MARS SAMPLE RETURN PROGRAM

Summary recommendations made by Mike Drake based on discussion with an integration team made up of Geoff Briggs, Chris McKay, Carolyn Porco, and Heinrich Wänke.

MARS SAMPLE RETURN PROGRAM

Focus:

• Did life ever get started on Mars?
  • is it still there?
  • what geological and climatological conditions led to its formation and sustenance, or the lack thereof?

• search for chemical, isotopic, physical indicators of life
• characterize Martian geological environment through time
• characterize Martian climatological environment through time
• evaluate resources for current robotic, future human exploration

GENERALLY AGREED-UPON GROUND RULES

• do not design a program that would generate the perception of failure early or ever - both finding and not finding life must be success indicators
• phased approach with measurable goals towards "the prize" with each mission
• inclusive strategy - most (all?) planetary science disciplines have contributions to make

GENERALLY AGREED-UPON FIRST MISSION CHARACTERISTICS

• homogeneous site of larger area than landing ellipse
• three broad classes of landing site
  • volcanic terrains
  • ancient brecciated highlands
  • ancient lake beds
• simple sample identification
• simple sample acquisition
• currently-planned orbital and lander missions will provide adequate data for site selection
• 2001 (and 2003?) lander to first sample return site
• do not now need to establish exact site or sample return mission sequence

FIRST MISSION

• demonstrate end-to-end sample return capability
• look for evidence of past life as part of planetary protection studies
• prove or disprove SNC/Mars connection

LAKE-BED MISSION OPPORTUNITY

• lander with rover
• collect sample of atmosphere, loose soil, duricrust, one-or-more sediments
• either return samples or beacon beckons next mission
• accomplishments (not exclusive)
  • characterize sediment mineralogy, petrology, geochemistry, formation process
  • get age (?) of well-characterized surface - tie down crater- based chronology
  • search for past life - stable isotopes, physical fossils
  • calibrate "ground truth" for orbiting, in situ instruments
• dangers (not exclusive)
  • high elevation site could be tricky
  • we don't know there are coherent lake sediments
  • we don't know that we can sample sediments

VOLCANIC AREA MISSION OPPORTUNITY

• lander with rover
• collect sample of atmosphere, loose soil, duricrust, one-or-more hard rocks
• either return sample or beacon beckons next mission
• accomplishments (not exclusive)
  • search duricrust for stable isotope evidence of past life
  • search for past magnetic field (imp. for life)
  • characterize hard rock mineralogy, petrology, geochemistry, formation process
  • get age of well-characterized surface - tie down crater-based chronology
  • calibrate "ground truth" for orbiting, in situ instruments
• dangers (not exclusive)
  • Goldin, Congress, public might get bored if we find a SNC but no life

ANCIENT HIGHLAND BRECCIA MISSION OPPORTUNITY

• lander with rover
• collect sample of atmosphere, loose soil, duricrust, one-or-more breccias and other rocks
• either return samples or beacon beckons next mission
• accomplishments (not exclusive)
  • characterize highland igneous, mineralogy, petrology, geochemistry, breccia formation process
  • get age (?) of well-characterized surface - tie down crater- based chronology
  • search for past life (?) - hydrothermal alteration?
  • calibrate "ground truth" for orbiting, in situ instruments
  • get sample of ancient as well as modern atmosphere
• dangers (not exclusive)
  • high elevation site could be tricky
  • we don't know there are coherent breccias
  • we don't know that we can sample breccias

SUBSEQUENT OPPORTUNITIES

• TBD
  • hot spring deposits
  • hydrothermally altered areas
  • ????????????

ISSUES NEEDING THOUGHT

• Sample Return in 2003?
  • INTERMARSNET?
  • too expensive?
  • too fast?
  • collect in 2003, return in 2005?
  • reconnaissance in 2003, collect samples in 2005?
• recommendation
  • Science and Implementation (McCleese) Committee to study the following for each proposed class of landing site
    • sample identification
    • sample selection - which samples to bring back - masses
    • sample acquisition
    • sample container sealing
    • trade of large volume/mass atmosphere sample for more solid matter
    • sample return cruise environment
    • sample curation
      • JSC?
      • CDC?
    • development and purchase of laboratory instruments

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