>> Hi. Welcome to Inside the International Space Station
Flight Control Room.
Today, I have a special guest with us.
We've been watching, just now, some live downlink
of Steve Swanson, aboard the Space Station,
who is actually preparing one of the spacesuits
that he'll be working -- wearing during a contingency spacewalk
that is now scheduled to take place on April 23rd --
that is provided the SpaceX Dragon is launched
on April 18th, this Friday.
So today, right now, I have NASA Astronaut Chris Cassidy.
Chris is a two-time flyer.
He flew aboard the space shuttle on STS-127?
>> Yeah.
>> And then also did a long duration tour aboard the Space
Station this time, last year, on Expedition 35.
>> Yeah. A year ago, I was up there.
It's hard to believe.
>> And he actually did three spacewalks,
and he's actually working to help come up with the procedures
for this spacewalk that will be to prepare -- to repair the --
what we've been calling the MDM.
It's the Multiplexer De-Multiplexer
that is outside the Space Station.
So first of all, explain real briefly what is the MDM?
What is that, exactly?
>> It's basically a computer,
and there are several different kinds.
There are some higher level ones -- - Control MDMs.
We call them Tier 1.
And then the Tier 2 MDMs -- these --
of which the external MDM is one of those --
many of them, or most of them, are inside.
This one happens to be outside, and it controls the --
some structural mechanical things.
But what we care about this week, relative to SpaceX,
are the targe [phonetic] angles
and the solar array rotary angles.
And if the second MDM were to fail,
we wouldn't have the ability to control those.
So that's why it's such an important piece
to the whole equation.
>> Okay. Well, thank you for that.
Real quick, also, just describe what that task --
what the task is going to be at hand, that Swanson
and Mastracchio have, at going out and replacing it.
They're actually taking one that is onboard right now.
They have a replacement.
I think you have that --
>> Right. We have one --
we happen to have one right here, as a matter of fact.
So the spare is inside, just like you mentioned.
It's inside with them.
It's older, though.
And so they need to do some work on the inside to update it
and make sure that it's got the right software,
and the ground teams are doing all that procedure right now.
Once they do that, and they're ready to go outside next week,
this is what the box looks like.
And basically, there's computer cards,
just like in your home computer, at home,
inside this big metal box.
What those guys will do is -- there's three bolts.
The center one -- as we call it, the jacking bolt,
because it actually drives the box in and out.
And then these two outside bolts just kind of make it secure.
There's no connection.
This is not -- this connection here won't be on the real box.
All of the electrical connections happen
on the back side of the box.
We call them blind mate connectors,
because once the box slides in, as you screw it in,
all the connectors are made in the back.
So all that they really have to do is these three bolts.
It's pretty -- pretty straightforward,
in terms of EVA jobs, you know?
We anticipate it to go quickly, but as with anything in space,
operations -- particularly EVAs --
you never know what's going to be thrown at you.
>> Right. And you would know that, more than anyone.
So also just briefly -- just describe for me,
what's your involvement in coming up with the --
you know, the procedure for their spacewalk?
>> It's actually been kind of fun for me.
Just like you said, last year,
I was up in space and doing my things.
And plans and procedures would arrive electronically,
and we'd read them and be ready to go.
Now, being part of the team of folks
that are putting all the plans
and procedures together, it's kind of neat.
And there's a large kind of army of folks here, right here,
in this building -- Building 30 -- putting all that together.
I'm representing the crew office in the spacewalk,
more specifically, the spacewalk branch, as we kind of figure
out all the nuances of what is needed to go outside.
>> Right. And I understand, even in just coming
up with how you would go about and do that duty --
the spacewalk -- you actually do perform it
under the water at the MBL.
In fact, you have a run scheduled for Friday.
>> Friday.
So we'll be doing the same job and going through some
of the contingencies, the what-ifs.
And we call it the crib sheet, you know,
which is basically the answer to any
and all problems that we can think of.
And of course, we can't possibly think of everything,
but as best we can, we have all those answers in our hip pocket.
So as they get thrown at us on the game day,
we can give the crew a quick answer.
>> Yeah. Very good.
Okay. And so, from a crew member's point of view,
explain to me what that's like to get that, "Okay,
you've got to go out and do a contingency spacewalk"?
Because that's obviously an interruption
in what your normal timeline would be.
>> Right. Well to be quite honest, it's exciting.
A spacewalk is a highlight of most crew members,
if they get their chance -- get a chance to do them.
And I was lucky enough to have that happen to me.
So I remember very specifically --
we had a leaky ammonia system.
There was a pump that we had to change out back, I guess,
about this time last year.
>> With that -- Luca Parmitano, on the site?
>> With the first one, with Tom Marshburn.
That's when he and I woke up one morning,
and we were told we were doing a spacewalk the next day.
A little bit the same situation now, and there's --
it's an exciting feeling.
There's so much you have to do,
and you're very much, "All right."
You have a few minutes of just your own personal emotions.
And then you get on to business with all of the work that has
to happen to make it so.
Basically, making the spacesuits right
and making the equipment ready to go.
>> Like these guys.
I mean, they've been working right now --
>> And they have the added task of dealing with some
of the suit issues that have been the problem for us
for the last -- I guess, what?
Nine months or so, since last summer, when Luca
and I had the water problem.
Luca had the water problem in his suit.
>> Sure. And what are they doing about that now?
>> Yeah. They're -- there are three good spacesuits up there.
It turns out, the one that Luca was wearing -- 3,011 --
is the best suit that we have, of those three, prior to --
because it already had had the --
we call it the fan pump separator -- was changed out,
and all that work was completed.
It had some flushing of the water done.
So we knew that was one that -- going to be one of the two used.
The other two were sort of both equally suspect, if you will.
And just recently, in the last few days, based on a lot
of meetings and trying to figure out what's the right answer --
what's the right suit --
and we've changed out the fan pump separator in 3,005.
And those are the two suits that will be used outside.
It's a lot of work, diving into the bowels of that backpack
of the suit and changing out pieces and parts
that suit technicians do in a lab here in Houston,
with white outfits and all kinds of special tools --
not necessarily made to be done onboard the Space Station.
>> Sure. Yeah.
We've been watching a lot of that take place.
In fact, they're still working on that today.
Again, thank you so much for coming out
and talking with us today.
I think that's about all the time we have now,
but we really do appreciate your coming out.
And good luck on your run on Friday.
>> Absolutely.
Thanks a lot.
Nice to see you.
>> Thank you. ------------------------------414510eb67f7--