>> Dan Huot: Well, welcome back inside
of Mission Control, Houston.
Dan Huot here, and I'm joined now by Ann Esbeck,
one of our ADCO flight controllers here
in Mission Control.
Now Anne, first off, thanks so much for being here.
It's always great to get a little insight
on what you guys are doing behind the scenes.
So, first off, what does ADCO stand for?
What is it that you guys are doing
for the International Space Station?
>> Ann Esbeck: Okay.
ADCO stands for the Attitude Determination
and Control Officer.
So, essentially, the simplest way
to describe what we do is we're the pilot.
>> Dan Huot: So you're the one sitting
at the sticks flying the International Space Station,
basically?
>> Ann Esbeck: Yes.
So we don't actually get a stick down at the console,
but we do get to send our commands via the computers.
So we orient the space station where it needs to be going,
and make sure it stays there.
>> Dan Huot: Okay.
And so you're orienting the space station
and that's really important for visiting vehicles.
Right? We have a [inaudible] coming up soon.
What's some of the work you guys have to do
to get the station ready for any visiting vehicle?
>> Ann Esbeck: So one of the primary things that we have
to do is that we hand over control to the Russian segment,
and typically our attitude control is performed via four
control [inaudible] gyros,
and those gyros are 200 pound spinning discs
that produce momentum.
As we move that momentum through space we can control
where the space station points.
That doesn't work whenever you have to maneuver the vehicle
over a large direction.
So in this case we actually need
to pitch the vehicle up 90 degrees.
So instead of flying, like you would think
of an airplane flying straight and level
so you have your wings out,
we fly essentially pitched 90 degrees up.
So instead of flying this way, you're going to come up
and pitch this direction here,
and then continue to fly through space.
And we're doing that because the [inaudible] that's coming
up to dock is docking on the nadir side of the vehicle.
So on the bottom side of the vehicle.
>> Dan Huot: Okay.
>> Ann Esbeck: So we need to make sure
that that docking port is available for that vehicle
to reach, and so by pitching the vehicle up they can come
in along the velocity vector and dock nice and easy
with the sun pointing right where it needs
to so they can see it.
>> Dan Huot: So flying.
Flying in space, you know, isn't quite like flying
in the atmosphere where you can just kind
of turn your spaceship, you know, the wrong way
to how it looks and you're still flying because you don't have
that wind resistance and problems like that.
So we're looking at a picture right now of the [inaudible]
and how it'll look when it's docked.
So aside -- So you're going to be flipping it up 90 degrees.
Is there any other maneuvers you're going to be doing
to get the station ready for that [inaudible] docking?
>> Ann Esbeck: So the order of operations for the day is
that we actually turn on a lot of different --
they're called ORUs, on orbit replacement units,
and that's things like an extra rate gyro
so that we can measure the rates on the space station
as we're doing a maneuver and it gives us additional redundancy.
So if we have a sensor fail during the operation,
we have an additional one already turned
on so it'll switch over automatically
and we don't have any interruptions.
So we have a lot of configuration that happens
on the space station prior to getting ready to dock,
and that -- all of that's completed well before we hand
over to the Russian segment.
Then we hand over to the Russian segment, perform the maneuver
up to 90 degrees, and we'll be flying zero ninety zero.
And then, as the crew is coming in, they will monitor
to determine whether or not we are holding
to a tight enough attitude for them to dock.
If, for some reason, they don't think
that the docking is going well, they will hand over
and do what's called a manual docking
and they actually take the [inaudible]
out of their automatic mode and fly the vehicle in manually.
And then, once we're docked, the vehicle will go to free drift.
When the vehicle's in free drift it reduces the loads
on the docking mechanism so that they can close all of the hooks
and do a hard mating properly.
After they get mated, then we can turn the thrusters back on
and regain attitude control and get back
to that zero ninety zero attitude.
After we've gotten back to that attitude, we'll then pitch back
down into our normal flying attitude.
And once we're there we'll actually disable thrusters again
so that the hooks can be installed on the [inaudible],
and open the hatches so the crew can come inside.
After the hooks have been installed then we'll turn the
thrusters back on and we'll be able to continue our day.
>> Dan Huot: Okay.
Wow. So not as easy as just, you know, two things linking
up when they're flying at -- what?
17 thousand, 500 miles and hour.
It's pretty tricky to go --
>> Ann Esbeck: Yeah.
As simple as that sounds, no.
We have a lot of other operations
that we have to do during the day.
>> Dan Huot: Okay.
Well, what about some of the other visiting vehicles?
I know you're pitching 90 degrees for this one.
Is that kind of standard for most vehicles or --
>> Ann Esbeck: If we're going to dock nadir which is
on the bottom side of the space station, yes,
we'll typically dock at zero ninety zero.
If we have something that's coming to the aft portion
of the vehicle, so the backside of the vehicle,
we'll have a different attitude.
Typically we actually stay pretty close to our TEA
which is our torque equilibrium attitude.
So that's what we fly on a nominal day.
Or we might have to turn the space station around backwards
to put that point of the vehicle in the velocity vector.
So that's called a 180 degree [inaudible] maneuver.
So instead of flying straight and level this way,
we actually turn around backwards
and then fly backwards for that docking.
And then there are also others where we'll actually turn
around 180 degrees the day before and then pitch
up the day of docking.
And that's so that we can dock to the zenith port.
And then we'll pitch back down
and then turn another 180 degrees back before we get back
to normal ops.
And those sort of dockings actually take a 3 day time
period because we have to maneuver the day before and wait
in that new -- It's called [inaudible].
And then on the day of docking we'll do the pitch up attitude,
and then pitch back down following.
And then we have to wait another day,
and then we'll maneuver back to the nominal attitude.
>> Dan Huot: All right.
So flying in space, you're making it sound a lot harder
than I always thought it was.
But I'm glad you guys are on top of it
and you're always controlling it.
Well, we'll certainly be looking forward
to all the work you're doing to get this station ready
for that [inaudible] docking.
And thanks so much for coming on today
and telling us a little bit about what ADCOs are doing
to keep our space station flying.
>> Ann Esbeck: No problem.
I'm glad to be here.
>> Dan Huot: All right.
Thanks.