>> Pat Ryan: [Background sounds] [Background talking] Now,
the assembly
of the International Space Station is a task
that has relied very heavily on the use of robotics,
most notably, the station's remote manipulator system,
Canadarm2.
That was used to put entire modules into place, as well as,
to move astronauts and other equipment from place to place.
But the fact that the assembly is almost over doesn't mean
that the use for robotics is over.
In fact, last week, robots were front and center on a task --
a cargo transfer job, that didn't require astronauts
to suit up and go outside.
We're going to take a few minutes today to talk
about that recent work and the use
of robotics onboard the station.
With me is Ian Mills, who is one
of the Robotics Officers here in Mission Control.
The task last week that I was mentioning was moving things
called CTCs.
Let me get to start by telling us what a CTC is
and why these needed to be moved.
>> Ian Mills: Sure.
Okay, the CTCs are a cargo transport container,
effectively just a big metal box with a hinged lid.
They contain orbital replacement units --
ORUs, things that we can replace
on orbit robotically or EVA crew, but...
>> Pat Ryan: These are just spare parts
that are just stored out there.
>> Ian Mills: That's correct.
Now, these particular CTCs contained the remote power
controllers that we use there to switch boxes that we power on
and off different loads.
Why we were moving these particular boxes.
While we currently -- or we had, sorry, at the beginning
of last week -- we had one
of these CTCs stored onboard Dexter,
as he is commonly referred to.
We refer to him as the Special Purpose Dexterous Manipulator.
Obviously, you can see where he gets his name.
We had a CTC already onboard the SPDM, and that was
to support replacing a failed RPCM;
however, that did not happen.
There were certain thermal issues
that were brought forward before those operations were able
to take place, so we've just been holding this CTC on,
effectively on our back, as we have gone along
with other operations.
The time has come now to prepare
for the next H2 Transfer Vehicle coming, HTV-4,
and the expectation is that we will not have any cargo onboard
the SPDM because it will be used as part of those operations.
So, the main goal for the task last week was
to relocate the CTC that we had -- we'll call that one a CTC3 --
and put it in its expected location for the HTV-4 mission.
>> Pat Ryan: And in the process, freeing up a spot
on the SPDM for other uses.
>> Ian Mills: That's correct; for the transfers.
The cargo transfer that's coming
up on HTV-4 will utilize the SPDM storage location,
so we needed to clear that.
Combined with that, the program had decided
that it made more sense to put the CTC that was outboard --
we'll call that one CTC5 -- put it in the place,
move it closer to the crew airlock.
And, since there are orbital replacement units, the spares,
inside these boxes, putting that particular CTC closer
to the U.S. airlock makes it more accessible to EVA crew
if they have to go out and perform some kind of repair.
So that was the main goal for the operations last week.
>> Pat Ryan: I mentioned Canadarm2.
People are very familiar with that,
and it's very dramatic when you see it.
You don't see the SPDM that much.
Tell us what it does that the arm can't.
What makes it special?
>> Ian Mills: Okay, well, you may not see it very often...
>> Pat Ryan: Well...
>> Ian Mills: ...but, yeah, it's come to the forefront as far
as robotic operations.
What it does, allows us to do, it's different than we do
with the Canadarm, is -- it is a smaller robot that allows us
to have finer control for doing the detailed task work
that we need to do to effect repairs on the station.
Its main purpose is to allow us to repair certain units
that are robotically compatible without having
to send EVA crew out, which frees up the crewmembers
to continue with science onboard.
So that's the primary difference
between the SPDM and the Canadarm.
>> Pat Ryan: If the RMS is an arm, is the SPDM a hand?
>> Ian Mills: It's more -- I would think of more like a,
it's an extension of a -- yes, that's reasonable.
So, yeah, we use the SRMS, which is a 56-foot-long manipulator,
and it is -- it was designed and built
for space station assembly.
It was designed also to be able to pick
up the SPDM to do the fine work.
So, yeah, that's a fair analogy to call the SRMS big and the...
>> Pat Ryan: The smaller one.
>> Ian Mills: ...the smaller one would be the hand
for the dexterous work.
>> Pat Ryan: And in this particular case,
all of these operations that went on didn't involve the crew
at all, and by that I don't mean just the crew didn't have
to go outside to do work; they weren't involved
in controlling the arm, either.
It was controlled from the ground, right?
>> Ian Mills: That is correct.
Since, I want to say, 2005,
when we first started executing maneuvers of the Canadarm2,
we call it the SSRMS, that's its acronym name.
We have to use those since we're NASA.
>> Pat Ryan: Yes.
>> Ian Mills: Since we started ground control with SSRMS
in 2005, we have progressively increased our capability.
We started out with very small scripted maneuvers,
and now we're to the point where --
yes, we are engaged from the ground, solely from the ground,
with fine ORU replacement tasks that can also be executed
by the crew by EVA, but it does make a lot of sense for us
to be able to do it from the ground.
>> Pat Ryan: When we say that you can move it from the ground,
we don't mean just over here in this room, right?
There are more than one place from which you can run the arm.
>> Ian Mills: There are.
We have -- we do have a console here
in Mission Control, where we sit.
We also have a control center in Canada, at Montreal,
the Canadian Space Agency, where we do have operators
that are trained and certified as well, that do the flight,
safe flight control job.
We don't have them -- we don't have the primary position there
yet, but I know that that is in work.
So, primarily, it's run out of here.
And then, the backroom support, if you want to call it that,
is frequently manned
by our trained personnel in the -- at CSA.
>> Pat Ryan: What is it like to sit here in this room
and command a 50-foot-long robot that's in orbit.
Is that fun?
>> Ian Mills: It is fun.
For me, it's exciting to sit here and be able
to send the commands -- yes, and have the arm move,
go where you tell it to go, or complete an install of the CTC,
as we were talking about.
For me, it's very exciting;
there's a high degree of complexity to it.
I know it's probably not very fun to watch, because the rates
that we operate with are very slow.
So, to make it interesting, we have to do a time lapse playback
so that you can actually perceive some of the motions,
because that is one of the constraints that we operate
with to maintain safety, is that we operate this
in a very controlled, slow, deliberate manner,
especially when we're in contact or engaging a mechanism.
>> Pat Ryan: Your CTC operations last week proved
that it's always something that can go wrong.
Explain what it was that happened.
There were operations on two days, Thursday
and Friday last week, and Thursday you were starting
to move one of these --
the CTCs, and what did you encounter?
>> Ian Mills: Well, let me start by just saying
that I have been here at NASA for 17 years.
I've been in the Robotics Operations Group
that entire time.
And one thing for sure that I have learned is
that nothing ever goes exactly as you planned, and the issues
that you encounter are not necessarily what you are
prepared for.
So when we -- what happened
to us last week was the operation involved first picking
up CTC5 and bringing it
around to the stowage platform close to the airlock.
When we got over there and began to put it down, it got stuck;
it would not go all the way down.
And we, after a quick video survey,
realized that there are some straps, some thermal straps,
coming off of the adjacent box to where we were putting this
down that we did not account for in our models,
combined with the CTC itself actually has a handrail.
We also did not have that handrail in our model.
So, it was the interference between these straps
and this handrail that caused us to not be able
to put the CTC down...
>> Pat Ryan: It wouldn't fit in the spot.
>> Ian Mills: ...in that spot.
>> Pat Ryan: You got to stop and think
about what you're going to do next.
How do you resolve that situation?
What was the answer here?
>> Ian Mills: The answer ended up being the box,
since it contains spares, they require thermal conditioning
to maintain their survivability, their usability,
and so a 10-hour thermal clock was started
when we pulled the box off of its original location.
And so, we were working against that clock.
And so, it may have been possible for us to figure
out how to work around these straps, wiggle our way
down at this location; however, to me, I didn't feel
like we had enough time.
So what we ended up doing was standing down for an hour
and a half or so, put together a plan
to just backtrack the same trajectory that we came from.
>> Pat Ryan: Return it.
>> Ian Mills: Return it back to its original location.
>> Pat Ryan: And yet you were ultimately able
to achieve the other goal, and that was to free
up that spot on the SPDM.
>> Ian Mills: That's correct.
Since both of these boxes that we're moving around were CTCs,
and they are mounted on a common attachment system
that we call the FRAM,
that's Flight Releasable Attachment Mechanism.
Either can go in either spot.
And we did stand down and evaluate the situation.
Since we ran into our models being incorrect, we first needed
to validate the CTC config, so we took some video onboard just
to verify what its config was.
It did not have the handrails we expected,
so there would not be the interference between the straps
and that handrail, so we decided to just go ahead and put the CTC
down where we were planning to put the CTC5.
And I know that's a bunch of numbers,
and it gets all jumbled, but eventually we ended
up in the same config.
We had these two boxes in their same locations;
they were just reversed from what we had intended.
>> Pat Ryan: And you found the solution and got
into the configuration that you were after,
a little ingenious thinking that actually won you a lot of praise
at the Mission Management Team Meeting yesterday,
for creative thinking.
>> Ian Mills: Yes.
I won't necessarily take that all for myself.
It is a team effort.
We have three people that man the console
for the robotics operations, and so,
as well as we had other people back in the office,
scrambling to help us put this plan together.
So, it truly was a team effort.
>> Pat Ryan: It's interesting to hear how it goes,
because it reminds us that working in space is not as easy
as it sometimes looks.
You've got to do what -- to take care of things as they crop up.
>> Ian Mills: Absolutely, and that is one of the other things
that I have learned in my 17 years is that it is important
to prepare for the unknown.
I have rarely, if ever, encountered the issues
that we planned for; however, going through that process
of being prepared to deal with things
in real time just makes you that much more prepared
to handle whichever scenario you may be working (inaudible).
>> Pat Ryan: That does come up.
Ian, thanks very much.
Enjoyed hearing about this.
Ian Mills is one of our Robotics Officers here
in Mission Control in Houston.
[ Inaudible Conversations ]