Thornton, William E. (William Edgar), 1929-2016-03-312016-03-311972http://hdl.handle.net/2152.3/622Image depicting the SL-4 pre-flight, in-flight, and post-flight postures of "SPT" (Simulation Support, Dr. William Thornton).Space flight--Physiological effect.Weightlessness--Physiological effect.Skylab Program.Space medicine.Image