If all goes to plan, the next generation of explorers will be doing the same thing except they'll be sailing to the stars. Recent advances in materials and, most importantly, a shift in attitude, could see an old science fiction dream become a reality by the end of this decade. This is a stretch goal that is among the most audacious things we ve ever undertaken. Light years ahead The basic concept of a light sail spacecraft is almost like a parachute in reverse. A capsule containing a probe or human beings is tethered to an immense sheet of reflective material spread out towards the desired direction of travel.
Solar radiation coming from behind the capsule moves past it and is captured by the sail.
The minuscule impact of each photon transfers a tiny amount of kinetic energy to the craft, eventually resulting in forward momentum. Although the acceleration is none too dramatic, once the light sail is up and running, the speeds it can obtain make our current spacecraft look sluggish. Other plans are in development for similar craft that would be powered by burst of microwaves or laser beams fired from orbiting satellites. Such interstellar probes will be the largest and fastest spacecraft ever built. The maiden interstellar voyage would probably be to our closest neighbouring system, Alpha Centauri.