IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun) is a Japan Aerospace Exploration Agency (JAXA) experimental spacecraft.

[3][8] The craft's name is an allusion to the legendary Icarus (Ancient Greek: Ἴκαρος, Ikaros), who flew close to the Sun on wings made of bird-feathers and wax.

[9] On 8 December 2010, IKAROS flew by Venus at a distance of 80,800 km (50,200 mi), successfully completing its planned mission, and entered its extended operation phase.

[14] It was designed to demonstrate four key technologies (comments in parentheses refer to figure): The mission also includes investigations of aspects of interplanetary space, such as gamma-ray bursts, solar wind and cosmic dust.

[18][19][20][21] The Jupiter Trojan Asteroid Explorer was a finalist for Japan's Institute of Space and Astronautical Science (ISAS)' 2nd Large Mission Class.

[citation needed] According to JAXA, IKAROS finished all planned experiments in Dec 2010, but the mission continued beyond that date "in order to enhance the skill of controlling solar sail".

Available communication time through the Usuda Deep Space Center antenna was limited, so data was gathered only intermittently to estimate the speed, trajectory and rotation of the satellite.

[42][43] JAXA scientists stated on 9 July 2010 that the measured thrust force by the solar radiation pressure on IKAROS' 196-square-meter (2,110 sq ft) sail is 1.12 millinewtons (0.0040 ozf).