1. Aldrich , A. D. NASA Office of Aeronautics, Exploration, and Technology, The Space Exploration Initiative February 17, 1990 4
2. For example, the Space Studies Board of the National Academy of Sciences and the Synthesis Group, a committee chartered by the White House and NASA to examine alternative ways to establish a lunar base and reach Mars. See America at the Threshold (Washington, DC: The White House June 1991
3. Bailey , S. et al. Artemis, Common Lunar Lander Phase 2 Study Results , NASA-JSC March 10, 1992
4. Draper , R. F. The Mariner Mars 11 Program , AIAA Paper 88-0067 January 1988
5. Bourke , R. D. Kwok , J. H. Friedlander , A. Mars Rover Sample Return Mission AIAA Paper 89-0417 January 1989