Solar Sail

Today, September 7, a special day for a great nation, Brazil celebrated its independence from Portugal. More than half a century ago good winds brought the Portuguese to this beautiful land, where everything that seeds, rises, we were blessed with a tropical climate which gives us the brigadier skies all year, in addition to several miles of coastline and other natural beauties.
This was only possible thanks to the invention of the Portuguese caravels, which is an adaptation of the triangular sail set on the Mediterranean Sea region.

In twenty-first century man is still sailing, but now he is sailing on other the seas far greater than any man can dream for half a century ago. I'm talking about the vastness of Space. Currently there are several consolidated technologies: propulsion liquid, solid and there are others still in development as the ion and, more recently, the technology that leverages the solar wind.

Today I talk a little about the Solar Sail its history and its operating principle.

The idea of using solar wind for propulsion is not new, the operating principle is based on the pressure caused by solar radiation and solar wind pressure itself focusing on a surface, and this can absorb or reflect radiation. And it was proven by a Russian scientist Peter Lebedev that when a surface absorbs radiation instead of reflecting it generates twice as much traction.
Thus the proposed designs for solar sail today has been based in large "parachute" for that can absorb more radiation and then have more traction, but it brings us some problems in low orbit around 800km altitude for example the spacecraft suffers the drag caused by air. Above this altitude the solar sail gradually got smaller accelerations and can take months or years to reach the desired speed.

Despite the limitations, the Japanese space agency JAXA has obtained the first proven success in this type of technology with the launch of IKAROS after two frustrated attempts of other agencies both caused by faults in the rocket launch the project of NASA and the Russian COSMO1 the project NanoSail D.

Now the question is whether this technology will progress and allow us to reach new worlds, new lands wonderful as the Portuguese did half a century ago! That the solar wind to guide us beyond the solar system!