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Let's see.

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The original schedule today had Colonel Gordon
Fullerton going to come and talk to us about

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both cockpit design, but primarily about test
flying the Shuttle.

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Unfortunately, he is in charge of Flight Operations.

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Well, not unfortunately.

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He is in charge of Flight Operations at Dryden
Flight Research Center for NASA.

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Unfortunately for us, since the time that
we had agreed on this date, they scheduled,

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at the beginning of next week, a major base
inspection.

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And if any of you are connected with the military
you know what that involves.

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And, since he is head of flight operations,
he really has to be there to make sure that

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they are ready for it.

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He has rescheduled.

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He will be here in November.

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And I will make adjustments to the syllabus.

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On Thursday, Bob Ried is going to talk about
aerothermodynamics.

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And what I thought I would do today is kind
of a potpourri maybe doing a little bit of

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recap on where we've gotten to so far.

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And also I brought a few videos just to give
you a visual reminder of some of the things

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that we've been talking about with the Shuttle.

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Any sort of general questions about what I
handed back to you?

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I am happy to meet with teams individually
to discuss any specific questions.

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OK.

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Let's see.

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One thing that I -- Hi.

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I was just telling the class Gordon Fullerton
was supposed to be here, but he has had to

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postpone to November because they're having
a base inspection of flight operations.

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So, he is not here.

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I had an email from Professor Cohen who will
be here.

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And let's see if this is -- He had an idea
that now that we've kind of started going

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into details on various subsystems that it
might be interesting to work our way through

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a Shuttle flight and just remind ourselves
of the different subsystems that are brought

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into play at various times during a Shuttle
mission.

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This is kind of part of the systems integration
process.

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And remember that we talked at the beginning
how in the systems engineering process we

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always want to keep in mind the eventual operational
use of the systems that are being designed.

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So, the idea, for instance, would be start
at the very beginning.

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You're sitting on the pad.

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You could even go further than that because
remember we talked about how systems had to

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be developed, for instance, for loading the
payload into the cargo bay.

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They have that big payload changeout room.

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They had to design the hypergolic reaction
control and OMS motors in such a way that

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the pods were actually removable from the
Shuttle because they were using hazardous

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hypergolic fuel and they cannot be serviced
in the main hanger.

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They have to be taken over to a remote section
of the Kennedy Space Center.

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And then, of course, the servicing of the
tiles.

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There is a lot of servicing and maintenance
work that has to be done on all the subsystems.

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And, ideally, it should be designed in from
the beginning.

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Of course, in many cases, we got a lot smarter
after we started to use the Shuttle.

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And, if we were doing it again, which is something
that you will be thinking about, we would,

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in fact, have built certain things into the
subsystems which would have made it easier

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for them to be maintained and repaired.

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What I am going to do, just as an experiment
here, let's think briefly about these subsystems.

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And I've got a little video taking us through
the launch and the entry stages.

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And then I have one or two other things to
show you, which will just illustrate certain

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other aspects of the Shuttle Mission.

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Right at the moment of liftoff, just kind
of to set the stage, the final countdown starts

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at T minus nine minutes.

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They typically will have holds built into
the count so that particularly when you're

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going for a very tight launch window, like
if you're on a rendezvous mission to the Space

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Station, you have to launch when the Space
Station basically is pretty much going overhead.

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And, since the Space Station is in a 51-degree
orbit, it takes more energy to get into a

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51-degree orbit.

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Because normally if you launch from Cape Canaveral,
hopefully you understand the orbital dynamics,

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if you launch due east you get the full speed
of the earth's rotation.

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And since the latitude of Cape Canaveral is
28 degrees that puts you into an orbit which

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is inclined 28 degrees to the equator.

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That is what we did when we did a rendezvous
with the Hubble Telescope which is in 28 degrees.

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In fact, I remember my brother was telling
me that we launched about 4:00 AM so it was

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night.

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And just about 20 minutes before we launched
they saw Hubble fly over and everybody thought

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that is a good sign, they seem to know what
they are doing.

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[LAUGHTER] The thing is that when you have
an object that is in orbit, and the orbit

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you can think of as being roughly fixed in
inertial space, obviously it precesses a few

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degrees every day.

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But if you think of it as fixed in inertial
space on the time scale of a day or so then

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the earth is turning underneath it.

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And you have to launch basically when you
are in that orbital plane.

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Now, if you have a little bit of extra energy
to burn you can launch a little bit earlier

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or a little bit later and use that extra delta
V to change your velocity to get into that

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plane.

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If you're launching to rendezvous with Hubble,
say, which is in a 28-degree orbit, you have

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a bigger launch window than you do if you
launch into the Space Station at a 51-degree

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orbit.

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Because, going into a 51-degree orbit, you
are using a lot of extra delta V just to change

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from a 28 to a 51-degree inclination.

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So the launch window to rendezvous with the
Space Station is very short.

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It is only about five minutes.

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So in order to make sure that they have the
maximum chance of making the launch window,

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they actually build in some extra large holes,
even more so than for a normal launch.

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But you pick up the final count at nine minutes.

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The Shuttle, at that point, is on external
power.

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At about seven minutes, the pilot, that is
the person sitting on the right-hand side

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who should be called the copilot, and I've
talked about this with a few of you.

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None of the astronaut test pilots, you know,
these are kind of big ego people.

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Nobody wants to be called a copilot.

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The person sitting in the right seat is the
pilot.

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The person sitting in the left seat, who is
really the pilot, is called the commander.

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The pilot does not fly the Shuttle, except
for usually if you have a nice commander he

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will let the pilot -- when you're pulling
away from the Space Station it is kind of

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a tradition that you give the pilot the stick
and let the pilot do a fly around.

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And, in the old days, some of the commanders
actually gave the pilots a little bit of stick

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time before landing.

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But that generally doesn't happen now.

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Anyway, the pilot is in charge of a lot of
the subsystems, the main engines, the electrical

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power system, the auxiliary power units.

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It is the pilot who has to throw a switch
to put the Shuttle on internal power.

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At about eight minutes before a launch you
go onto fuel cell power.

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Then at about 5.5 minutes before a launch
you turn on the auxiliary power unit.

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Remember we talked about that subsystem.

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That generates the hydraulic pressure to move
the flight control surfaces and the main engine

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bells.

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And you will see, if you watch a launch sequence,
starting at about three minutes after the

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auxiliary power unit comes on -- at that point
you can sort of feel a little bit of humming

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in the vehicle when you're sitting in it -- they
then move the engine bells back and forth

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through their entire range just to make sure
that the hydraulics are working.

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And actually the whole Shuttle shakes when
that happens so you can sort of feel that

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when you're sitting there.

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And then, of course, one of the challenges
with a cryogenic engine -- and this going

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to be an interesting development project for
the future when they want to have a restartable

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engine.

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Remember these are cryogenic engines and so
you have to do a cool down.

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And so you start to flow the liquid oxygen
and liquid hydrogen through the piping.

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Again, inside a minute you can feel kind of
a rumbling down below as valves are opening

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and things are starting to flow.

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At 31 seconds the launch control center gives
control over to the Shuttle computers.

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And the last 31 seconds are controlled entirely
by the Shuttle computers.

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They look at thousands of data points to make
sure that everything is working properly.

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At T minus six seconds the engines go through
an ignite sequence.

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The engine starts are staggered.

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And you will see that when you look at the
slow motion of the video that I am going to

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show you.

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That reduces the shock on the system.

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It only takes a couple of seconds for the
engines to come up to full power.

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You certainly don't want to commit yourself
to lighting the solid boosters unless you

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are 100% sure that your main engines are firing.

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Because if even one main engine is not operating
at 100% efficiency you cannot make it to orbit.

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In fact, if you have one engine out on the
pad, you have to do a return to launch site

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abort.

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We will talk about the details of that whole
process at some point.

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AUDIENCE QUESTION You can abort launch right
up to when the solid -- Once the boosters

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are lit you are going.

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Just hope you're pointed in the right direction
because there is no thrust termination on

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the solids.

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And it has happened four times that we have
had pad shutdowns.

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The engines are monitored.

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On two of those occasions it turned out that
the problems were instrumentation.

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On two occasions it turned out that there
were, in fact, real engine problems.

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And I would say, for a 50% success rate, you're
doing well.

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I mean it was the right thing to shut down
the engines all those times.

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Although, the very first time when they had
an engine shutdown on the pad, well first

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of all, just an acronym is MECO, main engine
cutoff, which normally happens about 8.5 minutes

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after launch.

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The comment by Steve Hawley, who was the flight
engineer in the center seat when they had

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-- this was on the fourteenth Shuttle flight
-- when they had a pad abort, his comment

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was, "Somehow I thought we would be a little
bit higher at MECO." And it turned out, they

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didn't realize it at the time, but they actually
had a hydrogen fire on the pad.

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Remember we talked about how there was a lot
of hydrogen.

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And, of course, before the engine ignition,
we have those sparklers to get rid of the

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excess hydrogen.

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But, in the process of shutting down the engines,
there was also a lot of excess hydrogen which

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got into the engine [UNINTELLIGIBLE].

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And the problem is that a hydrogen fire, as
you know, is pretty much invisible.

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And they didn't have any infrared cameras
at the time.

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And so basically everybody went around, the
crew took their time and everybody went out.

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Once they realized it, they put on a water
douse.

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Now we have infrared cameras.

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And, whenever you have an engine shutdown,
you have to be very careful that you don't,

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in fact, have a hydrogen fire.

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Coming back to the subsystem, the last stage
of the launch, the main engines have gone

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on.

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You have turned on the hydraulic system both
for the main engine and the boosters have

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their own hydraulic systems and the boosters
have their own auxiliary power unit.

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Guidance navigation and control, of course,
is absolutely critical.

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Now, first stage is what they call basically
open loop guidance.

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There is a specific projectory that you are
supposed to follow.

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Once the solid boosters are off you are following
a closed loop guidance which is taking you

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to a specific point and velocity in time and
space and the trajectory is actively adjusted

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to get there.

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Because the solid boosters have so much thrust
you don't want to do a lot of sporty maneuvering.

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In fact, the biggest challenge from a maneuvering
point of view is when you're going through

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max Q and maximum dynamic pressure and you
have to relieve wind shear loads on the aero

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surfaces.

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Basically, when the boosters are firing, from
the crew's point of view, it is hands-off.

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There is now way that you could take manual
control over the boosters.

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There is just too much power.

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And just a little bit of deviation from your
course and you will break up aerodynamically.

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It is hands-off.

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The fuel cells are generating all of the power.

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The guidance, navigation and control is being
done inside the Shuttle and the results are

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sent to the solid boosters.

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The gimbals can move.

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So the roll maneuver, for instance, is done
by the solid engines.

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How do the solids gimbal?

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The solids can gimbal, yeah.

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How do they gimbal?

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The same way as the main engines.

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I mean they are on a mounting with hydraulic
actuators.

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And so the actuators expand and contract.

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And you can imagine the forces that are involved
there because these are 2.5 million pound

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thrust engines.

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It is pretty amazing.

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Going through maximum dynamic pressure, SRB
separation, main engine cutoff, basically

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the same systems are working.

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The critical things are, of course, the main
engine has to be throttleable.

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This was a big challenge, as we heard, in
making the main engine.

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It is throttleable for two reasons.

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Going through a maximum dynamic pressure.

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And at that point, the solids are also, you
know, the way the solid propellant is loaded,

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the actual cross-sectional profile is such
that you don't have a constant thrust profile.

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The thrust profile is very high right at liftoff
where you need a lot of thrust.

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It falls off as you're going through maximum
dynamic pressure.

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And then it builds up as you burn through
the last two minutes of SRB firing.

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The Shuttle is pulling about 2.5 Gs at SRB
cutoff.

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The aerodynamic separation of the solids got
a lot of attention.

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To have a re-contact would be a disaster,
so you have four separation motors, two at

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the top and two at the bottom which basically
push the solid boosters away from the Shuttle.

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And, of course, those motors are pointed right
at the Shuttle in order to move the boosters

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00:19:26,390 --> 00:19:26,640
away.
It is pretty spectacular when you're inside,
especially at night.

219
00:19:30,880 --> 00:19:37,880
They are little solid rocket motors and they
are firing right at you so visually it's spectacular.

220
00:19:40,929 --> 00:19:47,929
But it also, unfortunately, leaves kind of
a nasty coating on the front windshield most

221
00:19:49,679 --> 00:19:52,970
of which luckily gets burned off during reentry.

222
00:19:52,970 --> 00:19:59,970
But the pilots were a little bit concerned
that that might hurt their visibility in landing,

223
00:20:00,010 --> 00:20:02,500
particularly if you had a bad sun angle.

224
00:20:02,500 --> 00:20:09,500
They always try to consider the sun angle
for landing, as well as winds.

225
00:20:12,100 --> 00:20:17,059
After SRBs come off, now you're back to about
one G.

226
00:20:17,059 --> 00:20:21,909
You have second-stage guidance, which is closed
loop.

227
00:20:21,909 --> 00:20:27,390
You're sensing acceleration and orientation.

228
00:20:27,390 --> 00:20:34,390
Nowadays they often fire the OMS engines for
part of liftoff as well just to get a little

229
00:20:38,669 --> 00:20:45,330
extra oomph when they're going up to the Space
Station, so that's another system which is

230
00:20:45,330 --> 00:20:52,100
brought into play during ascent.

231
00:20:52,100 --> 00:20:59,100
Then you get into, after MECO, 8.5, 8.75 minutes.

232
00:21:00,370 --> 00:21:07,370
Now you have to get rid of the external tank
and you've got a lot to do basically to power

233
00:21:11,279 --> 00:21:12,669
down the main engines.

234
00:21:12,669 --> 00:21:17,409
Remember, you have been burning liquid oxygen,
liquid hydrogen.

235
00:21:17,409 --> 00:21:22,440
You've got a tremendous amount of ice which
forms in the engine.

236
00:21:22,440 --> 00:21:27,690
I have some pictures to show you of what that
looks like when you get into orbit.

237
00:21:27,690 --> 00:21:34,200
Also, you've got thousands of pounds of hydrogen
and oxygen left inside the pipes.

238
00:21:34,200 --> 00:21:41,200
And if you just close your valves, eventually
that will all vaporize, build up pressure

239
00:21:42,460 --> 00:21:46,090
and actually could cause an explosion.

240
00:21:46,090 --> 00:21:51,580
One of the first things that you have to do,
when you get into orbit, is to vent the main

241
00:21:51,580 --> 00:21:56,570
propulsion system.

242
00:21:56,570 --> 00:22:00,240
Let's see.

243
00:22:00,240 --> 00:22:06,370
Actually, Professor Cohen did not put on RCS
here, which is absolutely critical, because

244
00:22:06,370 --> 00:22:11,640
you have explosive bolts to separate you from
the external tank.

245
00:22:11,640 --> 00:22:17,130
But basically the external tank has no propulsion
on its own so you, on the Shuttle, have to

246
00:22:17,130 --> 00:22:17,820
fly away from it.

247
00:22:17,820 --> 00:22:20,159
So you use your plus Z.

248
00:22:20,159 --> 00:22:23,510
That is the downward thrusters.

249
00:22:23,510 --> 00:22:28,000
Remember we talked about how the Shuttle has
two RCS systems.

250
00:22:28,000 --> 00:22:34,929
It has the primary systems which have about
850 pounds of thrust for each thruster.

251
00:22:34,929 --> 00:22:39,529
And then once you're in orbit and you don't
have to do a lot of propulsive maneuvering,

252
00:22:39,529 --> 00:22:45,529
then we shut down the primaries and we use
the verniers which only have 25 pounds.

253
00:22:45,529 --> 00:22:46,990
That takes a lot less fuel.

254
00:22:46,990 --> 00:22:53,990
But those primary thrusters we use not only
the ones in the aft but in the forward so

255
00:22:54,610 --> 00:22:55,929
that you have balanced thrust.

256
00:22:55,929 --> 00:23:02,929
If you're trying to move away from the external
tank you want to fire the thrusters both in

257
00:23:02,970 --> 00:23:06,779
the nose and in the tail so that you move
straight up.

258
00:23:06,779 --> 00:23:09,360
Well, we're sitting up in the nose.

259
00:23:09,360 --> 00:23:15,880
And when those thrusters go off, I mean I've
never been in a war or a battle, but it strikes

260
00:23:15,880 --> 00:23:20,000
me that the sound is what you would get if
mortar shells were exploding around you.

261
00:23:20,000 --> 00:23:23,620
I mean it is just a boom.

262
00:23:23,620 --> 00:23:30,620
And right after riding through launch, the
first thing that happens is you go weightless.

263
00:23:32,309 --> 00:23:37,309
But then the next thing is you're hearing
these explosions all around you.

264
00:23:37,309 --> 00:23:39,679
And it can be quite exciting.

265
00:23:39,679 --> 00:23:43,110
Actually, I will just share a story with you.

266
00:23:43,110 --> 00:23:50,110
On my first flight, they decided to do a special
kind of a test.

267
00:23:51,390 --> 00:23:58,390
There are fill and drain valves for the main
engine on the side of the Shuttle.

268
00:23:58,799 --> 00:24:05,570
Usually we vent the propulsion out through
the engines themselves, but they wanted to

269
00:24:05,570 --> 00:24:07,419
look for a quicker way to do it.

270
00:24:07,419 --> 00:24:08,659
Let's see.

271
00:24:08,659 --> 00:24:13,169
This was the sixteenth Shuttle flight, which
was my first flight, and they gave us what

272
00:24:13,169 --> 00:24:20,080
they call a detailed test objective where
right after external tank separation we opened

273
00:24:20,080 --> 00:24:22,990
the side fill and drain valve.

274
00:24:22,990 --> 00:24:29,990
And I remember the commander asked some of
the guidance and control people is the Shuttle

275
00:24:30,779 --> 00:24:36,539
RCS going to be able to compensate for the
extra thrust that you get?

276
00:24:36,539 --> 00:24:40,490
They said, yeah, no problem, we've done the
calculations and it looks fine.

277
00:24:40,490 --> 00:24:45,909
And this is the reason why you do tests because,
in fact, what happened was we came off the

278
00:24:45,909 --> 00:24:52,909
tank, opened the fill and drain valve and
the Shuttle rolled over 90 degrees and the

279
00:24:53,149 --> 00:24:59,700
RCS jets started going like crazy to try to
correct us.

280
00:24:59,700 --> 00:25:03,380
They were in a force fight.

281
00:25:03,380 --> 00:25:09,279
After about 15 seconds the pilot said to the
commander, do you think I should shut the

282
00:25:09,279 --> 00:25:13,799
valve, because the noise was incredible.

283
00:25:13,799 --> 00:25:16,090
Like I say, it was like you were in the middle
of a battlefield.

284
00:25:16,090 --> 00:25:20,289
And at that point the commander said, well,
it's too late now because we had gotten through

285
00:25:20,289 --> 00:25:21,419
most of the disturbance.

286
00:25:21,419 --> 00:25:27,320
And we did recover and got to normal attitude,
but it was pretty exciting.

287
00:25:27,320 --> 00:25:34,320
The point is that at that point you are in
a transitional state.

288
00:25:35,429 --> 00:25:40,370
Your computers are still in the launch configuration.

289
00:25:40,370 --> 00:25:42,909
You have your primary RCS.

290
00:25:42,909 --> 00:25:49,909
And what you have to do is transform the Shuttle
now into an on-orbit configuration.

291
00:25:54,330 --> 00:25:57,289
The Shuttle computers are so ancient.

292
00:25:57,289 --> 00:26:04,179
Has anyone here ever, never mind used an overlay
technique, but, even heard of computer overlays?

293
00:26:04,179 --> 00:26:08,470
No, I didn't think so.

294
00:26:08,470 --> 00:26:15,450
Back in the old days when computers had rather
small memory and you had to run large programs,

295
00:26:15,450 --> 00:26:20,919
what you would do is you would have your entire
program, well, originally it was on punch

296
00:26:20,919 --> 00:26:23,010
cards and then eventually on magnetic tape.

297
00:26:23,010 --> 00:26:29,919
But you would segment your program and then
you would load the first part of your program

298
00:26:29,919 --> 00:26:31,789
as much as you could fit into memory.

299
00:26:31,789 --> 00:26:38,789
Run that, save the results, load the second
part, transfer the results, run on that and

300
00:26:39,100 --> 00:26:40,429
so on.

301
00:26:40,429 --> 00:26:43,289
Well, believe it or not, that's the way the
Shuttle computers still operate.

302
00:26:43,289 --> 00:26:45,779
It is an overlay system.

303
00:26:45,779 --> 00:26:52,779
They cannot hold all the software for the
entire flight so we have a launch overlay,

304
00:26:53,200 --> 00:26:58,779
an ascent, an on-orbit and an entry.

305
00:26:58,779 --> 00:27:04,269
Now, the backup flight system is stripped
down.

306
00:27:04,269 --> 00:27:09,019
And so the backup computers hold the software
for the entire mission, but there are a lot

307
00:27:09,019 --> 00:27:13,429
of things that they don't do that the main
computers do.

308
00:27:13,429 --> 00:27:20,429
What you actually have to do is perform what
they call a major mode transition, which basically

309
00:27:22,570 --> 00:27:29,570
means you punch a few buttons, tell the computers
to go into orbit mode and then all the screens

310
00:27:30,850 --> 00:27:31,850
go blank.

311
00:27:31,850 --> 00:27:34,059
I mean it is a very kind of a strange feeling.

312
00:27:34,059 --> 00:27:38,080
And you just have to sort of hold your hands
and not touch anything for about a minute

313
00:27:38,080 --> 00:27:43,440
or so while the tape recorders are spinning
down in the guts of the Shuttle and they're

314
00:27:43,440 --> 00:27:46,630
loading the stuff onto the Shuttle computers.

315
00:27:46,630 --> 00:27:53,630
Now, I think they upgraded the tape recorders
to solid state, I believe.

316
00:27:55,510 --> 00:27:57,679
That's correct, isn't it?

317
00:27:57,679 --> 00:27:58,970
Do you know that?

318
00:27:58,970 --> 00:28:05,620
I don't think they use tape recorders in the
Shuttle anymore, but they did, in any case,

319
00:28:05,620 --> 00:28:08,630
at the beginning.

320
00:28:08,630 --> 00:28:15,630
I mean just maintaining this computer system
has been a big challenge.

321
00:28:18,470 --> 00:28:25,470
And then you get into the orbit configuration.

322
00:28:26,460 --> 00:28:33,130
In the ascent configuration your vernier RCS
isn't even enabled.

323
00:28:33,130 --> 00:28:38,980
And inside the ascent configuration, of course,
you have not just your nominal ascent but

324
00:28:38,980 --> 00:28:44,940
you have all of the launch abort modes or
return to launch site, transatlantic abort

325
00:28:44,940 --> 00:28:50,830
and abort to orbit or abort once around.

326
00:28:50,830 --> 00:28:56,330
All that gets flushed, and now you are on-orbit.

327
00:28:56,330 --> 00:29:02,679
Your on-orbit software does not give you the
ability to do entry and landing.

328
00:29:02,679 --> 00:29:08,169
You are going to have to re-do another overlay
or what we call major mode transition before

329
00:29:08,169 --> 00:29:08,750
you do that.

330
00:29:08,750 --> 00:29:09,880
Yeah?

331
00:29:09,880 --> 00:29:16,880
[AUDIENCE QUESTION] There are several different
landings spots, right?

332
00:29:19,480 --> 00:29:20,090
Right.

333
00:29:20,090 --> 00:29:27,090
[AUDIENCE QUESTION] There is always one picked
as a prime, but you have the ability to re-designate

334
00:29:31,389 --> 00:29:36,889
depending on where in the ascent you run into
a problem.

335
00:29:36,889 --> 00:29:43,889
[AUDIENCE QUESTION] All options are available,
but there always is a prime transatlantic

336
00:29:45,929 --> 00:29:50,870
abort site which is chosen.

337
00:29:50,870 --> 00:29:57,870
And usually what happens is, I mean there
are several transatlantic launch sites, sometimes

338
00:29:58,370 --> 00:30:00,659
one or more of them is down because of weather.

339
00:30:00,659 --> 00:30:05,350
And, in fact, if all of them are down, even
if the weather is perfect in Florida, you

340
00:30:05,350 --> 00:30:11,690
scrub because you need to have an abort site.

341
00:30:11,690 --> 00:30:11,940
OK.
I am going to show you a video now.

342
00:30:56,950 --> 00:30:57,200
OK.

343
00:30:57,130 --> 00:31:04,130
I will try to walk you through some of these.

344
00:31:08,659 --> 00:31:15,570
Remember that is the water deluge to stop
the shockwave coming back.

345
00:31:15,570 --> 00:31:17,830
Now you have the stage combustion.

346
00:31:17,830 --> 00:31:21,230
These are the OMS engines, the RCS and the
main engines.

347
00:31:21,230 --> 00:31:27,009
Remember we talked about the off-angle thrust.

348
00:31:27,009 --> 00:31:34,009
Those are the bolts which hold the solid boosters
down.

349
00:31:35,750 --> 00:31:42,659
All eight of them have to fire at exactly
the moment of SRB ignition.

350
00:31:42,659 --> 00:31:47,830
If you watch closely, when you see it go up,
you can actually see it sort of moving that

351
00:31:47,830 --> 00:31:54,830
way, again, because of the off-angle thrust
of the main engine.

352
00:31:55,389 --> 00:32:02,389
This is the roll maneuver which puts you -- You
go over on your back, headed towards the proper

353
00:32:06,299 --> 00:32:12,210
orbit.

354
00:32:12,210 --> 00:32:19,049
And then, as you go through max dynamic pressure
and break mach one, you often get those condensation

355
00:32:19,049 --> 00:32:26,049
trails.

356
00:32:27,450 --> 00:32:30,960
This is a pilot's eye view now of a Shuttle
launch.

357
00:32:30,960 --> 00:32:35,769
This is speeded up by a factor of two.

358
00:32:35,769 --> 00:32:42,769
That was the roll maneuver and the Florida
coastline.

359
00:32:44,769 --> 00:32:50,799
And I always thought one of the amazing things
was actually how fast the blue sky turns black

360
00:32:50,799 --> 00:32:52,230
as you are going up.

361
00:32:52,230 --> 00:32:59,169
SRB separation, you're up at an altitude of
about 20 miles.

362
00:32:59,169 --> 00:33:06,169
And you can see up there that very quickly
the blue sky of earth is turning into the

363
00:33:07,009 --> 00:33:11,309
black of space.

364
00:33:11,309 --> 00:33:17,169
This launch was a high inclination launch
so they were actually going into a 58 degree

365
00:33:17,169 --> 00:33:20,259
orbit, so they flew literally right up the
Eastern seaboard.

366
00:33:20,259 --> 00:33:27,259
AUDIENCE QUESTION

367
00:33:36,669 --> 00:33:40,120
It was a SpaceLab mission, I believe, and
one of the things they were going to do was

368
00:33:40,120 --> 00:33:44,899
observe the earth so they wanted to get into
as high an inclination as possible.

369
00:33:44,899 --> 00:33:51,750
Remember when Bass Redd was talking about
the aerodynamics of the Shuttle he said that

370
00:33:51,750 --> 00:33:56,909
one of the things that they never were able
to get quite right was the plume.

371
00:33:56,909 --> 00:34:02,600
And he talked a lot about the angle of the
skirt and how that affects the aerodynamics

372
00:34:02,600 --> 00:34:04,309
of the plume.

373
00:34:04,309 --> 00:34:11,309
And you can watch how the plume is continually
changing as you are getting higher in the

374
00:34:11,418 --> 00:34:16,349
atmosphere and you have less and less pressure.

375
00:34:16,349 --> 00:34:22,260
You also notice some of the flames are getting
sucked back.

376
00:34:22,260 --> 00:34:28,010
In between the Shuttle and the external tank,
of course that is where we had the problems

377
00:34:28,010 --> 00:34:33,239
with the foam shutoff, you've got supersonic
shockwaves bouncing around.

378
00:34:33,239 --> 00:34:37,329
It is a very, very nasty environment in there.

379
00:34:37,329 --> 00:34:43,550
And you see, when the external tank comes
off, often there is a lot of area here which

380
00:34:43,550 --> 00:34:47,460
is charred and burned out just because of
the shocks.

381
00:34:47,460 --> 00:34:53,489
You can see now that the plumes are tremendously
expanded.

382
00:34:53,489 --> 00:35:00,490
The other thing that you can -- Well, I will
wait until SRB separation.

383
00:35:01,310 --> 00:35:08,000
As I say, you are up to about 2.5 Gs at this
point, and now you can see that the solids

384
00:35:08,000 --> 00:35:11,200
are starting to tail off.

385
00:35:11,200 --> 00:35:17,560
You can see a qualitative difference in the
flame pattern.

386
00:35:17,560 --> 00:35:20,339
And now you can definitely feel this inside.

387
00:35:20,339 --> 00:35:23,369
You see the separation motors.

388
00:35:23,369 --> 00:35:25,720
The boosters fall off.

389
00:35:25,720 --> 00:35:28,380
And, as you know, they were recovered.

390
00:35:28,380 --> 00:35:35,380
Making sure that the thrust tail-off matches,
as we heard, was critical.

391
00:35:35,579 --> 00:35:42,230
Now here is a picture from a belly camera
of the boosters falling off.

392
00:35:42,230 --> 00:35:47,010
Now the main engines are firing.

393
00:35:47,010 --> 00:35:54,010
When this happens -- I don't know if you have
seen pictures of Saturn launches.

394
00:36:01,770 --> 00:36:08,220
They actually have some of the most beautiful
patterns of the reentering plumes.

395
00:36:08,220 --> 00:36:13,839
But the plumes, as you get up into a vacuum,
the exhaust plume expands.

396
00:36:13,839 --> 00:36:20,839
And it actually folds back around the vehicle
which is not a danger to the vehicle, but

397
00:36:24,190 --> 00:36:26,690
visually can be quite spectacular.

398
00:36:26,690 --> 00:36:33,690
On the first night launch of the Shuttle -- During
the day the plume is so faint that you really

399
00:36:35,680 --> 00:36:39,170
cannot see it from outside the windows.

400
00:36:39,170 --> 00:36:43,700
From the ground you can see the bright points
when you're looking right at the tail of the

401
00:36:43,700 --> 00:36:45,960
Shuttle but you don't actually see the plumes.

402
00:36:45,960 --> 00:36:52,960
But the second flight engineer who has a good
view out the overhead window, about five minutes

403
00:36:55,480 --> 00:37:01,560
into launch he asked the pilot, who is in
charge of looking after the main propulsion

404
00:37:01,560 --> 00:37:05,869
system, is everything OK with the engines?

405
00:37:05,869 --> 00:37:07,020
Yeah, everything is OK.

406
00:37:07,020 --> 00:37:10,680
In about six minutes, everything OK with the
engines?

407
00:37:10,680 --> 00:37:12,109
Yeah.

408
00:37:12,109 --> 00:37:19,109
And after they were on-orbit the pilot asked
him why did you keep asking me about the engines?

409
00:37:21,450 --> 00:37:22,560
Everything was fine.

410
00:37:22,560 --> 00:37:29,130
Well, apparently the guy had been looking
out the overhead window and had seen flames

411
00:37:29,130 --> 00:37:33,210
starting to come out which is essentially
the expanding plume.

412
00:37:33,210 --> 00:37:38,400
Of course it was the first night launch so
nobody had ever seen that on the Shuttle before.

413
00:37:38,400 --> 00:37:43,030
And so you're always looking for something
off nominal.

414
00:37:43,030 --> 00:37:49,829
But, as it turned out, it is just normal plume
behavior.

415
00:37:49,829 --> 00:37:56,829
Now we've got a few minutes riding on the
main engine to build up to orbital velocity.

416
00:37:58,859 --> 00:38:00,710
Essentially, we are flying up the Eastern
seaboard.

417
00:38:00,710 --> 00:38:04,770
And it will give you some sense of the acceleration.

418
00:38:04,770 --> 00:38:10,020
Hopefully, you will recognize some of the
geography.

419
00:38:10,020 --> 00:38:17,020
When they talk about taking the Shuttle from
Washington to Boston or back, this is the

420
00:38:18,910 --> 00:38:25,060
real thing.

421
00:38:25,060 --> 00:38:32,060
It takes about 8 minutes, 8.5 minutes, to
get from Cape Canaveral to Cape Cod.

422
00:38:37,579 --> 00:38:39,250
There is Long Island coming up.

423
00:38:39,250 --> 00:38:45,880
I heard Plattsburgh, New York was an alternate
landing site?

424
00:38:45,880 --> 00:38:46,550
Yeah.

425
00:38:46,550 --> 00:38:48,940
We are really moving at this point.

426
00:38:48,940 --> 00:38:53,790
You're going about five miles a second orbital
velocity.

427
00:38:53,790 --> 00:38:55,400
There is Cape Cod.

428
00:38:55,400 --> 00:39:02,400
And now you will see a little bit of a pitch
as we separate from the tank.

429
00:39:10,470 --> 00:39:17,470
And here, again, is the belly camera as the
tank comes off.

430
00:39:25,829 --> 00:39:28,660
And you can see these little charred patterns
in here.

431
00:39:28,660 --> 00:39:35,660
That is where the big piece of foam came off
which destroyed the Columbia.

432
00:39:36,569 --> 00:39:43,569
We've talked about, for its orbital operation,
it was all the different things that the Shuttle

433
00:39:58,819 --> 00:40:03,089
was supposed to do that really drove the design.

434
00:40:03,089 --> 00:40:08,380
Speaking of which, how did things go last
Thursday?

435
00:40:08,380 --> 00:40:12,359
Colonel Young gave the lecture on the military.

436
00:40:12,359 --> 00:40:19,359
I haven't had a chance to talk with him yet
but hopefully maybe he had some new insights.

437
00:40:19,730 --> 00:40:25,809
I know we talked a lot already about military
requirements.

438
00:40:25,809 --> 00:40:32,809
But, in addition to launching large satellites,
of course we have repaired satellites, we

439
00:40:35,260 --> 00:40:41,290
have done science experiments, we have done
a lot of educational activities.

440
00:40:41,290 --> 00:40:48,119
And I am not going to deal with those subsystems
so much now.

441
00:40:48,119 --> 00:40:55,119
Remember that the computers now really don't
deal with the main propulsion system anymore.

442
00:40:59,130 --> 00:41:06,130
The only thing that you have to be concerned
about generally in orbit you still have to

443
00:41:06,680 --> 00:41:13,680
maintain thermal control over all of the parts
of the Shuttle, so the thermal subsystem is

444
00:41:14,980 --> 00:41:17,980
very critical.

445
00:41:17,980 --> 00:41:20,069
We talked about the problems with hydrazine.

446
00:41:20,069 --> 00:41:27,069
If hydrazine freezes and then it expands when
it thaws it can break the lines.

447
00:41:27,460 --> 00:41:29,290
Hydrazine leaks are very nasty.

448
00:41:29,290 --> 00:41:36,290
We had one instance on a Shuttle flight where
one of the thrusters did develop a leak, and

449
00:41:37,650 --> 00:41:44,650
you could just see the exhaust coming out
of it until they shut off the isolation valve.

450
00:41:49,000 --> 00:41:56,000
There are several sets of RCS thrusters, each
of which is connected to the tanks by a set

451
00:41:57,390 --> 00:42:00,450
of isolation valves.

452
00:42:00,450 --> 00:42:05,010
You have essentially triple redundancy in
your reaction control system.

453
00:42:05,010 --> 00:42:10,990
And if any one of the systems develops a leak
you can isolate individual thrusters to tell

454
00:42:10,990 --> 00:42:17,990
them not to fire if it's a leak which only
occurs when you fire it, or you can shut down

455
00:42:18,750 --> 00:42:22,559
an isolation valve for an entire set of jets.

456
00:42:22,559 --> 00:42:29,119
I won't go into great details but we talked
about the importance of redundancy.

457
00:42:29,119 --> 00:42:34,740
And that is one of the ways that it is built
in.

458
00:42:34,740 --> 00:42:35,319
Let's see.

459
00:42:35,319 --> 00:42:39,660
What else do we want to say about subsystems
during orbit?

460
00:42:39,660 --> 00:42:46,660
What are some of the other subsystems which
get called into play for orbital operations?

461
00:42:49,530 --> 00:42:50,740
Environmental subsystems.

462
00:42:50,740 --> 00:42:51,339
Environmental.

463
00:42:51,339 --> 00:42:56,119
Is that controlled by the computer or is that
kind of done separate and automated?

464
00:42:56,119 --> 00:42:59,730
A little bit of both.

465
00:42:59,730 --> 00:43:06,730
For instance, pressure valves are mechanical
so they will open at a specific pressure mechanically.

466
00:43:09,910 --> 00:43:16,910
If you have an overpressure or you set your,
we have different settings.

467
00:43:21,630 --> 00:43:24,800
The normal setting is for sea 0:43:20.526
level atmosphere.

468
00:43:24,800 --> 00:43:29,359
And, of course, you have to balance the oxygen
and the nitrogen.

469
00:43:29,359 --> 00:43:33,200
And so there is a fairly complex algorithm.

470
00:43:33,200 --> 00:43:34,940
Well, it is fairly simple, I suppose.

471
00:43:34,940 --> 00:43:41,220
But there is an algorithm which senses both
the overall pressure and the oxygen partial

472
00:43:41,220 --> 00:43:47,079
pressure so that if your pressure goes down
a little bit, the system has to know whether

473
00:43:47,079 --> 00:43:52,839
to open up the oxygen valve or the nitrogen
valve.

474
00:43:52,839 --> 00:43:59,839
Also, if we are going to be doing extended
space walks, and I will be giving a talk on

475
00:44:00,550 --> 00:44:06,869
the airlock and the spacesuit and the other
systems that get involved in space walks,

476
00:44:06,869 --> 00:44:12,130
so I won't go into that in detail here, but
we actually have to bring the cabin down to

477
00:44:12,130 --> 00:44:16,309
two-thirds of an atmosphere, 10.2 pounds per
square inch.

478
00:44:16,309 --> 00:44:22,079
We keep the partial pressure of oxygen at
sea level so that raises the oxygen concentration

479
00:44:22,079 --> 00:44:22,869
to about 30%.

480
00:44:22,869 --> 00:44:28,829
And the reason we do that is to purge the
nitrogen out of our bodies so that you don't

481
00:44:28,829 --> 00:44:35,720
get the bends when you go down to the 4 psi,
at pure oxygen, which is what we run our suits

482
00:44:35,720 --> 00:44:39,470
at.

483
00:44:39,470 --> 00:44:46,470
At that point, we actually have to trick the
system because they didn't build in a 10.2

484
00:44:51,000 --> 00:44:51,250
controller.
They have a 14.7 psi controller.

485
00:44:56,150 --> 00:45:01,339
But, in any case, that we control manually.

486
00:45:01,339 --> 00:45:08,339
And we basically bring the cabin down to 10.2
psi.

487
00:45:08,790 --> 00:45:11,900
Humidity control, we have the water system.

488
00:45:11,900 --> 00:45:18,900
Of course, we make a lot of water with our
fuel cells for the electrical power system.

489
00:45:20,119 --> 00:45:22,400
There are five different water tanks.

490
00:45:22,400 --> 00:45:25,250
One of the tanks is sterilized for drinking.

491
00:45:25,250 --> 00:45:31,480
In the early days they put too much iodine
in the water.

492
00:45:31,480 --> 00:45:35,430
In fact, when I came back from my first flight
my teeth were totally brown.

493
00:45:35,430 --> 00:45:40,230
The dentist had a fit, and they actually have
cut back on that.

494
00:45:40,230 --> 00:45:43,339
And the water is actually reasonably palatable
at this point.

495
00:45:43,339 --> 00:45:47,210
You couldn't drink it early on unless you
mixed it with Kool-Aid or Tang or something,

496
00:45:47,210 --> 00:45:51,849
which is even worse, but that's another story.

497
00:45:51,849 --> 00:45:58,770
The rest of the water tanks, there is just
a lot more water than anybody can drink, and

498
00:45:58,770 --> 00:46:02,859
so those are called supply water tanks.

499
00:46:02,859 --> 00:46:06,730
And we use that water for cooling.

500
00:46:06,730 --> 00:46:10,480
Remember that is another part of the environmental
control system.

501
00:46:10,480 --> 00:46:13,130
We have talked about all of these a little
bit.

502
00:46:13,130 --> 00:46:17,210
This is just kind of a review.

503
00:46:17,210 --> 00:46:22,270
Remember that during ascent, once you get
above 100,000 feet and during the early time

504
00:46:22,270 --> 00:46:29,270
on-orbit, we get rid of excess heat by water
boiler.

505
00:46:29,420 --> 00:46:36,420
Now, it is an interesting system, a multi-component
system.

506
00:46:40,800 --> 00:46:47,800
Out in the cargo bay we use Freon to bring
the heat through the radiators.

507
00:46:48,069 --> 00:46:54,400
First it goes through the radiators, and so
once the payload bay doors are open, particularly

508
00:46:54,400 --> 00:47:00,770
if you're pointed away from the sun, you can
radiate a lot of heat.

509
00:47:00,770 --> 00:47:07,770
After the Freon runs through the radiators,
if it is still hot, you can activate the water

510
00:47:08,960 --> 00:47:09,260
boilers.

511
00:47:09,260 --> 00:47:14,869
And so if the payload bay doors are closed
or if there is some problem with the radiators

512
00:47:14,869 --> 00:47:19,010
and you need excess cooling capacity you activate
the water spray boilers.

513
00:47:19,010 --> 00:47:26,010
Now the water boilers, if that is your only
cooling system, they use water at a rate faster

514
00:47:28,920 --> 00:47:31,609
than the fuel cells produce it.

515
00:47:31,609 --> 00:47:37,309
If you cannot get your payload bay doors open
-- and that is part of the whole mechanisms,

516
00:47:37,309 --> 00:47:43,329
remember, which Henry Pohl talked about -- if
you cannot get your payload doors open within

517
00:47:43,329 --> 00:47:49,890
a few hours, you have to turn around and come
home because you will run out of water.

518
00:47:49,890 --> 00:47:54,309
Now, on the other hand, how do you get the
heat out of the crew cabin?

519
00:47:54,309 --> 00:47:59,530
You don't want Freon running around the crew
cabin because it is nasty stuff if you develop

520
00:47:59,530 --> 00:48:01,500
a leak.

521
00:48:01,500 --> 00:48:06,040
There are actually two ways.

522
00:48:06,040 --> 00:48:12,990
First of all, you circulate the cabin air
which gets heated up both by the people and

523
00:48:12,990 --> 00:48:14,270
the electronics.

524
00:48:14,270 --> 00:48:20,160
And you run the cabin air through a heat exchanger
where it dumps its heat into a cold water

525
00:48:20,160 --> 00:48:20,410
loop.
And the cold water loop takes cabin heat,
and then the cold water loop is also circulated

526
00:48:26,369 --> 00:48:27,670
by some of the electronics.

527
00:48:27,670 --> 00:48:31,000
Some of the electronics are air-cooled.

528
00:48:31,000 --> 00:48:38,000
And, of course, there is no density driven
thermal convection in weightlessness.

529
00:48:39,579 --> 00:48:43,349
You have to have forced-air convection, so
there are fans all over the place blowing

530
00:48:43,349 --> 00:48:50,349
air at the electronics and at the crew as
well.

531
00:48:52,079 --> 00:48:59,079
And these are all small fans running at very
high RPM and so they tend to be very noisy.

532
00:49:00,130 --> 00:49:07,130
In fact, the typical environment in a space
cabin is dominated by high-pitched fan noise.

533
00:49:08,640 --> 00:49:15,640
In fact, it gets so bad that in the Russian
Mir, we found this once US astronauts starting

534
00:49:16,730 --> 00:49:22,000
to fly up there, it was actually causing permanent
hearing damage in a lot of crew members.

535
00:49:22,000 --> 00:49:29,000
And people were having to wear earplugs or
headphones while they were working near some

536
00:49:30,190 --> 00:49:30,980
of the equipment.

537
00:49:30,980 --> 00:49:37,980
From a human factors point of view, to have
earplugs in and then somebody tries to call

538
00:49:39,230 --> 00:49:42,859
to you from the next module because there
is an emergency, that is not a good deal.

539
00:49:42,859 --> 00:49:45,369
Yeah.

540
00:49:45,369 --> 00:49:52,369
[AUDIENCE QUESTION] No.

541
00:49:52,900 --> 00:49:59,900
There are a lot of electrical signals up there
because the crew uses wireless headsets, but

542
00:50:00,250 --> 00:50:03,470
everything is checked for electromagnetic
compatibility.

543
00:50:03,470 --> 00:50:08,450
And, in fact, if you try to fly a payload
on the Shuttle or the Station, you have to

544
00:50:08,450 --> 00:50:15,450
pass a lot of EMC compatibility testing.

545
00:50:16,460 --> 00:50:21,000
Anyway, the water from the cabin, which is
taking the heat both from the air and the

546
00:50:21,000 --> 00:50:28,000
electronics, is then taken out of the cabin
and passed through a water Freon heat exchanger.

547
00:50:28,490 --> 00:50:33,890
And then the Freon takes the heat further
aft where it is dumped into the radiator or

548
00:50:33,890 --> 00:50:40,760
the water spray boiler.

549
00:50:40,760 --> 00:50:45,059
Cabin air revitalization.

550
00:50:45,059 --> 00:50:47,299
We re-breathe the air.

551
00:50:47,299 --> 00:50:52,730
It's not like in scuba diving where you take
a breath of air and then you just blow it

552
00:50:52,730 --> 00:50:53,549
all away.

553
00:50:53,549 --> 00:50:59,040
We cannot afford that so the air is re-breathed,
which means you have to scrub out the carbon

554
00:50:59,040 --> 00:51:00,020
dioxide.

555
00:51:00,020 --> 00:51:07,020
The Shuttle is not designed for long duration,
and so we use lithium hydroxide scrubbers,

556
00:51:08,290 --> 00:51:13,670
lithium hydroxide plus carbon dioxide makes
lithium carbonate plus water plus heat.

557
00:51:13,670 --> 00:51:20,540
And so those are canisters which have to be
replaced twice a day.

558
00:51:20,540 --> 00:51:27,510
And, in fact, the preparation for replacing
the lithium hydroxide scrubbers is you have

559
00:51:27,510 --> 00:51:34,510
to turn the cabin fans off so you don't get
a lot of air going through the cylinders where

560
00:51:38,839 --> 00:51:41,140
you put the scrubbers.

561
00:51:41,140 --> 00:51:48,140
For that one minute, you can actually appreciate
the peace and quiet of being in orbit.

562
00:51:48,990 --> 00:51:52,200
And then you turn the fans on again and you
realize how noisy it is.

563
00:51:52,200 --> 00:51:57,510
Because, after a while, you get used to it
and you don't hear the noise until you turn

564
00:51:57,510 --> 00:51:59,530
it off.

565
00:51:59,530 --> 00:52:02,150
So, that's air revitalization system.

566
00:52:02,150 --> 00:52:03,780
Humidity separation.

567
00:52:03,780 --> 00:52:10,780
You're pumping out a lot of humidity in your
sweat, and that is put through a cooler and

568
00:52:12,990 --> 00:52:17,440
essentially a centrifugal, they call it a
slinger which gets rid of the water.

569
00:52:17,440 --> 00:52:23,210
And that goes into the wastewater tank, along
with urine from the waste collection system.

570
00:52:23,210 --> 00:52:24,700
And that is also dumped overboard.

571
00:52:24,700 --> 00:52:31,700
There are separate dumps for the supply water
and the waste water.

572
00:52:34,319 --> 00:52:41,319
And, when the water is dumped overboard, of
course up in orbit the pressure is below the

573
00:52:43,180 --> 00:52:47,950
triple point of water so liquid water cannot
exist.

574
00:52:47,950 --> 00:52:54,950
You either have gaseous water vapor or ice.

575
00:52:55,150 --> 00:53:02,150
And so, as soon as the water comes out the
wastewater dump valve, it solidifies.

576
00:53:04,890 --> 00:53:10,559
And you get essentially a snowstorm blowing
away from you.

577
00:53:10,559 --> 00:53:16,960
And, if the sun is lighting it up in just
the right way, it can be quite spectacular.

578
00:53:16,960 --> 00:53:22,950
If I have time, I will show you a picture
of that.

579
00:53:22,950 --> 00:53:23,200
Let's see.

580
00:53:23,040 --> 00:53:25,030
Other on-orbit systems?

581
00:53:25,030 --> 00:53:29,750
Of course, we have the payload systems.

582
00:53:29,750 --> 00:53:36,750
We talked about the remote manipulator, the
robotic arm.

583
00:53:37,490 --> 00:53:44,490
Anything else?

584
00:53:47,230 --> 00:53:54,230
[AUDIENCE QUESTION] The crew uses lots of
checklists and cue cards.

585
00:53:59,970 --> 00:54:06,970
Typically, the center of the front cockpit
has mostly the airplane-type controls which

586
00:54:08,589 --> 00:54:10,510
you use for flying the Shuttle.

587
00:54:10,510 --> 00:54:13,869
The systems controls tend to be around the
sides.

588
00:54:13,869 --> 00:54:19,970
And then the controls for doing rendezvous
and operating payloads are in the aft part

589
00:54:19,970 --> 00:54:21,400
of the cockpit.

590
00:54:21,400 --> 00:54:28,400
The forward center cockpit is not used very
much when you're on-orbit.

591
00:54:28,589 --> 00:54:31,760
Overhead panels is mostly OMS and RCS.

592
00:54:31,760 --> 00:54:36,329
And then electrical stuff is over the right.

593
00:54:36,329 --> 00:54:41,270
And environmental control is over on the left.

594
00:54:41,270 --> 00:54:48,270
[AUDIENCE QUESTION] Yes.

595
00:54:49,190 --> 00:54:55,819
During the early phases of the rendezvous,
when you cannot see anything, typically the

596
00:54:55,819 --> 00:54:58,710
commander and the pilot will sit in the front
seats.

597
00:54:58,710 --> 00:55:05,710
But once you get close enough to have visual
contact, you typically don't approach straight

598
00:55:05,910 --> 00:55:12,910
on, you typically approach with your payload
bay pointing towards the object you're rendezvousing

599
00:55:13,839 --> 00:55:14,089
with.
That way the rendezvous radar can pick it
up.

600
00:55:19,559 --> 00:55:26,559
There is a rendezvous radar system, KU band
radar, which is on the starboard side.

601
00:55:28,400 --> 00:55:32,970
And there are also star trackers which can
pick it up when it is farther away.

602
00:55:32,970 --> 00:55:36,520
And then visually you just look out the overhead
windows.

603
00:55:36,520 --> 00:55:43,520
And so you control the final phases of the
rendezvous, which we call proximity operations,

604
00:55:44,369 --> 00:55:45,289
from the aft flight deck.

605
00:55:45,289 --> 00:55:48,760
And there is a controller stick there.

606
00:55:48,760 --> 00:55:53,339
And, actually, it is interesting.

607
00:55:53,339 --> 00:55:54,940
This is part of the human factors.

608
00:55:54,940 --> 00:56:01,940
Both for controlling the manipulator arm and
the Shuttle, there is a switch.

609
00:56:03,400 --> 00:56:09,260
For instance, there is a translational hand
controller and a rotational hand controller.

610
00:56:09,260 --> 00:56:16,260
The translational is to make the Orbiter go
in plus or minus X, Z or Y.

611
00:56:20,940 --> 00:56:27,940
Normally, you think of the Shuttle, when you
push the stick back, you want the Shuttle

612
00:56:28,549 --> 00:56:31,829
to go in the direction of the stick.

613
00:56:31,829 --> 00:56:36,520
And so that would be a plus or minus X, which
is along the long axis of the Shuttle.

614
00:56:36,520 --> 00:56:38,990
And that is the way the forward controller
works.

615
00:56:38,990 --> 00:56:42,510
And you can set the back controller up so
that it is just the inverse of the forward

616
00:56:42,510 --> 00:56:46,130
controller so, when you push on the stick,
the Shuttle goes backwards.

617
00:56:46,130 --> 00:56:53,130
But, when you are actually looking out the
window and you see the object -- the Space

618
00:56:53,230 --> 00:56:58,280
Station, or Hubble or whatever you're rendezvousing
with -- is ahead of you and you want to go

619
00:56:58,280 --> 00:57:01,289
towards it, you would like to be able to push
the stick.

620
00:57:01,289 --> 00:57:08,289
And so what they've done is,
here is the upper window, they have the stick
actually at an angle.

621
00:57:20,460 --> 00:57:25,880
Depending on how you set the switch, you can
make it so that when you push on that stick

622
00:57:25,880 --> 00:57:32,880
it gives you a minus X or you can put it in
the Z mode so when you push the stick it gives

623
00:57:34,170 --> 00:57:37,910
you a minus Z.

624
00:57:37,910 --> 00:57:40,440
And that is a nice human factor.

625
00:57:40,440 --> 00:57:47,440
They have a similar situation for the manipulator
arm.

626
00:57:48,980 --> 00:57:55,980
On the end of the end effector, when you're
coming into a grapple fixture, there are actually

627
00:58:01,510 --> 00:58:03,619
three wires inside the end effector.

628
00:58:03,619 --> 00:58:10,619
And those actually are moved around like so,
so that they tighten up over the little knob.

629
00:58:13,289 --> 00:58:17,720
But there is a camera up here.

630
00:58:17,720 --> 00:58:24,720
And then above the grapple fixture there is
kind of a bull's-eye with a little stick on

631
00:58:27,240 --> 00:58:29,470
it.

632
00:58:29,470 --> 00:58:31,059
The stick is like this.

633
00:58:31,059 --> 00:58:38,059
And if you're off to the side a little bit
you can see by the angle on the stick both

634
00:58:39,160 --> 00:58:45,349
how you are in translation and in the attitude
of the end effector.

635
00:58:45,349 --> 00:58:50,609
The thing is when you're actually flying the
(UNINTELLIGIBLE) and you're looking out the

636
00:58:50,609 --> 00:58:57,609
window, I might want to be able to push the
translational hand controller and the end

637
00:58:59,250 --> 00:59:02,069
effector will move away from me in the cargo
bay.

638
00:59:02,069 --> 00:59:05,200
That is called a Shuttle Coordinate Mode.

639
00:59:05,200 --> 00:59:07,770
And they have a nice setup.

640
00:59:07,770 --> 00:59:11,940
Again, this was from a lot of human factor
studies.

641
00:59:11,940 --> 00:59:17,200
You can then go into a different mode when
you're actually bringing the end effector

642
00:59:17,200 --> 00:59:22,260
right up to the docking fixture where you
switch over into what they call end-effector

643
00:59:22,260 --> 00:59:23,099
mode.

644
00:59:23,099 --> 00:59:30,099
Now, I am actually looking in the television
picture and I see this image.

645
00:59:35,250 --> 00:59:39,339
And I want to correct it and I want to move
to the side a little bit and go in, but I

646
00:59:39,339 --> 00:59:42,839
want to do that in the frame of reference
of the end effector.

647
00:59:42,839 --> 00:59:47,710
And so by going into end-effector mode, when
I'm working the translational and rotational

648
00:59:47,710 --> 00:59:52,119
hand controller, it actually works around
that coordinate system.

649
00:59:52,119 --> 00:59:57,640
And there are actually two other coordinate
systems for different types of payload operations.

650
00:59:57,640 --> 01:00:04,640
They have done a lot of work in these systems
essentially to use computer-assisted modes

651
01:00:09,660 --> 01:00:16,660
to make it easier to operate both the robotic
and also the Shuttle rendezvous and docking

652
01:00:16,710 --> 01:00:17,119
system.

653
01:00:17,119 --> 01:00:22,660
What else do we want to say about on-orbit?

654
01:00:22,660 --> 01:00:24,849
That will probably do it.

655
01:00:24,849 --> 01:00:29,190
Let's take a two-minute break and then we
will move ahead to entry.

656
01:00:29,190 --> 01:00:36,190
Enough of a stretch.

657
01:00:36,309 --> 01:00:36,799
Yeah?

658
01:00:36,799 --> 01:00:43,799
Before we leave the on-orbit part, how much
of the crews' time was taken up with changing

659
01:00:45,760 --> 01:00:52,760
the carbon dioxide scrubbers, dumping wastewater,
just the general like you've got to do it

660
01:00:55,960 --> 01:00:59,369
to survive stuff versus [UNINTELLIGIBLE]?

661
01:00:59,369 --> 01:01:06,369
Typically one person can take care of most
of the on-orbit just maintenance activities.

662
01:01:13,890 --> 01:01:20,890
You have to do things like periodically check
your filters.

663
01:01:22,690 --> 01:01:26,859
Every one or two days you have to go through
with a vacuum cleaner and clear your filters.

664
01:01:26,859 --> 01:01:30,020
You have to change the lithium hydroxide.

665
01:01:30,020 --> 01:01:34,990
There you want somebody to help to turn off
the cabin fans while the person downstairs

666
01:01:34,990 --> 01:01:40,089
is changing them out.

667
01:01:40,089 --> 01:01:43,760
Periodically clean the toilet.

668
01:01:43,760 --> 01:01:44,930
Prepare food.

669
01:01:44,930 --> 01:01:51,930
I would say more or less one person around
the clock can take care of most of the things

670
01:01:52,039 --> 01:01:53,190
that have to get done, if nothing goes wrong.

671
01:01:53,190 --> 01:01:56,700
You kind of alternate between crew members?

672
01:01:56,700 --> 01:01:56,950
Yeah.

673
01:01:56,930 --> 01:02:03,930
Typically, you can have either a one shift
or a two shift flight, depending on whether

674
01:02:05,069 --> 01:02:08,510
your payload requires 24-hour operations.

675
01:02:08,510 --> 01:02:15,510
And typically the pilot and the commander
are considered to be the Orbiter crew, and

676
01:02:17,170 --> 01:02:20,069
so they will take care of Orbiter-related
things.

677
01:02:20,069 --> 01:02:27,069
And other people concentrate more on the payload
or doing space walks or whatever the mission

678
01:02:28,029 --> 01:02:30,359
is about.

679
01:02:30,359 --> 01:02:35,859
Everybody is more or less trained to perform
maintenance activities so you can share the

680
01:02:35,859 --> 01:02:42,859
load, but typically with a crew of six or
seven you have the luxury of specialization.

681
01:02:48,619 --> 01:02:49,410
Let's see.

682
01:02:49,410 --> 01:02:55,849
I spoke at length about what goes on during
entry so I am not going to go through all

683
01:02:55,849 --> 01:02:56,430
that again.

684
01:02:56,430 --> 01:03:01,849
I will just run the video here to remind you.

685
01:03:01,849 --> 01:03:08,849
But do remember, again, before you are ready
to do your de-orbit burn once again you have

686
01:03:11,069 --> 01:03:15,490
to reconfigure your computer system.

687
01:03:15,490 --> 01:03:21,329
Again, everybody gets in their seats, hands-off
because you don't want to throw any switches,

688
01:03:21,329 --> 01:03:25,609
and you definitely don't want to touch the
computer while it is going through this major

689
01:03:25,609 --> 01:03:26,760
mode reconfiguration.

690
01:03:26,760 --> 01:03:31,140
It is sort of like when your computer is booting
up, you don't want to mess with anything around.

691
01:03:31,140 --> 01:03:34,660
You just keep your hands off.

692
01:03:34,660 --> 01:03:41,660
Once you are in the de-orbit and entry major
mode, that is actually then subdivided into

693
01:03:47,599 --> 01:03:54,250
sub-modes where one of the software loads
controls your de-orbit burn and then another

694
01:03:54,250 --> 01:04:00,150
one is in effect while you are essentially
in free fall before you hit the atmosphere.

695
01:04:00,150 --> 01:04:06,279
And then, once you hit the atmosphere, you
go through a series of sub-modes depending

696
01:04:06,279 --> 01:04:07,390
on your altitude.

697
01:04:07,390 --> 01:04:14,390
And remember we spoke about how the flight
control system continually has to upgrade

698
01:04:15,270 --> 01:04:21,230
its flight control laws depending on the atmospheric
condition, so you need to know your nav.

699
01:04:21,230 --> 01:04:23,400
state.

700
01:04:23,400 --> 01:04:29,339
And then finally it switches into the final
approach and landing mode when you go around

701
01:04:29,339 --> 01:04:31,460
the heading alignment circle.

702
01:04:31,460 --> 01:04:35,440
That is the final step, which I don't think
we talked about.

703
01:04:35,440 --> 01:04:41,609
Remember I pointed out to you that since the
Shuttle is a glider that energy management

704
01:04:41,609 --> 01:04:44,130
is absolutely critical.

705
01:04:44,130 --> 01:04:48,029
And so you always come in with a little bit
more energy than you are going to need because

706
01:04:48,029 --> 01:04:53,359
it is easier to bleed the energy off through
a series of S turns.

707
01:04:53,359 --> 01:05:00,359
And then they make the transition when you're
essentially mach 2 or mach 3 and you are over

708
01:05:01,230 --> 01:05:07,190
the landing field, either in Florida or in
California.

709
01:05:07,190 --> 01:05:14,190
If this is your landing runway, a regular
airplane will typically do a downwind, a base

710
01:05:16,260 --> 01:05:19,210
and then come in for a landing.

711
01:05:19,210 --> 01:05:26,210
With the Shuttle, we actually want a much
larger pattern to give you more opportunity

712
01:05:26,369 --> 01:05:27,400
for energy control.

713
01:05:27,400 --> 01:05:34,400
At about 50,000 feet the Shuttle should be
essentially overhead.

714
01:05:35,670 --> 01:05:38,809
And then it makes a big spiral.

715
01:05:38,809 --> 01:05:43,380
And, since you're in this big spiral, you
have the option of either making the spiral

716
01:05:43,380 --> 01:05:47,980
slightly bigger or slightly smaller in order
to control your energy.

717
01:05:47,980 --> 01:05:53,730
If you're a little bit too hot, have too much
energy, then you make your spiral a little

718
01:05:53,730 --> 01:05:54,430
bit bigger.

719
01:05:54,430 --> 01:05:57,779
If you are a little low on energy you make
your spiral smaller.

720
01:05:57,779 --> 01:06:04,779
But by having every landing end in this spiral
which you can adjust the radius, but the basic

721
01:06:10,660 --> 01:06:15,538
procedure and navigation is not going to change
from flight to flight, so that makes the whole

722
01:06:15,538 --> 01:06:19,859
training process much easier.

723
01:06:19,859 --> 01:06:26,859
You go into the so-called heading alignment
circle and the pilot does have energy displays

724
01:06:28,490 --> 01:06:32,069
available so you get predictors.

725
01:06:32,069 --> 01:06:38,700
It tells you where you will be 30 seconds,
one minute and 90 seconds in the future.

726
01:06:38,700 --> 01:06:42,559
You get a vertical display showing your energy,
a horizontal display.

727
01:06:42,559 --> 01:06:47,680
Unfortunately, and this is something for the
people who are looking at displays, the horizontal

728
01:06:47,680 --> 01:06:51,990
and the vertical displays are not well integrated.

729
01:06:51,990 --> 01:06:57,260
In the talk that some of you heard on the
cockpit electronics upgrade, they had some

730
01:06:57,260 --> 01:07:01,500
plans to upgrade that and have a unified landing
display.

731
01:07:01,500 --> 01:07:04,779
But at the moment we don't have that.

732
01:07:04,779 --> 01:07:11,779
There is active guidance so that there are
guidance needles which you can fly to.

733
01:07:12,200 --> 01:07:17,400
And, of course, the pilots are well enough
trained that they are using their out-the-window

734
01:07:17,400 --> 01:07:23,170
cues as well to make sure that they get the
right visual picture just in case something

735
01:07:23,170 --> 01:07:24,849
should be wrong with guidance.

736
01:07:24,849 --> 01:07:25,869
Yeah.

737
01:07:25,869 --> 01:07:31,010
This is a ways back.

738
01:07:31,010 --> 01:07:38,010
How noticeable are the big changes in acceleration
during like SRB separation or de-tail?

739
01:07:42,670 --> 01:07:49,670
SRB separation, as I said, right before SRB
tail-off, F equals MA and the force is pretty

740
01:07:50,460 --> 01:07:55,309
much constant at that point, but the mass
is decelerating because you're burning a ton

741
01:07:55,309 --> 01:07:58,900
of fuel, over a ton per second.

742
01:07:58,900 --> 01:08:00,630
So the acceleration is increasing.

743
01:08:00,630 --> 01:08:07,538
And you've built up to about 2.5 Gs when the
SRBs finally tail-off.

744
01:08:07,538 --> 01:08:12,710
Then you drop down to about one G.

745
01:08:12,710 --> 01:08:13,549
You're sitting in your seat.

746
01:08:13,549 --> 01:08:15,839
This is one G into your chest.

747
01:08:15,839 --> 01:08:20,470
Remember at this point the Shuttle is kind
of upside down.

748
01:08:20,470 --> 01:08:27,470
And, since you haven't achieved orbital velocity
yet, you still have some weight pulling you

749
01:08:27,680 --> 01:08:28,330
out of the seat.

750
01:08:28,330 --> 01:08:30,490
But you are strapped into the seat.

751
01:08:30,490 --> 01:08:33,890
And mostly you feel yourself pulled back into
the seat.

752
01:08:33,890 --> 01:08:39,250
And, of course, as your velocity increases
and you get closer and closer to orbital velocity

753
01:08:39,250 --> 01:08:45,950
then the downward acceleration to the earth
essentially matches more and more the acceleration

754
01:08:45,950 --> 01:08:49,870
of the Shuttle itself until, by the time you're
in orbit, you are in freefall.

755
01:08:49,870 --> 01:08:56,870
MECO is different.

756
01:08:57,729 --> 01:09:00,750
The same thing happens.

757
01:09:00,750 --> 01:09:05,840
The main engines are working at maximum, well,
104% thrust.

758
01:09:05,840 --> 01:09:09,080
We don't take them up to the 109% which is
emergency only.

759
01:09:09,080 --> 01:09:16,080
They are working at 104% thrust and your acceleration
now starts to pick up.

760
01:09:17,109 --> 01:09:20,830
After about seven minutes you've gotten up
to 3 Gs.

761
01:09:20,830 --> 01:09:23,559
And the Shuttle was designed for a 3 G maximum.

762
01:09:23,559 --> 01:09:28,250
They wanted to have smooth, easy right for
the payloads.

763
01:09:28,250 --> 01:09:35,250
And they also wanted to make it possible for
nonprofessional astronauts to fly on the Shuttle

764
01:09:35,729 --> 01:09:38,309
as well, the payload specialist scientists.

765
01:09:38,309 --> 01:09:45,100
The engines start to throttle down in order
to hold your acceleration to 3 Gs.

766
01:09:45,100 --> 01:09:52,100
And they throttle down eventually to about
65% right at MECO.

767
01:09:53,430 --> 01:10:00,430
So you are sitting in your seat pulling 3
Gs, eyeballs-in, for the last minute and a

768
01:10:02,390 --> 01:10:03,000
half or so.

769
01:10:03,000 --> 01:10:10,000
3 Gs is not particularly comfortable but,
on the other hand, any healthy person can

770
01:10:11,080 --> 01:10:13,250
tolerate 3 Gs for a minute or two.

771
01:10:13,250 --> 01:10:17,330
It is not a real big deal.

772
01:10:17,330 --> 01:10:21,120
There have been concerns.

773
01:10:21,120 --> 01:10:26,250
If the pilots have to reach some of the overhead
switches to reconfigure the OMS or the RCS

774
01:10:26,250 --> 01:10:31,470
at 3 Gs, could they actually reach it?

775
01:10:31,470 --> 01:10:38,470
And some of the shorter pilots decided, with
the Gs, they probably couldn't.

776
01:10:38,770 --> 01:10:45,140
And so they actually made a special tool,
we called it a swizzle stick.

777
01:10:45,140 --> 01:10:52,040
It is an aluminum rod about, I don't know,
80 centimeters long, that has an interface

778
01:10:52,040 --> 01:10:53,720
so you can actually use that.

779
01:10:53,720 --> 01:10:57,390
And you have a little mirror if you need it
as well so that you can flick the overhead

780
01:10:57,390 --> 01:10:59,990
switches when you're pulling Gs.

781
01:10:59,990 --> 01:11:05,100
You cannot ignore human factors in these things
when you're designing it.

782
01:11:05,100 --> 01:11:07,580
If you've really got to flip those switches.

783
01:11:07,580 --> 01:11:11,390
And it is not just the problem of being able
to reach it.

784
01:11:11,390 --> 01:11:15,559
It's also you have a helmet on.

785
01:11:15,559 --> 01:11:21,180
And, when you're pulling 3 Gs, your helmet
which may have weighed 15 pounds now weighs

786
01:11:21,180 --> 01:11:22,430
45 pounds.

787
01:11:22,430 --> 01:11:25,790
And so you really cannot move your head around
very much.

788
01:11:25,790 --> 01:11:32,160
And so just being able to pull yourself away
from the seat and look up, you cannot do at

789
01:11:32,160 --> 01:11:33,790
3 Gs.

790
01:11:33,790 --> 01:11:39,380
So you do need some assistance there.

791
01:11:39,380 --> 01:11:46,380
In principle, for future designs, I would
think taking advantage of the ability to send

792
01:11:51,970 --> 01:11:57,080
commands through computers would make a lot
of that easier, if your computer is within

793
01:11:57,080 --> 01:11:58,970
easy reach.

794
01:11:58,970 --> 01:12:05,890
This was the early days of fly-by-wire and
people felt that they really wanted to have

795
01:12:05,890 --> 01:12:07,870
a hard switch that they could throw.

796
01:12:07,870 --> 01:12:14,480
But, in fact, in most cases, not all, but
in most cases the switches go through the

797
01:12:14,480 --> 01:12:15,559
computer system.

798
01:12:15,559 --> 01:12:20,330
And it is possible, in fact, to go into the
guts of the computer.

799
01:12:20,330 --> 01:12:23,080
And all the switches tend to be multiple pole.

800
01:12:23,080 --> 01:12:28,960
I am getting into some of the details now,
maybe more than ever wanted to know, but just

801
01:12:28,960 --> 01:12:33,130
to give you an idea of the levels of redundancy
that they have.

802
01:12:33,130 --> 01:12:37,610
Every switch has multiple poles, and it is
possible that you can get a little solder

803
01:12:37,610 --> 01:12:44,610
ball or a little piece of wire or just one
of the pole units that stops working.

804
01:12:46,270 --> 01:12:53,170
You can actually call up that switch on the
computer and disable one or more of the poles

805
01:12:53,170 --> 01:12:57,940
or you can disable the entire switch and take
over computer control of the switch.

806
01:12:57,940 --> 01:13:00,600
Like I say, most of the switches work like
that.

807
01:13:00,600 --> 01:13:01,410
Not all of them.

808
01:13:01,410 --> 01:13:08,020
But it is very much a computer-controlled
system.

809
01:13:08,020 --> 01:13:08,770
Yeah?

810
01:13:08,770 --> 01:13:15,770
How does the acceleration compare to a de-orbit
burn?

811
01:13:17,210 --> 01:13:20,150
De-orbit burn is interesting.

812
01:13:20,150 --> 01:13:26,480
When two OMS engines fire they only produce
about a tenth of G acceleration.

813
01:13:26,480 --> 01:13:33,480
However, you have been weightless for a week,
a month, six months depending what your mission

814
01:13:33,809 --> 01:13:34,160
has been.

815
01:13:34,160 --> 01:13:41,160
And I will tell you, the Shuttle is accelerating
forward, although you're actually going backwards.

816
01:13:44,110 --> 01:13:51,110
But internally, the Shuttle is accelerating
forward, so everything wants to go aft.

817
01:13:52,160 --> 01:13:53,960
And, in fact, it is kind of fun.

818
01:13:53,960 --> 01:14:00,960
We have done just experiments and taking pictures
of it where you can actually pour water at

819
01:14:03,250 --> 01:14:08,520
a tenth of a G and watch the water slowly
go through an arc into a cup.

820
01:14:08,520 --> 01:14:12,970
And then, of course, you've got to get it
closed up before the burn stops.

821
01:14:12,970 --> 01:14:19,970
And you can take a little pencil and push
it in the y-axis and watch it gradually curve

822
01:14:24,750 --> 01:14:25,559
as you're accelerating.

823
01:14:25,559 --> 01:14:32,180
It is only a tenth of a G but, I will tell
you, it feels like you're pressed against

824
01:14:32,180 --> 01:14:38,390
the wall if you're not sitting in your seat,
just because you haven't been experiencing

825
01:14:38,390 --> 01:14:40,180
any acceleration for all that time.

826
01:14:40,180 --> 01:14:45,559
And then it gets a lot worse, as you hit the
atmosphere.

827
01:14:45,559 --> 01:14:49,210
By that time hopefully you are sitting in
your seat.

828
01:14:49,210 --> 01:14:51,280
It is kind of interesting.

829
01:14:51,280 --> 01:14:57,390
What I tended to like to do is keep a pencil
sort of floating in front of me.

830
01:14:57,390 --> 01:15:02,580
And, after a while, you see very slowly the
pencil is starting to come down.

831
01:15:02,580 --> 01:15:07,960
And then you would pick it up and then it
is coming a little faster.

832
01:15:07,960 --> 01:15:13,570
One of the early things that you realize,
you know, if you've seen pictures of people

833
01:15:13,570 --> 01:15:16,230
in orbit, you're hands are always floating
up here.

834
01:15:16,230 --> 01:15:21,530
The same thing as if you go into a swimming
pool, just hold your breath and float under

835
01:15:21,530 --> 01:15:22,830
water.

836
01:15:22,830 --> 01:15:27,630
Your natural total relaxed body position is
sort of bent over a little bit and your hands

837
01:15:27,630 --> 01:15:28,540
are out front.

838
01:15:28,540 --> 01:15:29,110
Try it some time.

839
01:15:29,110 --> 01:15:33,300
It is quite relaxed, quite comfortable.

840
01:15:33,300 --> 01:15:35,210
And it was a strange feeling.

841
01:15:35,210 --> 01:15:38,270
Again, I got used to it after my first entry.

842
01:15:38,270 --> 01:15:42,770
But the first time, when I realized that I
was sitting in my seat and my hands were actually

843
01:15:42,770 --> 01:15:46,100
in my lap, and that hadn't happened.

844
01:15:46,100 --> 01:15:50,900
I had realized all the time before that your
hands were sort of floating out there.

845
01:15:50,900 --> 01:15:56,850
And then I reached for the camera to take
a picture out the window of the shockwaves

846
01:15:56,850 --> 01:16:02,270
behind the Shuttle, and all of a sudden it
has got weight.

847
01:16:02,270 --> 01:16:08,920
It is amazing how the human mind can get used
to a very bizarre situation, you know, like

848
01:16:08,920 --> 01:16:15,620
weightlessness, such that when you get back
it feels strange.

849
01:16:15,620 --> 01:16:17,030
It doesn't stay strange for long.

850
01:16:17,030 --> 01:16:24,030
I mean you grew up in one G and your body
has a pretty good memory, so it doesn't take

851
01:16:25,460 --> 01:16:26,460
long to get back.

852
01:16:26,460 --> 01:16:33,460
But there are potential vestibular problems.

853
01:16:33,470 --> 01:16:38,270
We have people in the Manned Vehicle Lab who
have spent their lifetimes studying some of

854
01:16:38,270 --> 01:16:40,910
these phenomena.

855
01:16:40,910 --> 01:16:47,910
A lot of your orientations for up or down
come from your inner ear, which have gravity

856
01:16:48,050 --> 01:16:49,400
receptors.

857
01:16:49,400 --> 01:16:52,510
Well, those basically don't work very well.

858
01:16:52,510 --> 01:16:59,510
They don't work at all, because the little
bone particles inside there are basically

859
01:17:01,580 --> 01:17:02,710
floating around.

860
01:17:02,710 --> 01:17:09,710
You don't get the proper feedback, but you
still get visual feedback and you get rotational

861
01:17:11,100 --> 01:17:13,580
feedback from your inner ear.

862
01:17:13,580 --> 01:17:20,580
And so your body has to essentially reprogram
the feedback loops so that you can maintain

863
01:17:22,250 --> 01:17:24,260
your sense of orientation.

864
01:17:24,260 --> 01:17:26,540
And that leads to space sickness.

865
01:17:26,540 --> 01:17:33,540
And about roughly two-thirds of people who
go up experience some form of space sickness.

866
01:17:33,660 --> 01:17:35,870
It is sort of like seasickness.

867
01:17:35,870 --> 01:17:42,870
Anywhere from mild -- [LOST VIDEO AND AUDIO]
[LOST VIDEO AND AUDIO] -- the feeling ofweightlessness.

868
01:19:48,180 --> 01:19:55,180
But launch is really an overwhelming experience
with all the vibration and the power and the

869
01:19:56,120 --> 01:19:58,430
acceleration and everything.

870
01:19:58,430 --> 01:20:05,080
And I remember thinking to myself at MECO
when I started floating, I thought now I'm

871
01:20:05,080 --> 01:20:06,920
in an environment that I understand.

872
01:20:06,920 --> 01:20:13,920
Because I had had so many 135 parabolas that
the feeling of being weightless was not as

873
01:20:17,870 --> 01:20:20,710
overwhelmingly new as it otherwise might have
been.

874
01:20:20,710 --> 01:20:27,210
Although, what I realized after about a minute,
I was sort of holding onto the seat waiting

875
01:20:27,210 --> 01:20:27,950
for the pullout.

876
01:20:27,950 --> 01:20:33,870
That is when I realized, no, wait a minute,
no pullout, you're really in orbit.

877
01:20:33,870 --> 01:20:38,180
And that is when I got really excited and
sort of floated over to the window.

878
01:20:38,180 --> 01:20:44,450
And I basically couldn't wipe the smile off
my face for about seven days.

879
01:20:44,450 --> 01:20:46,120
Yeah?

880
01:20:46,120 --> 01:20:53,120
What about the internal clock?

881
01:20:54,460 --> 01:20:57,400
Do you still have 24-hour days?

882
01:20:57,400 --> 01:20:57,890
Yeah, basically.

883
01:20:57,890 --> 01:21:03,350
The sun rises and sets every 90 minutes.

884
01:21:03,350 --> 01:21:09,230
What we try to do, this wasn't done in the
early Shuttle flights, but often you have

885
01:21:09,230 --> 01:21:15,460
to launch at odd hours, if you're doing a
rendezvous particularly.

886
01:21:15,460 --> 01:21:21,960
For instance, when we launched to repair Hubble,
the launch was 4:00 AM because that's when

887
01:21:21,960 --> 01:21:23,860
Hubble happened to be flying over.

888
01:21:23,860 --> 01:21:30,860
Now 4:00 AM, typically your body is at about
its lowest point in the 24-hour cycle.

889
01:21:31,809 --> 01:21:34,250
You know, your basal metabolism, your temperature.

890
01:21:34,250 --> 01:21:40,900
Not the condition you want to be in when you
go through a launch in case there is any problem.

891
01:21:40,900 --> 01:21:43,780
What you want to do is adjust your sleep cycle.

892
01:21:43,780 --> 01:21:50,200
It is very hard to adjust your sleep cycle
when you have the sun rising and setting every

893
01:21:50,200 --> 01:21:55,550
90 minutes because you don't get any light
feedback, but what we do is, starting a week

894
01:21:55,550 --> 01:22:01,000
before a launch, the crew goes into a medical
quarantine so that you don't get exposed to

895
01:22:01,000 --> 01:22:06,140
any cold germs because you don't want to get
sick on-orbit.

896
01:22:06,140 --> 01:22:13,140
And so at that time what they have done is
use some medical research over the last 20

897
01:22:14,400 --> 01:22:21,400
years or so which indicates that bright lights,
at the right time of day, can actually help

898
01:22:24,790 --> 01:22:27,059
your body change to a new time zone.

899
01:22:27,059 --> 01:22:32,030
That's why they say when you fly over to Europe,
you fly overnight and you don't usually sleep

900
01:22:32,030 --> 01:22:33,100
too much in the airplane.

901
01:22:33,100 --> 01:22:34,530
You land early in the morning.

902
01:22:34,530 --> 01:22:40,290
And a lot of people then want to go to their
hotel and go to sleep for a while, but the

903
01:22:40,290 --> 01:22:43,710
doctors tell you that is the worst thing to
do as far as getting used to the new time

904
01:22:43,710 --> 01:22:44,000
zone.

905
01:22:44,000 --> 01:22:48,580
What you really want to do is go stay out
in the bright sunlight at a time when your

906
01:22:48,580 --> 01:22:54,540
body thinks it should be dark, get the sunlight
into your brain.

907
01:22:54,540 --> 01:22:55,400
And that is what we do.

908
01:22:55,400 --> 01:22:59,230
In the quarantine quarters everything is white.

909
01:22:59,230 --> 01:23:00,870
The tables have white butcher paper.

910
01:23:00,870 --> 01:23:03,020
And the walls and the ceiling are white.

911
01:23:03,020 --> 01:23:08,640
And there is essentially wall-to-wall fluorescent
lights on the ceiling.

912
01:23:08,640 --> 01:23:09,750
And so it is really bright.

913
01:23:09,750 --> 01:23:13,820
I mean you have to wear sunglasses when you
first go in the room.

914
01:23:13,820 --> 01:23:20,820
And it is too bright to watch television or
even to use your computer, but it works.

915
01:23:21,550 --> 01:23:28,230
And after about two days you are pretty much
accommodated to the new time.

916
01:23:28,230 --> 01:23:35,230
And then, if you want to go out during the
day when the sun is out but it is a time when

917
01:23:35,460 --> 01:23:38,790
the sun shouldn't be out for the time you
are trying to switch to, you have to wear

918
01:23:38,790 --> 01:23:43,400
really, really dark sunglasses so you don't
get deprogrammed.

919
01:23:43,400 --> 01:23:50,400
The problem is sometimes when you're on-orbit,
because of the procession of orbits, you tend

920
01:23:53,320 --> 01:23:58,400
to have to re-enter, on a short shuttle flight
-- this is different for the Space Station

921
01:23:58,400 --> 01:24:05,400
-- but on a short Shuttle flight you typically
reenter a few hours earlier than your equivalent

922
01:24:07,120 --> 01:24:09,050
launch time.

923
01:24:09,050 --> 01:24:14,760
And that means that you have to often do a
sleep shift in orbit.

924
01:24:14,760 --> 01:24:18,370
And that is much more difficult, particularly
if you try to shift earlier.

925
01:24:18,370 --> 01:24:23,110
It is relatively easy to stay awake for an
extra hour.

926
01:24:23,110 --> 01:24:25,410
I mean everybody likes to lie in bed for an
extra hour.

927
01:24:25,410 --> 01:24:26,110
That is easy.

928
01:24:26,110 --> 01:24:32,100
But to go to bed an hour or two hours early
it is hard to get to sleep.

929
01:24:32,100 --> 01:24:35,520
And then you have to wake up two hours early,
that is difficult.

930
01:24:35,520 --> 01:24:38,770
But that typically is what you have to do.

931
01:24:38,770 --> 01:24:45,770
The medical people have actually imposed maximum
shifts both per day, per week and per month

932
01:24:47,370 --> 01:24:52,140
for how much the crew can be asked to shift
their sleep schedule.

933
01:24:52,140 --> 01:24:59,140
The Russians have another problem when they
do space walks because they don't have a full

934
01:24:59,750 --> 01:25:05,140
equivalent of a TDRS system, tracking data
relay system, like we do.

935
01:25:05,140 --> 01:25:12,140
They like to be doing their space walks when
they're making passes over Russia so that

936
01:25:13,250 --> 01:25:15,290
they can get ground tracking.

937
01:25:15,290 --> 01:25:22,290
And so often when a Russian crew is preparing
for a space walk, they have to shift sometimes

938
01:25:22,500 --> 01:25:23,860
by eight hours at a time.

939
01:25:23,860 --> 01:25:28,380
And it can be really tough on a crew to have
to do that.

940
01:25:28,380 --> 01:25:29,840
If any of you have worked third shift.

941
01:25:29,840 --> 01:25:36,840
It's not like pulling an all-nighter where
the next day you go back onto your normal

942
01:25:39,190 --> 01:25:39,600
shift.

943
01:25:39,600 --> 01:25:45,200
To actually stay on a different shift for
three or four days at a time can be tough

944
01:25:45,200 --> 01:25:48,400
when you don't have any light cues to accommodate
you.

945
01:25:48,400 --> 01:25:48,650
Yeah?

946
01:25:48,450 --> 01:25:52,230
Just an observation that all those measures
to shift the sleep cycle are obsolete now

947
01:25:52,230 --> 01:25:59,230
with the no night launches, right?

948
01:26:01,890 --> 01:26:08,890
As long as there are no night launches that
is probably true.

949
01:26:08,980 --> 01:26:15,130
And what that means, of course, is that they
can only launch to the Space Station at certain

950
01:26:15,130 --> 01:26:15,970
times of the year.

951
01:26:15,970 --> 01:26:19,380
That is the price you pay.

952
01:26:19,380 --> 01:26:19,630
Yeah?

953
01:26:19,540 --> 01:26:26,540
On the launch pad, what is supporting the
entire weight of the Orbiter?

954
01:26:34,850 --> 01:26:35,730
And, secondly, if you are on the mid-deck,
are there any windows?

955
01:26:35,730 --> 01:26:35,980
And, if not, can you see?
I should bring in the launch bolts.

956
01:26:37,710 --> 01:26:38,830
I have a couple in my office.

957
01:26:38,830 --> 01:26:43,830
The entire weight of the Shuttle stack is
supported on the two solid rocket boosters,

958
01:26:43,830 --> 01:26:49,680
so the bottom skirts of the boosters are actually
sitting on the launch pad.

959
01:26:49,680 --> 01:26:56,680
And so on each of the boosters there are four
big nuts and bolts, four on each booster.

960
01:27:00,230 --> 01:27:03,809
They are explosive nuts.

961
01:27:03,809 --> 01:27:10,809
And at the moment that the solid rocket boosters
ignite, all eight of those nuts are split

962
01:27:12,660 --> 01:27:16,540
in half so that the boosters can lift off.

963
01:27:16,540 --> 01:27:20,230
Now, I asked the question what would happen
if one of them didn't go.

964
01:27:20,230 --> 01:27:25,230
And the answer was, well, we think that the
booster is strong enough that it would just

965
01:27:25,230 --> 01:27:28,860
rip it out, but nobody wants to find out.

966
01:27:28,860 --> 01:27:34,790
Obviously, these are redundant explosive bolts
or nuts.

967
01:27:34,790 --> 01:27:41,090
They did have, on one flight, they found that
one or two of the redundant firing units did

968
01:27:41,090 --> 01:27:42,300
not fire.

969
01:27:42,300 --> 01:27:44,400
And that got people's attention.

970
01:27:44,400 --> 01:27:46,960
And I don't know what the final resolution
was.

971
01:27:46,960 --> 01:27:53,960
But basically those bolts, you know, if there
is wind blowing and the Shuttle is rocking

972
01:27:54,210 --> 01:27:59,190
back and forth, all of that load is taken
through those bolts.

973
01:27:59,190 --> 01:28:04,670
The structure of the solid boosters has to
be able to accommodate that.

974
01:28:04,670 --> 01:28:07,690
You asked me another question as well.

975
01:28:07,690 --> 01:28:12,000
Oh, the mid-deck.

976
01:28:12,000 --> 01:28:16,330
The hatch, where the crew gets in, has a window
in it.

977
01:28:16,330 --> 01:28:23,200
Before Challenger, one seat in the mid-deck
was right next to the hatch.

978
01:28:23,200 --> 01:28:30,200
My first flight, I actually sat next to the
hatch during ascent downstairs but had a great

979
01:28:30,330 --> 01:28:32,870
view out the window.

980
01:28:32,870 --> 01:28:39,870
Now, after Challenger, we have an ejection
pole, a telescoping pole which is suspended

981
01:28:45,930 --> 01:28:46,490
from the ceiling.

982
01:28:46,490 --> 01:28:50,630
I think we talked about this before.

983
01:28:50,630 --> 01:28:57,630
If the Shuttle is in a situation where it
is in stable flight but you cannot make it

984
01:28:57,820 --> 01:29:02,730
to a runway, at about 40,000 feet you blow
the hatch.

985
01:29:02,730 --> 01:29:09,730
The telescoping pole, you release the pin,
the pole will extend, and then one by one

986
01:29:11,400 --> 01:29:14,460
you clip onto the pole and you jump out.

987
01:29:14,460 --> 01:29:21,050
And the pole takes you below the wing so that
you won't hit the Shuttle structure.

988
01:29:21,050 --> 01:29:25,690
And then eventually your parachute will open.

989
01:29:25,690 --> 01:29:32,610
That now takes up the area over by the window
and the three seats no longer have a view.

990
01:29:32,610 --> 01:29:39,610
If you're sitting on the mid-deck how during
a launch, how do you know what is going on...?

991
01:29:42,360 --> 01:29:43,150
[UNINTELLIGIBLE] You hear the comm.

992
01:29:43,150 --> 01:29:43,640
loop.

993
01:29:43,640 --> 01:29:47,980
And if you have a nice commander he will tell
you.

994
01:29:47,980 --> 01:29:52,730
For instance, if you have a rookie astronaut
onboard, they want to know when they go through

995
01:29:52,730 --> 01:29:58,590
100 kilometers because that means you have
officially been in space and you can get your

996
01:29:58,590 --> 01:29:59,440
astronaut wings.

997
01:29:59,440 --> 01:30:04,250
So, if the commander is nice, he will call
100 clicks on the way up and congratulate

998
01:30:04,250 --> 01:30:05,840
the new rookies.

999
01:30:05,840 --> 01:30:08,050
But basically that is about it.

1000
01:30:08,050 --> 01:30:12,020
And the same for entry, you don't have a view.

1001
01:30:12,020 --> 01:30:17,660
There are still plenty of physiological things
to keep your attention, so it is not like

1002
01:30:17,660 --> 01:30:23,140
it is a boring ride, but you don't have the
view.

1003
01:30:23,140 --> 01:30:23,809
OK.

1004
01:30:23,809 --> 01:30:30,809
Let me run the entry picture here.

1005
01:30:36,020 --> 01:30:36,270
OK.

1006
01:30:36,250 --> 01:30:43,250
OMS engine ignition is when you see that big
flame pattern.

1007
01:30:44,460 --> 01:30:49,920
During the burn you don't see anything.

1008
01:30:49,920 --> 01:30:55,500
Now, looking out the front, you see the plasma
sheath.

1009
01:30:55,500 --> 01:31:02,500
It goes from a dull red gradually to orange
and then eventually white hot.

1010
01:31:04,620 --> 01:31:07,940
You can only see this at night.

1011
01:31:07,940 --> 01:31:14,940
It is fairly faint, but typically a lot of
flights you land during the early part of

1012
01:31:15,570 --> 01:31:16,750
the day on the ground.

1013
01:31:16,750 --> 01:31:23,670
And, of course, you do your burn halfway around
the world so the early part of your entry

1014
01:31:23,670 --> 01:31:29,940
is very often at night and then you fly into
the day.

1015
01:31:29,940 --> 01:31:36,940
And then I think there is another shot looking
out the aft window where you actually see

1016
01:31:37,450 --> 01:31:39,960
the plasma wake in the back of the Shuttle.

1017
01:31:39,960 --> 01:31:46,960
And you can see this is the old-fashioned
computer screen.

1018
01:31:53,220 --> 01:31:57,570
That is the wake looking out the overhead
window.

1019
01:31:57,570 --> 01:32:02,930
And, where these converge, that little point
there they say is about 10,000 degrees Fahrenheit,

1020
01:32:02,930 --> 01:32:04,640
which is the surface temperature of the sun.

1021
01:32:04,640 --> 01:32:10,900
It is remarkably stable, although every once
in a while you get those instabilities.

1022
01:32:10,900 --> 01:32:16,380
And every once in a while you get big bright
things go flying past, which I assume are

1023
01:32:16,380 --> 01:32:17,760
gap fillers coming out.

1024
01:32:17,760 --> 01:32:24,760
And I remember I would always think to myself
I hope that is nothing important.

1025
01:32:24,910 --> 01:32:30,730
You're basically riding on a meteorite because
it is supposed to make it all the way down

1026
01:32:30,730 --> 01:32:32,220
to the earth.

1027
01:32:32,220 --> 01:32:38,130
But that is essentially what you are seeing,
that trail behind you.

1028
01:32:38,130 --> 01:32:40,420
And I am sure you have all seen these landings.

1029
01:32:40,420 --> 01:32:44,110
Remember all the talk about the landing gear
and the brakes.

1030
01:32:44,110 --> 01:32:48,770
I looked for a video from my first flight
to show you the blowout.

1031
01:32:48,770 --> 01:32:55,770
I couldn't find one, but if I find one I will
bring it in and show you another time.

1032
01:33:03,960 --> 01:33:06,490
This is a landing out at Edwards.

1033
01:33:06,490 --> 01:33:10,670
Have you ever landed at night?

1034
01:33:10,670 --> 01:33:13,010
I have landed at night.

1035
01:33:13,010 --> 01:33:14,930
I was going to show you one other.

1036
01:33:14,930 --> 01:33:18,150
It doesn't have a landing light, does it?

1037
01:33:18,150 --> 01:33:18,400
No.

1038
01:33:18,309 --> 01:33:19,790
Do they light up the runway?

1039
01:33:19,790 --> 01:33:20,520
Yeah.

1040
01:33:20,520 --> 01:33:27,520
They have two banks of xenon lights which
light up the runway for you.

1041
01:33:36,880 --> 01:33:43,840
Actually, this next video is from my last
flight where we deployed the tethered satellite.

1042
01:33:43,840 --> 01:33:47,840
I am not going to show you all that stuff,
but I wanted to show you the launch sequence

1043
01:33:47,840 --> 01:33:52,250
because we have a few pictures showing the
opening of the payload bay doors.

1044
01:33:52,250 --> 01:33:58,410
And then you can actually see back to the
aft end of the Shuttle where you have the

1045
01:33:58,410 --> 01:33:59,420
main engine.

1046
01:33:59,420 --> 01:34:06,420
And remember I talked about how the hydrogen
and oxygen have now combined into water and

1047
01:34:06,770 --> 01:34:07,920
that forms ice.

1048
01:34:07,920 --> 01:34:14,309
And so for the first day or so on-orbit there
are just constant ice particles coming out

1049
01:34:14,309 --> 01:34:19,500
of the engines, and you are surrounded by
this cloud of ice.

1050
01:34:19,500 --> 01:34:23,930
Unfortunately the pictures are black and white
because it is low-light level TV, but visually

1051
01:34:23,930 --> 01:34:30,639
it is spectacular because these little ice
particles glint in the sunlight.

1052
01:34:30,639 --> 01:34:37,639
And they are rotating so they go through all
the different colors of the spectrum and you

1053
01:34:37,670 --> 01:34:38,790
are surrounded by this.

1054
01:34:38,790 --> 01:34:45,790
You will also see one of the RCS jets firing.

1055
01:34:54,700 --> 01:34:56,260
Water deluge.

1056
01:34:56,260 --> 01:34:59,410
Main engine sequence.

1057
01:34:59,410 --> 01:35:00,850
Again, you see the whole tilt.

1058
01:35:00,850 --> 01:35:07,690
When it gets back to vertical we take off.

1059
01:35:07,690 --> 01:35:13,550
This is a much shorter sequence here for the
launch than the last one.

1060
01:35:13,550 --> 01:35:20,550
How does it roll?

1061
01:35:23,940 --> 01:35:27,150
The SRB boosters go like that.

1062
01:35:27,150 --> 01:35:32,340
Is it the entire stack or just the lower...?

1063
01:35:32,340 --> 01:35:39,340
No, it is just the nozzle at the bottom.

1064
01:35:40,450 --> 01:35:42,500
This was Columbia.

1065
01:35:42,500 --> 01:35:46,860
You can always tell Columbia because, if you
look at the vertical stabilizer up here, that

1066
01:35:46,860 --> 01:35:49,110
is an infrared pod.

1067
01:35:49,110 --> 01:35:51,250
I will talk about that in a minute.

1068
01:35:51,250 --> 01:35:56,670
The payload bay doors open right away.

1069
01:35:56,670 --> 01:36:03,300
And so now you can see, when we've done the
engine vent, you can see all the ice particles

1070
01:36:03,300 --> 01:36:03,990
coming out.

1071
01:36:03,990 --> 01:36:10,550
And you will see a primary RCS thruster go
in there.

1072
01:36:10,550 --> 01:36:14,520
It can be pretty spectacular.

1073
01:36:14,520 --> 01:36:19,270
And that just keeps going for about a day
and then you've gotten rid of most of the

1074
01:36:19,270 --> 01:36:19,820
ice particles.

1075
01:36:19,820 --> 01:36:21,020
OK.

1076
01:36:21,020 --> 01:36:26,930
That is enough of that.

1077
01:36:26,930 --> 01:36:29,250
Yeah?

1078
01:36:29,250 --> 01:36:36,250
[AUDIENCE QUESTION] That was a primary RCS
thruster.

1079
01:36:41,710 --> 01:36:47,500
[AUDIENCE QUESTION] Yeah, absolutely.

1080
01:36:47,500 --> 01:36:54,500
In fact, all of the vernier thrusters are
downward thrusting only.

1081
01:36:55,440 --> 01:37:02,440
Remember we talked about with the primary
thrusters, they were designed and sized for

1082
01:37:02,510 --> 01:37:07,460
rendezvous where you actually have to have
controlled propulsion.

1083
01:37:07,460 --> 01:37:14,460
And if you want a Z propulsion of the Shuttle,
you want to be able to get a pure Z so you

1084
01:37:16,670 --> 01:37:20,150
fire thrusters on each end.

1085
01:37:20,150 --> 01:37:23,210
And the same for roll and yaw.

1086
01:37:23,210 --> 01:37:30,210
And you don't want a lot of cross-coupling
because you're targeting your burn to fractions

1087
01:37:31,670 --> 01:37:36,000
of a foot per second in order to get your
rendezvous to come out right.

1088
01:37:36,000 --> 01:37:41,610
And so that is when you're using the primary
thrusters.

1089
01:37:41,610 --> 01:37:45,690
Other than that, the primaries use a lot of
propellant.

1090
01:37:45,690 --> 01:37:49,630
And so we disable the primaries and use the
verniers.

1091
01:37:49,630 --> 01:37:56,230
With the verniers there are two verniers in
the nose which are sort of canted down at

1092
01:37:56,230 --> 01:37:58,550
about 45 degrees.

1093
01:37:58,550 --> 01:38:03,590
And, in the rear, there are two pointing straight
down and two pointing straight out.

1094
01:38:03,590 --> 01:38:10,590
Typically, for a given maneuver, you will
fire only one or two.

1095
01:38:10,770 --> 01:38:17,770
If you want to do a roll, for instance, you
will fire the 45-degree down forward thruster

1096
01:38:17,940 --> 01:38:24,940
and the downward pointing aft thruster.

1097
01:38:25,180 --> 01:38:28,770
But they are not completely balanced so you
will get a little bit of pitch and a little

1098
01:38:28,770 --> 01:38:30,020
bit of yaw.

1099
01:38:30,020 --> 01:38:34,400
And you don't use the verniers for propulsion
at all.

1100
01:38:34,400 --> 01:38:41,400
Although, because all of the verniers are
essentially downward firing, if you are, for

1101
01:38:41,480 --> 01:38:47,380
instance, station keeping, if here is the
Space Station and you're in the same orbit

1102
01:38:47,380 --> 01:38:53,860
but, say, half a mile in front of it, now
you're station keeping using your vernier

1103
01:38:53,860 --> 01:39:00,860
thrusters, typically that does give you, after
a while, a little bit of propulsive maneuver

1104
01:39:01,250 --> 01:39:02,250
which pushes you in.

1105
01:39:02,250 --> 01:39:05,050
So, you have to compensate for that.

1106
01:39:05,050 --> 01:39:07,420
The verniers are single string.

1107
01:39:07,420 --> 01:39:09,210
There is no redundancy.

1108
01:39:09,210 --> 01:39:13,250
They do have access-to-access cross-coupling.

1109
01:39:13,250 --> 01:39:20,250
They are designed for attitude control only;
25 pound thrusters are reasonably efficient.

1110
01:39:26,840 --> 01:39:33,840
I thought at the end we could explore a little
bit together some of the ideas of improvements

1111
01:39:39,370 --> 01:39:41,820
to the Shuttle which you are going to be thinking
about.

1112
01:39:41,820 --> 01:39:47,620
And one of the things that I thought would
be interesting to think about, you know we

1113
01:39:47,620 --> 01:39:54,620
talked about the fact that if you're designing
the Shuttle to the same set of requirements

1114
01:39:56,840 --> 01:40:03,840
that were originally put on it, your ability
to change some of the major physical characteristics

1115
01:40:06,570 --> 01:40:09,450
of the Shuttle are very limited.

1116
01:40:09,450 --> 01:40:16,450
We can do a lot with electronics and some
of the other systems.

1117
01:40:21,130 --> 01:40:28,130
The new vehicle, the crew exploration vehicle,
is being designed not just to go to earth

1118
01:40:29,010 --> 01:40:36,010
orbit but they want a vehicle that can actually
return to the earth from the moon or from

1119
01:40:36,130 --> 01:40:36,770
mars.

1120
01:40:36,770 --> 01:40:43,770
That means instead of an orbital velocity
of five miles per second you have a reentry

1121
01:40:48,880 --> 01:40:55,880
velocity, a hyperbolic velocity, of about
eight miles per second.

1122
01:40:58,490 --> 01:41:04,900
Does anybody remember the relationship between
low orbital velocity and escape velocity?

1123
01:41:04,900 --> 01:41:11,630
If your lower velocity is V, what is your
escape velocity?

1124
01:41:11,630 --> 01:41:12,690
Square root of 2V.

1125
01:41:12,690 --> 01:41:14,670
That is a nice thing to remember.

1126
01:41:14,670 --> 01:41:21,670
It is an easy way to keep those things straight.

1127
01:41:23,290 --> 01:41:24,880
First of all, you don't need wings to go to
the moon.

1128
01:41:24,880 --> 01:41:26,360
They don't do you much good when you get there.

1129
01:41:26,360 --> 01:41:33,360
To have a winged vehicle that you can thermally
protect against a hyperbolic reentry velocity

1130
01:41:35,000 --> 01:41:35,860
just doesn't make sense.

1131
01:41:35,860 --> 01:41:38,840
It would be too heavy.

1132
01:41:38,840 --> 01:41:40,550
We don't think we can do that.

1133
01:41:40,550 --> 01:41:47,440
And, in fact, the Russians are now talking
about building this new clipper vehicle which

1134
01:41:47,440 --> 01:41:50,980
possibly will have wings on it or be a lifting
body.

1135
01:41:50,980 --> 01:41:57,980
And that actually probably means that they
will only use it for low earth orbit.

1136
01:41:58,820 --> 01:42:05,820
But it does bring up the interesting question,
if you are designing a vehicle that is only

1137
01:42:08,530 --> 01:42:15,190
designed to go to earth orbit as a passenger
carrying vehicle, one of the first things

1138
01:42:15,190 --> 01:42:22,190
that we ought to ask ourselves, if we're doing
a new design, is should we have wings?

1139
01:42:22,590 --> 01:42:28,800
Think a little bit about the advantages and
disadvantages of wings.

1140
01:42:28,800 --> 01:42:33,900
If you're sitting down now with a blank drawing
board going through a design process, first

1141
01:42:33,900 --> 01:42:37,820
of all, what are the advantages of wings?

1142
01:42:37,820 --> 01:42:44,570
You've heard quite a bit about Shuttle aerodynamics.

1143
01:42:44,570 --> 01:42:48,900
What advantages do you get from using wings
during a reentry?

1144
01:42:48,900 --> 01:42:53,110
And, obviously, it's only during entry that
the wings are going to help you because they

1145
01:42:53,110 --> 01:42:55,050
are a real nuisance during ascent.

1146
01:42:55,050 --> 01:43:01,590
Greater cross-range?

1147
01:43:01,590 --> 01:43:03,360
Cross-range helps with the wings.

1148
01:43:03,360 --> 01:43:09,480
The glide?

1149
01:43:09,480 --> 01:43:14,190
Yeah, it allows you to land on a runway.

1150
01:43:14,190 --> 01:43:20,300
In terms of having to design against the shock,
you know, the Crew Exploration Vehicle is

1151
01:43:20,300 --> 01:43:21,820
going to land with parachutes.

1152
01:43:21,820 --> 01:43:27,570
And they still don't know are they going to
use airbags or retrorockets or crushable structure

1153
01:43:27,570 --> 01:43:28,050
or whatever.

1154
01:43:28,050 --> 01:43:28,420
They don't know.

1155
01:43:28,420 --> 01:43:35,420
But it is going to take a much harder hit.

1156
01:43:35,590 --> 01:43:40,700
That may potentially affect reusability, maintainability.

1157
01:43:40,700 --> 01:43:41,360
Yeah?

1158
01:43:41,360 --> 01:43:48,360
I was going to say just purely control while
coming back in ...

1159
01:43:48,590 --> 01:43:54,920
[UNINTELLIGIBLE PHRASE].

1160
01:43:54,920 --> 01:43:56,600
Well, we had the cross-range.

1161
01:43:56,600 --> 01:43:58,710
But targeting I guess, too?

1162
01:43:58,710 --> 01:43:59,170
Targeting.

1163
01:43:59,170 --> 01:44:03,660
If you were to land, say, in a certain part
of the desert in New Mexico, you would want

1164
01:44:03,660 --> 01:44:07,230
to have a lot more accuracy?

1165
01:44:07,230 --> 01:44:08,170
Right.

1166
01:44:08,170 --> 01:44:12,920
For the CEV, they are just basically saying
they are going to land out in the Western

1167
01:44:12,920 --> 01:44:13,360
desert somewhere.

1168
01:44:13,360 --> 01:44:16,940
Now, the Apollo shots were getting pretty
accurate.

1169
01:44:16,940 --> 01:44:23,940
The last couple of Apollos landed within visual
range of the aircraft carrier that went to

1170
01:44:25,300 --> 01:44:26,800
pick them up, so they were getting pretty
good.

1171
01:44:26,800 --> 01:44:33,040
But that's within a couple of miles, which
is fine when you're landing in the ocean.

1172
01:44:33,040 --> 01:44:36,150
And maybe it's OK if you're landing in the
Western desert.

1173
01:44:36,150 --> 01:44:38,230
It is certainly not OK if you're going to
land on a runway.

1174
01:44:38,230 --> 01:44:43,120
Hardly an engineering consideration, but how
much thought in the design was put into making

1175
01:44:43,120 --> 01:44:49,330
it a winged vehicle for it to be a comfortable
and familiar look to people, especially if

1176
01:44:49,330 --> 01:44:52,900
the idea was to have nonprofessional astronauts
fly?

1177
01:44:52,900 --> 01:44:58,690
It seems more comfortable to get in something
that looks like an airplane?

1178
01:44:58,690 --> 01:45:03,330
I don't know about comfort from that point
of view, but there is no question that the

1179
01:45:03,330 --> 01:45:08,480
whole aviation metaphor dominated discussion
in the early days.

1180
01:45:08,480 --> 01:45:10,520
And I think you have gotten a sense of this.

1181
01:45:10,520 --> 01:45:15,730
The idea was we want a reusable vehicle.

1182
01:45:15,730 --> 01:45:19,750
That means we have to have airline-type operations.

1183
01:45:19,750 --> 01:45:24,800
Well, if you're going to have airline-type
operations then you want a vehicle that lands

1184
01:45:24,800 --> 01:45:25,380
on the runway.

1185
01:45:25,380 --> 01:45:26,520
You take it into the hangar.

1186
01:45:26,520 --> 01:45:27,400
You turn it around.

1187
01:45:27,400 --> 01:45:29,600
You launch it again.

1188
01:45:29,600 --> 01:45:33,100
I mean it's a very powerful metaphor.

1189
01:45:33,100 --> 01:45:37,750
What are some of the disadvantages of wings?

1190
01:45:37,750 --> 01:45:41,670
What are some of the things that argue against
wings?

1191
01:45:41,670 --> 01:45:46,520
Again, we're going right back to the conceptual
design exercise here.

1192
01:45:46,520 --> 01:45:52,600
And this is not what you're doing for your
papers because we're totally changing the

1193
01:45:52,600 --> 01:45:53,620
concept of the Shuttle.

1194
01:45:53,620 --> 01:45:58,320
But, for the purpose of the class, let's think
it through.

1195
01:45:58,320 --> 01:46:00,150
What are the disadvantages of wings?

1196
01:46:00,150 --> 01:46:05,510
I think a lot of what we talked about is initial
design cost versus, you know, and no wings

1197
01:46:05,510 --> 01:46:09,170
obviously has a lot less initial design cost
because you don't have to design the structure

1198
01:46:09,170 --> 01:46:12,240
to support the wings and it is a lot simpler
design, I think.

1199
01:46:12,240 --> 01:46:19,240
So, that probably saves you money in your
initial development.

1200
01:46:22,889 --> 01:46:29,889
[AUDIENCE COMMENT] Now, on the other hand,
I don't know how much any of you have studied

1201
01:46:30,120 --> 01:46:37,120
the theory of reentry bodies, but the reentry
of a ballistic capsule typically gives you

1202
01:46:42,690 --> 01:46:48,570
much higher Gs than you can get if you have
a lifting body.

1203
01:46:48,570 --> 01:46:54,030
And, of course, with wings you get much more
lift.

1204
01:46:54,030 --> 01:47:01,030
You can actually decrease the G loading so
that with the Shuttle we can have a reentry

1205
01:47:03,370 --> 01:47:06,190
pulling no more than about 1.5 Gs.

1206
01:47:06,190 --> 01:47:13,190
Whereas, you come back in a capsule even from
low earth orbit and you're going to be pulling

1207
01:47:14,100 --> 01:47:18,230
4, 5, 6 Gs.

1208
01:47:18,230 --> 01:47:23,639
And that does relate back to the idea that
we wanted the Shuttle to be able to take much

1209
01:47:23,639 --> 01:47:30,639
more delicate payloads and hopefully take
people who were not necessarily trained astronauts.

1210
01:47:31,440 --> 01:47:37,320
So, again, it's an advantage but a disadvantage
of wings.

1211
01:47:37,320 --> 01:47:44,320
The area under the wings is huge, so that
puts huge demands on your thermal protection

1212
01:47:45,860 --> 01:47:51,570
system.

1213
01:47:51,570 --> 01:47:56,980
I don't know what they're going to end up
using on the CEV, but it is going to be a

1214
01:47:56,980 --> 01:48:02,880
much smaller area that has to be protected.

1215
01:48:02,880 --> 01:48:06,550
Another interesting thing, when you think
about a winged vehicle like the Shuttle, now

1216
01:48:06,550 --> 01:48:13,180
I know that Buran, the Russian Shuttle, made
its one flight unmanned.

1217
01:48:13,180 --> 01:48:20,180
They had some tense moments at the end, but
they did manage to land it successfully.

1218
01:48:20,300 --> 01:48:27,300
But the way we fly our Shuttle, we have to
have two trained pilots who spend a tremendous

1219
01:48:29,100 --> 01:48:36,100
amount of time doing nothing but learning
how to land the Shuttle.

1220
01:48:36,820 --> 01:48:43,820
Sometimes we don't think about the crew requirements
on the design, but training is not an insignificant

1221
01:48:45,440 --> 01:48:47,880
part of the cost of operating the Shuttle.

1222
01:48:47,880 --> 01:48:54,880
There is a huge enterprise involved in training
astronauts.

1223
01:48:55,820 --> 01:48:59,270
And training pilots particularly is very expensive.

1224
01:48:59,270 --> 01:49:05,559
You have to keep them qualified as pilots
so NASA maintains a fleet of T38 supersonic

1225
01:49:05,559 --> 01:49:06,780
jets, which are great fun.

1226
01:49:06,780 --> 01:49:09,210
I mean I love to fly backseat in them.

1227
01:49:09,210 --> 01:49:14,880
But the only justification for having them
is if somebody is going to be a pilot they

1228
01:49:14,880 --> 01:49:17,860
have got to stay current as a pilot which
means you have got to fly.

1229
01:49:17,860 --> 01:49:21,790
And we have the Shuttle Training Aircraft
which I have spoken to you about.

1230
01:49:21,790 --> 01:49:27,190
And we have all the simulator time.

1231
01:49:27,190 --> 01:49:32,520
And then we have the problem that people said
-- there was a time when they were talking

1232
01:49:32,520 --> 01:49:38,940
about having the Shuttle spend extended periods
of time up at the Space Station, you know,

1233
01:49:38,940 --> 01:49:43,600
a month, maybe two months, make some adjustments
to the Shuttle System so you can do that.

1234
01:49:43,600 --> 01:49:50,600
Then the problem is, well, who is going to
land the Shuttle, because I talked to you

1235
01:49:50,940 --> 01:49:55,190
about the spatial disorientation and everything
that you feel during reentry.

1236
01:49:55,190 --> 01:49:58,360
Well, you don't want a pilot to do that.

1237
01:49:58,360 --> 01:50:03,410
And, if a pilot has been up in the Space Station
for one or two months, has not had any stick

1238
01:50:03,410 --> 01:50:10,410
time, is going to have potentially serious
neurovestibular problems during entry.

1239
01:50:10,670 --> 01:50:17,670
And so the real question was what's the maximum
time that it is OK for a pilot to spend in

1240
01:50:19,580 --> 01:50:19,830
space?
We will never actually have to answer that
because 17 or 18 days was the maximum Shuttle

1241
01:50:25,040 --> 01:50:25,400
Mission.

1242
01:50:25,400 --> 01:50:28,380
That turned out to be OK.

1243
01:50:28,380 --> 01:50:31,780
And we are never going to do long duration
missions with the Shuttle and the Space Station.

1244
01:50:31,780 --> 01:50:32,030
Yeah?

1245
01:50:31,930 --> 01:50:38,930
[AUDIENCE QUESTION] No.

1246
01:50:42,130 --> 01:50:47,840
They learn a lot of the malfunction procedures,
but you don't actually fly the ballistic capsule.

1247
01:50:47,840 --> 01:50:54,320
I mean I am not in any sense denigrating the
training that the Apollo astronauts needed

1248
01:50:54,320 --> 01:51:00,980
to land their capsule, but it did not compare
in the least to the amount of training, for

1249
01:51:00,980 --> 01:51:04,500
instance, to land on the moon where you were
actually piloting the vehicle.

1250
01:51:04,500 --> 01:51:06,700
OK.

1251
01:51:06,700 --> 01:51:13,700
Well, I hope just that very brief exploration
will make you think about designing new vehicles

1252
01:51:21,820 --> 01:51:24,139
from a slightly different point of view.

1253
01:51:24,139 --> 01:51:31,139
In other words, when we designed the Shuttle,
it was just assumed as gospel essentially

1254
01:51:31,630 --> 01:51:37,350
that if you want a reusable vehicle put wings
on it.

1255
01:51:37,350 --> 01:51:39,000
I don't know what the right answer is.

1256
01:51:39,000 --> 01:51:44,440
It probably depends on some of the details
of the mission, but you really have to go

1257
01:51:44,440 --> 01:51:47,690
back and question your most basic assumptions.

1258
01:51:47,690 --> 01:51:53,170
When you're doing your concepts and you're
setting out your requirements, you don't want

1259
01:51:53,170 --> 01:51:58,250
to write your requirements in such a way that
they presuppose the technical solution.

1260
01:51:58,250 --> 01:52:05,250
If you write your requirements for a winged
vehicle you have already shut down a whole

1261
01:52:05,650 --> 01:52:07,000
part of designed space.

1262
01:52:07,000 --> 01:52:09,330
And, as designers, you don't want to do that.

1263
01:52:09,330 --> 01:52:09,580
Yeah?

1264
01:52:09,420 --> 01:52:10,070
Last question.

1265
01:52:10,070 --> 01:52:15,710
[AUDIENCE QUESTION] No.

1266
01:52:15,710 --> 01:52:20,980
The Russians have actually taken, my understanding
is, they have taken some of the electronics

1267
01:52:20,980 --> 01:52:25,090
out of capsules and reused internal parts.

1268
01:52:25,090 --> 01:52:31,480
But the exterior shell of the capsules I don't
believe have ever been reused.

1269
01:52:31,480 --> 01:52:31,980
OK.

1270
01:52:31,980 --> 01:52:32,730
We will see you Thursday.

1271
01:52:32,730 --> 01:52:36,630
Bob Ried is going to give a talk on aerothermodynamics.

1272
01:52:36,630 --> 01:52:39,190
And I will look forward to seeing your journals.

1273
01:52:39,190 --> 01:52:46,190
Any questions on the reports, the outlines
that I returned, email me, come to see me.

1274
01:52:47,540 --> 01:52:48,900
I am happy to talk with you about it.