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So our next speaker is Marcus Landgrab,
who currently works for the European
Space Agency ESA, you
might have heard of them. They're like
the NASA of Europe.
He's going to talk about space elevators
because, you know, the rocket equation is
pretty it's pretty unforgiving.
And the drive doesn't really get you out
of gravity wells.
So we might need a space elevator.
Please welcome our speaker.
Thank you.
Who have you have heard of the space
elevator?
Who have you believe?
Keep your hands up. Keep your hands up.
Who have you believes to see a space
elevator in their lifetime?
All right. OK, I get the picture.
So most of you have heard about
the space elevator and about
half, I would guess,
believe it would become reality.
So I would like to make it extra
real for you tonight.
It's about as real as it gets, I believe,
because I'm going to talk about the
elevator to the moon
since I'm also a representative
of ESA. I would also like to talk about
what ESA does today to go
to the moon and why to
go to the moon. So let me give
just a quick overview on
why and how one,
anyone can get to the moon and then talk
about why ESA goes to the
moon today or
how we actually do that.
And then we come to the really
the the core of the talk, which is
beyond rockets, going beyond rockets.
And of course, that's the elevator.
And then talk about benefits because
you're a big community, you are very
successful community.
What draws you here?
But what really draws you here is the
benefits that drive you.
Everybody, every one of you has
is looking for benefits, for fun,
for knowledge, for
meeting people.
And the community is really exists
because you draw benefits from it.
And that's also true for anything
that we try to do in society.
And space exploration is part of that.
And that brings me to the final point,
which is the community. I would also like
to share a couple of links with you
that will enable you to engage in
the space elevator in lunar exploration
in general and with ESA, of course.
All right. Enough said about the
overview. So why the moon?
This is a little fun bit that I put
together and I would just read it to you.
I will not comment on it because
it is a bit the folklore about
space and the moon,
and you can form your own opinion about
those things.
Some of them. I will also talk
during my talk today.
So there's this famous guy by the name of
the casing who, of course, says that
Apollo was filmed in a Hollywood studio.
Everybody who likes to watch
British animated films
knows Wallace and Gromit, and they insist
that the moon is made of cheese, which
solves that cracker problem.
Of course, you all know the Apollo
program that ended in 1972.
So there is an issue of the TIME magazine
that says soon
robots will be intelligent so there
is no need to risk human lives.
2010, President Obama said
while talking about his vision
on the space program that we have
been there before.
And I will leave that without any
comments.
And there's another nice movie by the
name of Aaryn Sky and
and that movie.
Yeah, I like to.
And then, of course, in that movie, you
have President Sarah Palin
and she says that who are these guys
anyway? Nazis from the moon, Wahaha.
So so this is, I think, very
inspirational folklore about the moon.
Let's get to the to the real
thing, why we explore
space.
Now, if I say we I always
am in these talks with ESA, I'm always
talking about us Europeans.
But the European idea is bigger
than Europe. So so let's just
feel as Europeans for a minute,
because the moon is in our exploration
DNA. We Europeans are
explorers. And I just
visited my hometown of CUSA in
Hessen, south of here
a couple of last days, and
I took a picture there in a museum.
And that's a picture of 18th century
artist scientist
who made you observe the total eclipse
of the moon.
And he did that under contract of
a nobleman in CUSA
who sponsored
artists, scientists to come to his court
and teach about science.
So already, two hundred years ago
and even earlier, we have been really
engaged in science because we understand
this is part of our cultural heritage.
Actually, this
nobleman is the grand grand grandson
of another nobleman who hired
the Swiss guy to come also to CASA
to measure the position of the stars
in the sky at the time,
a very difficult undertaking
because the sky, the stars move
in the sky due to the Earth's rotation.
So you have to know the time very
well. If you want to tell what is the
position of a star, because it's if you
don't know the time, it's moving all,
all, all the time.
So this guy used Bourgie,
made a clock and that
clock was so precise and
it needed a third indicator,
which was the indicator for the second.
So the second the time unit second was
invented in my hometown of customers.
Not many people know that.
And that shows that exploration is not
only in our DNA, but it is also
to our benefit, because without the
second hand on our watches,
we would be in trouble. Now, these days
we don't need them anymore.
But but it tells
you that our everyday life is really much
inspired by inspiration
and inspired by exploration.
Of course, another
reason why we should go to the moon is
discoveries now a little bit arguing
against President Obama.
We have not been there.
We have been in a couple of places which
are very special,
but the moon is largely unexplored
country.
There's a nice book by Arlene
Cross University Press.
You can get it for cheap on any
even as you book. I believe that beside
him there
is a new moon. Many of the most dramatic
recent discoveries in planetary science
are lunar.
Only in the past few years has lunar
exploration accelerated again, and many
do not realize how rapidly our
knowledge of the moon is changing.
Have just put the two pictures here that
are from recent observations of the moon.
The upper right one is
a hole that was punctured by a meteorite
in the roof of a cave on the moon
and the underground world of the moon.
We have no idea what's inside there.
And of course, the first idea that comes
to everybody's mind is we could live
there. We could be protected from
meteorites and from
solar radiation.
The lower image
is in this
very mysterious region is called enough.
And Einer is apparently the tip of a
volcano, ancient volcano that
blew away this dusty
lid of the moon.
So what you see here, this more bright
stuff is probably the real surface
of the moon while the rest of the real
surface is still hidden under this
dusty, little bit more dark,
what people call the regolith.
So there's so much more to explore.
And certainly if aliens would come to
Earth and would take a couple of samples
in the Sahara Desert and some in the Gobi
Desert, they could not claim that
they've been on Earth and have explored
Earth completely.
So here's a philosophical
take on it. And because it's philosophy,
it has a lot of text
and will not read that.
I will ask you to read it after the talk
and then report back to me what you take
from it.
Now, I will just say the
basic idea.
So there are two school of thoughts.
One school of thought says there's limits
to growth.
Earth will run out of resources soon.
So we better be very
careful with them and the other school of
thought, which is much less famous.
Says there there's a limitless
amount of resources because we are
connected to the universe and
the letter one is called The
Extraterrestrial Imperative, was
formulated first time by Cruft Ellika,
a German philosopher philosopher who was
also part of the team of the Fondren
engineering team that went to the United
States to build the moonwalk.
And he basically says nature
has shown to us that whenever
there is a limit, evolution
will overcome that limit.
And he gives the example of
phytoplankton, which is a bacteria
or a single celled organism
that ran out of energy at some point
but discovered the
use of extraterrestrial
energy source, which is the sun.
So to plankton discovered
by evolution, how
sunlight, which is extraterrestrial,
could be used to make energy and store
energy on Earth.
And by the same token, he says, human
technological development is the
kind of evolution and we
will be able to overcome that.
And how do we overcome that is
pretty clear that we use resources that
are not from this planet.
So this is the extraterrestrial
imperative.
The third reason why we should use the
moon is, of course,
you see this nice gravitational well
that is made by the earth and it's
difficult to get out of it because you
need energy to get out.
But the moon creates an extra
spot there, which has
this interesting structure that allows us
to put spacecraft in a
equilibrium state and
put it like stations there so that
you can reach the surface of the moon
as well as deeper into the solar system.
So really, these three things we
can it's in our culture,
it there is new knowledge to
be gained and it is
a great starting point for further
exploration. So these three things are
reasons to explore the moon.
Why is it so hard to go there?
Why are we why did we stop?
And the reason is the rocket equation.
This is the rocket equation formulated by
Konstantin Sikorski in 1895
is basically an expression of the
Newtonian law of mechanics that says
to each reaction, you need an equal
but opposite reaction
and this is the only way
to propel yourself in space.
If I'm walking across the stage,
what I'm doing is I'm pushing the stage
behind me so that I'm
propelled forward.
And the the link
that makes it possible for me is my
soles of the shoes.
If there was if there was a slippery
surface that would not allow the
transmission of momentum between myself
and the stage and we just slip and fall.
But if in that case,
I would have to use
reaction principle of Newton to propel
myself.
And in this formula there's a very
important parameter is the Delta V that's
on the left hand side, which gives you
the amount of how much you have to change
your velocity to reach a certain target.
And in the lower part, you see the
numbers here that are not very important,
but it's
very difficult to get from Earth into low
earth orbit, which is the first little
gravestone there, and then three
thousand two hundred meters per second to
go to the lunar vicinity and then on top
to go to lunar orbit, to need another 800
and then to the surface of the moon, you
need two thousand.
If you know that our current technology
limits us to use exhaust velocities,
which is the V, they're of
less than 5000 meters per second.
That tells you why we need
big rockets to launch small
payloads.
We need a 10, 700 ton around
five rocket to launch a ten ton
satellite into geostationary transform.
And that makes it so expensive.
Now, expensive means what is the
economics of space transportation?
And what you see on the right hand side
is much more interesting.
This is a table of how much it costs
today.
If you would go to a launch service
provider to launch your stuff into space
in Earth's orbit is about ten thousand
euros into cislunar space is
ten, ten times that or a hundred
thousand to lunar orbit.
Two hundred thousand down to the surface
of the moon, one million euro,
one kilo to bring
anything back from the moon.
Ten million euros.
So if you even would get back
platinum or the most precious
stuff that you can think of, it's
still cheaper to get it on Earth.
So forget about
the space economy with rockets
that will not work.
The only thing that the private sector
can do is they can make space
travel more efficient so
that for the governmental players,
everything becomes a little bit cheaper.
But there will be never be able to get
stuff from the moon and sell it here
on Earth. That's just physically
impossible. If they use rockets
and the left hand side, you see that
actually the.
The cost raises with
the square root of the matter.
So if you have a big rocket, it's more
expensive, but
the rate of increase is
lower than one. So that means that
for each kilo, you'll pay less if you
have a big rocket.
And that's why around five is, for
example, bigger than our own four.
So this is the economics of space
transportation in this situation
that we have today.
And in that situation,
ESA has a program that that
takes us indeed to the moon.
And I think just to
sleights about how ESA goes to the moon
today, like I said, the biggest
problem is gaining access to the moon.
And that is why there is the big blob and
there is the little bit smaller, but
still a challenging problem of surface
operations.
And these two problems really
break down into smaller bits.
We need to get to the moon.
We need stagings. So we have to change
the vehicle. You know, let it let some
stages that already spent the fuel go
away so that everything is lighter
than we need landing, which is difficult
because it's difficult terrain.
And then we also have to launch from
the moon, which is something that is
incredibly difficult given the fact that
already launching from Earth is difficult
and then you can break it down further.
And each of these topical problems
has a program, for example, to
get humans astronauts
go to cislunar space.
We are cooperating with NASA to build
a human space vehicle that will launch
first time in 2018 around
the moon.
Issa proposes a program to build
a habitation module for this
cislunar habitat.
This is a habitation staging post
in this house, in cislunar space that
will enable access to the lunar surface,
but also into deeper space
than ESA works together with Roscosmos,
the Russian space agency, to build a
landing system for lunar applications.
And there is a camera that will first go
in 2018 2019
to prepare our technology for landing on
the moon. And then further down the road,
we're working together with an
international consortium or with
international partners to build
a demonstrator mission that
does everything so we land.
We would take off and we have
a little rover that shows mobility on the
surface.
And this is an integrated system that we
are currently proposing to our member
states.
And I would like to play the
part of the essent getting
away from the launching a rocket from the
moon. The problem here
and then the final
problem that we face is habitation
on the lunar surface.
And that is, of course,
challenging is perhaps not as challenging
as habitation and free space, but still
there's difficult problems.
Another topic that still
needs to be addressed is getting
resources from the moon, not
necessarily to make money from it.
Like a plane is probably not going to
be a good profit, good business.
But we already have a payload
that tells us how we could use resources
to sustain a base on the lunar surface.
So now this is a little bit of a time
arrow arrow here
to show you how we want to develop that
over over time.
So the first thing is like
a show. This is the drill and the camera,
and that goes already in 2018 and 2021
in two missions together with Roscosmos.
Then there is the Orion vehicle, first
launch in 2018, the first human
mission in 21.
Then the cislunar habitat are
going to be built up somewhere around the
mid 20s, perhaps a little bit earlier.
And then this interesting demonstration
mission in the mid 2026.
And then ESA does indeed
plan or propose in cooperation
with international partners to have a
human mission or a series of human
missions to the moon to really
start the exploration.
But all of that is still limited
by our transportation problem.
But that's what we can do today.
Like, I promise that that's the realism
of the situation right now.
But let's go beyond this
goal. Let's go beyond rockets.
When I said that it
can propel ourselves
only in space, only by pushing
something back by actually
equals the actual.
I lied a bit, so I was not completely
honest with you guys,
because if you have a physical connection
to the planetary body that you're
orbiting, then you can transmit
momentum.
And that physical connection is created
by a space elevator.
And the basic principle, I think really
many people in the room already know it.
So I will skip tours quite quickly.
The idea is to have a long rope
and the rope as the center of mass
and that center of mass is orbiting the
planet in sync with the
planet's rotation.
So in the end, the
rope will touch the surface
of the planet, but will not necessarily
exert a force in it.
So it's simply it's like a satellite,
but it's going around the planet at the
same rate as the planet is rotating.
And then you can climb up and down that
rope with with the cabin.
You make a nice cabin around
you with air and you can go up and down.
And I'm not I know you're your heads
are full of questions and I'll try to
answer some of them.
And certainly the broader space elevator
community can answer most questions
today.
So just as a start,
the energy actually is not so much
the problem. Indeed, we still have to
provide the energy to go from Earth's
surface up into the gravity.
Well, but that's only one
kilowatt hour per kilogram.
And how much is a kilowatt hour in
Germany today? It's like 40 cents.
I guess
that's twice the price than in France.
But never mind.
It's still cheap enough, right?
Then the climate can go up and down
with electric energy.
Has electric motors attached to that
cable can go up and down.
The cable is actually kept port
by the forces of gravity and center
should centrifugal force.
So gravity pulls the part
to the left down and
centrifugal force pulls it to
the right up so
that the cables always taught
then of. As the climate goes up and down,
the climate creates what's called the
Coriolis force, and that puts
the sideways force on the cable
and the sideways force creates a wave
in the cable.
And what does the wave to look much
because of the high tension on the cable
and then left hand side, you see a couple
of wiggly lines, which is the free motion
of the elevator. And if you can read the
small numbers, we are talking
about 700 meters
of maximum
amplitude of of that.
And if you go to higher vibrational
modes, it's it's really not
causing a lot of
a lot of vibration in terms of spatial
vibration.
Of course, the cable for Earth and this
is the Earth cable would
be 150, 4000
kilometers long.
So this is not to scale right on the Y
axis. You have one hundred fifty four,
forty four thousand kilometers.
And the Y axis, you have just
kilometers.
And you see that is the free motion of
the cable. And by introducing a little
bit of wiggle on the base of the cable,
you can even manage that vibration.
So if you have a vibration on it, you can
cancel it out.
So no problem.
And the other side shows you what happens
if the climate goes up.
And this is actually on the moon.
Cable is taken from a paper by Pearson
Atoll where
when the when the climate
goes up, you will have a bit of
oscillation in the order of a couple
of meters normally.
But that's not certainly manageable.
OK, so let's talk about strong cables
because we need strong cables to kind of
not make them rupture.
So what's the strong material like to
express strength of a cable
in terms of rupture length because it
expresses the strength of the cable
at the same time as its Pacific weight?
The rupture length is the length of a
cable you can suspended vertically
in a 1g constant 1g
without it snapping under
its own weight.
So steel cables are pretty strong.
You can have 11 kilometers if you make it
12, it would just go bang because
of its own weight.
Carbon fiber goes up to three hundred
thirty kilometers and
a mystical.
Material that's called material
nanotube that exists only
laboratories in very small quantities
makes it up to three thousand three
hundred kilometers for Earth,
you need for Earth Elevator and you need
about two thousand five hundred
kilometers of rupture length.
So so this mystical material would be
able to do the earth elevator.
So and there on the right hand side, you
see other materials that are available
today and you see somewhere figures about
250 to 500
kilometers length.
The longer the better.
Why does that?
Why is that important?
Because the magic of the taper
people have been asking, how strong does
the cable have to be to make a space
elevator? And there was a paper by Jeremy
Pearson at All in
Astronautical 1975, and
he explains that we can do it from any
kit, any material can even make it from
steel. Only you have to make it
much thicker at the center of gravity
than you make it at the base.
Now, this paper shows how
that is called becomes so extreme
for the Earth that for Veck
materials, that elevator becomes
not feasible.
So I show you this magical
material, nanotube material that
allow us to have a space elevator from
Earth with a table ratio of
about eight or
so
material that exists today is, for
example, carbon fiber
or the famous
honeycomb polymer.
So that these are fibers you can buy in
the shop today and you can see for
Earth it would be like thousands
of times thicker.
And it's not a problem of making
something bigger. But if you make
something you start with, say, a
centimeter and you have to make it
10000, 10 centimeters wide
at its widest point.
And the whole thing is four hundred forty
four thousand kilometers long to total
mass of this thing becomes humongous.
So that's not going to work.
So.
So but for Moon and Mars, this is much
easier. You can see.
And the reason is, of course, the moon
and Mars have lower gravity and they have
slower rotational rates than the Earth.
And then you end up saying that with
existing materials.
If I have a taper ratio of about eight
or five or four,
I can I can make an
elevator. So why
are space elevators easier on the moon
than on Earth?
We have a feasible ribbon material now.
We call this thing a ribbon.
And I will come back to why we
call the rope a ribbon.
We have very few artificial satellites
around the moon that could potentially
collide with the cable.
And we have no human made space debris
around the moon and there
is no atmosphere on the moon that could
kind of with chemical reaction, damage to
cable. And there is no there is no
strong trapped radiation
in because there's no magnetic field
around the moon. So so
the elevator around the earth
is quite futuristic.
It is quite science fiction.
But the elevator around the moon,
it is still science fiction, but it's
closer. So it's not two thousand
thirty one is 2000, 2001.
So if you compare the movies, then you
know what I mean.
Right. So one word about
the climber.
I know that climber is the most inspiring
part of the space elevator, but it's by
far not the biggest problem.
And in my life, I always try to crack
the thickest nut first.
So, you know, one day
when somebody gives me that cable,
I will start talking about the climber.
But there's a nice concept out
there that basically runs on two wheels.
You have electric motor and you have
solar arrays providing the energy and
you can have a couple of capsules
attached to it that transport the
transport the payload.
So what is it that we get
out of the moon elevator?
Why should we do it beyond
exploring the moon?
Well, first of all, you'll remember that
diagram, right?
What made us a lot of headaches
and stomach ache.
But if you have space elevator, the first
thing that goes away is this
because you can go from one orbit to
the lunar surface.
So this change in velocity
that you need to make in order to go
from one orbit down to the surface all
of a sudden
goes away.
So your rocket has to do much
less work.
Not only that, only this number goes away
another 800 meters per second
because you're starting already in
the lunar vicinity.
So this goes away.
Your rocket makes even less
work. So all you have to do is basically
now you have to launch an Ariane five
rocket. You get seven
tonnes to the lunar surface today with an
Ariane five, you get about
five hundred kilos.
So less than,
yeah, roughly 10 percent of it.
But if we had let's speculate
a bit. If we had also an Earth
elevator, you could also cancel
those two figures.
So the number that you see for Delta
V becomes zero.
That means you can have a free transfer
from the earth's surface to
the lunar surface.
No propellant needed in that show.
You in a minute how that looks like.
Not in a minute. I show you now,
right. This is a computer program is
publicly available on the Web.
And I have the URL shared with you.
In my final slide and what
I've done, I've played with it and you
see this in the
crosshairs, you see the earth and
downward pointing is the earth elevator.
And on this central ring, you
see the moon with the long line and
extending with a blue dot at the end.
That's the moon elevator.
Now, I put a payload, that's the little
green dot down there
and me and find my cursor so
I can play with it.
OK, so there is my payload,
right?
So now I'm starting to
let the earth rotate and you see the time
scale up there is 512.
So it's a fact of 512 over real
time. So the earth rotates
and the payload goes with the elevator,
of course.
And while the earth rotates, of course,
the moon is moving slightly but much
more, much less fast
when this reaches the 90 degree position
I let go.
So this payload will just be detached
from the cable and then
this will describe a freefall trajectory
to whatever it takes it because of
the loss of gravitation.
And then now I have speeded up to eight
thousand one hundred ninety two to make
it a little bit faster. So you don't have
to wait to sit here all evening
because things as they go farther
away from Earth, they go slower.
And then what you can do and you see now
every turn of the earth is, of course,
one day is
that at some point you find a trajectory
where you can this object can fly
a rendezvous with your moon elevator
and you can just latch on
and then descend on the moon elevator
all the way to the lunar surface.
So so you would have
a direct connection
from the earth to the moon and
the other way round from the moon, you
can bring any material, platinum,
gold from the lunar surface
back to earth without any use of
propellant.
And of course, what that would do is
to enable us to make real use of
space, economic use of space.
We could create structures that are so
humongous that they would just
no collect enough sunlight, for example,
24/7 to provide earth
with energy.
This is a little animation showing
you use microwaves to beam the energy
down to to the earth's surface.
And and you can make these structures,
you can make space hotels,
because all of a sudden you've broken
this, you hacked
celestial mechanics.
And I think that's the basic idea.
This is why there is interest
in the space elevator. So my final
thought here is that
perhaps if you want to
engage in space exploration,
in the moon exploration and I would also
like to point you towards the talk
by my boss, actually, and
Werner, the director general
of ESA at 8:00
and in room number one.
And he will talk about the Moon Village
and how this community
will make it happen, that we will engage
into lunar exploration.
And final word on the community.
Here are a couple of links, emails,
Twitter names and URLs
that you can use when you download
the presentation to make it happen
and be part of the space elevator.
Thank you.
We have a rather generous half
hour for Q&A, so
please get ready to queue at a microphone
for questions.
There's basically microphones everywhere
such as queue and also, of course,
as always, we have questions from the
Internet. So if you're in the chat
watching the stream, we'll take care
of you as well.
We'll just start with a microphone to
please.
Hello.
Thank you very much for your dog.
So what I was wondering
is that you do not mention at all
if there is going to be an
extra
problem that the cable will have to take
care of. That is the stretching
due to the difference in gravity as it
goes along the gravity?
Well, is that going to be a problem
or is that a very minor factor?
Thanks for the question.
I hid that, of course.
And the answer is that the purest model
is made such that the tension on the
cable is constant through the cable
by making it thicker at the place
of the biggest force.
Because, you know, tension equals force
divided by cross section, squared by
cross section, and then
that's taken care of.
OK, thank you.
Before we get to the next question, just
a little announcement, please try to
be quiet.
And if you need to leave, leave very,
very quietly.
And if you don't have to leave very
urgently, just do us a courtesy and wait
until the end of the talk.
Thank you.
Uh, could we get an Internet question,
please?
Could we get the microphone, please?
Question working with, OK,
is it already known how the elevator
affects the Earth's rotation?
It does not at all.
There's, of course, a small value,
you know, that by nature affects the
Earth, speeds up VirnetX contracts
because of its cooling down.
But it normally it slows down because of
the presence of the moon.
Attaching a
Aluna cable of about a thousand tons
will not affect any because
the moon is much more heavy.
Could we get microphone number seven,
please?
My question is, what will
this mean for future further
space exploration missions that
what are the implications for further
space exploration missions starting from
the moon, or does that have
other any implications for this?
Thanks for the question.
Yes, they are. And of course, that's part
of the deal, that we try to prepare
deeper space missions by making
propellant on the lunar surface and
then transporting it into cislunar space,
which could be then the starting point
for Mars missions or Jupiter missions
or even at some point missions to Proxima
Tantowi. But that's
an extra torque.
Thank you, Mike.
Number one, please.
Thank you for a great talk.
I'll try to keep the question brief and
feel free to direct me to the next talk
by your boss if you feel like he could
answer the question better.
But it seems to me that most of the
reasons for going to the moon.
Apart from the science, of course,
which is important, could
be solved easier from Earth orbit.
I'm thinking specifically of a
refueling spacecraft
and I believe that the low Earth orbit
fuel depots could be refueled from
asteroids and you wouldn't need
to build a space elevator on the
moon.
I'm with you 100 percent.
And of course, my boss can answer any
question better than I can.
But let me give it a try.
Let me give it a try.
Of course, that's actually my day job.
So I'm looking at architectures of
exploration to find out
what what's the best way.
And you're right, if you were
if your goal was to have a
Mars mission or a series of Mars missions
that use refueling, then you would
perhaps not use fuel from the lunar
surface. You would use asteroids and
transport the material, not necessarily
to low earth orbit because of the high
penalty.
But you're right there.
There's competing things.
And the real reason for this lunar
elevator to just make it clear
is if you want to exploit the moon
economically for not necessarily
use it for further space exploration,
but for bringing precious
metal to the earth, that would be the
real reason for the denial
of it.
But do we not also have access to those
materials and the asteroids?
Not necessarily.
If you have to bring it.
If you have to bring it out of
interplanetary space, because you have to
then fly a reentry trajectory.
And that is very expensive.
But let's take that offline.
Sure. Thank you.
Do we have Internet questions?
Yes. Why are carbon nanotubes
or graphene sorbent materials?
Can you repeat, please, I didn't catch
the.
OK, not to
a carbon nanotubes are graphene
has been in the materials
that have talked about a lot, we
haven't read this whole bed materials for
the elevator.
No, there are good materials, but they
are not there yet.
That's the thing.
I gave a talk in 2002
13 on TotEx.
Whoever wants to Google Duncalf space
elevator finds that on YouTube.
And there I am talking about how to make
that possible.
And and
you can tell from my talk back then that
I was a little bit younger at the time
and a little bit uncertain.
So and that's why.
And then it's and that's exactly
the reason is that that the nanotubes
are not there yet.
So thanks for the question.
Number eight, please.
So high up here,
high up there.
You talked about that we have the
material to build a lunar
elevator, but not the Earth one.
So is it possible to make the Earth cable
just shorter and then use a rocket to
connect to the lower part of
the elevator?
That is true.
And you were invited
to give a talk next year about that.
Now, it's yeah, there's a whole
community out there about space tethers
and yes, there's options,
but there are sometimes risky because you
have to fly around the room at the end of
the cable.
And ESA even was involved in tether
experiments back in the 90s.
So, yes, there is a community out there
that makes it possible.
But the real benefit
that solves a lot of operational problem
is when you create a real
elevator that actually attaches to the
celestial celestial body.
I have a follow up question.
If you have a space tether, don't
you need fuel on board to reposition it,
otherwise it flies away or come back,
correct?
That is correct. And normally people
you'll ever solve that problem by making
a low thrust transfer using
solar electric propulsion or using
the Earth's magnetic field by putting
in electric power.
So there's all kinds of solutions for
that.
Oh, thanks.
Could we get No.6, please,
when you travel to the moon and the
obvious advantage of rocket space
transportation is that you can
more or less freely choose the point
of your landing.
So with that
space elevator concept, allow
to reposition the the
elevator so you can more
freely choose where you're going.
Yes, there is a paper that I'm citing
also in this talk by Pearson
in two thousand five or eight,
where they basically connect the elevator
to a tramway.
So they bend the elevator a bit to
higher latitudes and then starting from
that higher latitude points to a tramway.
But in any case, you can once you're on
the surface, you can drive.
I mean, oh, come on, take
your take you over.
Always drive and just go.
Or there's
more easy solutions to that then than
with a rocket. And you're right, with the
rocket, you can choose your landing site,
Frehley.
Could we get my number three, please?
Yes, I have a question about
the failure state and how it differs
from for Earth cable
and the moon cable.
So I would guess an
Earth cable would burn up in the
atmosphere. If something goes wrong,
what would it be for a moon cable?
So so first of all, the moon cable, if
it disconnects so that there
is one part coming back, it would just
impact the lunar surface and be destroyed
upon impact, normally with high
velocity impact to get a complete
obliteration of the material.
And about only 10 percent or even five
percent stay on the surface.
The rest goes into the solar wind.
But that that
doesn't have to take place.
You can always sever the cable on purpose
when you have a break.
And there are a couple of other things
are the reasons that I didn't explain in
my talk why potentially
you can make it so that the cable never
breaks.
Make number four, please.
I your slides that the
calculations about to Caban Wobble were
taken with elevator speeds of about
250 kilometers per hour,
calculating that the cable
from Earth would be about 150000
kilometers long.
I make that four point five weeks
around that.
So the whole transfer would
take multiple months.
Yes. Are there any plans on sending
humans up with that space elevator or
would it be like
cheaper because they're faster?
The only reason we have unmanned space
program is because you can you
cannot make small humans.
And and if you have a system that
is so capable, like the space elevator,
you would take humans from day one.
So. So, yes.
And they would just have the food for
four, five, five months.
OK, thank you.
You're welcome. Well, technically, we
have small humans, very small.
But
could we get another question from the
Internet place?
Yes. How about the vote that's generated
by the magnetic field of the elevator?
Would it be a risk or another source of
energy both
for the Earth elevator?
It could be a source of energy
or depending on the material you choose.
But for the moon elevator, there is no
voltage because there is no
global magnetic field around the moon.
Number eight, please.
You saved
a space elevator from Earth
is not possible with
materials. We know
what is about a launch
loop or.
Something a
so you talk about
you try to connect
both ends of cable
up to the earth and
oh, OK,
I haven't looked at that concept, never
heard of it, but thanks for the
inspiration.
I will look it up.
Launch love. You said, though, like they
have both hands on the earth and then
with centrifugal force you can.
Yeah, OK. The tension will probably be
the same. But let me let me
check it out. Sounds interesting.
Thank you.
Could we get number three, please?
Coming back to your question from
the beginning, whether we will see it as
in our lifetime or not.
Can you give an estimate,
maybe an optimistic or realistic estimate
on the time line?
How far is the research?
So. So if I was president
of the world will have it in 2050.
It really depends very much on the
decisions that are taken on a global
scale and these days just look at
the new US administration and some
movements here in Europe that are
detrimental to the efforts of gaining
more knowledge.
So but if we take the path of knowledge,
I'm pretty sure that will have more.
Well, yes, I plan to have a moon program
in the 20s, 30s, and the
moon village will be implemented
that Boehner will talk about.
I'm pretty sure we'll have a permanent
settlement on the moon somewhere in the
mid 20s, 30s.
And then and then the necessity
of having the efficient transport system
will force people to build a space
elevator. And that will be then
20, 50.
And I plan on being around
that long.
Make number four, please, on the
topic of focusing resources, so we
talked about the cost effectiveness of
rockets, but we didn't talk about
reusable rockets as push for
now by Elon Musk and SpaceX.
I was wondering if you could talk about
the cost effectiveness of reusable
rockets versus space elevators in terms
of focusing our resources that we have
currently.
Right. Great question.
Thank you. We know from Elon
that that rockets,
reusable rockets are about 30 percent
better than your reusable ones.
Right.
So that brings down anything
back to the moon from
10 million to nine
hundred
nine million seven hundred thousand
per kilogram.
So that's great.
But it's still rocket technology.
The space elevators are estimated to
lower that by a factor of 100.
Now, that includes the
initial investment, but
assuming that the initial
investment will be less than 10 percent
of the turnover.
So the turnover, of course, you have to
put a lot of
business in it to make it work.
And that's that's the problem with the
space elevator. If there is not enough
business for it to do, then
people will never engage in it.
Mike, number six, please,
so thanks for the talk.
And first, and so
from our talk, I guess that the
moon elevator is currently already
technically feasible or
suitable. So are there any plans or
what's the timeline?
The ESA has not it does not have
a space elevator program.
We have made a couple of experiments
with space tethers that were
quite successful and we have that in our
knowledge base.
The reason why ESA is not engaging in it
is because our task is to enable
research for our member states.
And research is
not the prime target of the space
elevator.
There is a space elevator consortium
and you will find something on the
for example here, the one that I showed
the lift part dotcom.
You will find that they have a timeline
in them and it's a private consortium
and their plan is to make a business
case for the space elevator.
OK, thanks, Mike.
Number two, please.
Thank you at first.
Thank you for the nice talk.
I have the question.
There's often the argument that we
shouldn't engage in human space travel
because of the costs and the risks.
And it's really, really
hard.
What would you give as an argument
against that?
So I'm in space business in 16
years, so I have answered that question
in a couple of times. So forgive me if I
feel a little bit superior at this stage.
So so first of all, the cost
is not tremendously high.
And don't forget, any euro that you put
in the space program does not go to
space.
The euro stays here.
And we've done a benefit analysis by ESA
that roughly for each euro invested by
our member states, they get five
euros back.
And I can tell you about the details
if you if you want.
The second thing is that that
space is right now we're looking at about
one percent or less than one, much less
than one percent of national spending.
So there is not a big part of
the national budget.
The third point about the risk is human
space flight risk is really only to the
astronauts.
And they have a contract that says you
have a risky job.
Are you ready to take that risk?
And they say, sure, go, go, go ahead.
And so that's the risk bit.
And that was it, right?
Yeah. As opposed to the point
that we can do it without
humans or people
tell me I'm not really behind
this.
Tell me we can do it without you.
And so why don't we try?
So I cannot exclude that possibility
that someday we will have intelligent
machines.
But I've tried to know I've
I've fooled a security camera
the other day by just having
my glasses, my shades hanging out
of my mouth.
Right. Not putting them on.
Just put them in your mouth.
No security camera will recognize your
face.
So so that tells
you there is not intelligent computers
today because the security sector has
billions and billions of euros
to spend on this stuff.
And like I said in my beginning
in 1972, there was an article which
said that there will be intelligent
robots very soon and
I am still waiting for them.
I'm sorry, but it could be there in 20
years. No, could be.
Thank you.
Could we get the Internet, please,
if this is a quite practical question,
however, to deploy and fix the cable.
Yeah, that's a brilliant question.
And I skip that in my talk and apologies
for that.
Thanks. And that's why the question
gives me an answer opportunity to answer
it. So the rocket would bring
roughly a hundred to a thousand
tongue cable to the libration
point to this stable point that I showed
before. And then from that point on,
the cable would be deployed at the same
rate upwards and downwards,
maintaining the center of gravity at that
stable point and doing a little bit of
station keeping, not too much.
And once deployed, it will stay there for
decades. So so then after
that you can launch another rocket, very
small one with a with the climber and fly
rendezvous, attach it and then it could
go up and down any time.
So it's really and I would
prefer that the person who has
asked the question also to the
space elevator, Vickki, that I'm
listening here on my links because there
is some information there.
Mike, number three, please.
I have two questions, the first one is,
how are we going to build the cable?
Is it are we transporting materials from
Earth to moon or are we going to mine
it from there? And the second question
is, how
are we going to build the cable?
Are we using, like, 3-D printers?
So so first part of the question,
both options exist so you can bring
everything from Earth there.
That's the more expensive way, but the
more safe way.
The other alternative is you bring a
small pilot cable and then you start
building strands of the cable and pull
it along the pilot cable up
and then make a thicker cable out of the
pilot cable through through a
that's cheaper and less risky one.
And a yes, footprinting printing is
definitely an option.
And I actually deleted one slide that
showed how the structure of the cable is
because I wanted more of your questions.
So I deleted slides.
So so
the the idea is to have like a
crisscrossing set of strands that would
allow the breakage of one strand
without the cable breaking, or you can
make it breakage of five strands without
breaking of the cable.
And by that way and also that would
allow then crews to go up
and fix the cable if there is a broken
strand that would go up, displace
the cable and then get the strand
out, put the insert
the new splice and pull a new
cable thing and adjust the tension on it.
Thanks.
Could we get number six, please?
Arthur C. Clarke have never
thought of paradise and where
you described the elevator
concept and they have many papers
written about this concept
to using hyperbolic
structures like all independent
oil drilling platform are using it also.
And I would like to know they have
already calculated an equation how much
how much time it takes
to lift up
a human being from Earth to
Earth and
the sea global space exploration
strategy.
This is because it looks like the
International Space Station will be up
until 2025.
At least the financing is
secured until then.
And what it will be after is
also possible to use his
S4 as a springboard,
as is often mentioned to the moon.
OK, you think so at three
parts, right? So, yes, an orphan of
paradise, a very good book.
And it's really about the economic and
socio economic impact of
a space elevator.
So that's very interesting things worth
mentioning that now the technical
solutions and discussions that are in
this book and Arthur C.
Clarke as an engineer
are very interesting.
And honestly, I haven't looked into them
so, so very much.
There is a lot of interesting solutions
there for the anchor point.
The second part of the question was about
the the travel time, and that
was answered by a colleague before.
So we're talking about months.
If you have a slow elevator, you can
speed it up. You know, you're in a vacuum
so you can go a thousand kilometers an
hour without too much damaging
your haircut.
So so that would work.
So cut it down from a couple of months to
a couple of weeks.
And the third question was the global
space exploration is the International
Space Exploration Coordination Group.
And thanks for that question, because
in that group, we're preparing the next
steps together with NASA, with Roscosmos,
with the Chinese space agency.
And the next step will very likely be
the creation of a
small staging outpost
in cislunar space.
Could we get microphone number one,
please?
Yeah, OK, thank you.
Two small questions.
The first ones might seem
a little naive, but once the elevator is
in place
to climb up the elevator, wouldn't that
apply a downward momentum?
How do you keep the edge of the rope in
place?
Right.
Yes, but it's so small
that the one ton
cabin you would have a
you would have a
thousand tonne cable, No.
Two ton the two ton climber
would have a thousand tonne cable
simply because of the math, how it works
out. And you can check the papers.
So the Sea Org would go a
little bit slower, lower, and you
can compensate that by a little bit of
motion below its
intricate. So the horizontal motion
by a mobile platform that travels
100 meters on the lunar surface can
compensate, can provide the
energy to
attach it.
Once you have attached to this
cabin, then it climbs
up and the COAG will approach again its
original state.
But these are menu changes and mainly
they they cause oscillations that didn't
have to be managed in horizontal mode.
OK, and the other question
was, say we managed
to build an elevator on the moon, but
the whole technical thing for the earth
just doesn't work out.
And so we are stuck with just an elevator
on the moon. Yes.
How useful would that actually be?
So so the usefulness of that
and get back to that image
is.
This so you cut to
the delta in half,
enabling reusable rockets going
to and from the moon, so it will be
about half as expensive as it is
today. So you cutting from 10 million
to five million?
Is that enough for our economy?
I don't know.
OK, so it would be better, but
it wouldn't solve the problem at
all. Exactly.
OK, thank you.
Number two, please.
So you talked about economy
and I wondered, is there any
concerns about who owns the moon
or may we face the next war on
resources in 2050?
That that there is a
there is a consensus officially by the
UN, which means that nobody can no
nation can own the moon.
And that includes, by the way, private
companies, because each private company
has to have its legal framework
set up by a nation.
But, of course, you know, things always
go different than the official
ways. And already now there
is a lot of discussion about who owns the
moon. And I think we'll have to wait for
the war.
Maybe that's a chance to occupy the moon.
Could we could we get a question from the
Internet?
Traveling from wooden back to Earth
via elevator, would you amend the U.S.
atmosphere to break or would you have to
have some propellant
you don't need either?
Because when you go down on the cable,
you will keep rotating with
Earth. So unless there is a high
altitude wind, there will be no friction
with the atmosphere.
So we would basically go that the air
would become ever denser.
As you go down.
Basically the first 100 for
the one hundred
forty or more than
one hundred thirty thousand, no
mass on stage is just terrible mental
mass on stage.
You should try it one day.
So.
So the first ninety nine point ninety
nine percent of the cable will be in
vacuum and then
the last bit, the last 30 kilometers.
So so you know, one hundred forty four
thousand minus 30, that's
30 kilometers.
You would be in the air and then you
would feel the air becoming thicker
and of course, high in the atmosphere.
You have some winds, you know, you have
the jet stream.
But at that stage, you will still be in
your little cabin until you reach about
3000 meters
when you can basically get off the lift
if you want.
One last question from number one.
Please make a chart if you can.
Of course. Thank you, Mr. President, for
the nice talk
of actually.
My question is quite similar to the one
from Mike to just now, but
not the question who would own the moon
but who would own the elevator?
Because if you're not the president
of the world, obviously
in space, things go far better together
than on Earth, like an ISIS
and something.
But due to the cost of the elevator,
what do you think? Will it be a public
project like with either NASA or will
it be something like SpaceX and private
investors?
That's a very interesting question.
My my pretty and I really
haven't thought this through,
but my answer would be very
likely it's going to be private because
the benefits are really intrapreneur
benefits by getting
material from the moon or building big
infrastructures in space that offer
services.
So so I would guess would be private.
And then your question is very relevant
because it's a huge, powerful
piece of infrastructure.
Is that even possible to have a private
entity owning it without
interfering with national interest and
national strategic interests?
Because in the end, you could bomb any
place on the Earth from that elevator
if you want. So perhaps some nations
are not very happy to have a private
company controlling this thing.
And that is a little bit also addressed
if you if you read Arthur C.
Clarke's Fountain of Paradise, because
then this whole problem becomes
very clear.
And I don't have a good answer for you.
Sorry.
Thank you.
So we are out of time.
Please thank our future president.