An unmanned probe riding a solar sail through space has felt its first accelerating push from sunlight in a successful test of its novel propulsion system, Japan's space agency has announced.

Observations of the Ikaros solar sail built by the Japan Aerospace Exploration Agency (JAXA) confirmed that the spacecraft has received a growing speed boost from light radiated by the sun, the space agency said.

"The small solar power sail demonstrator 'Ikaros,' which successfully deployed its solar sail, was confirmed to accelerate by [the] solar sail receiving solar pressure," JAXA officials said in a July 9 update.  "This proved that the Ikaros has generated the biggest acceleration through photon during interplanetary flight in history."