Thornton, William M.D.2018-10-022018-10-021989-06-12https://hdl.handle.net/2152.3/10239A draft document from Dr. Thornton to the Director of Flight Crew Operations regarding concerns over Current STS Crew Operation and safety.Dr. William ThorntonSpace MedicineSTS Crew Operationsafety egressMissionsSpace Shuttledraft