CHRIS GIERSCH: Thank you for
joining us this morning again. Steve Sandford who was here last
week introducing the last week's lecture could not be here, he
is actually at NASA Glen on travel, so he asked me to go
ahead and introduce our next two presenters. As you know if you
were here last week we had a great talk about the path to
Mars and the Asteroid Redirect Mission by Pat Troutman and
Dan Mazanek. Now we are going to shift focus to our
transportation architecture, looking at the Orion spacecraft
and specifically the Launch Abort System. And joining us
today we have Kevin Rivers who is the project manager for the
Orion Launch Abort System and the lead flight dynamics person
is John Davison. They are going to give you an excellent talk
over the next 50 minutes to an hour on that system, and
hopefully some of those videos will work, we will stay tuned,
we will see what happens. I am going to turn over to Kevin,
and enjoy the presentation. [Applause] KEVIN RIVERS: Thank you.
Thank you for allowing me to spend some time with you guys
today. I am Kevin Rivers and I do manage the Launch Abort
System development for the Orion spacecraft, so I wanted to
kind of talk you through that particular development. I think
I need to begin though with a little bit of history
of human space flight, so I thought I would start
from the very beginning with the Chinese. You guys may know that
the Chinese invented gunpowder and as a result fireworks and
they very quickly weaponized those fireworks in the missiles,
those missiles were called fire arrows and about 900 AD is when
they first were used in warfare and I can just imagine if you
were used to a regular arrow coming sailing at you, if you
had one that was rocket powered coming at you that would
really ruin your day. But this technology advancement was
enabled through the invention of the gunpowder and exploration
through fireworks. So, there are some early pioneers
that need to be credited for space flight. Space flight,
actually human space flight is something that has been in mind
of the mankind for a very long time. As a matter of fact as
long as we had recorded history mankind has dreamed of traveling
in space. Constantine Topovski was the first person to actually
write about it. He has the first published works on space travel
and could be considered the father of space travel. Our very
own Robert Goddard here in the United States actually invented
and developed the liquid rocket and then many of you are
familiar with the father of rocket science as
Wernher von Braun is often to, he is a German scientist who
actually came to the United States after World War II and
became US citizen. The reason I bring all these folks up and you
can see on the photographs on the slide, the different dates
of when they actually did these things, Topovski actually at the
turn of the century as well as Goddard and then von Braun
actually led the development of the Saturn rocket for the
Apollo program in the '60s. The required technology for humans
to fly in space really did not become available to
us until the '50s, and that's why as soon as we
had the technology and the capability we certainly
took advantage of it and moved quickly into space. The first US
program for human space flight, the Mercury Program,
ran from 1958-1963, and had some very specific
goals. First goal was to orbit manned spacecraft around the
earth and return the occupants safely to the ground, to
investigate our ability to function in space was also a
very important goal. This was actually a very impressive
program and it was led here at Langley back in the '60s and
it is very impressive to me, they flew six crew
flights from 1961-1963, which I think was
very impressive, and laid the groundwork for
our understanding of how humans react to the space environment
in that situation. So, following, I am sorry--actually
there are several important things that occurred
in the Mercury Program. You guys are probably familiar with
Alan Shepard. He was the first American into space in a
suborbital flight in 1961. Astronaut John Glenn actually
was the first American to orbit Earth, he did that
on February 20th, 1962. And then after the
conclusion of that very successful program and on a path
to send humans to the moon the Gemini Program was conceived and
it was actually operated from 1962-1966, it was a
four-year program, and the goals of that program
were to develop key technologies necessary for humans to travel
to the moon and back. There were some amazing firsts that
occurred. Edward White was the first human to actually get
outside of his vehicle in space and he was the first space
walker. He did that on June 3rd, 1965, and Walter
Schirra, Thomas Stafford, Frank Borman and Jim Lovell
actually were the first people to accomplish space rendezvous.
They on Gemini 6 and 7 actually rendezvoused those two vehicles
which was a critical technology that we needed to develop and
demonstrate successfully in order to go to the Moon.
Following the Gemini Program the Apollo Program, very successful,
and probably the most widely known human space program in
history. That program was from 1963 through 1972. Obviously the
purpose as it was so eloquently expressed by President Kennedy
was to deliver human safely to the Moon and return them
safely to Earth afterwards. So, there were six missions where
crews landed on the surface of the moon, there were three other
missions where crews orbited the Moon, one of those three of
course the ill-fated Apollo XIII mission which you maybe very
familiar with. Apollo XI was actually the first mission where
humans actually reached the surface of the Moon and Neil
Armstrong actually was the first human to walk on the Moon. So,
the Apollo Program was extremely successful in understanding of
how humans interact with the environments that they
are exposed to when they go extraplanetary when they go to
other planetary bodies. This is just a photograph of the
lunar lander and the buggy and I believe that is
Commander John Young, I think that might be
him, I am not real sure, so anyway. These guys did a lot
of exciting things while they were on the surface of the moon.
So following the successful Apollo program, NASA actually
successfully executed the Apollo-Soyuz test project in
1975. This is where we docked our American developed Apollo
vehicle to the Russian developed Soyuz vehicle. This was the
first international partnership where two countries worked
together to successfully execute a human space flight endeavor.
And if you are interested this is Astronaut Don Slayton and
Cosmonaut Alexei Leonov. This is Slayton, that's Leonov. And
that's their greeting each other after the mating of
the vehicles. So, following that program the
Skylab was launched. Skylab actually was a converted third
stage of the Apollo IB. We put this vehicle up in orbit in May
of 1973. There were three crews that crewed the vehicle. The
longest any one crew stayed was almost three months before the
vehicle deorbited and reentered the Earth's atmosphere. This is
Skylab IV Astronaut Gerald Carr and William Pogue. They are
shown in the OWS and I would have no idea what an OWS is, but
they are in it. One of them is upside down, I don't know which
one is upside down. It could be him. And then following that
successful program obviously the space shuttle was developed and
flown. The first orbiter to fly was Columbia and that
was flown on April 12, 1981. Commander John Young and
Robert Crippen flew that vehicle successfully to orbit and back.
This is the first spacecraft that was capable of routinely
launching and returning from orbit and it was the first
reusable spacecraft to be developed. The space
shuttle had about 40,000 pounds payload capability and
the marvelous thing about this machine is not necessarily
that it could take 40,000 pounds to orbit, lot
of vehicles could do that, it is that it can
bring 40,000 pounds back, which is very amazing. So, that
program ran through 2011 and the space station actually on orbit
today that program started in 1998 and the vehicle is in its
full configuration currently in orbit above the Earth. The first
crew actually arrived to the space station in 2000. So,
that's kind of history of where we have been. Now I am going
to talk a little bit now about where we are headed.
Where we have been, obviously in the early '70s we
put humans on the Moon which was an amazing fete, but most
recently we have spent most of our time in low earth
orbit and I show this chart, and I know that you guys
last week if you were here you actually heard the story a
little bit. Our current systems are Earth dependent and low
earth orbit is only 200 miles away, that's trip to DC. So,
it's although in a much bigger vehicle. So to put things in
perspective the Moon is 240,000 miles away and Mars is
35 million miles away, quite a big difference in
distances. And so as we move towards that mission and try
to realize the opportunity of humans exploring Mars we have to
develop new systems to do that. So, we need to move from these
Earth reliant systems that we currently have and out, when we
do explore Mars in the 2030s we are going to need to have
systems that are planetary independent in order to explore
Mars and its Moons successfully. So, what we are doing now is
we are in that middle proving ground. So, we are trying to
prove out some technologies and capabilities that will allow us
to do that. The Orion vehicle is obviously the crew vehicle that
we are going to use to do that and flying some of these
intermediate missions like a mission to explore an asteroid
are opportunities for us just as we did in the old days
with the Gemini program, just where we can prove out the
technologies that we will need in order to successfully
explore Mars. So, this is the rocket that we are
going to fly on. It is currently under development by the
Marshall Space Flight Center. This is the Space Launch
System, the SLS if you will, I like to think it is an elegant
combination of the shuttle and Saturn. So use the shuttle parts
and it was painted like the Apollo, like the Saturn. So,
this is the SLS. The core stage is the primary vehicle. It is
actually propelled by the RS25 engines. These are the engines
that propelled the shuttle, these are the
shuttle main engines, and then it also has solid
rocket boosters to add thrust in the initial stages of flight.
The vehicle is 321 feet long. This actually shows the
configuration with the Orion Spacecraft to top it. The thrust
of this vehicle at liftoff is little over 8 million pounds,
that's 8.4 million pounds of thrust whenever it lifts off.
Just to compare the SLS vehicle to other vehicles that
have existed or do exist, I have shown the
payload capability, mass is in blue, volume is in
orange and you can see here, maybe my joke makes sense now,
we decided to go back to the Apollo Saturn paint
scheme. But anyway, the first SLS that we will field
will have a little bit less capability than the Saturn V,
maybe 2/3rd of the capability for payload, but ultimately we
will be able to do more than we could do with the Saturn vehicle
whenever we implement the second iteration of the version or the
payload carrying version of that vehicle. So, this is schematic
showing the various components of the Orion vehicle, so I am
going to move in and talk a little bit about
our human vehicle, the approved vehicle. This
is the Launch Abort System, this is the system that John and
I work on and John will give you a lot of great details on that
system in a little bit. The crew module looks a lot
like an Apollo capsule, it is a conical vehicle and
reenters the Earth's atmosphere on ballistic trajectory. And
then that vehicle is supported during its space travel by the
service module which provides all of the power and utilities
and things that are needed by the crew. The vehicle can
support crew members for short or long duration space
flights currently up to 21 days, and it supports a crew of
anywhere from two to four astronauts. You might ask how is
that different from the Apollo vehicle? This schematic shows,
actually the Orion is quite a bit bigger than the Apollo
vehicle. The Apollo vehicle could hold a crew of three with
a habitable volume of about 218 cubic feet. The Orion vehicle
can hold a crew of four and if we were going to low earth orbit
we could actually carry six crew members with a habitable
volume of about 350 cubic feet, so almost twice as big inside
as the Apollo vehicle. So I just want to show you a
little video of the Orion, highlight of the vehicle
and its development. [Video Presentation] So, that's Orion
in 30 seconds. AUDIENCE: Pretty good. KEVIN: Yeah, we
like our music. So, anyway, the Orion vehicle is
quite a marvel and as you can see through that video
developing a vehicle like this is a very complicated activity
and actually takes quite a few years. This kind of shows some
of the developments that we have been involved in to date and
I apologize that all these pictures are so small, but you
can just see by this host of activity early since we started
back in 2005 until today, a lot of development testing has
occurred including the Pad Abort 1 flight test which is the
demonstration of the Launch Abort System, and that was in
2010 when we flew that. We are gearing up now for our first
space test flight which is Exploration Flight Test 1,
that's where the crew vehicle is actually going to go into space
and then ultimately we will fly a couple of other test flights
as we certify the system for human space flight which is
not an easy endeavor and then ultimately we will fly our first
crewed mission in 2021 which is the EM-2 mission. So let me tell
you a little bit about some of the details of this as we move
forward. So this is the EFT-1 mission, we are going to fly two
orbits around the Earth. On the second orbit we are going to
swing out about 3600 miles which is the reason we are doing
that is so that we can actually reenter the Earth's atmosphere
at near lunar reentry speeds. We can't quite get lunar reentry
speeds but we want to get as close as we can, and obviously
we are doing this test to demonstrate some of those
critical systems like the heat shield, the thermal
protection system, the guidance, navigation and
control system and then finally the parachute landing recovery
system that's required. This test will demonstrate all of
those high risk areas which we believe will put us pretty
far ahead of the curve on development. So this is just
a photograph of some of the hardware for that mission. It is
going to fly on December 4th out of Cape Canaveral. This is,
this picture I am sorry is very dated, actually the vehicle is
completely closed out at this point and they are fueling
the crew module right now in preparation for integrating the
Launch Abort System on top of it. But I have a video, and this
is a video that may or may not work. So, let's see if it works.
This is the EFT mission. So we are flying on top of a Delta IV
Heavy for this mission. [Video Presentation] KEVIN: So this just shows
that we are going to orbit the Earth twice, on the
second go-around we are going to slingshot out. Get the vehicle
up to near lunar reentry speeds and then as we return the crew
vehicle will separate from the service module and reenter. That's that slingshot
maneuver. And we actually are going to use
this upper stage to accelerate once we are coming back, we are
not just going to throw it out and let it fall back, we are
actually going to accelerate it back. This is what the view
would look like if you are crazy enough to ride it. There we go, now there is
the crew module separating from the service
module and then reentering the Earth's atmosphere. And I
apologize I don't off the top of my head know what the heating
rates are for this vehicle when it reenters but it is
significantly higher than the vehicle experiences when it
reenters the low earth orbit. Then ultimately the parachute
opens out and the vehicle will splash down in the
Pacific Ocean. I do want to point out, the
recovery of this vehicle is being performed in conjunction
or in cooperation with the Navy and so the things that we do
are sometimes very complicated organizationally because we do
have to work across multiple agencies to get things done. So,
that's some example of that. So that is the EFT-1 as it
splashes into the Pacific Ocean. AUDIENCE: That's got
to be coming in at 25,000 miles per hour? KEVIN: Yes, it actually
will start its entry at 20,000 miles per hour. And
we believe it will splash down somewhere around
18-30 miles per hour, so quite a bit of deceleration
there. So that's the Orion. The other two missions
that we are going to fly, the first one obviously is to
demonstrate all of the deep space systems that will need
to successfully fly through, that is EM-1. We are actually
going to fly that vehicle around the Moon and that mission is
actually maturing a little bit now. We have actually probably
made a change or will make a change in the near future to fly
actually to the Lagrange Point, which we don't know what a
Lagrange Point is. Lagrange Point there are actually three,
that's the point where all of the gravity influences
are negated by each other, so it is a point where if you
actually went there you would require no energy to stay there.
So there is a point between the Earth and the Moon, there is a
point on the other side of the Moon and there is also a point
on the other side of the Sun, where the Sun's, Earth's and
Moon's gravity all equalize each other. They are called Lagrange
Points. We are actually going to fly to L3 which is a Lagrange
Point out behind the Moon. We are not going to
go and stay there, we are just going to go and do
a flyby because we believe that our next mission is actually
going to be to fly to a Lagrange Point and allow a crew to
operate from that point. And then our first
crewed flight EM-2, obviously this shows
schematically that we are going to put the crew in orbit around
the Moon. For those of you who are familiar with
the Apollo program, that was actually the first
crewed mission for Apollo where they put the crew in orbit
around the Moon and they did so on Christmas Eve. So, what
a Christmas present. So, I mentioned that it is
very complicated to do this technically but it is also very
complicated to do this because we have to partner and
collaborate with multiple entities. Actually our
NASA team, you can see here that all of
our NASA centers are involved in this mission. Obviously Johnson
Space Center is where the program is led. Langley is
where we are doing the Launch Abort System, etc. But a lot of
people are contributing across the country to this program. So,
Langley actually is contributing in multiple areas and this kind
of captures a multitude of those areas where Langley is
contributing to the development of Orion and I would like to
go through this real briefly, if you guys don't mind.
Obviously Langley has wind tunnels and we do a lot
of aero-sciences work, so we are doing a lot of wind
tunnel testing. We also have a facility which you can see
from pretty much anywhere on the peninsula, it is called the
gantry where we do the drop testing, so that we can
understand the dynamics of and loads associated with the
vehicle when it enters the water. And we have a group that
does the trajectory analysis for all of these entry simulations
so that they can understand the heating environment, etc., etc.
We are developing the Launch Abort System which includes
doing the guidance and control and design as well as the
performance predictions for the Launch Abort System which is
what Dr. Davidson does for us. We have obviously done
computational flow dynamic studies which is basically wind
tunnel is on the computer as well as investigating some
navigation systems and the like. So, this is, I think I am going
to show you a video next. Yeah, this is a water drop test that
was performed at the gantry that I mentioned. [Video Presentation] KEVIN: So, we have
actually performed several of these tests.
This was a pretty extreme impact and
that's why the vehicle actually rolled over. Don't worry though,
there is a riding system on the vehicle, it is not
on this test article, but the actual vehicle actually
has a system that allows it to flip back over and top up. So,
this is just a little bit more detailed view of the vehicle
as it impacts the water. So, these entry loads when it
impacts the water actually drive the size of the lot of the
structure and the secondary structure and so it is very
important that we understand these loads are hard to predict
and that's why we do test so that we can minimize the mass
of the vehicle to the greatest extent possible. So, Langley
also was very involved in the development of the heat shield.
This is actually a photograph of the EFT-1 heat shield. This is
at Textron Industry in Boston. This heat shield, actually
the material is AVCOAT material, it is the derivate of the
material that was used in the Apollo program, and it was quite
difficult to develop actually, because we lost the recipe and
actually took us about three years to reconstitute the
material and demonstrate it successfully in ground testing.
Langley was in the middle, very actively involved in that
activity in collaboration with Johnson Space Center and with
the Ames Research Center out in California. And then the Launch
Abort System I mentioned that, we lead that here at Langley.
The reason we lead it at Langley is because Langley has a breadth
of skill sets that's probably unique across the agency in
that we have the guidance, navigation and control folks,
the flight dynamic folks like Dr. Davidson. We also have the
structures folks and the loads and dynamics folks, so we can
take a very complicated vehicle like the Launch Abort Vehicle
and analyze it through all different phases of
flight and so we have had that responsibility since 2005 and
successfully demonstrated the Abort System in Pad Abort 1
which was in 2010. Little bit about the Launch Abort System.
Obviously it kind of makes Orion unique when compared to current
and existing systems or systems that we recently fielded like
the space shuttle in that we can actually recover the crew if
we have a launch accident and safely return them to
Earth. That makes our system substantially safer
than the shuttle was, and actually significantly safer
than the Apollo even though it has a launch escape system. This
system developed back in the 1960s actually was very limited
in its capabilities. There are actually many phases of flight
where it couldn't be used and our Launch Abort System is
designed to be operable from the pad all the way up to 300,000
feet through all phases of flight and all speeds. And
what allows us to do that is we actually have implemented an
active flight control system and actually I guess
at this time, John, if you want to come up I will
let you describe that system and talk a little bit more about
the Launch Abort System. JOHN DAVIDSON: Okay. Thank you. KEVIN: Thank you.
JOHN: So the rest of the talk is just going
to focus on the Launch Abort System. As Kevin said, we have
done a lot of work at Langley, worked at design and development
and also analyze the performance of the Launch Abort
System. So, as Kevin said, the Launch Abort System provides
the capability to do aborts from the pad all the way up
to approximately 300,000 feet. Above that you can use
the service module to do aborts, that's because we are
essentially outside the atmosphere at that point and
don't have like atmospheric drag and things like that to
overcome. Have got just here a graphic of the Launch Abort
System in Orion on an SLS and just a graphic of
what that abort system, the big abort motor firing
would look like. As Kevin said, similar in appearance on Apollo
they had a tower escape system, but the Orion system uses what's
called Active Flight Control, and that's a big difference
between us and Apollo, Apollo was a passive system.
And so what the active flight control does for you, it
allows us to actually steer the trajectory and also control the
attitude of the vehicle during the abort, and that
capability significantly, as Kevin said, improves the
crew's safety over a passive type system. So, this is just a
graphic showing an overview of what the abort sequence
would look like, should there be a problem on
the launch vehicle, you know you have sensors on the
launch vehicle and they tell you there is a problem with an
engine or you off course or something like that, you will
detect the abort and you would have a signal that you need
to do the abort and the abort sequence would look like this,
first when you start the abort, there is a big abort
motor that fires, that quickly pulls you away
from any trouble that might be occurring on the launch vehicle,
and at the same time there is this called an attitude control
motor, so a motor that produces thrust and forces to
stear the trajectory and keep you pointed nose
forward. The abort motor burns only for about four or five
seconds but produces like a peak of 400,000 pounds of thrust that
gives you about 12 to 13 Gs of acceleration that is to get you
away quickly from any problem on the launch vehicle. You then
coast for a while under control with an attitude control motor
keeping you in a nice stable nose forward condition because
you are probably going very fast coming off the launch
vehicle, you need to slow down, because what we need to do is we
need to turn around because the parachutes were used, we use the
same parachutes that are on top of the crew model. So
you need to turn around, slow down and
turnaround maneuver we call it reorientation maneuver that heat
shield forward and that's done again using the attitude control
motor so you need to get a turnaround in a steady condition
heat shield forward and that's another benefit of this attitude
control motor that it does that for us with the active flight
control. You then once you get steady you fire a
Jettison Motor, pulls the Launch Abort System
off the crew module and then you can, there is a little cover
that is called the Forward Bay that comes off that's a cover on
top of the parachute that comes off and you go through the
regular parachute sequence down to the water. As Kevin said, we
are designed to do water landing similar to Apollo. So, this
provides the abort capability up to 300,000 feet and as you might
imagine this happens pretty quickly, so right now, when you
are at high altitude the time from abort initiation from
leaving the launch vehicle all the way to LAS Jettison is on
the order of 25 to 30 seconds for this whole sequence of
events. When you are doing like a pad abort as you might imagine
it has to happen a lot faster because you are near the ground,
because you need to get up, out over the water, turned
around and got to get the system off and parachutes open so you
have enough time for the whole parachute sequence, as
you saw in the video, there are a number of
parachutes that open, they have to be of course fully
open to get you down to the water safely. So when you are
doing a pad abort it happens more on the order of 15 to 20
seconds. What I have here is an animation, apology it is an
older animation but it was an early concept for an abort test.
Kevin talked about we have got an ascent abort test coming
up in the 2017-2018 timeframe, so this is an animation showing
about what that would look like, and I apologize this is using an
older launch vehicle that we are not using anymore. So this
is not going to be the launch vehicle that is used in
the ascent abort test, but it is a good animation video
that shows you what the abort would look like. [Video Presentation] So we fire, fires
the abort motor to get you away, the
attitude control motor is firing to keep you
on course, there is the controlled
reorientation to get you back, this heat shield
forward condition, then Jettison, the abort system,
that's that cover on that top called the abort bay cover, and
then you go essentially into the standard entry sequence. The drogue parachutes
that come out when you are in higher altitudes
to stabilize the capsule before the main parachute. Then cut
those away and then go through the main parachute sequence.
It fires out small parachutes called pilots that pull out
the main parachutes. Just interesting, they open,
they are called reefed, so they don't open all at
once to reduce the stress on the parachutes, so they go through a
sequence of opening smaller and then slowly open larger
called reefing. Yes sir? AUDIENCE: During the
abort sequence, if there is a problem
with the reverse sequence is there enough room to try
the reverse again? JOHN: It is a solid rocket motor
so it has a fixed amount of burn time, but right now
the control system, because we have this
active control system, it is all computer controlled
and it continually senses your attitudes, the way the
active control system works, the computers in the crew
module that sends signals up, that sense your attitude,
make steering commands, send those up to this control
motor which we will talk about and that provides the turning.
So the computer on board is constantly determining you
attitude to get you on the right trajectory, so it is not
controlled by the crew. Yes sir? AUDIENCE: What assures that the
capsule will land in the water during an abort? JOHN: That you land
in the water? AUDIENCE: Yes.
JOHN: Yes sir. The trajectory we have
right now for like going to a lunar orbit,
going to an orbit first that will then take you on to a lunar
orbit is out over the Atlantic Ocean, and so the Launch Abort
System the farthest that you would abort going out
over initially is 300,000 feet in the orbit, puts you
out about a third of the way or so out into the Atlantic.
So higher than that you do a service module abort which
then you can target where, you are high enough up that you
can actually target where you reenter. So you can
probably skip back over, go high enough up to reenter
in the Pacific. AUDIENCE: Do you
still have on-board measurements to show your position?
JOHN: There is an inertial measurement unit in the
crew module to give you information about your
attitude and accelerations and positions and things like that.
AUDIENCE: Attitude control? JOHN: Yeah.
AUDIENCE: Will they be using reentry tile protect the heat
and if you do lose tiles how do you prevent
that becoming a disaster? JOHN: Yes sir, like
Kevin showed earlier we are using a system
similar to Apollo which is the AVCOAT
design, it is a monolithic, so there are no tiles, it is a
single piece. AUDIENCE: So it is
going to be a single piece? JOHN: Yes sir.
AUDIENCE: If during the launch, something happens to the
computer that controls the abort system, is there a backup?
JOHN: Oh yes sir, we have got redundant,
Apollo and the shuttle, most commercial and high
performance aircrafts have redundant computer systems.
Yes sir? AUDIENCE: Would you lose
consciousness at 12 or 13 Gs? JOHN: Oh that's why the system
is all computer controlled so it does not require
crew intervention, that's why it is made
computer controlled, should the crew, I am not in
the human factors area but I believe the humans can
take short periods of high Gs and still remain conscious but
you can't sustain high Gs for long periods of time and still
remain conscious. So we just have a peak of on the order of
10 to 12 Gs for a very small period of time. But as I
said, it is computer controlled, so it doesn't require crew
intervention to do anything during the abort sequence.
Yes ma'am? AUDIENCE: That answers
actually my question because when we brought back Apollo
XIII it was interaction between mission control and the astronauts in the capsule that
made the safe return and I was going to ask basically the
same question. JOHN: Yeah, that's
an advantage of our system is the abort system over Apollo is portions of the abort
with Apollo especially high altitude will actually require
crew intervention like to do that reorientation to get
to a steady heat shield, the crew had to take command
and actually fly it back to heat shield forward. Our system is
all computer controlled with this active control system
for the abort system. Yes sir? AUDIENCE: This is probably more
for Kevin. These flights create an awful lot of debris, what
happens to them? Lots of stuff gets peeled off,
where does it go, what happens to them?
KEVIN: So, that is actually a very good question. For any
launch that we do, we actually in order to satisfy
the requirements of the range the Air Force that controls that
space is we have to demonstrate that we are not going to leave
what is referred to as a water hazard, meaning we are not
going to leave something large floating around on the surface
of the ocean that a ship could actually impact and be damaged
by. So we actually do very complicated analyses, and
for the Launch Abort System, for this upcoming EFT-1 mission
actually we hear Langley did the water impact analysis. John
actually provided the boundary conditions, the initial
conditions for our structures analyst to do those analyses to
predict how this large piece of hardware behaves whenever
it impacts the water. So, I don't have that simulation, it
is actually very interesting to look at it. But essentially
this 30 foot tower actually is compressed into a very small 5
or 6 foot tall column of metal whenever it impacts the water
and actually sinks to the ocean floor very quickly. Yes sir?
AUDIENCE: If I was interested in composition,
history, development, and evolution of propelling
systems from the Saturn or i.e., the propellant fuels
both solid and liquid, where would you direct me to
go? JOHN: Marshall Space
Flight Center. KEVIN: Okay.
Let me see if I can, I will see if I can
help answer that, yeah you could certainly get
that information in Huntsville, Alabama. So, there is a lot of
information about the historical systems and materials that
were used for the liquid fuels. Obviously we NASA primarily
use hydrogen fuel and we have to carry oxygen with us, so we have
a lot of liquid oxygen that go along with us. Some of the other
rockets that are out there, for instance you guys may see
in the news SpaceX and Falcon Rocket they actually use
kerosene as their fuel and a lot of like the Atlas V uses
kerosene, the Delta IV Heavy that we are
going to fly on in December uses hydrogen. Now, when you talk
about the solid propellants, that's a little bit more,
sorry I can't help you, because those materials are used
in missile systems and weapons systems by our military and
their composition is tightly held and controlled
information. Now, you maybe able to find out some
information about older systems like the solid materials,
propellant materials that were used in the launch
escape system for Apollo, that information may
actually be out in the public, but materials that we use, we
cannot tell you the composition. I can tell you that the solid
fuel it is like an elastomer, it is like a rubberish material.
I can tell you that the solid propellant contains the fuel and
the oxidizer in a very precisely controlled mix, so we don't just
have like hydrogen and oxygen that is all mixed up together
so that when it burns we have to supply our own oxygen to keep
the fire going so to speak. And I can tell you that
our propellant systems, our solid propellants
are actually based on, for instance the Jettison Motor
propellant is designed to be a very clean propellant. The
reason it is designed to be clean is because we use that
motor for every mission and we don't want to fire up that
Jettison motor and contaminate the star trackers that are on
the surface of the crew module or the windows or any of
those kinds of things. So that propellant actually is designed
to burn very clean without any particulates or aluminum
particles and things like that flying out here and there. And
I can tell you that most solid propellant systems are, the fuel
is primarily aluminum but there is lots of other magic fairy
dust in there that we can't talk about. AUDIENCE: Potassium and
Hydrogen used for separation maneuvers? KEVIN: No, primarily
the separation maneuvers are done with solid rocket.
AUDIENCE: Can we go back to the Orion entering into the
atmosphere? You said that as the capsule is going to accelerate?
Did I understand the correctly? KEVIN: Yeah, I apologize,
if I said that I misspoke, it is not accelerating as
it enters the atmosphere, it is accelerated to a very high
velocity before entering the atmosphere. So we
accelerate it up to 20,000 miles per hour so that we can
simulate the speed that it would enter the atmosphere if we
were returning from the Moon for instance. So it is not actually
accelerating when it enters the atmosphere, it is actually
decelerating. AUDIENCE: Perhaps I
did not understand the answer which you gave to sort of the earlier question,
that service vehicle, does it completely disintegrate
since it has no heat shield when it comes over, all as it is into
the sea in single piece? KEVIN: So, I am a
little bit out of my technical area of expertise but there have not been large
segments of these vehicles to impact the earth whenever they
reenter. For the most part they are consumed in the atmosphere,
if you recall the shuttle, external tank is a very
large structure. That vehicle reentered and burned up in the
atmosphere mostly. I mean there were some parts that actually
did make to the surface of the Atlantic but they
were very small. So, for the most part, no, it is not
a large structure that impacts. JOHN: During a nominal entry
there are maneuvers to separate the crew and the service module
and the trajectories are chosen so that the service module hits
the water first and it is in a cleared corridor as you are
landing and then the crew module lands closer to California.
AUDIENCE: Could you distinguish between the SpaceX rocket
and the Orion? JOHN: Yeah, a big difference
between the commercial crew and Orion is commercial
crew is just focused on low earth orbit. Remember
the graphic Kevin showed you taking crews up
to the International Space Station and also cargo
up to the International Space Station. And the International
Space Station is in relatively low orbit and so
like 100 miles or so, 200 miles or so and the
orbit where the Orion is being designed for going
beyond low earth orbit, going out missions to
return to the Moon, go out to near Earth asteroids,
missions like that. Yes sir? AUDIENCE: It's probably safe to
have a pre-determined re-entry position, so you can service the
vehicle easily. JOHN: Yes sir, so right now our nominal entry
for a mission is off the coast of California, so close to you
know where we have large naval bases that can send the ship but
there is uncertainty due to the winds and things like that that
are taken into accounts so you get essentially like a
landing ellipse almost, it is steered as it enters to
try and reduce the variability of the landing point, but
you try and reduce that, and you do analyses, there are a
number of analyses that are done on the day of the entry to
try and more pinpoint where the landing is. AUDIENCE: So what's
a regular analysis? JOHN: I am not familiar.
I am in the Launch Abort Office, so I have seen analysis, a
lot of the analysis done by the entry people but I am not that
familiar with it. Questions? Okay, I think we had
some great questions here, we have already gone through
some of the issues of why it is hard here, but I have summarized
some of the key issues, as you might expect this is a
difficult technical problem, talking about the
Launch Abort System, designing the abort
trajectories. One of the big issues is like we talked about,
we have to have controlled flight flying nose forward, we
then have to slow down and then do this reorientation maneuver
and get into a steady condition heat shield forward. So the
reason the attitude control motor and active control allows
us to do that because as you might imagine if you got an out
of control launch vehicle or an explosion you might have
severe initial condition, a large tach slip, that system
can take that out and get you back steered on an appropriate
trajectory and control your attitude. Also as I talked
about getting steady heat shield forward is very important, both
to get a clean separation of the tower and a good condition for
your parachutes to deploy during entry. As you
might think about it, you know we have to design here
a system that can both fly well forward and backward, and you
really can't say that for any aircraft you have ever flown on,
you are only really designed to fly forward. So, we almost have
twice the problem here as far as the control design. We also have
to operate over a very large altitude and speed regime, going
all the way as we talked about from the pad up to 300,000
feet, so through most of the atmosphere and there is a large
amount of atmospheric change, the properties and density, the
temperature of the atmosphere change a lot over that altitude
range. And also that takes us a speed range of course from Mach
0 which is you are not moving on the pad all the way up
to hypersonic Mach 9, 9 times the speed of
sound up at the 300,000 feet at the top of our
operating condition. Also there is transonic region. The region
what we refer to as around Mach 1, actually is a very
challenging region to model and test. Here is just an
example of what that, some of the issues here,
this is like Kevin talked about computerized wind tunnel CFD
visualization. You see these are plumes from the--control motor
plumes from the abort motor and there is very complex
interaction both with the flow field because you are
moving very fast and the wind is blowing those plumes back and
also interaction between the plumes and actual the geometry
of the body and that makes it very difficult to get good aero
database models that we can use in our computer simulations. So,
we have done a lot of work at Langley in some of the big wind
tunnels to support development of the aero database. It has
been critical to the program. So here is just an example of
one of the launch abort system models in the NTF in one of our
14 x 22 wind tunnels and also here in the
vertical spin tunnel, tunnel that allows
dynamic--observe dynamic motions of the vehicle. Quickly, some
of the parts of the Launch Abort System, as Kevin said the tower
itself is approximately 30 feet tall but if you include the
ferring the whole thing is about 50 feet, 3 feet diameter
at the tower and 17 feet to clear the complete crew
module at the bottom here of the ferring. We have got from
the top got a nose cone, we have got this attitude
control motor which is actually this motor that enables the
active flight control for steering. It is the motor that
produces pitch movements to give us the steering of our
trajectory and controlling our attitude, really enables the
active flight control. Jettison Motor, which as we talked about
at the end of the abort and on a nominal mission that is a
smaller solid rocket motor that will pull the Launch Abort
System away from the crew module. The abort motor is this
really big motor here all the way from the nozzles, all the
way down here about to down here, it is called reverse flow,
the nozzles are actually at the top, it is what that means
the propellant is below. So it carries enough thrust here to
quickly pull the crew module away if problems exists or
happen during the launch, and as a peak we
talked about 400,000 pounds of thrust which is
only order of about 10 to 13 Gs of acceleration. And also then
at the bottom we also have this what's called the boost
protective cover we called the O Drive Ferring, and it is a
ferring that protects the crew module during a nominal launch,
it just protects the crew module from any aerodynamic
loads and heating, also reduces the drag of the
launch vehicle a little bit but during an abort also it protects
the crew module from the abort motor plumes as they fire. So,
I don't have time to talk about all those motors.
All those motors, as Kevin said, are solid
rocket motors and were designed especially for the
Launch Abort System. So, I am only going to talk here
about one which I think is the most amazing of our motors
developed by ATK in Elkton and it this is attitude
control motor. So, what it actually is, is a
motor that as talked about gets commands from the crew module,
go up to this motor and it produces thrust and pitch and
yaw moments which is thrusting in both the longitudinal and
lateral plains to actually allow us to initially steer the
vehicle and control the attitude. It is actually what's
called a Controllable Solid Rocket Motor, so you can
actually control where the thrust output goes which allows
us to do the steering and it can exert up to 7000 pounds of
steering force to the vehicle. So, here I have got a video of
a ground test that was done, we did a number of ground tests
before the actual pad abort flight test for development of
the motor. So just walking out, I saw this motor before the
test and it doesn't look very impressive, it just
looks like a big oil can, oil drum, but here if you see it
firing it is quite impressive. [Video Presentation] It is going through a set
of preprogrammed maneuvers here just to show you to show how
you can steer the thrust to any direction you want. AUDIENCE: It's pitching up? JOHN: No. It is
pitching yaw moments. So, let's talk about Pad
Abort 1, Kevin talked about, we had a successful flight test.
First flight test of Project Orion successfully
conducted May 6, 2010 at White
Sands Missile Range, that was the same location, that
was same area that was used for the early Apollo test. It was
the first test of an active Launch Abort System, and just
some fun facts here. It was 135 seconds flight from launch
to touchdown. We had about, we had, this was an
earlier motor that produced acceleration, it was
little warmer days, we actually got to be 15
Gs of peak acceleration, no crew, this was just a test
flight. Max velocity of 539 miles per hour and we got a
max altitude of 1.2 Gs. And of course you are
with the NASA talk, I couldn't--had to include some
technical data to show you. So what our group does here in the
Launch Abort System is we run big computer simulation models
that actually try and predict where the trajectory looks like,
where you are going to go before the flight, so you can answer
the questions like how far I am going to go, how
fast am I going to go, where am I going to land,
am I going to land safely, things like that we can do with
our computer models. So this is just an example here of
altitude versus time clock, so how high up you are going
with time and what we did before the flight test, it is very
difficult to predict the exact winds of the day and
the exact temperature, there might be some variation
in the weight of your vehicle, so we run our computer
simulations over and over again changing these things a lot, do
a run at one temperature and one set of winds, do another
run, another temperature, another way,
another set of winds, change the
aerodynamics, things like that, and do a lot of computer
runs. So this is like about 2000 computer runs, we were varying
a lot of things that we think might vary on that day of flight
and that gives us a bound on what we think the predicted
performance should be. And then we have like what we think is
the nominal condition we are going to fly at. So, that's what
the blue is here. The light blue are all our varying simulations,
varying a whole bunch of things, trying to predict the
performance before the flight and the blue darker blue here
is what if everything is nominal the way we think it is
based on our information, best understanding of the
winds, that's what we think the trajectory was. So over-plotted
here in red are the actual flight test results we got after
the flight just to show you. So, one actually we are pretty close
here to the actual prediction of the nominal performance, and you
can see here we are well within the band of given the variations
we thought could happen on that day. So that is just an example
of some of the analysis we do. So, of course, we do this you
know over and over and over again a lot because
as the design changes, we continually update
our computer models, some of those wind tunnel tests
that we talked about generate force and movement information
and we use that in our wind tunnel models, motor
information and all that. Okay, so coming up next I
have got a really nice, it is about a three minute video
on the Pad Abort 1 flight test. It is a summary. First
includes some of the firings, test firings and some
of the different motors, you will see the
attitude control motor again, the abort motor test firing
those are done on the ground, the Jettison Motor firing and
then compilation of some of the videos that were taken during
the actual PA-1 Flight Test to show you what that looks like. [Video Presentation] JOHN: That is the
Jettison Motor, that's the trailer we used to
put all the parts together. KEVIN: So, I believe that's
it for us. Just a slide to wrap it up, and then if
we have time which I do believe we will have a few minutes we
will take some more questions. So, just in conclusion the Orion
Multipurpose Crew Vehicle will serve as a next generation space
exploration vehicles. It is being worked by multiple NASA
centers and our prime contractor is Lockheed Martin. Launch Abort
System is being designed to significantly improve the safety
of this vehicle by allowing us to recover the crew in the event
of an emergency and deliver them safely to the ground and
then as John mentioned earlier, there are number of test flights
that we have planned. EM-1, the Ascent Abort Flight Test 2
and the final crewed flight EM-2 which is in 2021. AUDIENCE: What kind of score did
the December 4 test, that you mentioned?
KEVIN: Certainly, and I will get to your questions here. Briefly,
Exploration Flight Test 1 is going to fly December
4th, probably about 8 a.m. in the morning out of Cape
Canaveral. We are flying on top of a Delta
IV Heavy. We are going to do two orbits, accelerate
the vehicle to 20,000 miles per hour and then
reenter the Earth's atmosphere at that speed which is just
slightly below the speed that we would reenter from if we were
returning from the moon. Our primary purpose for doing that
test is to demonstrate the heat shield which is a very important
and critical system as well as demonstrate the flight control
and the parachute or landing recovery system. So, it is a
very important test for us to buy down what we believe are
some of our highest risk. We talk a lot about risk in
the space flight industry, so we want to make sure that we
understand that risk and that we address them appropriately and
so that's why we are doing this test. Thank you. Sir? AUDIENCE: You indicated
that a set of tiles that you recovered, that
you indicated had that paint. After it expands through that
atmosphere that heats it up, after you reverse
things and turn it around, is there any concern that there
will be a lack of contact after it recovers from
the heat? KEVIN: So, if I could explain
a little bit more about the thermal protection
material, it is obviously, we call it AVCOAT, it is
fabricated by Textron Industries in Boston. It is
the system that was, it is a reformulation of the
system that was used on the Apollo vehicle and if you ever
find yourself at the Air & Space Center downtown Hampton, there
actually is an Apollo vehicle there and you can actually
go look at the surface of the vehicle and see that
material. It is actually, if you are familiar
with honeycomb structure, it is actually a honeycomb
that is bonded on to the metal surface of the vehicle and they
fill each little cell of the honeycomb material up with this
AVCOAT ablative material. So, it actually, the way that, it
is a passive system if you will, the way that it keeps the heat
managed is through ablation. So, actually it is charring, it is
slowing burning away as it is reentering and actually we
size it to a certain thickness knowing that it is going to burn
away a certain amount and we want to make sure that we have
enough insulation whenever we get to that point that we don't
overheat the substructure below it. So that's kind of
how it operates. Now, the back shell, the conical
section of the vehicle actually is protected with tiles that are
similar to the tiles that were used on the space shuttle and to
hopefully preemptively address a question that might come up, I
believe if those tiles were lost during flight it would probably
not be a catastrophic issue because it is on the back
surface of the vehicle, so we might have some
local heating issue, but I don't think we would have
a catastrophic failure. Does that answer your question?
AUDIENCE: Yes. KEVIN: Okay, thank you. Yes sir? AUDIENCE: If anything
happens just after the launch pad, do you wait till you
clear the atmosphere or do you do something prior? KEVIN: Yeah, actually very
good question. So, you know, dependent on where
we are at, you know from the ground
all the way up to 300,000 feet we can successfully
abort. So if it is just after launch we are not going to
be that far from the ground, so we are not going to fly that
high. Just like if you fly off of the pad you are only
going to go a mile high, if it is early in the flight
we are going to move as quickly away from the vehicle as we can
but still it might not be that far. So, for instance, if we
were launching and we were a mile above the Earth's surface
we would probably at that point fly another mile or two away
from it. JOHN: That's another
thing that makes this such a challenging analysis problem is you don't have a
definite starting condition, it could be somewhere
along a trajectory, but you have to analyze a
trajectory all the way up because you could abort at any
point along that trajectory. AUDIENCE: What controls the
orbit? KEVIN: What controls the orbit? JOHN: Well the trajectory
gets this up into an orbit, the launch vehicle gets this up
into orbit and then to de-orbit, I believe there is de-orbiting
burn. AUDIENCE: Could you
show a picture of one where you changed the orbit?
KEVIN: Oh yeah, okay, I am sorry, thank you, now
I understand your question. So, you noticed in that animation
of that launch that there was a rocket engine on the end of the
vehicle that's what the industry refers to as the
Delta IV Kick Stage, it is the upper stage
of the Delta IV vehicle, and that stage and that rocket
motor are what are used to change the orbit. So we
ballistically enter into an orbit around the Earth, just
an elliptical orbit and then by igniting that motor we can
actually accelerate ourselves out to a higher orbit, actually
we go out to 3600 miles before we turn around
and, as I mentioned, we don't use all the fuel
getting out to 3600 miles, we actually keep some of the
fuel and turn it on and actually accelerate back in when we are
coming back. Yes sir? AUDIENCE: Tell me
something about the models you have up there.
KEVIN: Yeah, John, you want to? I will let John be my...
JOHN: So, starting here with the model of the SLS, as Kevin said the full scale
vehicle is about 321 feet, 1/200th, so 200
times bigger than that, so all of this as said is
the space launch system, the new rocket is being
developed to take us beyond low earth orbit, the little part on
top which we think is the most important part is the
Orion where the crew rides, there is launch abort
crew model is in there, service module. So we got a
smaller model here just of this upper part, so there would be
the Launch Abort System. KEVIN: As John said
we think this is the most important
part of the vehicle, we definitely want to
take it off and carry it with us. So, this is that kick stage
that I was referring to earlier. This is actually the upper stage
that allows us to accelerate in the higher orbit. JOHN: And Kevin showed the
different part, service module. And this is earlier design
of the solar panels, now we are going
to more, we are partnering with the
Europeans for service module and the design now is more
rectangular looking solar panels, so that's
an earlier design, so crew module and launch abort,
and just a larger scale so you can see the same thing of
the crew module of course, in there like that flying
when you do with your Abort, and you have to do the
reorientation and that is Jettison. AUDIENCE: That telescopes
to ten feet? KEVIN: Yeah, it
actually compacts. Yeah when you hit the water, our simulations indicate that
that 30-foot long tower actually is compacted and down into a
space that's about 6 feet. When we flew Pad Abort 1 and this is
just a little bit of interesting trivia, we flew Pad Abort 1
and the tower as you saw is streaking down to the ground
whenever the crew module is so beautifully floating to the
surface under the parachute. We decided to get there a lot
faster. Our Jettison Motor actually ended up in the
manifold of the abort motor whenever we pulled everything
out of the ground. And the whole vehicle was about 20 feet in
the ground I think. I think it buried itself right down in the
ground. But yeah we actually put the entire, I want to
make sure you understand, the entire Jettison Motor was
compressed and shoved into the little manifold which is where
the nozzles are on the Abort. So, that entire structure was
compressed and stuffed inside that little manifold from the
impact. Yes ma'am? AUDIENCE: Is the
Orion in the video, is that a test vehicle
or the real thing? JOHN: Actually, you just
saw that vehicle fly. That's the one that flew. And it was,
that vehicle was designed and fabricated by NASA
Langley Research Center, we are very proud of it, and
you can go see that. And it is interesting too to see that
because it is full scale, we have made a few
changes since then, the cone, the back cone actually
we have changed that to make it a little bit wider at the top,
we did that because we realized we needed bigger parachutes
after we did Pad Abort 1 flight test. So it is just a little
slightly different production vehicle. AUDIENCE: So most of the
people who were living here, the President moved to
Houston to work at NASA there, I don't think a lot of people
know that. KEVIN: So yes we
are actually doing fine. I have read a lot of the
history of NASA and that whole activity and it
is very, very interesting. That that team of people who
left this area and went to Texas were a very
interesting group of people, they were young, they were
excited and they were willing to take risk and they did that very
thing and so they were willing to go boldly forward and we are
glad that they were leading us at that time quite
frankly. But we didn't, Langley wasn't left in the lurch
at all and we are very excited to be I think at the epicenter
of activities of developing the new vehicle. AUDIENCE: Is any thought given
to an abort landing close to ocean?
KEVIN: Actually that's an excellent question. When
John and I were putting these pics together we actually
thought about putting a chart in to kind of
describe why we didn't do that. When we initially started
this program in 2005 we wanted
to land anywhere, please don't take that
literally. We wanted to land on the water and on land which
does significantly expand our operational capabilities, but
what we learned was the system to land on the land cost us
about 600-700 pounds of mass, that 600-700 pounds of mass that
we would have to carry with us to the Moon, to the asteroid,
eventually to Mars and it just was too costly to do that. So,
we had to get rid of that system and rely on the water landing
system which is much more mass efficient system
that we can use. Now, you will notice, as John said,
the commercial guys are only going to the low earth orbit
and some of them are actually proposing systems that will land
on the land and the reason we can't do that is because you
just can't carry that much weight with you whenever you
are going so far away. Another differentiation or question that
might come up is why do we have a tower that is
pulling us off the vehicle, why don't we use the service
module, it is a giant motor, why don't we just go ahead and
use it for all of the aborts, because as John said when
we get above 300,000 feet we can use the service module
to abort to orbit for a rapid reentry. And the reason is
our service for the Orion weighs about 36,000 pounds. We need
that large vehicle with all of the fuel that it carries with it
in order to explore to the Moon and beyond. It is just
a matter of physics, we just need that much
propellant to take with us so we can get back, get off there
and get back. Whereas if you are going to low earth orbit an
equivalent service module system would only be
about 12,000 pounds, so it is about 20,000 pounds
lighter. So when you are talking about getting away from a launch
vehicle which we have to do very quickly, if you are
trying to push yourself a 36,000 motor off it is just not
practical. So we had to go with the tower system on top so that
we could manageably remove the crew module over that full
flight regime successfully. [Applause] CHRIS: Thank you Kevin and
John for giving us the opportunity to presenting
today, and next week, next Thursday we are going to
be talking to the Space Launch System guys, who actually built
the launch vehicle and they may have a different story, they
think this is the most important part! So we need to
see how that plays out, you need to judge next week.
Thank you very much. [Applause] macaroni
