A space craft that is powered only by the energy of the Sun is mere months away from being launched, with a view to creating future solar-powered craft to explore the cosmos. The “sail” is six hundred square metres in size, and gathers and traps energy from the Sun which it uses to keep the craft going.

The project – known as Cosmos 1 – is a joint venture involving the Planetary Society and Cosmos Studios, an organisation of film-makers and writers which was created by the widow of Carl Sagan. The idea behind it is to find a way to cut the extremely high costs of interplanetary and interstellar travel, by providing a free ride on a solar sailing ship, in much the same way as the wind pushes ships on the oceans. Instead of winds, however, the ship is pushed along by reflected light pressure. More here.