Why send humans to Mars?
Sagan
C
C
Laboratory for Planetary Studies, Cornell University, USA.
D002170:Canada; D004989:Ethics; D005060:Europe; D007391:International Cooperation; D007564:Japan; D018535:Mars; D011639:Public Opinion; D011640:Public Policy; D012109:Research Support as Topic; D012426:Russia; D013026:Space Flight / Q000191:economics*; D014481:United States; D018557:United States National Aeronautics and Space Administration / Q000191:economics