Courtesy of Reaction Engines, Ltd., modified by Barbara Graham, laser additions by Anna Nesterova
Keith Henson has a new paper on Space based solar power satellites. It is called Rays of Hope: Propulsion lasers to get parts up, Microwaves to get energy down and the effect of large-scale deployment of power satellites on CO2.
Previously Keith Henson examined power satellites mostly as proposals to solve the big economic problem, the cost of transporting parts to orbit. There were unsolved problems in the last article such as how to return the launch vehicle to its runway.
This is all back of the envelope calculations but it could lower the cost of getting to geosynchronous Earth orbit (GEO) down to $100 per kilogram, about 100 times cheaper than it is today.
This means that it would be much cheaper to build space-based solar arrays in GEO to provide lots of energy back to the Earth.
It uses a Skylon space plane, which has an air-based engine to get to high altitude (say 25 km). It releases a payload that gets accelerated to escape velocity by heating hydrogen. And then the Skylon plane lands back on Earth for another load.
In this plan, lasers are used to heat up the hydrogen to high enough temperatures to get the velocity needed. The lasers come from space-based solar arrays in GEO.
Using this system, they believe that can raise 1440 tons of material a day to GEO!.The International Space Station masses about 500 tons. So they could raise to GEO the equivalent of 3 ISS a day!
It would be profitable very quickly.
But the really incredible possibility is using this energy to not only get us off of fossil fuels but also to be used to actively remove CO2.
Here is an example of a very simple model using excess energy to remove CO2.
It is not a sophisticated model but does demonstrate how rapidly we could get CO2 levels back down with excess energy.
Now there are some practical considerations. Pointing high power lasers at Earth in order to get the material into space would have political implications. Just like nukes, what can be used for peace could also be used for war.
So we will have to figure out how to deal with this on an international scale. I do not think any one country would be allowed to control the system.
Perhaps we could use regular means to raise things to low Earth orbit (LEO) and use this system to raise things to GEO. It might cost a little more but the lasers could probably be tuned so they do not penetrate the atmosphere very well.
Cool idea though.