Space Vlbi Satellite Halca and its Engineering Accomplishments

Abstract

The Institute of Space and Astronautical Science (ISAS), Japan, launched a satellite named HALCA in February 1997 by the ISAS's new rocket M-V. It has become the first space Very Long Baseline Interferometry (VLBI) satellite of the world by accomplishing a series of engineering experiments, representative ones of which are deployment of 8 m diameter parabolic antenna, precise attitude control of spacecraft, transfer of phase reference signal, high data-rate telemetry, single dish telescope operation, and interferometry with ground radio telescopes. Following the successful engineering experiments, HALCA has been operated for science observations under the science program named “VSOP” (VLBI Space Observatory Programme) in cooperation with many organizations and radio telescopes around the world.