The status of DECIGO

DECIGO ( DECi- hertzInterferometer Gravitational wave Observatory) is the planned Japanese space gravitational waveantenna, aiming to detect gravitational wavesfrom astrophysically and cosmologically significant sources mainly between 0.1 Hz and 10 Hz and thus to open a new window for gravitational wave astronomyand for the universe. DECIGO will consists of three drag-free spacecraft arranged in an equilateral trianglewith 1000 km arm lengths whose relative displacements are measured by a differential Fabry-Perot interferometer, and four units of triangular Fabry-Perot interferometersare arranged on heliocentric orbitaround the sun. DECIGO is vary ambitious mission, we plan to launch DECIGO in era of 2030s after precursor satellite mission, B-DECIGO. B-DECIGO is essentially smaller version of DECIGO: B-DECIGO consists of three spacecraft arranged in an triangle with 100 km arm lengths orbiting 2000 km above the surface of the earth. It is hoped that the launch date will be late 2020s for the present.