The Three EarthSavers of Space
Many in the space field are focused on establishing settlements or colonies on other worlds or the Free Space between them. I too believe this is not just the most important thing we can be doing as humans, but I believe expanding humanity and the precious life of Earth into space is why we exist. Yet, aside from some of us heading out there, and beyond the other rationales we often present for why space is important to humanity, the space community has not made a great case for the rest of the world to be excited or care about what we are doing. However, there are three grand projects we should undertake in space that if successful will both help save this precious planet, and have the side benefit of resulting in the establishment of humanity as a solar system level civilization.
From scouting them out, to characterization, to developing the means to move them into safe orbits, the technology and systems we need for defending the Earth overlap with those we will need to harvest their rich bounty of resources.
The sun shines 24/7 in space. Using the resources we find there and the fact that we can build light yet massively large structures in the weightless vacuum, building solar power plants in space has long been one of the dreams of the space community. As we face the possibility of cascading climate change, and the pressures of population and increased industrial demand at the same moment we need to cut back on fossil fuels, beginning the the development of power systems in space makes sense as soon as possible.
First tests can be between points in space, creating an energy grid for future space facilities and users such as satellite systems. Followed by beaming power to space to test atmospheric issues and interference, culminating in beaming the sun’s energy back to the Earth. Again, the development of this project both helps save the planet and develops the infrastructure to expand our domain into the Solar System.
Some have advocated what are called “geo-engineering” projects to help slow down or stop this effect. From sprinkling dust in the atmosphere to reflect sunlight to massive bubble making machines on the oceans to do the same thing, these projects, while possibly useful, involve making massive and hard to reverse changes within the fragile biosphere of the planet. Almost all of them are global in scale, and once started there is no way to turn them off.
What if we were able to create a little shade? What if we could give ourselves a little more time to make the society level changes we have to make to become sustainable tenants of this fragile world? And what if we could do so in very testable, very controlled, very graduated and easily reversible manner?
For example, imagine swarms of tiny Earth controlled robotic spacecraft attaching themselves to asteroids and moving some of them between the Earth and the Sun. First we would move one or two as an experiment. Then, using the same NASA technologies built to spot other worlds in other star systems by measuring the differences in light coming from those stars when local planets cross in front of them, we could measure the tiny change this would have on light hitting the Earth. We could try it several times, and then perhaps, if it seemed workable add another, then another, until we had the right balance. And if we found some unforeseen issue caused by the shade, we could simply move the asteroids back out of the way.
In fact, even at the scale needed to stop the greenhouse effect, we would still have complete control of the asteroids via the robots attached to them, and as we begin to shift our civilization to be more green and less polluting, we could eventually remove them entirely.
Papers have been written on this plan, some very basic, such as I describe here, others involving massive manufacturing of actual shutters.
Whatever the method is used to control the sunlight, this is not something that can be designed and built overnight. Nor can the other two projects be simply tossed together. We need to begin right now to engage in the conversation that leads to decisions, planning and eventually action on what I am certain will turn out to be some of the most important things we might ever do.
It has been estimated the Sun Shield project might cost as much as the combined cost of the Afghan and Iraq wars. The other two projects are also expensive. But they are also all scalable. They can begin relatively small, prove each step and grow them as they are proven to be useful and to work. Yes, they would indeed be the biggest projects ever undertaken by humanity, but if we can spend that much to slaughter each other, certainly we can spend it to save this amazing world?
As one observer commented long ago, the night of the fire is not the best time to create the fire department.