>> Rob Navias: Welcome back inside the International Space
Station flight control room.
We're joined by astronaut Cady Coleman.
Cady, as we've been talking throughout the past few days,
the Japanese cargo ship, the HTV-4, the Kounotori 4,
is on route to the International Space Station
after its launch back on Saturday
from the Tanegashima Space Center in southern Japan.
A series of rendezvous burns has fine-tuned its path,
and it's set up for an arrival at the station on Friday.
Now, Karen Nyberg and Chris Cassidy are in charge of trying
to haul that cargo ship in and to make it a part
of the International Space Station for a month.
You had the honor and the task
of actually grappling the HTV-2 back in January of 2011,
about a month after you arrived
on the International Space Station.
Tell us a little bit about the techniques and the complexity
of what they're going to be experiencing
out of the cupola on Friday morning.
>> Cady Coleman: So this idea, Rob of having, you know,
two things come close together in space and then reaching
out with a robotic arm and grabbing one of them
and attaching it, you know, it's not new
in that we've done it a lot of times on the space shuttle.
For example, the Hubble Space Telescope,
we would go rendezvous with that.
Reach out.
Grab it. Spend some time repairing it.
But the big difference here on a space station is that,
basically, the space station can't move away.
If things go wrong and you tip off the telescope
and it starts tumbling or it just doesn't look right to you,
the commander of that space shuttle can fly
that space shuttle away, but the space station is way too big.
So it makes it a more critical operation
to get things just right.
So as this supply ship comes closer and closer,
we always have the ability to tell it to go away
if we need to, but it's going to arrive at a place that's about,
you know, I don't know, five, 15, 30 feet away
from the station, 15 feet from the robotic arm,
and that's pretty close.
So it's going to arrive there, and the robotic arm is kind
of perched -- ready just to move in like this,
and that's Karen's job.
You'll actually hear Chris talking on the radio,
because the person who is M2, or robotics operator number two,
who's backing Karen up, he'll probably do most of the talking.
Where Karen is at the controls, and she's looking at a target,
and there's a target, there's a camera on top of the arm.
So one and then two, and that camera is moving in,
looking at a target.
Where the real arm, the part of the arm
that would actually grab this thing,
is actually about this big.
I mean it's giant.
So both of those things are moving,
and at the same time she's lining up perfectly, you know,
and if when we say, okay, ready, set, go,
that's when we don't want that spacecraft
to decide it wants to go here or there.
So we turn off the capability of it to go anywhere.
So if it was already kind
of on its way sailing a little bit left --
because while it was waiting it was kind of holding itself
in a little box, back and forth, up and down.
If it was on it's way sailing when we say, no more jet firings
for you, that means that Karen has to follow it
with the robotic arm, and that's where it could be tricky,
and it can be even trickier if it's on its way, you know,
with a little more force and motion,
and we always have to be ready for that.
So that's what they've been doing lately,
is just getting ready to, you know,
practicing following something that is racing away from you.
>> Rob Navias: Does the mass of HTV-4, 16 tons of mass,
does that make it even more complicated?
>> Cady Coleman: It does make it more complicated
because we basically don't want to hurt the robotic arm.
We're going to have supply ships arriving again and again
at the International Space Station, and if it was racing
to fast and you, you know, caught it in such a way
that you didn't, you know, didn't just kind of go with it,
then that can strain the arm, put forces on the arm.
So it really has to be a very precise, very much lined
up operation, and you know, I was nervous doing it.
I'll tell you I was certainly nervous doing it,
and at the same time that's where your training comes back
into play, where you've practiced this over
and over again, and knowing that you've done your best
to be ready, that's when you can put all that stuff
out the window and just kind of focus
on doing what you've done many times before.
I'd say what's significant is that in the training,
in the sort of cartoon virtual reality world that we train in,
nothing looks that big.
I mean, this thing is huge, and it's right next to the window
of the space station, and it's pretty cool looking
down at the Earth as it gets bigger.
You know, throughout the day on their Friday,
our Thursday night, that thing is going to looks like a tiny,
little speck on the horizon, and then it's just going
to get bigger and bigger and bigger,
and by the time it arrives and you're going
to catch it, it is huge.
>> Rob Navias: So they're going to be operating
out of the cupola, which of course is the station's
wonderful window on the world,
but in reality it's pretty cramped quarters.
So you have Karen and Chris side-by-side.
Luca's right there monitoring the spacecraft systems,
making sure that it's doing what it's supposed to do.
How much of a kludge is that for the crew?
>> Cady Coleman: It is challenging
because it is physically close.
There's really not any more room than you and I sitting here,
and yet they've actually practiced just that.
I mean, just yesterday morning they practiced using the robotic
arm and figuring out who is going to be where,
and when somebody needs to reach that button,
do they knock Karen out of the way.
You know, they will have figured out their own way to sort of use
that space and their own communication together too,
of saying, you know, wait, as the arm is approaching we need
to make sure that the spacecraft is in a certain state.
So, you know, Chris Cassidy will be looking at that
and telling Karen, you know, if the spacecraft is free drift,
you are go to proceed.
So there's a lot of precise communication back and forth,
and you know, we're NASA.
We practice that stuff, and we practice what
if this happens, what if this happens?
There'll be one more significant practice session
on basically their Thursday morning, to just reinforce --
you know, we have all these what if situations.
What if suddenly this spacecraft shows that it's got some systems
that are not ready and it would be better to send it away
and wait until we can understand the state of the spacecraft?
There's two things that Chris can do.
He can push a button that says retreat,
which means it goes back to the last place it waited,
which is about 100 feet away.
Or he can push a button that says abort,
which actually sends it, you know,
to a very far away waiting place.
So -- excuse me -- they've got some options.
We really talked through and practiced those options,
and also then, on top of that,
you want to capture these moments,
both for an engineering reason -- what if something goes wrong?
You want to understand.
You want the ground to understand.
What do we need to different on the next supply ship?
Also, you just want to capture the fact
that this is a significant thing that real people are doing.
>> Rob Navias: Then once it's captured,
the crew takes a quick break, catch its breath,
and then they go through this finely choreographed procedure
to maneuver it into place so it can slowly, but surely,
be mated to the Earth facing port of the Harmony module.
So how complex is that?
How precise a maneuver is that,
because in part it's also ground assisted here
by the robotics officer in Mission Control?
>> Cady Coleman: That's correct, and you know, we're always torn
in terms of who gets to do the work on the space station.
Ideally, as a crew member, as an astronaut,
we want to do all the robotic arm stuff
because we love to fly things.
We like to do things, but it's actually more efficient
for the controllers down here to make some of those moves.
Where they take it from out here where you captured it
to then a position that is all lined up,
but about six feet away from being mated to the station.
So it's more efficient for the ground
to go ahead and make those moves.
So they probably will make those moves,
but whether the crew makes them
or whether the ground makes them, no matter what,
there's math involved, and those things have been figured
out ahead of time, and it's a precise set of coordinates.
But then when you really are going to put metal to metal,
and you know, the HTV has like these kind of, you know,
little cutouts like this, and then the space station has ones
like this, and so those things are going to touch,
and they really have to exactly kind of mesh together.
That's where the ground can do that.
I mean, we're getting so the ground could do that,
where they bring it in
and we see little indications doing well, doing well.
We can actually feel with the robotic arm.
It's got sensors that say, hey, I'm being tugged this way.
I'm being tugged this way.
So as we do that we actually see how much strain is on the arm.
So we can make sure that even if we think our math is correct,
what if something's wrong?
You know, are the mechanical parts really meshing together
without putting strain on the space station, because we need
that port again, and we need to be able to undock safely
and send our supply ship, now a trash ship, away,
and we need to make sure our robotic arm isn't getting
strain either.
>> Rob Navias: So once in place,
ready-to-latch indications are seen by the crew,
and then it's a matter of bolting it in place
in a two-stage fashion, and then it's part of the space station
for the next month so its valuable cargo can be unloaded.
Cady Coleman, 180 days in space, on three flights,
159 days in space as part of expedition 26,
27 and who captured HTV-2 about 2 1/2 years ago.
Thanks for joining us today with the insight, and just a note,
our programming on Friday morning, in two parts,
will be on the air at 5 AM Central Time, 6 AM Eastern Time
for rendezvous and grapple of the HTV-4,
with the actual capture expected just before 6:30 AM Central Time
on Friday morning.
We'll take a break, and then we'll return for live coverage
of its installation beginning
at 8 AM Central Time, 9:00 Eastern time.
All of that on Friday morning.
Thanks very much, Cady.
>> Cady Coleman: You're welcome.
It's going to be really exciting.