The Japanese experimental spacecraft IKAROS (model pictured) flew by Venus at a distance of 80,800 km (50,200 mi), completing its planned mission to demonstrate solar-sail technology.

IKAROS is a Japan Aerospace Exploration Agency (JAXA) experimental spacecraft. The spacecraft was launched on 20 May 2010, aboard an H-IIA rocket, together with the Akatsuki probe and four other small spacecraft. IKAROS is the first spacecraft to successfully demonstrate solar sail technology in interplanetary space. The craft's name is an allusion to the legendary Icarus, who flew close to the Sun on wings made of bird-feathers and wax.

Solar sails are a method of spacecraft propulsion using radiation pressure exerted by sunlight on large surfaces. A number of spaceflight missions to test solar propulsion and navigation have been proposed since the 1980s. The two spacecraft to successfully use the technology for propulsion were IKAROS, launched in 2010, and LightSail-2, launched in 2019.