In the 8-d flight mission of Spacelab-J (STS-47) conducted in 1992, behavior of the dorsal light response (DLR) and EEG activity of the cerebellum were intermittently examined for two carp, normal and otolith-removed. The latter carp had immobilization trouble caused by twisting of the EEG cable on day 2 inflight. The problem continued for the remainder of the experiment. Analyses made on the normal carp provided additional evidence in fish for sensory-motor disorder and readjustment during early phase of microgravity, thus supporting the sensory conflict hypothesis for space motion sickness. In the present report, why and how this space experiment was conducted were reviewed with a brief summary of the results.