lunar space elevator infrastructure

Transcription

lunar space elevator infrastructure
Terasem Movement, Inc.
Journal of Geoethical Nanotechnology
Vol. 7, Iss. 2 (2012) 10 - 16
© Terasem Movement, Incorporated
www.TerasemCentral.org
LUNAR SPACE ELEVATOR INFRASTRUCTURE
CHARLES F. RADLEY
Systems Engineer, currently representing Liftport Group of Seattle, Washington.
cfrjlr@gmail.com
Toward establishing humanity beyond the Earth, Systems Engineer, Charles Radley,
emphasizes the development of space elevators as a manner of accessing and
transporting resources from the Moon, and possibly other planets, to Earth.
Keywords: Charles F. Radley, space elevator, Moon, Earth, Liftport, space
exploration, development, lunar, lagrange, centrifugal force, LSEI, orbit, EML1,
Yuri Artsunov, Konstantin Tsiolkovski, Sir Athur C, Clarke, terrestrial, carbon
nanotube, Lunar Laser Ranging Retrorefractor, LRRR, LSE, humanity, Martian,
Phobos, Deep Space Tether Pathfinder Project, DSTP, Stringsat, YES2, Kaguya,
Selene, Malapert Mountain, Shackleton Crater, Helium-3, Surveyor 4, Surveyor 6,
Sinus Medii, Delta IV, Zylon, NASA, solar, electric, propulsion, PicoGravity Lab,
Discovery Class mission.
“Sic Itur Ad Astra” ~ This way to the stars
I am on the Board of Advisors for the Liftport Group, a Space Elevator Company.
There has been much discussion in the last fifty years of space exploration using
megastructures; structures deployed in space, designed to facilitate our access to space
and our use of space resources. With current technology, these will be built of strings.
Liftport feel that the time is right to begin building and using these devices with existing
materials to quicken the pace of space exploration and development.
Why do we want to build a lunar elevator? It’s simple, greed for clean, green,
limitless energy. We can build solar powered satellites by using lunar resources and
foster space development to get humanity established beyond the Earth otherwise we face
global warming, a catastrophic problem on the Earth. Space elevators could one day lead
to positive, Star Trek-type scenarios.
A Lunar Space Elevator Infrastructure (LSEI) is a system built around a Ribbon
reaching from the surface of the lunar nearside, to substantially beyond the first EarthMoon Lagrange point (EML1). The large Earth-Moon distance means that, while the
dynamical forces are relatively small – to obtain sufficient tension – either a very long
Ribbon or a very large CounterWeight (CW) is required; one side of the Ribbon is
attached to the Lunar surface and the other side is kept taut by a CounterWeight. The
opposing force is the gravitational tidal force of the Earth, not rotational centrifugal
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force. Tidal force is balanced against the gravitational force of the Moon. The entire LSEI
is in a dynamically stable Earth-Moon orbit.
In the LSEI prototype, a small solar powered climber will be lowered to the lunar
surface; scientific instruments will be deployed and the climber loaded with surface
samples. The climber will then climb back to a sample return capsule, located at the EML
1 Lagrange point. The climber plus sample return capsule will be taken to a suitable
altitude above EML 1 for return to Earth. Sample return via the LSE requires no
expenditure of fuel.
Space elevators are a very interesting idea and we hope that it will get us to the
stars one day, but it’s not easy. Liftport is probably best known over the last ten years for
attempting to work on the terrestrial space elevator idea that was conceived by Yuri
Artsunov1 in Russia – actually, it goes back to Konstantin Tsiolkovski2 at the turn of the
20th century, but it’s been slowly refined by Yuri Artsunov in Russia and Jerome
Pearson3 in the U.S. in the 1970s and then it was popularized by Sir Arthur C. Clarke4 –
rest in peace. Liftport has been one of a number of groups working to promote space
elevators.
It’s obvious in hindsight, but building a terrestrial space elevator is very difficult
to do; the bottom line is, it cannot be done to date and we do not know when it can be
done. The materials that would be needed do not yet exist. Theoretically, carbon
nanotubes would be strong enough and light enough, but there is no process available for
building in sufficient lengths and quantities. Over the last ten years, the progress in
developing the technology has been proceeding at such a snail’s pace, that we’ve
basically decided to table the idea however, something that is very interesting to note, is
that we can actually build a lunar space elevator today! That’s a space elevator that would
go from the surface of the moon to a location stationary to the surface of the moon, and
that can be done with existing materials – actually four or five materials are strong
enough and light enough to do that; they’ve become available within the last several
years. That opens up some very interesting possibilities for developing lunar resources.
We are focusing on science directly related to monitoring, navigating or
controlling the elevator, including the Micro-Rover5 and the lunar sample return as proof
of concepts. We will use Lunar Laser Ranging Retroreflectors6 (LRRR) for navigation;
these also should provide solid science for decades after the landing. We are seeking
1
Artsutanov, Y. (1969). "Into the Cosmos without Rockets," Znanije-Sila 7, 25.
Tsiolkovski, K. E. (1895). Speculations of Earth and Sky, and On Vesta, (science fiction works). Moscow,
Izd-vo AN SSR, 1959.
3
Pearson, J. (1978). Lunar Anchored Satellite Test. AIAA Paper, 78-1427.
4
Clarke, A. C. (1979). The Fountains of Paradise. Harcourt Brace Jovanovich: New York.
5
Micro-Rover – “[A]n economical multi-dimension robotic tool that can be easily assembled, repaired, and
customized for interstellar missions.” Retrieved from http://robotics.nasa.gov/lmr/
6
Lunar Laser Ranging Retroreflector – “[A] series of corner-cube reflectors, which are a special type of
mirror with the property of always reflecting an incoming light beam back in the direction it came from.
Reflectors can be illuminated by laser beams aimed through large telescopes on Earth.” Retrieved from
http://www.lpi.usra.edu/lunar/missions/apollo/apollo_11/experiments/lrr/
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partners for science opportunities, both on the descent, with the CounterWeight, and with
the landing platform. What follows is what we see as some of the science opportunities
afforded by the LSE, and feel confident that others will emerge.
Once humanity begins to access resources of the moon and the asteroids in space
that introduces a lot of interesting legal questions. Another interim objective would be to
build a Martian space elevator – that’s harder to do than a lunar space elevator, but easier
than a terrestrial space elevator. The problem there is that the Martian moon, Phobos, gets
in the way, so the space elevator to the Moon would have to be anchored to the moon,
Phobos, which means it’d not synchronous with the Martian rotation. We have a plan that
involves the Deep Space Tether Pathfinder Project7 (DSTP), and then we have
incremental development plans involving what we call Stringsats in Earth Orbit. There
are various people that have already done these. The longest tether deployed in space so
far was the YES28 deployed to 31.7kilometers, a joint Russian/European space agency
mission that was remarkably successful and was accomplished through a budget of about
three million Euros.
This is a diagram of what the lunar elevator might look like. There are some
variations, but essentially, you see the Earth on the left, the Moon on the right – there’s a
location, approximately 200,000 miles from the earth and about 50,000 miles above the
surface of the Moon where the gravitational forces balance out, and that’s one of the so7
Deep Space Tether Pathfinder Project – “[A] tether, in space, of at least one megameter in length. Such
tethers are possible with current technology and offer the means for accelerating the exploration and
development of the solar system.” Eubanks, T.M. (2012). Sample Return from Shackleton Crater with the
Deep Space Tether Pathfinder (DSTP). 43rd Lunar and Planetary Science Conference. Retrieved from
http://www.lpi.usra.edu/meetings/lpsc2012/pdf/2870.pdf
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YES2 (Young Engineer’s Satellite 2) - “The YES programme offers a[n] opportunity for students,
professors and universities to jointly design and build real spaceflight hardware.” Retrieved from
http://www.esa.int/Education/Young_Engineers_Satellites/The_YES_programme
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Radley, C.F.
called Lagrange Libration points. The Lagrange point number one (there are five of them
that we know of), is gravitationally neutral, where the gravitational attraction of the
Moon and of the Earth balance out, so you can put a space station there and it will tend to
stay there and though it will drift somewhat, it will need a little bit of propellant to
maintain it there, but that is exactly the same problem commercial geosynchronous
satellites have today, it’s easily solvable, you just have to use a little bit of fuel for thrust
and that’s all you need. The tether is extremely long, about 250,000 kilometers; they
extend from the surface of the Moon through the L1 Station, to a counterweight, which is
extended about 80,000 miles above the surface of the Earth.
This system is very interesting because soft-landing payloads onto the surface of
the Moon using chemical rockets, which is the standard method, is extremely expensive.
This makes that process much cheaper. It’s not free, you still have to get from the surface
of the Earth to Earth’s orbit, but it reduces the cost by well over a factor of ten – it’s
actually more than that – and it will also reduce the cost of getting material to and from
the surface of the Moon, to Earth orbit, to essentially, zero.
This is an actual photograph from the Japanese Space Probe, Kaguya, (or Selene)
which means something like, Lunar Probe. The south pole of the Moon, two interesting
features, The Malapert Mountain, which is in permanent sunlight, and Shackleton Crater,
which is in permanent darkness. We are pretty certain there are large deposits of ice on
the surface in the Shackleton Crater –which is an interesting resource. There are many
resources on the Moon – one of my favorites is Helium-3. There is a huge demand for
Helium-3 on the Earth right now and there is a great shortage of it because the US
stockpile has basically been depleted. Sources of Helium-3 are now in short supply and
there’s a huge demand for neutron detectors – tens of millions of dollars per year is the
market.
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This is a scale picture of what a lunar elevator would look like. The lunar elevator
would attach to the surface of the Moon using what we call ‘Lawn Darts’. This is the
center of the Moons equator, what we call the zero longitude point (the center as seen
from Earth). Interestingly enough, an American space probe landed there in 1967,
Surveyor 6, landed very close to that spot, so we’ve got some pretty good data there.
Surveyor 4 attempted to land there, but we lost contact with it just a few seconds before
touchdown.
This is the view of Sinus Medii at the center of the Moon as seen from the
Surveyor 6 Probe in 1967. That’s a Flat-Mare area right there, which might be very good
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Radley, C.F.
for collecting Helium-3. Unfortunately, it’s quite a ways from the lunar poles, but we
have ideas on how to access it.
To make it clear, the Lunar Elevator will be very easy to build. All we need is a
single launch in a Delta IV Heavy, we need about 11,000 kilograms of Zylon9 thread,
which is commercially available, the cost of the thread is about twenty million dollars;
the cost of the launch would be about 500 million; and everything else would be about
another 500 million. The cost of the deployment system and the tether would be about
800 million. For that, we can get a system to deliver payloads of 100 kilograms, in a softlanding onto the lunar surface. It can also pull the same amount of payload off the lunar
surface. That’s pretty inexpensive compared to the rather expensive super boosters,
which NASA’s putting billions and billions of dollars into right now.
Liftport wants to be in the business of mega-structures and has been trying to
pitch this lunar idea to NASA, and they did fund a study with our partners, Star
Technology, a Jerome Pearson company in North Carolina. Liftport had a contract in the
early 2000s and then Jerome Pearson had another contract in 2005. This year, both
companies put a joint bid in to NASA, but it was declined, so there is no NASA funding
on this currently.
The DSTP is our precursor flight to LSEI, offering a way to get to the Moon at a
fraction. Liftport believes it’s the future of mega infrastructure development. It can be
done with the cost of a Discovery Class mission; it’s not too expensive and could become
man rated. These are some of the current products that Liftport is working on and are part
of our portfolio.
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Zylon fiber – “[A] super fiber with strength and modulus that almost doubles p-Aramid fiber. Zylon has
superior creep resistant to p-Aramid fibers and is very heat resistant, with a decomposition Temperature of
650°C (1202°F) and has extremely high flame resistance.” Retrieved from
http://csrbraids.com/index.php/zylon-fiber.html
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We plan to use solar electric propulsion to get the lunar elevator deployment
package kit from Earth orbit to the Moon. The Lagrange point is gravitationally balanced
so we can have what we call a ‘PicoGravity Lab’.
The DSTP and the LSEI offer a means of getting to the Moon again in an entirely
new fashion, using currently available technology. The DSTP is the linch-pin for all
future megastructure developments, and should provide a lunar sample return from a
currently inaccessible region. The LSEI would provide continuing access to the lunar
surface, plus sample returns and a lunar transportation infrastructure, for the cost of a
Discovery Class mission. While even a modest improvement in fiber technology would
bring substantial improvements in payload capacity, we do not require this. The DSTP
and the LSEI offer a path to a man-rated LSE and a Phobos-anchored Mars elevator.
This is Space 2.0: Space exploration for the 21st-century, not just an attempt to
repeat what was done forty years ago.
I encourage you to go to the Liftport site at www.Liftport.com as there are
interactive discussions ongoing in there as well as community forums where you may
post questions. Get involved; we do have many enthusiastic volunteers!
For Liftport film and social media
https://github.com/LiftportGroup/LiftPort/wiki
http://stars-space.com
http://youtube.com/elevatortospace
References
Artsutanov, Y. (1969). "Into the Cosmos without Rockets," Znanije-Sila 7, 25.
Clarke, A. C. (1979). The Fountains of Paradise. Harcourt Brace Jovanovich: New York.
43rd Lunar and Planetary Science Conference. Retrieved from
http://www.lpi.usra.edu/meetings/lpsc2012/pdf/2870.pdf
http://csrbraids.com/index.php/zylon-fiber.html
http://www.esa.int/Education/Young_Engineers_Satellites/The_YES_programm
http://www.lpi.usra.edu/lunar/missions/apollo/apollo_11/experiments/lrr/
http://robotics.nasa.gov/lmr/
Pearson, J. (1978). Lunar Anchored Satellite Test. AIAA Paper, 78-1427.
Tsiolkovski, K. E. (1959). Speculations of Earth and Sky, and On Vesta, (science fiction
works, 1895). Moscow: Izd-vo AN SSR.