Description of the payload

Solar sails are a proposed form of spacecraft propulsion using large membrane mirrors instead a rocket engine. It is pushed through space by light particles from the Sun reflecting off its giant sails. Althought radiation pressure is small and decreases by the square of the distance from the sun, the great advantage of this kind of vehicles is that they require no fuel.

The science of solar sails is well-proven, but the technology to manage large solar sails is still undeveloped.

The Kawaguchi Laboratory drives one research effort to develope such a vehicle specially focusing in craft's membrane unfolding and steering mechanisms both dinamyc and cuasi-static.

Details of the balloon flight and scientific outcome

Launch site: Sanriku Balloon Center, Iwate, Japan  
Balloon launched by: Institute of Space and Astronautical Science (ISAS)
Balloon manufacturer/size/composition: Zero Pressure Balloon model B200 200.000 m3
Flight identification number: B200-7

The balloon was launched by dynamic method on August 30th 2006 at 6:10 JST.

After a nominal ascent phase, the balloon reached the float altitude at 37 kms, flying over the sea. In that moment the deployment of the solar sail was done and after that the flight ended with the separation of the balloon at 9:48 JST, after a flight of more than 3 hours.

The payload descended in the Pacific Ocean and was recovered by helicopter.

During this flight was achieved the worldwide first quasi-static development with the world's largest membrane size ever using a balloon.

The data obtained is a invaluable reference for the use of this solar sail membrane in future spacecraft currently under development.

External references and bibliographical sources

Images of the mission

View of the launch platform with the gondola containing the solar sail in the background the fully inflated balloon Ballon ascent First develope phase of the solar sail taken by the onboard camera Second development phase when the balloon reach the float altitude The payload near touch the sea surface