Amateur Astronomers Found Planets Crashing Into Each Other
https://www.universetoday.com/164731/am … ach-other/
...to calculated the pressure at the centre of Phobos.
https://en.wikipedia.org/wiki/Phobos_(moon)
It works out to be 59.5KPa, which is 0.58 atmospheres. Therefore I would suggest that Phobos may be a useful potential shell world. A shaft could be dug to the gravitational centre of the moon and an internal cavity could be mined out, which could then be lined and pressurised. The excavated material could initially be used as reaction mass in mass driver impulse engines ferrying cargo between Earth and Mars. With a breathable internal atmosphere, mining of the moon will be substantially simplified.
As mining excavates larger proportions of the moon, pre-stressing cables could be laid across its surface to ensure it remains intact against internal pressure. These could also be made from excavated material.
A tower could be built to the L1 point some 3km above Stickney. Mass driver tugs could dock here to take on reaction mass and offload people and payload.
]]>Cometary bodies with a diameter of 10km and density close to that of water are hugely abundant in the Kuiper belt. My question is: how deep down into such a body would one need to dig before the weight of the ice and rock overhead is equal to 10tonnes/m2 (i.e. 1 bar)? The answer is about 4km.
My spreadsheet suggests that a body the size of Halley’s comet could support an internal pressurised cavity 2km in diameter if pressure were 1bar. For a cavity of this size, internal pressure would precisely match the force of gravity holding the hollow shell together. If this interior void were decked out such that ceiling heights were 30m (100ft), then a low-gee habitable space of 140km2 could be created.
]]>As for the Moon of Earth lots of Magnesium there I do believe. (I am thinking advanced interplanetary shipping, in the more future view).
http://zeenews.india.com/news/net-news/ … 02935.html
http://techxplore.com/news/2015-09-ion- … iency.html
Ion space drive is said to break fuel efficiency record
Making note also that among those worlds could be small asteroids, and phobos and demos.
While Ion drive is slow, being efficient, can't be without value.
Anyway shell worlds, sending payloads out, using a metal based propulsion method. This has to be something to keep an eye on.
And of course it would be valuable to have an efficient and convenient method to transport such a heavy object in the manner indicated previously:
http://zeenews.india.com/news/net-news/ … 02935.html
http://techxplore.com/news/2015-09-ion- … iency.html
Ion space drive is said to break fuel efficiency record
I would anticipate that local to the dome would be an artificial gravity machine as well.
Then having all that it could occur that as profits from mining accumulated, and speculation occurred, then indeed shell worlds, and the value of habitable real estate in the orbit of Mars, could be a real value added item.
Giant Machines!
]]>http://www.space.com/30582-asteroid-min … lsion.html
http://i.space.com/images/i/000/050/309 … 1442544639I think a humble start. (Actually this is quite ambitious). Hope they pull it off!
I have an idea from this picture. What if you inflated a balloon half a kilometer in diameter around a small asteroid, then you got a giant mirror and focused sunlight on the asteroid to vaporize a part of it at a time, the asteroid being something like 50 meters in diameter in the center of this balloon. the asteroid material vaporizes and recondense on the inner surface of the balloon. as it expands outward from the asteroid it cools and it cools and solidifies on the surface of the balloon to build something like this:
Or at least the sphere portion of it, we can cut holes in it as needed.
I think a humble start. (Actually this is quite ambitious). Hope they pull it off!
]]>With information about the likelihood of Mars visit capability/settlement by people as sponsored by government entities around the planet, on the Planet Mars, I suppose we should be in despair.
However Asteroids & Shells, which humble starts, might actually offer significant hope, that of economic interests that might expand over time, and yes I suppose in a very distant future, the very outer solar system, and if existing, the small objects of adjacent solar systems.
By this method, it is inevitable that eventually Mars would be settled.
So, really, unless someone like Musk comes through for Mars, I would say this thread is the "Last Best Hope".
Human motivations are human motivations. Governing entities always will have greater priorities than to expend wealth to create a new domain that they cannot extract wealth from. Since the governments on Earth cannot own/control settlements on Mars, no linkage exists that would impart to the governing individuals and groups special favors, so psychologically there are no primitive drives acting on them for the most part, drives such as gaining position/power/social satisfactions. It is hard to buy votes by promising to help some very fringe personalities to achieve such a dream. Fringe people for the most part, are going to be the ones who will invent a new reality, for their own motivations.
So, it looks like the business model, and a lot of patience are all that might work.
The present generation is very materialistic, needing and wanting materials. It is as it is scheduled to be. It is normal apparently that they should be this way. So the political game is to get wealth for them. Governments can get it for them from those who have some, and who are small enough to take it from. Even if a new baby boom generation were to come, (With spiritual values), they have not even been born yet, are not even in the cribs. So, find a way to get people rich from space, or really, other than a few (And most likely fewer) automated space probes, not much happening I think. Anyway, the baby boomers (Which I am one), kind of got spiritual in the wrong way, for the most part. Didn't really, or couldn't really make the big lifts in the end. Too bad.
Some sort of 'foot in the door' strategy would appear to be appropriate. Establish the colony with a single heavy lift and a crew that are prepared to stay long-term. The transfer vessel can be a light-weight reusable ion/reaction driven solar powered vessel and could be reused time and time again, rather like an ISS with engines. The crew would mine the asteroid with a boring machine that would be ballasted with local rock and would literally drill down into its centre. At that point, the crew would put in an airlock pressurise the deepest part of the tunnel and begin expanding the cavity.
What is needed is a minimalist mission concept, developed with off the shelf hardware and shown to be profitable on paper at least. A mission with a starting mass in LEO of no more than 100te and from then on much smaller annual launches to sustain the base.
As the habitable internal cavity expands through mining, no doubt governments will be interested in buying or renting the space. Agriculture on the surface of the asteroid could be expanded to support the growing base by reeling out poly tunnels.
]]>However Asteroids & Shells, which humble starts, might actually offer significant hope, that of economic interests that might expand over time, and yes I suppose in a very distant future, the very outer solar system, and if existing, the small objects of adjacent solar systems.
By this method, it is inevitable that eventually Mars would be settled.
So, really, unless someone like Musk comes through for Mars, I would say this thread is the "Last Best Hope".
Human motivations are human motivations. Governing entities always will have greater priorities than to expend wealth to create a new domain that they cannot extract wealth from. Since the governments on Earth cannot own/control settlements on Mars, no linkage exists that would impart to the governing individuals and groups special favors, so psychologically there are no primitive drives acting on them for the most part, drives such as gaining position/power/social satisfactions. It is hard to buy votes by promising to help some very fringe personalities to achieve such a dream. Fringe people for the most part, are going to be the ones who will invent a new reality, for their own motivations.
So, it looks like the business model, and a lot of patience are all that might work.
The present generation is very materialistic, needing and wanting materials. It is as it is scheduled to be. It is normal apparently that they should be this way. So the political game is to get wealth for them. Governments can get it for them from those who have some, and who are small enough to take it from. Even if a new baby boom generation were to come, (With spiritual values), they have not even been born yet, are not even in the cribs. So, find a way to get people rich from space, or really, other than a few (And most likely fewer) automated space probes, not much happening I think. Anyway, the baby boomers (Which I am one), kind of got spiritual in the wrong way, for the most part. Didn't really, or couldn't really make the big lifts in the end. Too bad.
]]>Call this a Botany Bay type of colony if you like. The Universe is vast! Once we send a Generation ship on its way, it will only have enough fuel to slow down upon arrival, it won't have enough to slow down turn around and come back, that would take much more fuel! Send it on its way toward Alpha Centauri, and they won't be able to turn around and come back until they get there and find some resources to fuel their ship for the return voyage back to the Solar System.
Also some people will choose isolation, such as they are afraid of runaway nanotechnology or something like that, and they just want to get out of the Solar System before it is consumed.
]]>The internal shell diameter for a 34KPa pressure is 38.8km. The internal void volume is 30,584 cubic kilometres. If decked out accordingly, such a body could house a population of hundreds of millions, i.e. an entire civilisation. Humans would need to spend the majority of their time in rotating buildings, but the ecosystem could be allowed to evolve to function in micro-gravity, in this case ~0.001g.
This raises the question as to whether a future civilisation would bother trying to colonise planets at all, when there exists such a huge number of cometary bodies and small icy moons capable of sustaining them.
]]>https://en.wikipedia.org/wiki/Near-Earth_object
Near-Earth object
From Wikipedia, the free encyclopedia
Near-Earth asteroid 433 Eros visited by the space probe NEAR Shoemaker (December 2000)
A near-Earth object (NEO) is a small Solar System body whose orbit brings it into proximity with Earth. All NEOs have a closest approach to the Sun (perihelion) of less than 1.3 astronomical unit (AU).[2] They include about thirteen thousand near-Earth asteroids (NEAs), more than one hundred near-Earth comets (NECs), and a number of solar-orbiting spacecraft and meteoroids, large enough to be tracked in space before striking the Earth. It is now widely accepted that collisions in the past have had a significant role in shaping the geological and biological history of the planet.[3] NEOs have become of increased interest since the 1980s because of increased awareness of the potential danger some of the asteroids or comets pose to Earth, and active mitigations are being researched.[4]NEAs have orbits that lie partly between 0.983 and 1.3 AU away from the Sun.[5] When an NEA is detected it is submitted to the IAU's Minor Planet Center for cataloging. Some NEAs ' orbits intersect that of Earth's so they pose a collision danger.[6] The United States, European Union, and other nations are currently scanning for NEOs[7] in an effort called Spaceguard.
In the United States, NASA has a congressional mandate to catalogue all NEOs that are at least 1 kilometer wide, as the impact of such an object would be catastrophic. As of June 2015, there have been 872 NEAs larger than 1 km discovered, of which 153 are potentially hazardous.[8] It was estimated in 2006 that 20% of the mandated objects have not yet been found.[7] As a result of NEOWISE in 2011, it is estimated that 93% of the NEAs larger than 1 km have been found and that only about 70 remain to be discovered.[9] Our inventory is much less complete for smaller objects, which still have potential for large scale damage.
Mining
http://www.space.com/19368-asteroid-min … tries.html
"They can be like the Iron Range of Minnesota was for the Detroit car industry last century
So, I see that this is appearing to get ready to happen relatively soon. Some stories have it 10 years off for automated retrieval of water from small objects.
So, that could be the start of the game.
But what I see above, is that as an insurance policy to protect the property of Earth, and beyond the value of the materials of the 872 NEAs, there should be a possibility to talk sense into many Earth bound powerful persons, pointing out that a NEA that can be made to have navigation (To avoid the Earth), and which has a population which does not wish to die by crashing into the Earth, is an advantage, because not only would it protect the assets of Earth, which make life more comfortable for common and rich people, but the objects can provide many things, such as riches, and cultural diversity. In some cases providing havens for cultures which would be harassed by other populations on Earth, and also allowing new cultures to develop.
So an economic case both for material expansion, and for an insurance protection could be made. Obviously the smaller objects matter as well, but the big few, are quite an assortment of opportunities in themselves.
I am wondering about a "Construction assembly" which could be propelled by a pulsed method, maybe the one mentioned by Tom, so as to allow it to visit each object in turn, and "Light" it's fire, that is establish an infrastructure sufficient to allow them all to develop as you have suggested.
That would be a lot of "Worlds".
]]>