Time-delay Interferometry for ASTROD-GW

ASTROD-GW(ASTROD[Astrodynamical Space Test of Relativity using Optical Devices] optimized for Gravitational Wave detection) is an optimization of ASTROD to focus on the detection of gravitational waves. Three spacecraft in the mission are positioned respectively in the vicinity of the Sun- Earth Lagrange points L3, L4 and L5. They form a nearly equilateral interferometerarray with the arm lengths of about 260 million kilometers. A set of optimized 20-yr mission orbits of the ASTROD-GW spacecraft are worked out by us. And with this, we have performed the numerical simulation of time-delay interferometry under the CGC2.7 (CGC: Center for Gravitation and Cosmology) ephemeris framework.