To investigate changes in spatial orientation ability and walking perf
ormance following space flight, 7 astronaut subjects were asked pre- a
nd post-flight to perform a goal directed locomotion paradigm which co
nsisted of walking a triangular path with and without vision. This new
paradigm, involving inputs from different sensory systems, allows qua
ntification of several critical parameters, like orientation performan
ce, walking velocities and postural stability, in a natural walking ta
sk, The paper presented here mainly focusses on spatial orientation pe
rformance quantified by the errors in walking the previously seen path
without vision, Errors in length and reaching the corners did not cha
nge significantly from pre- to post-flight, while absolute angular err
ors slightly increased post-flight, The significant decrease in walkin
g velocity and a change in head-trunk coordination while walking aroun
d the corners of the path observed post-flight may suggest that during
re-adaptation to gravity the mechanisms which are necessary to perfor
m the task have to be re-accomplished.