A high fidelity computational model and simulation of the whole human spine was created and validated for the purpose of investigating the mechanical integrity of the spine in crew members during exploratory space missions. As the spine adapts to spaceflight, morphological and physiological changes cause the mechanical integrity of the spinal column to be compromised, potentially endangering internal organs, nervous health, and human body mechanical function. Therefore, a spaceflight exposed spine has been developed through the adaptation of a finite element model of a healthy ground-based human spine in vivo. Simulation of intervertebral disc porohyperelastic response to mechanical unloading resulted in a model capable of accurately predicting spinal swelling/lengthening, spinal motion, spinal modes and internal stress distribution. Native biomechanics of this space adaptation exposed spine model were compared to a control terrestrial-based finite element model, indicating the potential of injuries to be seen in spaceflight crew members.