Space materials research: hanging by a thread.
D005380:Financing, Government / Q000191:economics*; D006078:Government Programs / Q000458:organization & administration* / Q000639:trends; D008420:Manufactured Materials; D012106:Research / Q000191:economics* / Q000458:organization & administration / Q000639:trends; D013026:Space Flight / Q000458:organization & administration* / Q000639:trends; D014481:United States; D018557:United States National Aeronautics and Space Administration / Q000458:organization & administration* / Q000639:trends; D014893:Weightlessness