26. Estimates provided to the committee by NASA representatives suggest that a Mars sample return mission would likely cost $3 billion to $5 billion. Given the Mars Exploration Program’s current budget, a Mars sample return mission would likely require that NASA bank the resources of three to five Mars launch opportunities. Implementing such a strategy would have numerous scientific, technical, programmatic, political, and budgetary pitfalls. Some have argued that a sample return mission will cost far more than NASA’s current estimates, whereas others have argued that a simple “grab sample” can be acquired at far less cost. Commenting on the realism of these competing claims and the scientific usefulness of grab samples versus carefully selected samples is beyond the scope of this current study.
27. See, for example, NASA, The Vision for Space Exploration, National Aeronautics and Space Administration, Washington, D.C., 2004, inside front cover.
28. NASA, 2006 Strategic Plan, National Aeronautics and Space Administration, Washington, D.C., 2006.