Ever since the space colonization visions of physicist Gerard K. O'Neill in the 1970s, colonizing space has captured the imagination of many. But even if launch costs were cut to a fraction of what they are now, ferrying all the items from Earth needed for a habitat in space isn't practical. <p> "We can't keep launching things like that into orbit, not if we're going to have long duration missions," said John Vickers, manager of the National Center for Advanced Manufacturing at NASA's Marshall Space Center. <p> That's why NASA is interested in building in space. There are certain advantages to this idea. <p> "You have near-infinite energy from the sun, an infinite heat sink, and a perfect vacuum," said Chris Lewicki, president and chief engineer at Planetary Resources, a company that has actually floated plans to mine asteroids. All three of those things are useful for several types of manufacturing on Earth. <p> There isn't any large-scale manufacturing in space yet, of course. To get there, launch costs will have to come down. "The best way to think of this is looking at industry before and after something brings the launch costs down," Jason Hay, senior analyst at the Tauri Group, a consulting firm that analyzes the space and defense industries, told InnovationNewsDaily. In the "before" world, launch costs are so high that any kind of manufacturing in orbit becomes prohibitive. In the "after" world, the situation changes — as it might if some of the emerging companies, such as SpaceX, succeed in building cheaper launchers. <p> The following are nine areas in which an industry in space could occur– some with existing technology, and some that will require advances we haven't made yet. All are well within reach and might be common mere decades from now, experts say.
The concept of a solar power satellite, or powersat, was first floated in the 1970s. At the time, skyrocketing oil costs made space-borne solar energy seem like a cheaper option than oil. Oil process didn't stay that high and the plans for demonstration projects got lost in the bureaucratic cracks between federal agencies. But technologically, it could be done today. The idea is simple: launch a huge solar panel into geosynchronous orbit, where the sun always shines, and the satellite always appears to be in the same place in the sky. The panel could be as large as scientists want, since structural strength isn't a problem. Transmit the power produced via a microwave or laser beam to a receiver on the ground, and voila, electricity. The beam's energy density would be small when it hit the ground, so there's no danger of frying anyone below it. But the total energy collected would be vast. Producing power in space produces no greenhouse gas emissions (or pollution of any kind).
Making alloys out of metals has been done for thousands of years. But all alloys are affected by gravity. Heavier elements sink, for example. That means it can be tough to get a perfectly even mixture, and it's why we don't see alloys of certain metals of wildly varying densities such as gold and germanium. On top of that, on Earth some alloys are weaker because crystal structures in them called dendrites form imperfectly. But in zero gravity, this doesn't happen. Decades from now, we could be seeing all kinds of exotic alloys impossible to make on Earth, or ordinary ones that are super-strong.
Like energy generation, mining is a huge environmental problem. Then there's the issue of supply – some rare metals are only found in remote places (which also increases the environmental costs). Planetary Resources thinks we can do better by sending robotic probes to asteroids to bring them into Earth orbit. Those asteroids have all kinds of metals — trillions of dollars' worth. Once in orbit, they can be broken up and dropped in for processing, or the metals can be used in space. Planetary Resources' business plan, while long-term, is at least a feasible one.
Proteins make crystals under certain conditions. But those crystals in 1-g, or Earth gravity, tend to be small and aren't very high quality. But it’s possible to make them larger, with fewer defects, in microgravity. And those crystals can then be sent to Earth, where their structure reveals a lot about how proteins interact with other chemicals. This is very important in the pharmaceutical industry. Pilot projects have already been done on the ISS and the Space Shuttle. But Lewicki noted that many of those experiments on the shuttle weren't conducted long enough to know their real value.
Growing human tissue would seem an Earthbound activity, but Hay noted that one of the mysteries of growing organs from cells is how they build functional structures. He noted that it appears that gravity – or the lack thereof – appears to plays a role, though what exactly is not clear yet. Developing fetuses, for example, are in a near zero-gravity environment in their mother’s womb. It may be that one day, it is more efficient to grow a human liver need in a microgravity satellite and have it shipped down. Bioreactors have made building organs on the ground the way to go for now, but people living and working in space might not be able to wait for a kidney to make the trip from Earth.
Perhaps a long time from now, once those orbital factories are in place, a true shipbuilding industry could emerge. To build a spacecraft of any size, it isn't economical to keep sending up payloads on huge rockets. Even if the launch costs come down, it's a rough ride up and things can get damaged. It is far easier to put up an orbital station, with materials delivered from elsewhere in space, and put it together there. There are no worries about a structure holding up its own weight, since there isn't any gravity. The ISS was assembled in orbit, so scientists know such a feat is possible (though in that case, the parts were launched form Earth).
Recently, NASA experimented with building a heat shield out of dirt. Heat shields can be heavy, and any spacecraft that plans to land back on Earth has to bring one along. But if they could be made with local planetary or asteroid dust (called regolith), that would solve a number of problems for both crewed and uncrewed vehicles.
Carting rocket fuel up to orbit is expensive, even though the fuel itself is often just hydrogen and oxygen. Hydrocarbons – such as hydrazine – are even more expensive. But there is lots of carbon, hydrogen, oxygen and nitrogen in the asteroid belt. Lewicki said that might be the most likely first step in asteroid mining, since being able to mine fuel in space means the amount of mass a rocket has to send to Mars is greatly reduced.
One thing that manufacturers on Earth need – especially in the electronics industry – is a vacuum. That's because a common method of building microchips is molecular beam epitaxy, which involves allowing one set of elements to condense very slowly on a silicon wafer. In space, the vacuum necessary for this process is better than any you can get on Earth. The initial plans ran into problems because gases surrounding the International Space Station would ruin the environment needed, but it is not hard to envision a facility separate from that creating more perfect microchips for use in space itself. <br><br> <i>Follow TechNewsDaily on Twitter @<a href=http://twitter.com/technewsdaily target="_blank">TechNewsDaily</a>. We're also on <a href=http://facebook.com/technewsdaily target="_blank">Facebook</a> & <a href=https://plus.google.com/b/100300602874158393473/100300602874158393473 target+"_blank">Google+</a>.</i>