Friday, July 20, 2007

Receive an MIT education for FREE!

For those of you who haven't heard about MIT's recent decision to host almost all of their class lessons online I am glad that you have stumbled upon this page. What MIT is doing is simply incredible. They now have over 1500 courses available online for free and they don't even require a registration. Most of the courses have notes, videos, quizzes and tests (plus answers), suggested or required readings, and assignments. MIT OpenCourseWare (OCW) is meant to be used by those who are currently studying material or who wish to remain up to date in their respective fields. But most commonly it is used by self-learners. So whatever category you fit into I highly recommend that you bookmark this site immediately. This is MIT's gift to the world, let's take advantage of it!

Check it out right now! MIT OpenCourseWare

For more information check out their FAQ's.

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Sunday, July 15, 2007

Colonization of Titan-- The Future Persian Gulf?

(Note: this is a continuation of the The Space Colonization Series)
In terms of potential locations in the outer solar system, Saturn's moon Titan is usually mentioned right off the bat. It is a prime location for human survival in the outer regions because of its great abundance of all the necessary organic materials. The atmosphere contains large amounts of methane and nitrogen and it is believed that both liquid water and liquid ammonia are locked under the surface and occasionally pushed out through volcanic activity. Water and methane could be used as both propellants for a rocket and for a colony's power supply. Nitrogen, methane, and ammonia could be used as a source of fertilizer for growing food. The water could also obviously be used for drinking and for oxygen.

Now, looking in an even more speculative nature, Titan would be a major target for a future fusion based economy. We will soon run out of oil on Earth and we will inevitably need to find another source of power. If we ever make a break through on fusion power we know we will need two things that aren't readily available on Earth: helium-3 and deuterium. Saturn has a relatively high amount of these resources available and Titan would be an ideal spot to mine and collect from.

True color image of Titan taken by Cassini. More images of Titan from NASA.

The Cold, Hard Facts

True color image of Titan Surface taken by Huygens. More information from NASA.
Titan is cold. Really, really cold. The temperature is about -180 degrees Celsius. This type of cold also isn't quite as easy to deal with as the cold we would encounter in space or on the Moon. No, Titan's thick atmosphere makes this very difficult. Thermo-insulation becomes a much bigger problem. Fortunately, this problem could potentially be solved be building a protective layer around a habitat. By evacuating a space in between an outer shell and the inner habitat heat loss could be lowered to a more manageable level akin to a lunar habitat's requirements for thermal insulation.

The thick atmosphere does provide some advantages, however. At about 1.47 times the atmospheric pressure of Earth--equivalent to 5 meters under water on Earth--the atmosphere would protect inhabitants from potentially deadly doses of radiation that would be of concern on outposts on Mars, the Moon, or the asteroids. The quality of Titan's atmosphere also greatly decreases the engineering complexity of any aerobraking and landing techniques.

At least one more advantage exists for its atmosphere when combined with Titan's relatively low gravity of 0.14 g's. This unique combination makes flying much easier. So much easier, in fact, that a human could simply strap on some wings and take flight (with a pressurized suit on of course). Other than for human enjoyment and recreation, easier flight requirements could be taken advantage of for more near-term, exploratory missions like sending probes that float around the atmosphere in blimps, hot air balloons, or autonomous planes. Alas, like the atmosphere of Titan, the low gravity also has its disadvantages. Namely the health problems associated with low-g environments.

Personally, I believe Titan will never be more than a mining or research outpost but who knows? Perhaps it could some day be terraformed and become a bastion for thousands or even millions of colonists in the future. It does, after all, contain an abundant amount of the necessary organic materials needed for life as we know it. What do you think? Could you see Titan in our future?

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at 2:28 PM 17 comments Category: , , , ,

Thursday, July 5, 2007

Great Space Quotes

"The earth is the cradle of humankind, but one cannot live in the cradle forever."
This is the quote that I keep at the top of every page on my Space Monitor blog. Konstantin Tsiolkovsky's words provide perhaps the best, most succinct way of describing my purpose for writing this blog. There are many other great quotes out there, though many not quite as short as Tsiolkovsky's, and I would like to share with you all a list of some of my favorite. I encourage any readers out there to submit any of their favorite quotes or perhaps one of their own and I will gladly add them to this list. In the meantime I hope you enjoy the ones I have provided for you.

Here's my list:

"The earth is the cradle of humankind, but one cannot live in the cradle forever."
—Konstantin Tsiolkovsky

"Don't tell me that man doesn't belong out there. Man belongs wherever he wants to go - and he'll do plenty well when he gets there."
— Dr. Wernher von Braun, in 'Time' magazine, 17 February 1958

"Earth is too small a basket for mankind to keep all its eggs in.
— Robert A. Heinlein

"Since, in the long run, every planetary civilization will be endangered by impacts from space, every surviving civilization is obliged to become spacefaring--not because of exploratory or romantic zeal, but for the most practical reason imaginable: staying alive... If our long-term survival is at stake, we have a basic responsibility to our species to venture to other worlds."
— Carl Sagan, Pale Blue Dot, 1994

"I don't think the human race will survive the next thousand years, unless we spread into space. There are too many accidents that can befall life on a single planet. But I'm an optimist. We will reach out to the stars."
— Stephen Hawking, interview with Daily Telegraph, 2001

"The dinosaurs became extinct because they didn't have a space program. And if we become extinct because we don't have a space program, it'll serve us right!"
— Larry Nevin

"Remember this: once the human race is established on more than one planet and especially, in more than one solar system, there is no way now imaginable to kill off the human race."
— Robert A. Heinlein

"People who view industrialization as a source of the Earth's troubles, its pollution, and the desecration of its surface, can only advocate that we give it up. This is something that we can't do; we have the tiger by the tail. We have 4.5 billion people on Earth. We can't support that many unless we're industrialized and technologically advanced. So, the idea is not to get rid of industrialization but to move it somewhere else. If we can move it a few thousand miles into space, we still have it, but not on Earth. Earth can then become a world of parks, farms, and wilderness without giving up the benefits of industrialization."
— Isaac Asimov, speech at Rutgers University

"As I stand out here in the wonders of the unknown at Hadley, I sort of realize there's a fundamental truth to our nature, Man must explore . . . and this is exploration at its greatest."
— Dave Scott, Commander Apollo 15, upon becoming the 7th man to walk on the Moon, 31 July 1971.

"It [the rocket] will free man from his remaining chains, the chains of gravity which still tie him to this planet. It will open to him the gates of heaven."
— Wernher von Braun

"God has no intention of setting a limit to the efforts of man to conquer space."
— Pope Pius XII

"When I orbited the Earth in a spaceship, I saw for the first time how beautiful our planet is. Mankind, let us preserve and increase this beauty, and not destroy it!"
— Yuri Gagarin

"Astronomy compels the soul to look upward, and leads us from this world to another."
— Plato, 'The Republic,' 342 B.C.

"... the United States was not built by those who waited and rested and wished to look behind them. This country was conquered by those who moved forward, and so will space."
— President John F. Kennedy

"But why, some say, the Moon? Why choose this as our goal? And they may well ask, why climb the highest mountain? Why, 35 years ago, fly the Atlantic? Why does Rice play Texas?"
— President John F. Kennedy

"It's human nature to stretch, to go, to see, to understand. Exploration is not a choice, really; it's an imperative."
— Michael Collins

"To go places and do things that have never been done before - that's what living is all about."
— Michael Collins

"To confine our attention to terrestrial matters would be to limit the human spirit."
— Stephen Hawking

"When you look at the stars and the galaxy, you feel you are not just from any particular piece of land, but from the solar system."
— Laurel Clark

"It's time for the human race to enter the solar system."
— Dan Quayle

"For me the singe overarching goal of human space flight is the human settlement of the solar system . . . no greater purpose is possible."
— Mike Griffin, NASA administrator, Congressional testimony 2004

"The regret on our side is, they used to say years ago, we are reading about you in science class. Now they say, we are reading about you in history class."
— Neil Armstrong, July 1999

"Many say exploration is part of our destiny, but it's actually our duty to future generations and their quest to ensure the survival of the human species."
— Buzz Aldrin, on the 37th Anniversary of the Apollo 11 Landing, July 2006

Reader Submissions:

"Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe."
— Albert Einstein

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Tuesday, July 3, 2007

Colonizing Mercury

(Note: this is a continuation of the The Space Colonization Series)
I'll be honest; a colony on Mercury is out there--waaay out there. Many would naturally assume that Mercury could never be colonized or that even if we could it would be highly impractical. Right now I would most definitely agree with that statement but, in the future, as we expand our horizons and colonize our solar system that first rock from the sun may prove to be one of the key locations for supporting a space-fairing civilization.


What Does Mercury Have to Offer?
Image of Mercury orbiting around the Sun. Source: NASA.gov
Quite a few benefits actually. One of the biggest is solar energy. The close proximity to the sun could allow for Mercury to be a potential location for harvesting solar energy. The solar constant near Mercury is 9.13 kW/m² or 6.5 times that of the Earth or Moon. Now, with this extra energy it would be possible to power mass drivers (similar to a maglev launch system) and launch folded up solar sails carrying any sort of cargo or mined resources from the planet. Once deployed into space and unfolded, the solar sail would receive an added boost from the stronger solar constant--6.5 times the thrust to be specific. Mercury could also be used as the starting point for either interstellar travel or simply travel into the outer solar system using the added solar boost to speed the process along.

Launching mined materials from the planet could prove to be lucratively advantageous considering the composition of it. Mercury is the second most dense planet (behind Earth). As a result it indicates that anywhere from 60-70% (by weight) of the planet is composed of metals with the rest primarily being silicate. In addition, it is theorized that Mercury may have some of the highest concentrations of several valuable minerals and metals of any surface in our solar system and in extremely concentrated ores on top of that. Other predictions include the possibility of the soil containing a large quantity of helium-3--an essential ingredient in a future fusion power plant.

Lastly, due to Mercury's prime location near the Sun, it could provide an excellent site for monitoring solar activity. A base could warn any traveling ships, other various colonies, or even Earth that a solar flare is approaching or a burst of solar radiation could make a certain area dangerous for the time being. A constant close-up watch of the Sun would definitely help us learn more about it and perhaps allow us to forecast any solar activity. Learning more about the Sun is definitely important and Mercury is the closest place to it.

How Could it be Done?

Colonizing and creating the necessary infrastructure would likely be both very difficult and very dangerous. This is not to say that it can't be done though. Long days (176 Earth days), no real atmosphere, and a lack of organic materials/elements requiring importation make it difficult but not impossible. This is because of the relatively static climate of the polar regions. It would avoid the extreme variations of temperature that are hot enough to melt lead during the daytime and the nighttime bone-chilling lows of -180 degrees Celsius. In fact, the polar regions may also harbor the ever essential water-ice in permanently shaded regions inside craters.
Magnetic field of Mercury. Source: NASA.gov
Mercury even limits a couple of other major, ubiquitous problems involved in space exploration and colonization. Perhaps its most important advantage towards allowing for a habitat is its magnetic field. Though only about 1% of the strength of Earth's own magnetic field, Mercury's field deflects solar wind about 1000 km from the surface and this may be more than enough protection for colonists. The strength of Mercury's gravity is also another asset that places like the Moon or asteroids can't provide. At about .377 g's, Mercury has twice the gravity of the Moon and approximately equal to that of Mars. This is especially important because some scientists believe that .33 g's is all that is necessary to be acceptable to the human body over an extended period.

As a colony establishes itself the non-polar regions of the planet may end up providing more room for habitats and mining operations. Underground bases could potentially insulate itself from the extreme temperatures on the surface above. Traveling outside of the underground base could easily be accomplished during times of twilight. Due to the planet's very slow rotational period the window of time for exiting or exploring the surface would also likely be significant.

In the end I do believe that the colonization of Mercury is inevitable. Whether it is used to support some lucrative mining operation, outsource power, be the starting point of journeys to the outer solar system and beyond, manufacture anti-matter with fusion reactors, as a futuristic Alcatraz/Australia, or some combination of all them, it definitely holds a future and purpose for mankind. How long that is before it is I can't answer you but, regardless, it's still fun to imagine it. Personally, I think it would just be fun to watch a giant sun rise above the horizon during the Mercurian morning. What do you guys think?


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at 5:07 PM 14 comments Category: , , , ,

Sunday, July 1, 2007

The Space Colonization Series

UPDATE 1 (July 15, 2007):. Four articles have now been completed with Titan being the most recent.

UPDATE 2 (July 15, 2007): from the suggestion from a reader I have decided to add a Space Habitat on my to do list. I plan on this one being one of the most extensive if not the most extensive article that I write on space colonization.


Having already completed articles on ways to colonize Venus and the Moon and also having already received a suggestion for writing about colonizing Mercury, I have decided to do an entire 'Colonization Series.' I plan on writing articles about five or six more potential sites for colonization (including Mercury). I may also eventually write an editorial covering humankind's reason to colonize space. So, I hope I give you all something to look forward to!

Here is the complete list of colonization options I plan on writing about (completed articles are linked in blue):

Also, if anyone has any suggestions or would like to see an article on perhaps another potential location for colonization I encourage you to speak up. Or, just anything space related that you believe would be appropriate/interesting.

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Saturday, June 30, 2007

Genesis II- Updates from Bigelow Aerospace

See original announcement of the successful Genesis II launch.

Las Vegas, NV 06/28/07 – Bigelow Aerospace has established contact with its second pathfinder spacecraft, Genesis II. Launched earlier Thursday from Yasny, Russia, Mission Control in North Las Vegas, Nev., made first contact at 2:20 p.m. PDT. Continue Reading...

Image taken outside of Genesis II. Source: BigelowAerospace.com

Not only has it made first contact already but it has also confirmed that it is successfully expanded and functioning correctly. During the past two days it was also able to send back some pictures of inside and outside of the module. (Two are on this page; the rest can be seen here). In the image of the inside you can see pictures of items that people paid to have sent into space through the "Fly Your Stuff" program. Also, in the coming weeks, Genesis 2 will start up its Bingo in Space game.

Difference Between Genesis I and Genesis II
Inside of inflated module; photos from
"Fly Your Stuff" program visible. Source: BigelowAerospace.com
Though identical in size and appearance on the outside--approximately 15 feet (4.4 meters) in length and 6.2 feet (1.9 meters) in diameter at launch, expanding to 2.54 meters (eight feet) in diameter after expansion in orbit--the two crafts differ substantially on the inside. One of the biggest upgrades has been the number, quality, and type of cameras on board. The Genesis 2 has 22 cameras compared to Genesis 1's 13. There are articulated cameras using dual FireWire and Ethernet camera interfaces and also a wireless camera for more exterior images.

Inside, sensors have been greatly improved with the addition of extra pressure, temperature, attitude control, and radiation detection sensors. With the added devices the craft will be sending back much more information in order to better characterize the low Earth orbit to prepare for an eventual manned spacecraft. The new improvements to the equipment will also help with the new habitat on board. Air and water-handling control systems, environmental sensors along with robotic manipulators are a part of the new additions aiding in preparation for the eventual accommodation of larger life systems.

The Genesis 2 also used a multi-tank inflation system as opposed to the single-tank method used on the previous Genesis. The multi-tank design increases the reliability of the inflation process and is testing methods for using multiple gas supplies that will be needed for future manned vehicles. Lastly, on the exterior, extra layers have been added to the outer shield in order to aid against micro-meteoroid damage and thermal management.
...
It's truly amazing that Bigelow Aerospace has encountered almost no problems during their launch and deployment of their first two spacecraft. If this is any indication of the kind of success they will have with future manned vehicles it's difficult not to get excited and even harder not to be able to imagine a big demand for jumping on board Bigelow's inflatable space hotel modules. All I can say is that the future of Bigelow Aerospace looks incredibly promising right now and that I can't wait to see what they unveil next.

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at 8:39 PM 7 comments Category: , , , ,

Thursday, June 28, 2007

"Genesis I is About to Have Company"

Note: Information on Genesis II has been updated.

Las Vegas, NV 06/28/07 – Genesis II, the second experimental pathfinder spacecraft by Bigelow Aerospace, has been successfully launched and inserted into orbit. The privately-funded space station module was launched atop a Dnepr rocket at 8:02 a.m. PDT from the ISC Kosmotras Yasny Cosmodrome located in the Orenburg region of Russia. Read More...
A Russian Dnepr rocket used for launching Genesis 2.
Actual photo is from the Genesis 1 launch. Source: BigelowAerospace.com
Just like its predecessor Genesis 1, Genesis 2 has also completed a successful launch into orbit. Barring any major mishaps during its deployment in space, the successful completion of this mission puts Bigelow Aerospace one step closer to launching a 'crew rated' spacecraft. The completion of Genesis 2 marks the halfway point to achieving this goal. Next in line is an entirely new model called Galaxy. Galaxy will have 45% more habitable space (16.7 cubic meters) than the two Genesis crafts. Bigelow plans to launch this sometime next year.

Following Galaxy is the Sundancer. The Sundancer will be the first 'crew rated' craft and is expected to be up and flying sometime in 2010. At a volume of 180 cubic meters, the craft will considerably dwarf all previous models and contain enough room for a crew of three. Once established in orbit, a connecting node and propulsion system is expected to be added in 2011 in preparation for Bigelow's final step in creating the first space hotel. The additions will eventually allow for the BA 330 module, a 330 cubic meter habitable volume craft, to dock with the Sundancer. Bigelow won't be wasting any time seeing as the two are to connect by 2012.

To compare the size of all of the planned (and current) modules the Bigelow Aerospace website has posted a growth chart. It really puts into perspective just how large this orbiting hotel will be.

With the launch of Genesis I and II, I believe we are in the midst of a very exciting time period that is about to unfold. Bigelow Aerospace corporate counsel Mike Gold, who was there to witness the launch, gave one of the best analogies describing this monumental moment in the private space industry. "With Genesis 1 we put one foot ahead of us. With Genesis 2 we put another foot ahead of us which means that we're walking," said Gold. "I look forward to running and what that's going to be like at Bigelow Aerospace."

The Bigelow Aerospace website will be posting updates soon as more information comes in once Genesis 2 passes over a SpaceQuest ground station in Fairfax, Virginia. Once they do I will soon likewise update with more information over their updates and the Genesis II module in general. Plus, I will definitely provide you all with some personal insight on the whole situation.

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Friday, June 22, 2007

New Player in the Game: European Aeronautic Defence and Space Company- Astrium

Inside of space jet cabin. Source: EADS.net
It seems that Richard Branson and Virgin Galactic are going to have some serious direct competition in the near future. The European Aeronautic Defence and Space Company, or EADS for short, has recently announced its plans to enter the suborbital space tourism race [see announcement]. The project leader, Marc Newsome, has said that they would like to begin the project in 2008 and if they are able to do so then a first commercial flight would possibly be available by 2012. Marc Newsome will be in charge of designing the interior cabin which is said to have "highly innovative seats [that will] balance themselves to minimize the effects of acceleration and deceleration, ensuring the greatest passenger comfort and safety." The Australian born designer has been named by Time Magazine as one of the 100 most influential people in the world. As Creative Director of Qantas Airways, he has also been responsible for the design of their entire fleet including the Airbus A380 and I can say from personal experience that Qantas has, by far, been the best airline with which I have traveled.

Space jet floating in suborbital space. Source: EADS.net
The Flight

The flight will consist of two stages on a space jet comparable to a business jet sized vehicle and will carry four passengers. The space jet will take off from a conventional airport and normal jet engines will carry the craft to an altitude of 12 km when the rocket engines will be ignited. In a mere 80 seconds the rockets will have propelled the space jet all the way up to an altitude of 60 km. The ship will receive enough boost from the rockets to lift it to its peak altitude of 100 km where it will hover weightlessly for 3 minutes and give tourists an incredible view of the Earth. Passengers will get plenty of opportunity to catch a view with the 15 windows, each 30% bigger than a standard jet window. The jet will then make its descent slowly until the jet engines can safely be initiated. The jet will then land at a standard airfield. In total, the entire trip will last between an hour and an hour and a half.

Below is the promotional video of a flight from EADS Astrium:


Financing

Estimated to cost around one billion euros, the project will largely be supported by private capital. Return on investment will from the emerging and very promising suborbital space tourism market. Astrium says that the price per ticket could be anywhere from €150,000 to €200,000. Following five years of operation, EADS Astrium hopes to have claimed 30% of the space tourism market.

...

It seems that the private space industry is growing at an ever faster pace. I can only hope that this is just the beginning. My guess is that we will witness several other companies make announcements about entering the great private space race before 2012--especially if Virgin Galactic's SpaceShipOne and Bigewlow Aerospace's space hotels take-off (no pun intended). I do believe we are at the start of an exciting time period here.

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at 2:55 PM 1 comments Category: , , , ,

Monday, June 18, 2007

Lunar Dirt Factories? A look at how regolith could be the key to permanent outposts on the moon!

(Note: this is a part of The Space Colonization Series)
The lunar regolith, or the powdery soil on the surface of the moon, is best known for the havoc it wreaked on the astronauts and equipment during the Apollo missions. Regolith was seen as one of the biggest hurdles for any trip to the moon but now it is being seen as possibly one of the biggest advantages for a permanent establishment.

A Little Background on the Lunar Soil...

Microscopic view of Lunar Regolith. Courtesy: CAS.USF.edu
Regolith, by definition, is the unconsolidated, fragmented material covering a solid surface. On earth regolith is our dirt or soil, hence the term "lunar soil." On the Moon regolith covers almost the entire surface. It is typically 4-5 meters thick in the dark, basaltic regions and anywhere from 10-15 meters deep in other areas. The creation of the lunar soil has been the culmination of a 4.6 billion year process involving the smashing of meteoroids onto the surface that have been in turn broken apart by micrometeoroids and further more by various charged particles traveling through space.

More importantly though, are the composition and properties of the regolith. This is where all the key advantages come into play. In most of the lunar regolith, roughly half of the particles are made of small portions of minerals fused by silica. Also, depending on the location, many of the minerals are rich in metallic iron. This particular combination of glass and metal amounts to some very unique properties.


A Diamond in the Rough?

Larry Taylor, Distinguished Professor of Planetary Sciences at the University of Tennessee, may have stumbled onto the answer serendipitously due to a quirky habit. In his words "[He's] one of those weird people who like to stick things in ordinary kitchen microwave ovens to see what happens." Dr. Taylor, armed with a small pile of lunar soil brought back by the Apollo astronauts, decided to appease his habit. He found that at mere 250 Watts he could melt the entire sample in less than 30 seconds.

The reasoning behind the incredibly easy method of melting the regolith has to do with the nano-scale iron beads that were embedded into the silica by micrometeorites. The micrometeorites, traveling at very high velocities, melt the silica into glass as the penetrate the soil and various lunar rocks. Still inside the glass they formed, the iron beads are then able to concentrate the microwaves so effectively that they turn a complex process of heating the rocks to temperatures of over 1000 degrees Celsius into one as simple as popping a bag of popcorn. In fact, taking the dirt out of the microwave and into a more 'scientific' setting where a single magnetron was focused onto a sample showed just how efficient this process is. Professor Taylor said, “With 50 watts of energy I took a one-centimeter block of lunar soil to 1700 degrees Celsius (3100°F) in 10 seconds.”

Sketch of Microwave "Lawnmower" made by Prof. Taylor. Courtesy: NASA.gov
The observation of this property has incredible implications. Dr. Taylor proposes a microwave 'lawnmower' that could make continuous brick down half a meter and leave a top layer of glass an inch or two deep to surface a lunar highway, a runway for incoming shuttles, or simply a launch pad for rockets. "Or," as he says, "say that you want a radio telescope. Find a round crater and run a little microwave 'lawnmower' up and down the crater's sides to sinter a smooth surface. Hang an antenna from the middle--voila, instant Arecibo!" (Arecibo is a massive 305-meter-diameter radio telescope created out of a natural circular valley in Puerto Rico). The ability to create solid surfaces eliminates many of the problems a lunar colony would face in one fell swoop. The only way for lunar dust to clog the equipment and spacesuits like it did to those in the Apollo missions is to kick it up by driving or walking through it or to send it flying everywhere with the exhaust of some rocket. But with a path to travel, land, and launch on and obviously no worries of wind you no longer have the concern of dust problems!

Other than solving the dust problem, that the regolith itself creates, it could also potentially solve two more major problems: oxygen and radiation. Naturally a manned outpost would require a breathable atmosphere but oxygen could also provide a valuable source of fuel. So, how can regolith glean more oxygen? Larry Clark, a senior manager and engineer at Lockheed Martin in Colorado, has been working on that very problem for over 15 years. Clark's lab has produced a prototype that uses the method of hydrogen reduction to extract the oxygen. The process runs at relatively cool temperatures between 1300 and 1600 degrees Fahrenheit but, unfortunately, is only primarily able to extract oxygen from iron oxides--a tenth of the total oxygen available. Though the yield is a fraction of what is possible, Clark predicts that a full scale factory of his prototype could garner enough oxygen for 3-4 astronauts for a year. Plus, if we were to establish the infrastructure for such a factory and store oxygen in inflatable containers prior to sending humans their we could potentially allow for more 'colonists' or for a more extended stay.

Beyond Clark's current viable method, a possible combination of microwaving the regolith into a molten state and using electrolysis could vastly improve oxygen extraction capabilities. Though very promising, this method would have to overcome some serious difficulties with containment and also the gathering of enough energy to power the electrolysis. Even if none of these ideas happen to pan out there is still always the possibility of water-ice sitting on the poles that could be harvested for oxygen or needless to say, water. And lastly we always have the option of simply bringing our own supply!

Concept art of an inflatable module for a lunar base. Courtesy: NASA.gov
Regolith could also be the answer to the ever-omnipresent problem of radiation. The Apollo astronauts were able to avoid this problem by making their visit a short one but those looking for longterm or even a permanent settlement can't quite run from this problem the same way; they can, however hide. Using the lunar soil to protect an outpost has been long suggested because of its availability and ability to effectively block radiation but other than clumping massive amounts of dirt on top of a habitat--a logistical nightmare--nothing has been considered practical. Even the simple idea of using lunar 'sandbags' faces many of the same difficulties as the mound idea. Ideas of building bricks out of the dirt were thrown around and tested but the process of sintering them was also found to be impractical. Impractical, that is, until now. Imagine a microwave factory that melts harvested regolith into casts and molds it into usable bricks among other construction materials. Not only are the bricks able to be used for sheltering an outpost in a safe and uniform manner but they are also able to be easily modified whenever a new attachment is to be added to the habitat. Another benefit is that the walls don't need to be nearly as thick to provide protection from the radiation because of their higher density.


The Future of Regolith

This observation is simply the beginning of what will require much more research. No one can be sure that the regolith will react the same way to microwaves on the moon as it does when subjected to our atmosphere. Further research on the lunar soil will be difficult and inexact. Due to the scarcity of lunar soil many simulant soils have been created but all have come far short of mimicking the real, unique properties of the Apollo samples. Even the actual samples collected from the moon aren't wholly representative. The handling and splitting of samples has caused them to lose a significant amount of the solar wind particles that have been embedded in them. In order to continue this very important research we will likely need to bring back more samples or possibly even conduct the experiments on-site.

But, for now, we can work on the fun part: thinking of uses for the regolith's capabilities. Everything from lawnmowers, brick factories, oxygen extraction, roads, launch pads, and radio telescopes has been discussed. The only limit to it's capabilities is our imagination. So, I'd like to hear what you can imagine. I will post ideas as either you submit them or I come up with them on my own.


List of Ideas for Use of Regolith:

  • Post 1 (nick)- Harvest thermal energy from molten regolith.
  • Me- Create a 'lunar-rail' by microwaving tracks then use tracks to transport dirt mined, research equipment, people, etc.
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Tuesday, June 5, 2007

Why Mine the Asteroid Belt?

I had never honestly considered this question before until I read the article "A Billion Tons of Nickel" by Chad Orzel (In case you were wondering his article was inspired by a previous article of mine: A Floating City on Venus). The author brings up a good point: What advantage would mining the asteroid belt really have? After reading his article I honestly could not come up with a reason off the top of my head. I had just assumed it would be a great thing that one would jump at the opportunity to take advantage of.

He made an excellent point questioning the economic viability of such a mining operation:

Absent some project that requires vast quantities of whatever you can mine out of the rock, the main effect of this would seem to be a global crash in the price of whatever you can mine out of the rock. At which point, I don't know how your recoup your investment. This is barely Economics 101-- if you have a billion tons of nickel sitting around, and nothing to do with it, the price will be very low. We've done the experiment, after all-- ask the Spanish about all that New World gold...
Frustrated that I could not find a good answer quickly enough I decided to a little research and here is what I came up with:

He's absolutely correct. Though the article is missing the true incentive to asteroid mining. The key to asteroids are that they have a relatively high proportion of precious metals such as platinum and those in the platinum group. On top of that they also contain many other metals in high demand such as aluminum, copper, and titanium among many others. Here is a chart of the approximate composition of a C-type (Carbonaceous) asteroid (including potential values per metric ton in dollars). According to the chart platinum contains roughly 1,000 parts per billion in a typical C-type asteroid. This equates to about 2,000 metric tons in a one kilometer diameter asteroid or approximately $50 billion worth of platinum. Albeit the price of the metal would drop as more metal is introduced into the market but nowhere near the catastrophic affect that Chad proposes with the mining of nickel. This is simply because platinum is in very high demand and an exorbitant amount isn't being introduced. The other metals I mention could also conceivably be very profitable though likely not to the same extent.

Image of C-type asteroid 253 Mathilde. Source: NASA.gov

Now the situation he describes with the introduction of Aztec gold is a bit different than platinum. During that time gold was primarily sought after for its beauty and luster alone. Platinum on the other hand is used in jewelery and industry--especially in electronics. This should further resist a collapse in the metal's economy and perhaps increase the economy overall. Even a drastic price drop in platinum wouldn't be so bad. One can simply look at the history of aluminum. Aluminum used to be worth more in weight than gold. Then in 1886 a young engineer from Oberlin, Ohio named Charles Martin Hall invented a new method of extracting aluminum that eventually made it cheaper to obtain by a factor of 200. Clearly the economy wasn't ruined by an over-abundance of aluminum. This is because aluminum was rare in pure form but had many potential uses. The case is very similar for platinum.

At the end of his article he also left us with this:
(And circular arguments like "We need a billion tons of nickel to build space ships to mine the asteroids/ colonize the moons of Jupiter/ fly to Alpha Centauri" are cheating.)
And though the space enthusiast in me really wanted to justify mining the asteroids with this I knew he was correct; we have to be realistic and know how the world works. I believe I've addressed the incentive to mine the asteroids without using this cheating circular argument though. Thus since we have created a market for going to the asteroid belt we can now fairly use this argument! Because with the advent of mining operations we will indeed create a whole new 'space market.' Sending materials up into space is costly (currently around $12 million per metric ton). This means that billion tons of nickel now has a new purpose--building those spaceships to mine the asteroids. So, while gleaning materials to build ships that can mine the asteroid belt or to build colonies is not the initial reason to mine the asteroid belt it is a natural progression and soon does become an incentive in itself.

For more information on the potential of mining asteroids I suggest reading through these two sites:

Asteroid Mining for Profit (chart came from this site)
and
PERMANENT

Also, if anyone has any counter-arguments or questions I would definitely like to hear them. I tried to stick to the main points to maintain the brevity of this post so I'm sure there is still much to discuss if anyone is interested.

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at 10:43 PM 16 comments Category: ,

Monday, May 14, 2007

Copy of PDF file

Sorry about the formatting, I'll try to make it more readable later, when I have the time. [UPDATE: I fixed the formatting. Hopefully it is much more readable now. Sorry it has taken so long for me to get to it; I have been very busy recently.] If you are wondering what this is about please see the "A Floating City on Venus" article.



Conference on Human Space Exploration, Space Technology & Applications International Forum,
Albuquerque NM, Feb. 2-6 2003.
Colonization of Venus
Geoffrey A. Landis
NASA John Glenn Research Center, mailstop 302-1, 21000 Brook Park Road, Cleveland, OH 44135
216-433-2238 e-mail: geoffrey.landis@grc.nasa.gov

Abstract.

Although the surface of Venus is an extremely hostile environment, at about 50 kilometers above the surface the atmosphere of Venus is the most earthlike environment (other than Earth itself) in the solar system. It is proposed here that in the near term, human exploration of Venus could take place from aerostat vehicles in the atmosphere, and that in the long term, permanent settlements could be made in the form of cities designed to float at about fifty kilometer altitude in the atmosphere of Venus.


INTRODUCTION

Since Gerard K. O’Neill (1974, 1976) first did a detailed analysis of the concept of a self-sufficient space colony, the concept of a human colony that is not located on the surface of a planet has been a major topic of discussion in the space community. There are many possible economic justifications for such a space colony, including use as living quarters for a factory producing industrial products (such as solar power satellites) in space, and as a staging point for asteroid mining (Lewis 1997). However, while the concept has focussed on the idea of colonies in free space,
there are several disadvantages in colonizing empty space. Space is short on most of the raw materials needed to sustain human life, and most particularly in the elements oxygen, hydrogen, carbon, and nitrogen. Oxygen could be imported from a rocky source, such as the lunar surface, but the volatile materials hydrogen, carbon, and nitrogen form primarily volatile materials that are not present in abundance on the lunar surface. Furthermore, for optimum performance, human beings require gravity-- it requires major engineering structures to simulate (via rotation) the
presence of gravity in a free-space colony.
Even for colonizing the asteroids, it is not clear that a free space base is the optimum location: any given asteroid is, on the average, rather distant from all the other ones, both in actual distance and in terms of the propulsion delta-V required to get there.
An alternate possibility is to locate a colony on the surface of another planet. Most recently, the case for colonizing the surface of Mars has been argued by Zubrin (1996). However, at least compared to the benign environment of Earth, the surface of Mars has several disadvantages. It has a low atmospheric pressure, low temperatures, and high exposure to cosmic radiation, and, while it is not a zero-gravity environment, it is not yet known whether the roughly one-third Earth-normal gravity of Mars is sufficient to avoid the bone decalcification and muscle tone loss experienced by astronauts in microgravity.
So let’s colonize Venus.


VENUS EXPLORATION

In many ways Venus is the hell planet. Results of spacecraft investigation of the surface and atmosphere of Venus are summarized by Fimmel, Colin, and Burgess (1983) and by Bougher, Hunten, and Phillips (1997):

· Surface temperature 735K: lead, tin, and zinc melt at surface, with hot spots in excess of 975 K
· Atmospheric pressure 96 Bar (1300 PSI); similar to pressure at a depth of a kilometer under the ocean
· The surface is cloud covered; with little or no solar energy
· Poisonous atmosphere of primarily carbon dioxide, with nitrogen and clouds of sulfuric acid droplets.

FIGURE 1[missing].
Venus, viewed in the ultraviolet by the Pioneer Venus mission (Fimmel, Colin, and Burgess 1983).

However, viewed in a different way, the problem with Venus is merely that the ground level is too far below the one atmosphere level. At cloud-top level, Venus is the paradise planet. As shown in figure 2, at an altitude slightly above fifty km above the surface, the atmospheric pressure is equal to the Earth surface atmospheric pressure of 1 Bar. At this level, the environment of Venus is benign.

· above the clouds, there is abundant solar energy
· temperature is in the habitable "liquid water" range of 0-50C
· atmosphere contains the primary volatile elements required for life (Carbon, Hydrogen, Oxygen, Nitrogen, and Sulfur)
· Gravity is 90% of the gravity at the surface of Earth.

While the atmosphere contains droplets of sulfuric acid, technology to avoid acid corrosion are well known, and have been used by chemists for centuries.
In short, the atmosphere of Venus is most earthlike environment in the solar system. Although humans cannot breathe the atmosphere, pressure vessels are not required to maintain one atmosphere of habitat pressure, and pressure suits are not required for humans outside the habitat.

It is proposed here that in the near term, human exploration of Venus could take place from aerostat vehicles in the atmosphere, and that in the long term, permanent settlements could be made in the form of cities designed to float at about fifty kilometer altitude in the atmosphere of Venus.

Is Floating Difficult? On Venus, breathable air (i.e., oxygen/nitrogen mixture at roughly 21:78 mixture ratio) is a lifting gas. The lifting power of breathable air in the carbon dioxide atmosphere of Venus is about half kg per cubic meter. Since air is a
lifting gas on Venus: the entire lifting envelope of an aerostat can be breathable gas, allowing the full volume of the aerostat to be habitable volume. For comparison, on Earth, helium lifts about one kg per cubic meter, so a given volume of air on Venus will lift about half as much as the same volume of helium will lift on Earth.).

FIGURE 2 [missing]. Pressure as a function of altitude in the atmosphere of Venus.
Science on Venus

Venus, the "greenhouse planet", is a scientifically fascinating place (Landis 2001, Landis et al. 2002). In many ways it can be considered "Earth's evil twin." A huge number of important scientific questions need to be answered:

· Before the runaway greenhouse effect, was early Venus temperate?
· Did Venus once have an ocean? If so, did it ever have life?
· What causes the geological resurfacing of the planet?
· What is the nature of the atmospheric superrotation?
· What are the aerosol particles in the atmosphere?
· What is the ÒsnowÓ on Venus mountaintops?
· Can we learn about EarthÕs climate from Venus?
· What is the nature of the disequilibrium chemistry in the Venusian atmosphere? Could it indicate atmopsheric life?

At a temperature of 450 Celsius, and with 90 atmospheres of pressure of carbon-dioxide atmosphere, the surface of Venus is far too hostile to land humans upon, but we can put humans in the atmosphere to explore the surface via
rugged telerobot. Venus Telescience Technologies In the telerobotic exploration scenario (Landis 2003), the humans remain in a habitat, and use teleoperation to rove across the surface of Venus and explore. This requires a high-fidelity, high-bandwidth connection to give the humans a fully-detailed virtual presence in the robotic body.

Humans participate in the exploration both by direct operation of the telerobots across a high-fidelity virtual presence link, and also by analyzing samples collected by the teleoperated robots in a fully-equipped on-site laboratory. Because of the high wind velocity in the middle atmosphere of Venus, an atmospheric aerostat habitat
would not stay over the same surface location, but would constantly move. Although this would have some disadvantages, such as requiring a relay station if long exploration of a single spot is required, it would also have some advantages in constantly moving over new ground. A robot to explore the surface of Venus will require new technologies; specifically, it will require electronics, scientific instruments, power supplies, and mechanical linkages designed to operate at a temperature above 450 C hot enough to melt the solder on a standard electronic circuit board. This will require devices made from advanced semiconductor materials, such as silicon carbide, or even new approaches, such as micro-vacuum tube electronics. Such materials are now being developed in the laboratory. In addition, for a fully immersive virtualreality, high-bandwidth virtual-presence technologies will have to be developed, as well as highly capable exploratory robotics.
While the human explorers could live in a habitat/laboratory in orbit around Venus, a better location for exploration is an aerostat habitat. Teleoperation from the atmosphere allows near "real time" operation with minimum time delay, giving a virtual presence on the surface. An atmospheric habitat has an advantage over an orbital habitat of advantages of gravity (90% of Earth surface gravity) and atmospheric protection against cosmic radiation (same equivalent mass as Earth’s atmosphere), and the presence of useful atmospheric gasses, including carbon dioxide and nitrogen. Breathing oxygen for life support can be easily provided by separation of oxygen from atmospheric carbon dioxide, either by zirconia electrolysis or by Sabatier processes. So it should be possible to explore the surface of Venus remotely from an aerostat habitat. An atmospheric location for the habitat has the addition advantage that it will be easy to bring samples up from the surface to be analyzed in the habitat. The atmospheric pressure is high enough that both airplanes (Landis 2001) or balloons could lift samples (assuming, of course, that the vehicles are adapted for high-temperature and pressure operation).


SETTLING VENUS

In the long term, permanent settlements could be made in the form of cities designed to float at about fifty kilometer altitude in the atmosphere of Venus.
The thick atmosphere provides about one kilogram per square centimeter of mass shielding from galactic cosmic radiation and from solar particle event radiation, eliminating a key difficulty in many other proposed space settlement locations. The gravity, slightly under one Earth gravity, is likely to be sufficient to prevent the adverse affects of microgravity. At roughly one atmosphere of pressure, a habitat in the atmosphere will not require a high strength pressure vessel. Humans would still require provision of oxygen, which is mostly absent from the Venusian atmosphere, but in other respects the environment is perfect for humans (although on the habitat exterior humans would still require sufficient clothing to avoid direct skin exposure to aerosol droplets). Since breathable air is a lifting gas, the entire lifting envelope of an aerostat can be breathable gas, allowing the full volume of the aerostat to be habitable volume. For objects the size of cities, this represents an enormous amount of lifting power. A one-kilometer diameter spherical envelope will lift 700,000 tons (two Empire state buildings). A two-kilometer diameter envelope would lift 6 million tons. So, if the settlement is contained in an envelope containing oxygen and nitrogen the size of a modest city, the amount of mass which can be lifted will be, in fact,
large enough that it could also hold the mass of a modest city. The result would be an environment as spacious as a typical city. The lifting envelope does not need to hold a significant pressure differential. Since at the altitudes of interest the external pressure is nearly one bar, atmospheric pressure inside the envelope would be the same as the pressure outside. The envelope material itself would be a rip-stop material, with high-strength tension elements to carry the load. With zero pressure differential between interior and exterior, even a rather large tear in the envelope would take thousands of hours to leak significant amounts of gas, allowing ample time for repair. (For safety, the envelope would also consist of several individual units).
Solar power is abundant in the atmosphere of Venus, and, in fact, solar arrays can produce nearly as much power pointing downward (toward the reflective clouds) as they produce pointing toward the sun. The Venus solar day, 116.8 terrestrial days, is extremely long; however, the atmospheric winds circle the planet much more rapidly, rotating around the planet in four days. Thus, on the habitat, the effective solar "night" would be roughly fifty hours, and the solar "day" the same. This is longer than an Earth day, but is still comfortable compared to, for example, the six-month night experienced in terrestrial near-polar locations. If the habitat is located at high latitudes, the day and night duration could be shortened toward a 24-hour cycle.

A permanent settlement will need access to the resources required for human life and for greenhouses to provide food and oxygen, and the atmosphere of Venus has these in abundance. Atmospheric carbon dioxide and nitrogen are a plentiful resource. Along with hydrogen reaped from condensing atmospheric sulfuric acid droplets, the basic elements needed for human survival can be found in the atmosphere. A settlement will require structural and industrial materials as well. These materials, such as silicon, iron, aluminum, magnesium, calcium, potassium, sodium etc. can be mined from the surface material, which is apparently
primarily a basaltic silicate. Access to the surface is relatively simple from an aerostat, since the thick atmosphere allows flight by airplanes (Landis 2001) or balloons (already demonstrated on Venus during the Russian VEGA mission (Bougher, Hunten and Phillips 1997)). In an alternative scenario, an cable in the form of a high-temperature fullerine tether could be used to directly lift ore from the surface to the habitat. Since the habitat will be stationary with respect to the middle-atmosphere wind, the lifting will be done with the habitat in motion with respect to the surface. It may simplify the process if the habitat temporarily lowers its altitude to take it out of the high altitude wind levels; while this will move it toward the higher temperature region of the atmosphere, a habitat of the size
considered would have an enormous heat capacity, and would likely have little difficulty with a temporary dwell at higher temperature levels. Finally, with surface area 3.1 times the land area of Earth, Venus has plenty of room. A billion habitats, each one with a population of hundreds of thousands of humans, could be placed float in the Venus atmosphere. Accessibility of Asteroids from Venus One possible economic objective for space colonization is to serve as habitats from which humans can prospect and mine asteroidal resources. It would be intuitive to think that a base to mine asteroids should be close to the asteroid belt, and hence further from the sun than the Earth, but detailed consideration of astrodynamics brings this conclusion into some question. In terms of flight time, Venus is closer to the asteroid belt than either the Earth or Mars. This is shown in figure 3 [missing]. For example, the minimum-energy trajectory to the largest main-belt asteroid, Ceres, takes 0.95 yeears from Venus, and 1.05 years from Earth. In terms of flight time, the closer you are to the sun, the more accessable the asteroids are. The asteroids are not actually close to each other, and hence if a habitat is to support prospecting and mining more
than one asteroid, the asteroid belt is in some ways the worst location for it. An asteroid is as likely as not to be on the opposite side of the sun, and although the Earth is further from the sun, that does not put it closer, on the average, to any given asteroid. The higher orbital velocity of Venus actually makes transfer orbits somewhat faster, as well as increasing the number of transfer opportunities (that is, decreasing the synodic period).

CONCLUSION

In the long term, permanent settlements could be made in the form of cities designed to float at about fifty kilometer altitude in the atmosphere of Venus. The advantages of the Venus atmosphere over other proposed space settlement locations includes an abundance of atmospheric volatiles, sufficient for life support, benign temperature and pressure, shielding from cosmic and solar-flare radiation, plentiful solar energy, and nearby access to the rocky (silicate) surface materials.

Earth to Vesta:
1.08 years
Venus to Vesta:
0.95 years
Earth to Ceres:
1.29 years Venus to Ceres:
1.15 years
Vesta orbit
2.36 AU

FIGURE 3 [missing]. In terms of flight time, Venus is closer to the asteroid belt than either the Earth or Mars. Minimum energy trajectories to the two largest main-belt asteroids, Ceres and Vesta, are shown.

REFERENCES

Bougher, S. W., Hunten, D. M., and Phillips R. J., editors, Venus II, University of Arizona Press, Tucson, 1997.
Fimmel, R. O., Colin, L., and Burgess, E., Pioneer Venus, NASA SP-461 (1983).
Landis, G. A., "Exploring Venus by Solar Airplane," presented at the STAIF Conference on Space Exploration Technology,
Albuquerque NM, Feb. 11-15, 2001. AIP Conference Proceedings Volume 552, pp. 16-18.
Landis, G. A., LaMarre C. and Colozza, A.: "Atmospheric Flight on Venus," paper AIAA-2002-0819, AIAA 40th Aerospace
Sciences Meeting, Reno NV, January 14-17 2002.
Landis, G. A., "Robots and Humans: Synergy in Planetary Exploration," Conference on Human Space Exploration, Space
Technology & Applications International Forum, Albuquerque, NM, Feb. 2-6 2003 [this proceedings]
Lewis, J. S., Mining the Sky: Untold Riches from the Asteroids, Comets, and Planets, Addison-Wesley (1996).
O’Neill G. K., "The Colonization of Space," Physics Today, 27 (9), pp. 32-40, Sept., 1974.
O’Neill, G. K., The High Frontier: Human Colonies in Space, William Morrow & Co; 1976; (Third Edition, Apogee Books,
2000)
Zubrin, R., The Case for Mars, The Free Press/Simon & Schuster, Inc., 1996.
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at 2:29 PM 1 comments

Sunday, May 13, 2007

Absolutely Awesome Images of Space

The technical and theoretical aspects of space and space travel are fascinating to me and most likely many others but, sometimes it's nice to just step back and take a look at why going to space would be awesome for the view alone. I have compiled several of my favorite images of space. Many were taken by Hubble but not all.


Known as the "Pale Blue Dot," this image was taken on February 14th, 1990 by Voyager 1. Four billion miles away from Earth, it is the longest distance away from Earth that a picture of Earth has been taken.

We succeeded in taking that picture [from deep space], and, if you look at it, you see a dot. That's here. That's home. That's us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives. The aggregate of all our joys and sufferings, thousands of confident religions, ideologies and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every young couple in love, every hopeful child, every mother and father, every inventor and explorer, every teacher of morals, every corrupt politician, every superstar, every supreme leader, every saint and sinner in the history of our species, lived there on a mote of dust, suspended in a sunbeam.
-Carl Sagan
The above quote by Carl Sagan is one of my favorite quotes of all time. It really puts things into perspective.

Another "Pale Blue Dot" taken by Cassini that is perhaps even more stunning (though not as far).
Explanation Courtesy NASA.gov:
In the shadow of Saturn, unexpected wonders appear. The robotic Cassini spacecraft now orbiting Saturn recently drifted in giant planet's shadow for about 12 hours and looked back toward the eclipsed Sun. Cassini saw a view unlike any other. First, the night side of Saturn is seen to be partly lit by light reflected from its own majestic ring system. Next, the rings themselves appear dark when silhouetted against Saturn, but quite bright when viewed away from Saturn and slightly scattering sunlight, in the above exaggerated color image. Saturn's rings light up so much that new rings were discovered, although they are hard to see in the above image. Visible in spectacular detail, however, is Saturn's E ring, the ring created by the newly discovered ice-fountains of the moon Enceladus, and the outermost ring visible above. Far in the distance, visible on the image left just above the bright main rings, is the almost ignorable pale blue dot of Earth.

The Helix Nebula. I like this one because it reminds me of the Eye of Sauron from "The Lord of The Rings" trilogy.



From the Ashes of the First Stars. Above is one of the most beautiful pictures I have ever seen. It is an artist's impression of a primordial quasar surrounded by sheets of gas, dust, stars and early star clusters.

The Jupiter's 4th largest moon IO. The spectacular surface is dotted with volcanoes and as a result of the many volcanoes its appearance is created by the sulfur and silicates released. The bluish cloud seen coming from the surface is known as the Prometheus Plume and is the result of a volcano. It is speculated that the plume has been active for over 18 years (from 1997).



The Vela Supernova Remnant. It is referred to as a remnant because it is left over from a supernova that exploded 10-12 thousand years ago.

The Flame Nebula. The beautiful array of light is caused by excited gas particles (primarily Hydrogen).
The Eta Carinae Nebula (aka the Great Nebula in Carina or simply the Carina Nebula). Breathtaking is the only way to really describe this photo.

I hope you all enjoyed these as much as I did when I first stumbled upon them.

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Friday, May 4, 2007

A Floating City on Venus

Hellish Venusian surface. Courtesy NASA.gov
(Note: this is a part of The Space Colonization Series)
When space colonization is mentioned many things come to mind: Mars, the Moon, the future, terraforming, and even occasionally asteroids. One thing that rarely comes to mind, however, is Venus. And why should it? After all, Venus is Earth's sister planet from hell, registering a spicy 450 degrees C average on the surface or, in other words, hotter than Mercury. As if the temperature wasn't enough incentive to destroy any thoughts of visiting Earth's closest planetary neighbor, reaching the surface is practically impossible to do safely. Atmospheric pressure reaches 90 times that of ours on the surface or equivalent to being under 1 km of water. Venus also has a relatively slow rotation, completing one rotation every 243 earth days. Thus nights would last a very long time--not that you could see the sun during the day anyway. So, if Venus seems so obviously irrelevant to the idea of space colonization why make an article connecting the two? Well, it is Venus' hellish properties that ironically make it so appealing. The common misconception about space colonization is that colonies are built on the surface. The key to a Venusian colony is it's incredibly dense atmosphere. Remember, "...or equivalent to being under 1 km of water?" Well, things float on water; don't they...?

The Idea

The concept is actually based on a rather simple premise--buoyancy. So, we all know lower density materials rise to the top but how could this apply to Venus? Simply put, breathable gas has the equivalent lifting power on Venus as half of Helium's lifting power on Earth (about 1 kg per cubic meter). This property allows for breathable air domes to lift a colony in addition to their own weight. Tweaking the lifting power could also easily be done by storing helium or hydrogen (both extractable from the atmosphere) filled tanks. The Colonies would float at an altitude of roughly 50 km where the air pressure is equal to Earth's. At this altitude the former problems encountered with a surface colony start to disappear. The temperature chills to a much more normal range of 0-50 degrees Celsius or liquid water temperatures. This altitude also happens to sit above the thick clouds providing abundant solar energy. The clouds themselves are so reflective that pointing solar panels downward would provide almost as much energy as they would pointing upward. The solar power available above Venus' cloud top is approximately 1.9 times that of Earth's providing plenty of power for a potential colony. Ah, that sounds great, but the issue of incredibly long dark periods still looms doesn't it? Fortunately, Venus' atmospheric winds bail us out of that situation giving us a manageable 50 hour solar day and likewise, a 50 hour solar night. Increase the latitude of the 'Bubble' and everything could be packaged into an Earth-like 24 hour cycle.

Bespin from the movie Star Wars: The Empire Strikes Back.
Other than the extreme density of Venus' atmosphere providing buoyancy, it also provides many important resources necessary for food and oxygen. Carbon dioxide and Nitrogen are very abundant in the atmosphere and could easily be harvested. Hydrogen can also be extracted from condensed sulfuric acid droplets, thus providing all of the basic elements required for human survival. Industrial minerals, also very important for maintaining an outpost or colony, could be mined from the surface. The hazards of reaching the surface drastically decrease in difficulty when making the attempt from an already established floating colony (or aerostat habitat). Large cables stretching the 50 km distance or less if the city lowers altitude temporarily could lift minerals from the surface directly to the habitat. Such a large habitat would have an incredibly large heat capacitance and thus be able to withstand momentary dips into much higher temperatures. So, it is starting to become clear how a floating city on Venus could theoretically become self-sustaining. That is great, but we are still left with a legitimate question: why should we want to go to Venus?!


The Reason

Obviously research of the planet is one simple and arguably lame reason to visit. That excuse could be made for practically anything. Everyone knows scientific research would take place. The type of research possible, however, could be highly relevant to our own planet. Global warming is currently a great debate across the globe and an in-depth look into Venus' extreme example of the greenhouse effect could open up many doors to explaining our own climate. Some other topics of interest include:

Before the runaway greenhouse effect, was early Venus temperate?
Did Venus once have an ocean? If so, did it ever have life?
What causes the geological resurfacing of the planet?
What is the nature of the atmospheric superrotation?
What are the aerosol particles in the atmosphere?
What is the —snow“ on Venus mountaintops?
What is the nature of the disequilibrium chemistry in the Venusian atmosphere? Could it indicate atmopsheric life?

View rest of paper [pdf]
[NOTE: pdf file is currently down so to view a transcript of the file I have decided to host it here.]
There are many other reasons to colonize Venus. First and foremost, human survival is dependent upon our expansion and colonization of space as Stephen Hawking recently made so clear. Venus is enticing for such a proposal for the three very important reasons: location, location, location. One, it is Earth's closest neighbor (excluding the Moon). Two, the colony is located in the dense atmosphere and thus it blocks harmful solar radiation naturally--problems that would be encountered on the Moon and Mars. The third is Venus' relative position to the coveted asteroid belt. It seems counterintuitive that Venus has a prime location for reaching the asteroid belt considering it is closer to the sun than Earth and the asteroid belt is even further than Earth but astrodynamics says otherwise. Here is more from the previous [pdf] explaining the concept in further detail:

In terms of flight time, Venus is closer to the asteroid belt than either the Earth or
Mars. This is shown in figure 3. For example, the minimum-energy trajectory to the largest main-belt asteroid, Ceres, takes 0.95 yeears from Venus, and 1.05 years from Earth. In terms of flight time, the closer you are to the sun, the more accessable the asteroids are. The asteroids are not actually close to each other, and hence if a habitat is to support prospecting and mining more than one asteroid, the asteroid belt is in some ways the worst location for it. An asteroid is as likely as not to be on the opposite side of the sun, and although the Earth is further from the sun, that does not put it closer, on the average, to any given asteroid. The higher orbital velocity of Venus actually makes transfer orbits somewhat faster, as well as increasing the number of transfer opportunities (that is, decreasing the synodic period).

View rest of paper [pdf]
Clearly, Venus presents a distinct advantage concerning mining asteroids, a potential 'gold mine.'

Establishing a floating city colony also gives humans much more 'practice' with inhabiting alien worlds. Learning to become air and land dwellers could prove to be a valuable asset in the future. Venus gives us a unique opportunity in regards to this because its gravity, at.904 G's, is only slightly less than Earth's. This means that colonists would not need to make frequent trips back to Earth to avoid bone loss or any other negative side effects of low gravity environments.

OK, but there are still problems right?

Of course there are. Many obstacles face a floating colony on Venus, though not as many nor the type that most would expect. The atmosphere is filled with sulfuric acid and other corrosive particles. Ceramics or some other type of layer would be necessary to prevent corrosion. Sulfuric acid fortunately has many industrial uses and could also be harvested for use. Scooping raw materials would also require quite an engineering feet, not to mention the whole project itself being a gargantuan task. The hazards overall are similar to any ambition of colonizing a planet. One big concern would be leaks. Fortunately, since the pressure is approximately equal on the inside and out, leaks of even large proportions would be slow and manageable.

Personally, I wouldn't say that colonizing Mars or the Moon first is a better or worse idea. Clearly those two options get the most attention and seem the most viable options to many. A floating city may not be as easy or as difficult as what has been proposed but the idea deserves merit. I believe the proposal is worthy enough for deeper consideration and more research. Hopefully my spreading of this idea has sparked a few of you with your own ideas. If anyone has any questions feel free to post them and I will try my hardest to address them and find an appropriate answer.

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