To provide on-satellite observation equipment having a self- discrimination function for whether observation data are to be recorded or to be transmitted or not, corresponding to the characteristics of the relevant observation data without depending on a command control from the earth.

A recording discriminating means 16 comparatively collates the characteristics data of observation data extracted by an observation data characteristics extracting means 14 with reference characteristics stored in a reference characteristics storage means 15, discriminates whether or not the relevant observation data are to be transmitted to an earth station or whether or not they are recorded into an observation data recording means (mission data recorder) 17, and outputs the discriminated result as the instruction control signal (NPC) of transmission or recording.