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
