Monday, February 1, 2010
I have been reading this book, a more comprehensive collection of space sailing information than the previous. The price is listed at $155 in hardcover, but $5 in soft. So one should go with the latter.
Space Sailing by Jerome Wright
This is an article about the economic concerns related to beamed energy and space sailing, and discusses such matters as sail material and driver energy source.
The cheapest possible scenario is a microwave sail carrying a very small payload (say a 100 kg sail with 1 kg of payload) that can travel to a local star. If we have 1000 years to wait, it can be much cheaper and carry much more payload (or stop rather than just conduct a flyby mission.) However, up to .3 c could be realistic for a flyby mission allowing a visit to the nearest stars in well under a century. This craft could be accelerated very quickly using future power plants that may be built in space. These power plants will operate in the gigawatt range, and will normally beam the power back to earth. By borrowing a few days of power, the costs will only be on the order of millions of dollars at a time. In any event, the ultimate cost of interstellar travel is going to be high, higher, or highest depending on what plan you pick.
If you can't afford the book or don't want it right now, this PDF discusses some interesting "advanced concepts."