|An early (1949) vision of space habitation from Russia|
In my blog post, "The Zombification of Innovation?", I list a cheap way of getting into space as one of the tech voids waiting to be filled; something to leapfrog SpaceX and, possibly, rocket science altogether; something on the order of a space elevator. So what?, you say. There's radiation and muscle atrophy and no air in space. What's the point of a cheap way to get somewhere unless there's a viable reason to go there and at least 3 star digs when you get there?
|No, I am not talking about a moon base. We'd still be stuck in a gravity well.|
There is a ratio tool called EROI (energy returned on energy invested). When EROI is high like it was a century ago at the beginning of big oil (100:1), things are rosy. As EROI begins to drop, the rainbows and lollipops begin to diminish. Currently it's about 3:1 in the U.S and about 10:1 in Saudi Arabia. Let me put it another way. It took 1 barrel of oil to get 100 barrels of oil 100 years ago. Today, for the U.S., it takes 1 barrel of oil to get 3 barrels of oil. Do a graph, plot a curve, count some beads; whatever you do to visualize this, it's not good as a future trend. The price of fuel skyrockets as the ratio gets closer to 1:1.
The EROI is a very simple tool that does not take into consideration the environmental costs of energy extraction and use. Not only are we running out of convenient, inexpensive liquid fossil fuels, we are stewing in the products of combustion from those fuels. We have a choice now of settling for the finite and the limited or opting for the infinite and limitless. Going into space will transform humanity. Our EROI will go back to well over 100:1 with nearly limitless solar energy. That's why we have to go into space.
|We don't know what's out there; maybe space whales.|
Image courtesy of elbardo at deviantART
Let's assume that we do have that elevator into space. At the least, let's assume we have completely re-usable rockets fueled by liquid hydrogen made cheap by fusion or some other energy breakthrough. What are the steps to make space our home sweet home?
Credit: Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
under Creative Commons License
First, take one asteroid. Literally. Asteroid 2012-DA14 flew by on February 15, 2013, closer to Earth than some satellites. Imagine an interceptor launched from Earth that attaches to this space-faring boulder and guides it into an orbit around the Earth. This does two things. First, it's close enough to work on without long space flights. Secondly, we know right where it is. One less asteroid to worry about hitting Earth. As to the details of how to hijack an asteroid, a device similar to what I describe in Saving the World From an Asteroid Strike can be used. It is an OLED blanket that attaches to the asteroid and turns from flat black to a mirror surface, controlling the light pressure that hits the asteroid and, thus, its orbit. It can use that same process to control the spin of the rock by causing light pressure to change on different quadrants of the asteroid at different times. Click on the drawing below for a larger view.
|Basics of an asteroid catcher.|
This is technologically feasible right now, and it is something we should be doing right now. Why? Because to tame the orbit of these huge rocks will take decades. This is the time we will use to develop that cheap means of orbital access so that when these big boulders begin their close orbit of Earth we can go to work on them. We will mine them for their minerals and turn the scrap into a space habitat.
Melt that orbital scrap heap into a molten ball and then blow it up like a glass bauble. Using inexpensive inflatable, focusable orbiting mirrors (more completely described in my post The Space Mirror Hack) the sun's energy is concentrated onto the remnants of an asteroid that's been stripped of precious metals, minerals and water. Once this detritus is melted, forming a sphere in zero gravity, a high temperature resistant metal or ceramic pipe is inserted until the end is near the center of this ball of liquid rock. An inert gas, probably nitrogen, is introduced, inflating it until we have an empty sphere with, ideally, at least 6 foot thick walls. This will protect against even the most potent of cosmic rays. With 6 foot thick walls, asteroid 2012-DA14 would provide a spherical shell with an inside diameter as big as a football field. Click on any of the following illustrations for a larger view.
|An inflatable, orbital mirror|
|Using space mirrors to melt an asteroid|
|Inflating a molten asteroid|
After it cools down, the inside of this sphere can be fitted out to accommodate human habitation. Oxygen is mixed with the nitrogen inflating gas to form a breathable atmosphere. The whole thing will be be parked at a Lagrange Point and set spinning to provide artificial gravity. Several cylindrical layers will be installed to form floors to divvy up into living quarters. The metal mined from the asteroid can be turned into sheets and structural shapes for this purpose. The central area will be a weightless area used for working on space vehicles docked for loading, unloading, or repairs. The low-gravity areas are public spaces where you can rent wings and go flying under your own power. The high-gravity areas near the perimeter of the shell contain gyms and running trails to keep people in shape. In between are apartments and commercial areas.
|The Space Egg - how it might look on the inside|