The Japan Aerospace Exploration Agency says it has successfully unfurled a solar sail in space, more than 7 million km from Earth.
The BBC reports the agency is testing the principle of using sunlight as an efficient means of propulsion, using no chemical fuels.
The 200-sq-metre membrane is attached to a small disc-shaped spacecraft named Ikaros, which was put in orbit last month.
JAXA is now watching to see if Ikaros produces a measurable acceleration, and how well its systems are able to steer the craft through space.
Deployment of the solar sail began on 3 June (JST). On 10 June, Jaxa said confirmation was received that the sail had expanded successfully and some thin-film solar cells embedded in the membrane were generating power.
