Animals have been used in space research since the earliest orbital flights, with welfare challenges from launch stress, microgravity effects, radiation exposure, and limited veterinary care in space environments.
Space research animals face welfare challenges that are unique to the environment: launch stress, sustained microgravity, radiation exposure, and isolation from normal sensory environments, with limited immediate veterinary intervention capacity. The welfare framework for space research animals has improved substantially from the early orbital missions where animal welfare was secondary to mission success. Modern space animal research applies 3Rs principles, requires welfare assessment from launch through recovery, and limits procedures to those that cannot be replicated in ground-based simulations. As commercial spaceflight expands the space research environment, welfare standards will need to keep pace with new actors and contexts.