal of being an astronaut?
Sure. My uncle
recommended that I go into the military and become a pilot and learn
to fly and get into the Astronaut Office that way. But, I decided
that, my real love was for science and technology, and that the
right thing for me to do was to go and get a Ph.D., a physics degree,
and to enter the space program as a civilian scientist, and to use
those skills that I had developed in the laboratory to bring those
into NASA as part of the team that makes up a successful spaceflight.
What's
been your most memorable experience since becoming an astronaut,
If you could just pick just one or maybe a few?
It'd be definitely
while I was in space. And, there were, there were several. But most,
very, very high on the list was my very first spaceflight, STS-51,
which finally launched in September of 1993. And, when we first
got to orbit it was, of course, exhilarating. But, we had tried,
we had tried to launch three times unsuccessfully, we had scrubbed,
inside of 20 minutes. And, once we'd even lit the main engines;
and they had stayed on for about 3 seconds. And then, a sensor had
failed, and shut them down. So, we were, we were anxious to get
into space. And finally, when we did, I can remember getting out
of my seat and going to the windows in the aft flight deck. And,
the Orbiter was upside-down so that we were able to look and see
the Earth below us! And, it was just a spectacular flight, a spectacular
vision! If you've ever seen the IMAX movies of spaceflight, they
almost capture it all. But, to be floating, to be seeing the Earth
with my own eyes, was, was really spectacular!
Got
to imagine there's nothing like that feeling.
Yeah, it,
it's, so far it's been unique. The other one that really stands
out is on the third flight that I was on, STS-88, in December of
1998. This was the holiday season, so we were up from, the 4th to
the 15th. And, while we were up there, we had accomplished most
of our tasks in assembling the, the International Space Station,
the first two elements. And, what we'd do is, late in our evening,
which was even later in the evening of the people in America, we
were going over from south to north, going across the US, and at
first across the eastern seaboard, and then we'd go across Texas
and up, and, of course, we always go up through Canada, and then
we'd cross to California. And, as we were going over, it was one
of those unique times when the entire United States was free of
clouds. And, it was maybe midnight-ish on the eastern seaboard;
maybe a little later. And, we, all six of us were on board, and
it was in our evening (as I said), so we'd already finished the
chores of the day and we were winding down, getting ready to go
to sleep, and we were all gathered up on the flight deck. And, as
the space shuttle Endeavour, with the fledgling space station still
attached, as we went over the Earth, we looked out across a continent
of 275 million people; and we were looking at all of them, and knowing
that they, most of them probably didn't even know we were there.
But, it was very, very special in that holiday time of year. Very,
very, very beautiful.
When
all is said and done and, and you guys have completed your task
up there on STS-109, personally and professionally, what impact
do you think, being on that mission and doing what you guys are
going to do, is going to have on you, having had such an integral
part of such an important scientific tool?
Well, Hubble
Space Telescope is truly a national treasure. So, it's quite a privilege
to be assigned to go to work on the Hubble space telescope. So,
what we're looking forward to doing is, after five demanding space
walks, where we refurbish the entire telescope, really literally
make a new telescope out of it, we're going to come back and wait
for those first pictures. And, I think just feel very, a sense of
pride at being part of the team, because it takes a huge team of
people, innumerable people on the ground as well as the seven of
us in space, to end up bringing to a point, to a focus, the efforts
of all those people. So, I think it's being a part of that team
that [has] made the Hubble Space Telescope what it will be in the
future, is something that's going to be very exciting for us. The
opportunity to contribute to a science instrument of such magnitude
is rare!
It's
a good transition into talking about the mission. So, let's do that.
To help set the stage for what you and your crewmates are going
to do, can you first give us some background on Hubble? Talk about
why we even have Hubble. And, what it can do that some telescopes
on the ground and some on orbit can't do.
For the technical
details on some of that, John Grunsfeld will be a better person. But, from a science point of view, one of the problems with telescopes
on the ground is the atmosphere. As we look through the atmosphere,
typically the stars twinkle because of temperature and density gradients
in the air cause the light not to go straight through, rather to
bend and waver a little bit. Therefore, for telescopes on the ground,
until very recently (and they still haven't achieved their full
potential), is impossible for them to focus perfectly, just because
of the wavering of the light. The goal was to get above the Earth's
atmosphere in order to avoid all the problems associated with that.
And then, that way they could have longer observing times and a
very stable platform. And it enabled the telescope to, with great
pointing accuracy, to, resolve some of the finest details, which
is required in order to get a visual picture of the universe, to
see the galaxies in detail and so on and so forth.
Can
you discuss the main goals of the mission? And, talk a little bit
about what achieving those goals will accomplish for Hubble.
The main goals
of the mission, André, are really bound up in the five space
walks. And so, I'll just give a quick mention of each of the space
walks. The first one, for John and Rick, will be the replacement of the first of the old solar arrays. Mike and I will go out on
the second day and replace the second solar array. On the third
day, John and Rick will go back out (we always alternate one after the other, to give a day of rest between space walks); on the third
day, John and Rick will replace the Power Control Unit (or PCU). It's the heart of the power system on Hubble, and that's a particularly
challenging day. On the fourth day, Mike and I will go back out
and replace an old camera (the Faint Object Camera) with the ACS
(or Advanced Camera for Surveys). This camera is really the scientific
highlight of the mission. It uses recent advances in CCD technology
to literally improve the telescope 10-fold its ability to see into
the universe. And finally, on the fifth day, John and Rick will go back outside in order to put a radiator and a cooler on in order
to, refurbish an infrared detector which is now dormant because
it no longer has sufficient cooling. In order to see in the infrared,
they need a detector which is very, very cool because it's so sensitive
to the, the infrared spectrum.
As
MS-4, what is your primary responsibility on the mission?
My primary
responsibility is as a member of the team of space walkers. Mike
Massimino and I will be going out on the second and fourth space
walks. And, as the experienced space walker of Mike and I, of our
little section, then my job is to make sure that our space walks
are well-choreographed, that Mike has the opportunity to learn what
he can from those of us who have been outside before; and then when
we go out together, we'll combine our skills to make a strong team
in order to get our jobs done.
On
flight day 3, you and your crewmates will rendezvous with, grapple,
and eventually pull the telescope into the payload bay. Talk us
through that scenario, if you will, and tell us what your duties
will be during that procedure.
During the
rendezvous, most everybody is busy at some time or another. It's
a, it starts off the key players are the Commander, of course, and
the Pilot and the Flight Engineer. Our Flight Engineer, Nancy Currie,
is also our robotics operator. So, she will be not only involved
in the rendezvous part of it when we're catching up to the Hubble
and finally getting very close to it; but she'll then transition
into the role of robotic, prime robotic operator, where she's responsible
for reaching and grabbing Hubble once the Commander, Scott Altman,
has flown the shuttle, Columbia, up to a stable position with respect
to the telescope. So, in order, so the choreography of getting us
close to the Hubble space telescope starts right at launch. We launch
into about the same plane as the Hubble, and then typically we end
up in a catch-up orbit where we are catching up to Hubble in every
revolution; every time we go around the Earth, we get a little closer.
The closer we get, the finer the degree of control has to be; because
in the end we want to get within a few feet of the Hubble, and we
start off perhaps many hundreds of thousands of miles away. The
Commander and the Pilot will be responsible for performing those
burns, with the help of the Flight Engineer. And, as we get closer
and closer then, others of us start helping out as well. We bring
in some computer assistance for situational awareness, a rendezvous
and prox ops program, which I'll be running; and that brings all
the sensors together in one place on a laptop that allows us to
see where we'll be in the next 10 to 20 minutes, which is something
that, in space, is hard to visualize. On the Earth, it's very simple.
If I tell you I want to catch up to something that's out in front
of me, I speed up until I catch it and then I slow down. Well, in
space, it's just the opposite! Because things that are in a higher
orbit go slower than things in a lower orbit, in order to catch
up to something that's in front of us, the first thing we do is
slow down a little bit so that we'll drop into a lower orbit, which
on average goes around the Earth faster. So, by slowing down, we
speed up. And then, after we've sped up for a while, we catch up.
And then, in order to raise ourselves up to a high orbit to stay
with the satellite, we have to speed up. And, speeding up actually
slows us down on average. So, it's a different way of thinking about
it when we go into space to do a rendezvous, which again on Earth
is something as simple as catching up to something or slowing down
to it and then matching speeds. In the end, we do simply match speeds.
Once we're very close, the Commander will match speeds with the
Hubble space telescope and keep it in a stable position so that
Nancy can use the arm to reach out and grab the grapple fixture.
And,
is there, any more details about what you'll be doing specifically
during that time?
During the
final phase of the rendezvous, Rick Linnehan is responsible for
using the handheld laser, and that allows us to sort of like what
the police officers or state troopers use when they're checking
your speed in an automobile. We use that same piece of equipment
in space with a slightly different frequency tuned for space use.
But, using that laser, handheld laser, we can, once we get to about
1,000 feet from the Hubble, we can use that as a backup to the radar
mode, which again, of course, we also use on Earth in order to keep
track of our speeds on freeways and highways. And, then we can use
that as a backup and then finally as a prime method of telling how
far away we are from the Hubble, and how close we're getting to
it. And then, again, I'll be making sure that all of that information
comes together in the laptop computers that we use to enhance our
situational awareness of where we are, where the payload is, and,
and where we'll be in the next 10 to 15 minutes.
As
you envision the mission unfolding, which activities (I know we
mentioned the PCU and we'll get to more of that later), but which
activities do you think will present the biggest challenges and
why?
Right now
we're thinking that the biggest challenge we'll have on the mission
is probably the Power Control Unit, the PCU for short, is a box
which was not originally designed to be removed or reinstalled by
space walkers. It is what we call a difficult or marginally acceptable
task, which by building very good tools and by doing a lot of training,
we feel we've been able to mitigate the risk associated with doing
a change-out like this. It's not really planned for a space walk.
For a space walk, since we're working in pressurized gloves, our
hands don't have the same level of tactile sense or strength even
that we have in our bare hands. So, what they've done typically
with connectors that are designed for a space walk is to make them
oversize with large wing tabs on them, so you can easily operate
them with a gloved hand. The connectors on the PCU are standard
connectors with no special provision for space walkers. They're
literally impossible to do with a gloved hand. So, we've developed
a special tool which allows us to get in at sort of a pliers, which
is a simplification, but a pair of special pliers which allows us
to reach in to a double row of connectors (one set of connectors
in front; another set in back), to reach in at an unfortunately,
a difficult angle as well, so we're kind of actually doing it with
our left hand and using our left eye in order to see what we can
because we're kind of scrunched up against the door on the one hand
and against the instrument itself, the PCU itself, on the other.
So, we go through with this special tool to remove the connectors,
and then we put in the new power control unit, which they have kindly
put a 15-degree slant in so that sometimes we can get both eyes
on it. And, then we put the connectors, back on. That's considered
to be the most challenging because of the nature of the connectors.
Typically, we try to avoid that kind of work. But, it's felt to
be imperative in this case because the old Power Control Unit has
started to exhibit some faults. There's some relays that have failed;
and, in particular, one of the main bus bars is showing some resistance
to ground. And, as a ground bus bar, it needs to have zero resistance
to ground. So, the PCU (Power Control Unit) may fail at some point
in the near future. And, in order to avoid that, because it would
entail the loss of some science, quite a bit of science on the Hubble
space telescope, until somebody else could come up and fix it, we're
trying to make sure we do some preventative maintenance to ensure
many years of successful operations.
Can
you, having been on the ISS assembly mission, and, having trained
for this Hubble mission, can you draw any similarities or differences
between the two as far as logistics? What goes on on both of those
missions?
The first,
International Space Station mission, STS-88, Bob Cabana the Commander
and then, five others of us, were filled with uncertainty because
it hadn't ever been done before. So, we weren't quite sure how it
was going to work. These two pieces of hardware that we were putting
together, one built in Russia, one built in America; they'd never
been put together before. So, we were all anxious and hopeful that
it would work. And, it did work! It worked surprisingly well, which
is a testament to the number of people who worked so hard on it.
The same thing is true in many ways to the Hubble. There, it has
a, a very strong record of success because of the number of people
who have worked so hard on it. Now this is the fourth servicing
mission, so the rendezvous, the grapple, the going in and out of
the doors on the Hubble, these are not new tasks. But, what we're
doing is a series of very highly choreographed, very challenging
space walks to remake the telescope. And, so that, I think, is where
the challenges really come in. Again it's an integration task. We
have worked out what we feel the best sequence of space walks is
in order to accomplish the, priority tasks. And, if there's a glitch,
if the hardware ends up not fitting as expected (because Hubble
has been in space for more than a decade and has never been totally
powered down), so we expect that Hubble could throw us some surprises.
And, that's where the two missions and any spaceflight, really,
has its similarities, and that is that you never know what's really
going to happen.
Talk
a little bit, if you would, about how your experience on STS-51
helped you train for this mission and how you expect the experience
to translate, up there with Hubble.
All of my
spaceflights (STS-51, -69, and -88) have all been robotics-, and
space walk-intensive. And from that point of view, STS-109 is another
one just like that. It's a little more intensive in the space walk
area; it still has a strong component of robotics; and it has very
few other distractions. So, we're really going to focus on those
primary tasks. So, what I see is that STS, my, the first flight
I was on STS-51, was really very good training for all of the flights
I've had since. It helped set a framework with a space walk that
Carl Walz and I did on that flight. And, if we do fly in February
as planned, Carl Walz will be on orbit again on the International
Space Station with my other crewmate from STS-51, Dan Bursch. So,
I'm hopeful we'll all be in space again at the same time. they'll
be inside the lower orbit than we, so we'll have to wave down at
them! But, it'll be very exciting to be in space the same time they
are. But, I'd say the work that Carl and I did on our space walks
set the groundwork for being able to be successful on STS-69, and
then on my space walks on STS-88 as well. So, I hope to take all
that experience, bring it to STS-109 (the Hubble re-servicing mission,
refurbishment mission), and again have a successful flight.
Okay.
Let's talk a little bit about some of the equipment if we can. First,
we'd like you to give a brief description of the particular pieces
of equipment, starting with the ACS. What does it do? And, how is
it expected to enhance the telescope's ability? You touched on it
a little bit earlier, but if you could just expound on it a little
bit more.
Yeah. In general
terms, the Advanced Camera for Survey, surveys, uses modern CCD
(charge-coupled device) technology as the core of its camera. And,
of course, we've always had CCDs, but, on the Hubble because we
can't take film pictures on Hubble and get them back to Earth. So,
we always use electronic devices. But, the Advanced Camera for Surveys
is just that: it's very advanced, using very large CCDs of unprecedented
quality and sensitivity. And, that's the heart of it. It's like
a camcorder; all of our camcorders that we buy nowadays have these
little CCDs in it. Well, Hubble's going to have a huge one and,
a very, very sensitive one! And, it's going to be able to take pictures
and integrate the pictures over long periods of time, and, therefore,
be able to, using the optics and using the enhancements in the CCD
technology, to deliver unprecedented quality and clarity of pictures.
For
EVA-3, the telescope's power will be turned off since the first
time it was launched. Why is powering down the telescope a particular
concern?
One of the
interesting parts about the Power Control Unit (the PCU) is that
since Hubble has never been turned off in over a decade, think about
when things break at home. Typically not during normal operation.
Once they're running, they just run. But, if you turn something
off and then it's when you turn it back on again, usually the light
bulb will flicker out or the TV will crackle. So, we're all very
concerned about when we power back on, are very interested in that
process of when we power back on the Hubble Space Telescope after
the Power Control Unit has been successfully replaced because we
feel that it, it's really at that point that there is, there's actually
probably our greatest risk to the telescope. And so, the Goddard
Space Flight Center and the Hubble team have gone to extraordinary
pains in order to analyze all of the equipment and to look at the
redundancy that they have available in order to ensure that when
we power things back on, that we'll have a successful telescope,
an operating telescope to release once we're done.
Let's
talk about the EVAs now, if we could, in more detail. On flight
day 4, John and Rick are going to egress the airlock and start a series of EVAs for this mission. Can you take us through the timeline
of EVA-1 and talk about what you and Mike are going to be doing
inside the Orbiter for EVA-1?
During the
space walks, obviously the focus of attention will be on the two
space walkers outside. They're the ones doing the work. But, the
way we organize it inside is also very important, although we're
more of the behind-the-scenes people. We call the space walkers
"EVAs," the extravehicular activity. And the space walkers
themselves are EV-1 and EV-2. On the inside, it's called intravehicular
activity, or IV. And so, I'll be, as the experienced person, I'll
be running the IV side of the show and Mike will be watching me
the first couple of times; then he'll be in charge of one of the
later space walks as the IV. The IV, or the intravehicular activity
person, actually is responsible for the checklist and for managing
the space walk as it develops. If everything goes per plan, then
we know approximately how long we think things will take and we'll
be able to step right through things, one after the other. I'll
be calling out the reminders to the space walkers of what they're
expected to do next. I'll be telling them how tight to tighten the
bolts, what torque settings to set on the power tool in order to
loosen the bolts, when to do the various activities they're doing,
really, the real-time choreographer. If things start to, if problems
occur, for example, then Mike and I work as a team. He's responsible
for backing me up, making sure I don't miss anything, making sure
that we have the right checklist open, the right information at
our fingertips. If something, if a bolt weren't to turn, for example,
say it were stuck, then what we have is a, what we call a "crib
sheet," a list of, for every bolt that we're going to touch.
What we can do. How high a torque can we torque on it before it'll
break, for example. What do we want to do if this doesn't work?
What do we want to do if that doesn't work? So, together Mike Massimino
and I will be the IV team. Nancy at that time, Nancy Currie, the
robotics operator, she's the prime robotics operator, so she'll
be flying the arm around with one of the two space walkers on it.
And, they will then be able to carry around large pieces of equipment,
the solar arrays or anything else that we need moved from one place
to another. Now, her backup there is Scott Altman, the Commander.
And, he'll be helping out where, whenever she needs help with her
systems. So on the inside we also have a very tightly choreographed
and rehearsed support group. Our goal is to support the space walkers
while they're outside to make sure they know what they need to know
and to be able to, as efficiently as possible, use that space walk
time. Going on a space walk is inherently dangerous. One has to
be aware of the risk. But, we manage them carefully so we feel very
comfortable doing them and, in particular, in the service of a telescope
like Hubble.
Are
your and Mike's, IV activities, do they differ from day-to-day,
or will they basically stay the same?
What we'll
do is, since every space walk is different, we'll have different
activities. But, the concepts will be very, very similar. We'll
have set up the team. I'll lead the first two space walks, for John and Rick. That'll be space walk number 1 and space walk number 3.
And then, I'll give Mike the reins. He'll be the lead for the fifth
space walk, and I will support him. That way, again, we're mentoring
the new guys, bringing them up to speed so that they will be able
to provide the experience base for the future flights where they
are space walkers and lead space walkers. On EVA space walks 2 and
4, John Grunsfeld will be the lead IV for the second space walk, and then he will transition to Rick Linnehan to bring him up to
give him an opportunity to be the lead IV, the lead choreographer
on the, on the fourth space walk.
On
flight day 5, you and, Mike are scheduled to go out and, perform
EVA-2. Can you talk a little bit about what will happen? Take us
through the timeline of what you guys will do? And, talk about any
differences there might be between EVA-1 and EVA-2 outside.
Mike and I
will be going out on the second space walk on flight day 5. And,
currently we, if we assume that everything went well on the first
space walk, then John and Rick will have replaced one of the old solar arrays with one of the new solar arrays and done a little
bit of get-ahead task in preparation for the really hard day space
walk 3. Mike and I have a similar day on the second space walk,
but we don't have as much initial configuration to do. Since John and Rick are the first ones out the door, they have to do a little
bit of initial configuration in order to set up the payload bay
for the rest of the space walks. And, they'll do some final de-configuration
on the very last space walk. When Mike and I go outside, I'll immediately
head back and get to work and Mike will take a couple of minutes,
just to get his space legs. He will have an opportunity to translate
a little bit around in the payload bay in order to become familiar
with what it's like to be a space walker, and then we're going to
put him right to work as well. He'll start off on the arm, and will
immediately go to work, getting ready to take the old solar array
off and stow it in preparation for taking the new solar array up
out of the bay. And, Mike will in the end handle that by himself
for a certain period of time as Nancy maneuvers him around so that
we can install it into the telescope. I'll be working on the telescope
at that time myself, and driving the bolts, changing out diode boxes
and, in general, working with Mike. He'll bring equipment up there,
and I will install some of it. I'll give him old stuff, and he'll
take it away. Towards the end of the space walk, Mike and I will
swap roles on the arm in order to give him some experience with
the space walking task while he's not on the arm in preparation
for our next space walk. So, I'll be on the arm for the very end
of the space walk; and Mike will have an opportunity to what we
call "free float." He'll maneuver around throughout the
payload bay and on the telescope by himself without the assistance
of the arm. The arm is really a very useful platform to work from.
So, I always enjoy being on the arm. It, with both of your feet
stabilized, then you have both hands free to work wherever you need
to. When you're a free-floater, you have to use your hands to crawl
around. And, we call them space walks; but in truth, they're really
space crawls because there's nothing to walk on in space. So, we
actually crawl on handrails from one place to another. And, it's
very hand-intensive. And so, it'll give Mike and myself a good refresher
on what the other's on, on what the other side is like.
EVA-3
is the only scheduled space walk, scheduled for more than 6½
hours. Why is it expected to run longer than the rest of the EVAs?
The PCU change-out
is, right now, timelined at 7 hours. And, that's for planning purposes.
When John and Rick go into the pool, into the Neutral Buoyancy Lab, they are able to get it done in 6½ hours. The 6½ hours
includes a 20% margin, which means that it actually only takes them
a little less than 5 hours, 20 minutes. But, we add 20% to that
time just for the differences between the NBL and (the Neutral Buoyancy
Lab, the big swimming pool) and spaceflight. Because there's always
differences and you're not sure whether it'll take you longer or
a shorter amount of time to actually do the task. To be conservative,
to be prudent, we take what, however long it takes us in the pool
and add 20% just for a safety margin. And then, because PCU has
all these connectors I was describing that may or may not be easy
or difficult with the special tool, they added an extra half-an-hour
just for those connectors in case some connectors are particularly
hard, in case we can't get the old PCU off because one of the nut
plates was to spin. So, we've added in some extra safety margin.
If everything goes well, they could be done early. If things don't
go well, they could spend some extra time outside.
In
general terms, what is the purpose of a breakout planned strategy
and how did this concept come about?
The Hubble
space telescope is a very, very important piece of astronomical,
of our astronomical observatory. It's the, the jewel. And so, every
day when we finish with our space walks, we're supposed to leave
it, we, it's desirable to leave the telescope in a safe-to-deploy
configuration. And, that's because you never know what could happen
overnight. It is extremely unlikely that anything will happen, but
a fuel cell could fail, a micrometeorite could make a small leak
in the Orbiter. Something could happen. Very unlikely, but something
could happen that would result in the need for us to very rapidly
deploy the Hubble space telescope. And, in order to make sure that
we don't lose the capabilities of the Hubble, we want to leave it
in a safe configuration whenever we can. Just in case. So, on the
PCU day, because it may run long (if things don't go well), they
want to have some breakout points where they can say, "Well,
it looks like it's just going to take too long today. We're not
going to be able to get it done. The space walkers will run out
of oxygen, or they'll run out of lithium hydroxide to scrub the
carbon dioxide out of the air, or they'll run out of battery power.
So, if they're going to run out of time, then we need to be able
to leave the telescope as safe as possible." And, that's what
the breakouts are designed to do, is to leave the telescope hopefully
in a safer deploy configuration which would then, if something were
to go wrong with the space shuttle, we could deploy it and it would
be safe until the next crew of astronauts could come up and finish
whatever job it was we were on.
Why
is the successful completion of EVA-3 so critical to the future
operation of the telescope?
The third,
space walk, EVA-3, is critical not just to the future operation
of the telescope because of the Power Control Unit itself (it gets
the power to all the instruments), it's also critical to even finishing
the space walks as planned. Because we have so much to do and only
five space walks to do it in, we need to try to finish each space
walk on its day. And, because PCU is the potential challenge, and
things are so highly choreographed, if we don't finish that one
and Mike and I have to go out, for example, the next day to finish
the job, then we may not have a chance to finish all of the Advanced
Camera for Surveys work, depending on what was wrong with the PCU.
And then, that might then take the next day of John and Rick to finish up the Advanced Camera for Surveys. And then, we still want
to get this infrared detector, because that's one of the really
fantastic detectors that, it discovered this dark energy concept,
just recently for example, which is revamping the way we think about
the expansion and contraction of the universe. So, it's really desirable
to get all these done. And, that's sort of the, the lynchpin there,
is the, if we don't get that one done, it may impact what we do
on the other space walks. It may necessitate adding a sixth space
walk that Mike and I would then do in order to complete any tasks
that weren't completed on the first five space walks. And then,
again, just from the simple point of view of if the Power Control
Unit doesn't work properly, then it may not direct power to some
of the necessary instruments. Which would, of course, impact the,
the future of the telescope.
Good
deal. On flight day 7, you and Mike are back outside Columbia for
EVA-4. Can you take us through that EVA and explain to use what
you'll be doing up here?
On the fourth
space walk, when Mike and I go out again, we will swap roles. We
will have Mike start out as the free-floater and I will get immediately
onto the robotic arm. And, in that way I will be responsible for
the removal of the old instrument and the insertion of the new one
from the end of the arm. These instruments are hundreds of pounds
(700, 800 pounds), and so it really makes sense to use the robotic
arm with a person on it to move them around. While I'm doing that,
Mike will be providing the hands-on, at the telescope. He'll be
driving bolts as well, helping me open doors, and doing a number
of other tasks. So, it's similar to what I was doing on the, on
the first time Mike and I went out. And, but, on the first time
Mike and I go out, he'll be handling the large stuff on the arm;
the second time, I, I'll be doing that. Once we have completed the
extraction of the old instrument and the installation of the ACS,
then again, Mike and I will swap our roles on the, on the arm; and
we'll go back to the back of the spaceship, back of the payload
bay and we'll get out the ESM. And, that particular piece of equipment
is used as part of the NICMOS cooling system. And so, we will be
bringing them, installing that in preparation for the next day.
So, what we're going to do, once we finish the main task, which
shouldn't take the whole space walk, we do some cleanup from the
previous day and we do some get-ahead for the next day.
The
ACS is, from my understanding, the most important component of the
mission. What are your thoughts about having such a critical role
in its installation?
When Mike
and I first started training for this flight, the order of the space
walks was a little bit different. And, Mike and I were responsible
for doing the PCU, which is also an important and a very challenging
task and John and Rick were doing the ACS, the Advanced Camera for Surveys. When they swapped it, it was kind of good news/bad news
thing. 'Cause we, were no longer were responsible for PCU, which
is expected to be quite a challenge; but we now were responsible
for this very delicate, very, very expensive, very, very important
instrument. And, Mike and I are both very excited actually to be
doing it. It's a, as part of the team, it doesn't really matter
who has hands on when we do this. It's all really part of the team,
and we're all working at it together. We all succeed or fail together,
as a team. But, we, we're not totally sad to be doing the Advanced
Camera for Surveys. It's a very exciting instrument. We're looking
forward to being able to say to our children someday that we helped
as part of the team that took some of these new pictures.
Something
happened with Hubble, at some point last year that made it necessary
to add a new task. Can you tell us what happened with Hubble? And
what the result is? And what you guys are going to do.
One of the
reaction wheel assemblies (RWAs, for short) did experience a sensor
failure last year. The speed sensor, tachometer sensor tells the
ground how fast this reaction wheel is spinning, stopped functioning.
And what the ground determined, the Hubble space telescope control
center determined was that that wheel is still spinning normally.
So they're still able to point the telescope (because that's what
these reaction wheel assemblies are for is for the accurate pointing
of the telescope and holding it stable that allows them to take
these unprecedented pictures that we see so often). They determined
that the reaction wheel assembly's working well enough and is understood
that they can continue operating Hubble. It's not an impact. So
from the point of view of impact to any science, observations astronomy
that they're doing, there hasn't really been any. However, there's
a possibility of another failure resulting, which would then cause
Hubble to be unable to point accurately enough to continue doing
its observations. And therefore, fairly late in the program, in
the training flow, they have added a new task, which is to swap
out the reaction wheel assembly that has had a problem. And, it's
timelined at a little bit over an hour of a task. So it's not a
large task. It's not a complicated task. And we see this as something
that won't really be in the end all that difficult to train for.
And
it is a task that's been done on Hubble before,--
Right. It
has been done. It was, last, in fact, the same, this same reaction
wheel assembly that has experienced the failure was the one that
was changed out on the second servicing mission, STS-82. And we've
talked to Mark Lee who performed that change out; and learned from
him what we could. And what he basically said was that it took them
about as long, about 45 minutes, about an hour to do, as they had
trained for in the big water tank. And that…[we] should expect
no surprises. That it's fairly straightforward. A very, only four
connectors, three bolts. And so…inside…one of the bays.
And
are there things that have moved as a consequence of this new task?
Yes. We, the
timeline that we had choreographed for the five space walks prior
to the addition of this task was optimized for the tasks that we
had. And also based on the priorities. So the reaction wheel assembly
is the number one priority now for the flight because it is the
one potential threat to doing science with the Hubble space telescope
to do any more astronomy. So it's the highest priority. But since
it's a relatively short task and straightforward, we don't have
to do it on the first day. So we found an opportunity on the second
day where we can move a few things around, move them out to other
space walks; and so Mike and I will go out and do it the last thing
that we do on the second day. And if it turns out that for whatever
reason the solar array that Mike and I are changing out on that
day runs a little long, then we can always have a backup time for
that on the fifth space walk. So it is a high priority. But it's
a fairly straightforward task. It did cause us to move around some
of the other tasks in order to fit that in. And of course, when
it, with any change like that, you have to rethink it, make sure
that the changes you make still make sense, that you've got the
right tools with you. And that's the most important thing. You've
got the right tools and the right procedures in place to ensure
that, with this change, you'll still be able to get the job done.
What's
it been like, having to start training for a new task so late in
your preparation for the mission? You guys were in a good groove
and pretty much fully trained for the mission.
Yeah. Since
it was a fairly straightforward task, it hasn't been too difficult
to add it in. Mike and I have had an extra training run. We're going
to get one more extra training run in order to make sure we've got
all our choreography down. We took an extra trip to Goddard Space
Flight Center in order to look at the hardware in the high-fidelity
simulator that they have there. And we'll look at it again at the
Kennedy Space Center. So, taking these extra trips, doing a little
bit of extra training, we're able to add it in, I think, without
much trouble. The bottom line being that, for most space walks,
you want to learn a set of skills. Being outside, how to use the
equipment? Where the things are. And then once you have those generalized
skills, you want to apply that to the task that you're doing. So
even if something changes on orbit, we have got all of the training
that'll allow us to come forward and do whatever it is that's required.
Even if it's not in the same order! Because anything could happen.
Hubble usually throws a surprise or two to the team. And so, if
we're lucky, everything will go just as planned. But if it doesn't,
we have got the training and the background, the skills to enable
us to go out and do whatever tasks are required.
Are
you guys approaching this with some sense of enthusiasm? Like, well,
here's something else we can do! You know. Or is it, is there more
enthusiasm, I guess, just about being able to do something else
on the telescope, I guess?
Yeah. We are
glad to be able to do this; and we know it's important. And that's
why people really just want to go and do their jobs. And since this
is, and we want to do it well; we really need to. So we're taking
it seriously. So on the one hand it's fun to do something new, something
a little different. But on the other hand, we are, even though it's
a relatively short task, we're taking the appropriate steps to make
sure that we've got the right conservatism built in. Hubble is such
a national asset that a number of people have mentioned to us, starting
with the Administrator and others have let us know how important
it is to them and to the Agency and to the scientific community
that our part of the bargain, our part of the team do its job well.
And so we're taking that very seriously. And we're applying that
same rigor, that same margin, conservatism, to this task as we do
to any other. We want to make sure that we do our jobs and do them
well.
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