  We present 5 GHz space-VLBI observations of the quasar pair
B1342+662/B1342+663 that demonstrate the feasibility of phase-reference
techniques using an antenna in space. The space-based data were taken by the
satellite HALCA, of the space-VLBI mission VSOP. From residual (referenced)
phases we derive an upper bound of 10 meters to the uncertainty of the
spacecraft orbit reconstruction. An analysis of the phase-reference maps of the
sources additionally suggests that the above mentioned uncertaintyis likely not
larger than 3 meters. With errors of this magnitude, HALCA is a useful tool for
astrometric studies of close pairs of radio sources.
