Sign by the Lower Body Negative Pressure experiment.  It reads
    
    
    
    
    
    
    
Lower Body Gravity Pressure Tank
    
    
    
    Skylab astronauts put
    their lower body into this tank, and a partial vacuum, simulating
    gravity, caused blood to pool in their legs.  Circulation and heart rate were
    then monitored.  The equipment on display is an exact duplicate of that used on
    Skylab.