Like everything else with the LightSail spacecraft, the picture did not come easily.

LightSail, an ambitious privately financed project to demonstrate using the force of sunlight for propulsion, has had a bumpy life in orbit since it launched last month. Particles of light reflect off an expansive sail of shiny Mylar, providing momentum, and the hope is that this could be an effective way to push future space probes through the solar system without fuel.

But twice during the mission, LightSail dropped completely out of touch and then later revived. On Sunday, it received the command to extend four 13-foot booms and the sail, which spans nearly 345 square feet.

LightSail ignored it.

On the next orbit, the command was sent again, and this time, the spacecraft’s tiny electric motor started whirring. Data including the 134,200 turns of the motor and the slowing of the spacecraft’s spin indicated that the sail was out.

“The deployment was perfect, better than anyone expected,” said William Sanford Nye, the chief executive of the Planetary Society, who is better known as Bill Nye the Science Guy.