Japan's kite-shaped "space yacht" has successfully started sailing through space using solar-power generation.

A Japanese rocket last month launched the experimental Ikaros - or Interplanetary Kite-craft Accelerated by Radiation of the Sun - which is designed to be propelled by the pressure of sunlight particles.

The technology could eventually enable space travel without fuel, as long as there is sunlight.

Similar to an ocean yacht pushed by wind, the device has a square, ultra-thin and flexible sail measuring 14 metres by 14 metres that will be driven through space as it is pelted by solar particles.

The sail, which was fully expanded on Thursday, is only a fraction of the thickness of a human hair and is partly coated with thin-film solar cells to generate electricity.

Japan Aerospace Exploration Agency (JAXA) has released a statement confirming "the full expansion of the sail and electric generation with thin film solar cells at about 7.7 million kilometres from Earth".

The spacecraft's name alludes to Icarus, the figure from Greek mythology who flew too close to the sun.

The space yacht is headed in the direction of Venus, however.

Ikaros, which cost 1.5 billion yen ($19 million) to develop, will be the first use of propellant-free technology in deep space, although it has been tested in orbit around the Earth before.

JAXA has said the navigation technology "will mark the first spectacular achievement of its kind in the world".

- AFP