HALCA

HALCA (for Highly Advanced Laboratory for Communications and Astronomy, also called VSOP for VLBI Space Observatory Program) was a Japan Aerospace Exploration Agency (JAXA) 8-meter space radio telescope designed to participate in very-long-baseline interferometry observation in conjunction with ground radio telescopes. It was launched in 1997 and operational until 2005. HALCA was presumed to be just the first satellite of the VLBI Space Observatory Program and a follow-on (VSOP 2, VSOP B, aka Astro G) was designed but canceled. More recently the Russian satellite Spektr-R carried out such VLBI observation.