HALCA (Highly Advanced Laboratory for Communication and Astronomy), a.k.a. VSOP (Very Large Baseline Interferometry Space Observatory Programme) or Muses-B, is the first astronomical satellite dedicated to Very-Long Baseline Interferometry (VLBI). It was launched on its maiden flight by ISAS's M-5 [KM-V1] launch vehicle from Kagoshima Space Center on 12 February 1997.

As suggested by its development name MUSES-B, the satellite is the second in the series of ISAS's Mu Space Engineering Satellites. Since the satellite's successful deployment, in particular the main reflector mesh, and the testing of new engineering technologies incorporated within it, such as the two-way communications link between the satellite and tracking stations, HALCA has been used for space VLBI observations.