Overview

The small solar power sail demonstration spacecraft IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun) was developed by the Institute of Space and Astronautical Science (ISAS) of the Japan Aerospace Exploration Agency (JAXA). IKAROS aims to achieve space travel without relying on conventional chemical fuels by using a “solar sail” that obtains propulsion from the pressure of sunlight.

IKAROS was launched together with the Venus probe “Akatsuki” on May 21, 2010, by an H-IIA rocket from the Tanegashima Space Center. IKAROS was mounted as a secondary payload to Akatsuki, making the mission cost-efficient by leveraging the primary mission’s launch for Venus exploration.

Mission Instruments

Solar Sail

The solar sail is a thin, membrane-like sail that navigates by receiving the pressure of sunlight. The IKAROS sail is 20 meters in diameter, extremely thin (7.5 microns), and made of a highly reflective material.
Part of the sail contains thin-film solar cells that generate power for the spacecraft. This allows for long-term space exploration without additional power sources.
IKAROS deploys its sail by spinning, utilizing centrifugal force. This is an effective deployment method in the weightless environment of space.

Gamma-Ray Burst Polarimeter (GAP)

GAP is an instrument designed to observe gamma-ray bursts (GRBs). It collects observational data on high-energy phenomena occurring in space, contributing to scientific research.

Achievements

IKAROS was launched on May 21, 2010, by an H-IIA rocket. About a month after launch, IKAROS successfully deployed its sail and demonstrated propulsion using the solar sail. The mission of IKAROS was primarily to demonstrate solar sail technology and confirm its navigational characteristics. This mission proved that solar sail technology is viable for future space exploration. Additionally, IKAROS provided valuable technical and scientific data, including sail deployment technology, propulsion characteristics using the solar sail, the efficiency of thin-film solar cells, and observational data from the GAP instrument on gamma-ray bursts. This information has been instrumental in the design and development of future missions utilizing solar sails. Following the success of IKAROS, JAXA and other space agencies are advancing the development and practical application of solar sail technology. This progress broadens the potential for sustainable space exploration without fuel dependence, making long-term missions and distant space exploration more feasible.