Revolutions in technology - like the Industrial Revolution that replaced horses with cars - can make what seems impossible today commonplace tomorrow.
Such a revolution is happening right now. Three of the fastest-growing sciences of our day - biotech, nanotech, and information technology - are converging to give scientists unprecedented control of matter on the molecular scale. Emerging from this intellectual gold-rush is a new class of materials with astounding properties that sound more at home in a science fiction novel than on the laboratory workbench.
Imagine, for example, a substance with 100 times the strength of steel, yet only 1/6 the weight; materials that instantly heal themselves when punctured; surfaces that can 'feel' the forces pressing on them; wires and electronics as tiny as molecules; structural materials that also generate and store electricity; and liquids that can instantly switch to solid and back again at will. All of these materials exist today ... and more are on the way. With such mind-boggling materials at hand, building the better spacecraft starts to look not so far fetched after all.