Now that our colonies in space and on the moon are completed and functioning, we can turn our attention to our final entry into this diary series, in which we discuss various ideas for advanced colonization.
We will be discussing ideas that will make our foothold in space even stronger, and prepare us to go further into the solar system, and, quite possibly, beyond. We will even overcome the detrimental effects of weightlessness!
Each of the ideas that will be presented today have advantages and disadvantages. If the advantages outweigh the disadvantages, NMSTARG will recommend that the idea should be further explored. The same will be true for the reverse, i.e., if the disadvantges outweigh the advantages, then NMSTARG will not recommend a further study. Which is a long-winded way of saying that we wound up not recommending one of the items listed below.
These advanced systems are:
- Lunar Cycler: a space station that orbits the earth, where the high point of the elliptical orbit is at the Moon
- Habitat Wheel: The kind of space station depicted in old science fiction movies, such as "2001, A Space Odyssey"
- He-3 Energy Source: Fusion energy will power space stations and lunar bases
These systems will take a lot of effort and money. Of course, money really is not a problem, because we will be make a tidy profit from our space endeavors. The effort will be tremendous, and will require much a lot of time to complete.
But we're already in space, and enjoying the view. So we have all the time in the world.
Continued below the fold...
Advanced colonization means a population in space that is in the 4-digits. This will require larger and more frequent payloads going to LEO. We envision this vehicle to be a NextGen Skylon spacecraft.
Once such a vehicle starts flying, other advanced systems can be considered.
The concept of a cycler is both brilliant and simple (the very definition of brilliant?). It is a space station that, in this case, has such an elongated orbit around the Earth that the high point of the orbit (apoapsis) is at the Moon. The orbit would take about two weeks to complete.
Because the Moon orbits the Earth in about a month, the space station in this Earth orbit would be at the Moon every second orbit.
So all a rocket crammed full of passengers headed to the Moon has to do is to rendezvous and dock with this cycler during the second orbit, and ride the trip to the Moon in comfort. Nice.
It turns out that the delta V requirement are only slightly higher than what we are using now. The round trip is longer (14 days vs 10.5 days), but again, the passenger rides in comfort.
Disadvantages: Passenger service can only occur once a month. Want to make it two times a month? Then get two cyclers. Want to go 4 times a month? Get 4 cyclers. So, you want to go n times a month, you need n cyclers.
Each cycler also needs a steady diet of Logistics Modules. If the space station is as big as the LEOS, that means 4 Logistics Modules every 38 days. For each cycler!
This also means that remote-piloted vehicles would be better off not using the cycler, because it would take less fuel and less travel time to reach the Moon.
Therefore, we do not recommend this idea for immediate further study. We further recommend that the idea be studied as a possible science station more than a space hotel. We also recommend that the idea be seriously looked at again when a space wheel becomes available (see below).
This idea is as old as science fiction. It really is a natural solution to weightlessness that does not involve advanced technology. So it is inevitable that colonization will lead to spinning wheels. But the sound of inevitability can never be heard, because it occurs in space.
Aside from really advanced physics, the only sure-fire way to generate artificial gravity is by spinning.
The structure involved must therefore be very strong, and very large. Using the Spin Calculator, we find that the minimum radius of a spinning wheel is about 224 meters (735 feet), which is a diameter of over a quarter of a mile! We also see that the wheel must spin at less than 2 revolutions per minute. Any more, and the passengers would notice.
So, a fifteen hundred foot diameter wheel spinning in space at slightly less than 2 rpm will provide the crew a comfortable Earth-like gravitational environment that is virtually indistinguishable from Earth. Nice.
Now, for a space station that has a wheel width of, say, 30 meters (almost 100 feet), the floor space can be calculated.
Surface Area = 2 * pi * radius * wheel width
Surface Area = 2 * 3.141592653589793 * 224 m * 30 m = 42,223 m^2
So the floor area is 42,223 square meters, which is about 454,585 square feet, which is over 10 acres!
Of course, that's just one level. Several levels could be constructed, with each level containing 10 acres. Build 5 levels and there is now over 50 acres of prime real estate in space, along with free Earth gravity (shh, don't tell anyone it's artificial).
Constructing the wheel is going to be very difficult. The central hub would probably have to be built first, then the two sets of opposing arms built. The whole contraption can then be set spinning (look out for debris being flung off!). The ends can then be connected together in the same way a suspension bridge is constructed.
The location of this space wheel should be at L-5. We'll even call it O'Neill City! This location will provide the space wheel a fairly stable location that will need very little station-keeping capabilities.
A person located one-sixth of the way down from the hub of our spinning city would feel one-sixth gravity. We can use an Arthur C. Clarke trick and acclimatize people Earth-bound in this area. They can get used to Earth gravity slowly before actually going there.
The edge of a 1,500 ft wheel spinning at just under 2 RPM is about 0.047 kps (about 104 mph!). This will present a hazard to anyone working outside. Astronauts that "fall off" the space station will need to be rescued. We also can get a small boost from there as well for any rockets being launched.
One last point: with half the available acreage set aside, plants can be grown in abundance to feed any size colony, replenish the air, etc. In other words, the space station can be finally self-sustaining, in that it no longer needs Logistics Modules for resupply. Which is to say, it no longer needs Earth. The station will then become a true child of Earth, and like all children will constantly seek to break away.
We say this because with climate change the most disturbing issue facing humans since forever, and without anyone willing to provide gutsy solutions (absurdly enough, our current political climate forces us into inaction), there can be really only one solution to Earth's coming woes: escape. These space wheels could provide a refuge for the survivors of the ecological disaster that awaits us all.
Of course, if we can save ourselves in time (if that's indeed even possible), then our city becomes a bright shining example of how high and how far humans can climb on their way to the stars. Of course, this requires gutsy politicians making gutsy calls, but hey, stranger things have happened! So let's all root for this scenario.
We therefore highly recommend this idea for further study. The possibilities indeed seem endless.
He3, or Helium-3, is a product of the union of hydrogen and the solar wind. It is one of only two stable nuclides in existence where protons outnumber neutrons.
He-3 is also a natural in Aneutronic fusion, since the substance is not radioactive. The energized proton is contained simply by using magnetic fields. As the proton "bounces around" inside the magnetic field container, it interacts with the magnetic field, releasing enormous amounts of energy. Nice!
So, of course, it is exceedingly rare on planet Earth. However, it is of (relative) great abundance on the lunar surface. Mining operations, therefore, is fairly easy; just scoop up some dirt and throw it in a container. Once the He-3 has been extracted, fusion devices can be assembled and fired up.
Even though solar panels are an excellent way to generate electrical power, we believe that this type of fusion energy will one day be a better way to generate power. It is pretty much a clean energy source, and the lunar base will flourish as a result.
Of course, these fusion reactors will operate on Earth first, so we will harvest He-3 and export it there. Some envision He-3 reactors as the ultimate clean energy solution to Earth's climate change problem. We believe that the technology is too far away to be a viable solution in time to save the planet.
There does exist controversy in even the very concept of viable He-3 fusion energy. And certainly, government is operating in their usual petulant ways. Quoting Dr. Gerald Kulcinski, a professor of nuclear engineering at the University of Wisconsin-Madison (from the above-linked article):
“the Department of Energy will tell us, ‘We’ll make fusion work. But you’re never going to go back to the moon, and that’s the only way you’ll get massive amounts of helium-3. So forget it.’ Meanwhile, the NASA folks tell us, ‘We can get the helium-3. But you’ll never get fusion to work.’ So DOE doesn’t think NASA can do its job, NASA doesn’t think that DOE can do its job, and we’re in between trying to get the two to work together.”
So we'll let the science go through its due course. But it certainly seems promising enough to be worth a try.
We therefore highly recommend this idea for further study. It seem to be one of those too-good-to-be-true stories, but, it is worth the try.
Our journey is now complete; the last piece of the puzzle is now in place. We have discussed many things that seem disparate at first, but do come together in the end. It is like a great jigsaw puzzle, whose ragged edges seem to be chaotic and random, but actually provide clues to how they fit.
But seeing the picture that the completed puzzle has made necessitates that we step back a bit, so that we can see it in its entirety. The forest and the trees and all that. Stepping back a bit seems like going backwards, but, oh, the view! And what we can learn from this view.
Of course, that's a story for another day.
A version of this diary was cross-posted at NMSTARG.
The DKos diary series so far:
- History, Part I
- History, Part II
- Space Port
- Space Plane
- Space Stations
- Space Ships
- Recharge and Resupply
- Lunar Ships
- Lunar Base
- Lunar Propellant
- Clean Up
- Space Health
- Advanced Systems
FULL DISCLOSURE: I work for the New Mexico Space Technology Applications Research Group (NMSTARG), a commercial space flight venture, which in its current form exists as an unfinished technical paper. NMSTARG is not affiliated with any of the businesses that were discussed in these posting. These diaries exists as a way for the DKos community to get a first look at our research, and to ask said community for any technical and non-technical (just as important!) feedback. The paper provides information on how to make a profit in space, detailing the infrastructure that will be needed and all of the associated costs involved. As such, we hope that it eventually attracts the attention of investors, where the paper then becomes the technical portion of a space-related business plan.