Vasco da Gama In Situ Mars Explorer Vd

Vasco da Gama In Situ Mars Explorer Vd. G: ISME - July 2004 0

Scientific Goals • Follow the Carbon – Methane, Other Organics – Possible association with water • Link carbon and geological features to possible extant and extinct life Vd. G: ISME - July 2004 1

Roadmap • Precursor Mission & Assumptions • Landing site discussion – Scientific and Technical Justifications • Rover concept • Payload package – Bioscience and Geochemical Science • Summary Vd. G: ISME - July 2004 2

Precursor mission • Spaced-based remote sensing (in development) – Avoids terrestrial atmospheric extinction – Spatially resolved measurements of atmospheric CH 4 and photochemical products on Mars (Organics Origin Observatory) • Fundamental assumption and problem definition – Precursor space-based mission has spatially resolved methane gradients, focusing the search for carbon reservoirs in potential Vd. G: ISME landing sites Vd. G: ISME - July 2004 3

Landing Sites • Equatorial Meridiani – Relatively near Opportunity • Hale Crater Gullies – 35 o S, 324 o E Vd. G: ISME - July 2004 4

Landing Sites Vd. G: ISME - July 2004 5

Scientific Justification: Meridiani • Atmospheric CH 4 localization assumed – Interesting even if this is not assumed • Nature of hydrogen detection? • Relatively warm • Surface sulfates, hematite co-localized – Carbonates below these? • Aqueous precipitates can preserve micro-fossils (Squyres 2004, Int’l School for Astrobiology) Vd. G: ISME - July 2004 6

Hale Crater Gullies • Again, assumed CH 4 (although very tentative “current-day” detections indicate equatorial presence) • Possible water signatures (possible carbonates) • Natural surface excavation • Possible hydrothermal alteration Vd. G: ISME - July 2004 7

Malin and Edgett 2000 Gullies Vd. G: ISME - July 2004 8

Technical Justification-Landing • Landing error ellipse shrunk to 5 km x 10 km – Practical, uncomplicated, low-mass methods to increase accuracy – Navigation telemetry from existing positions to increase transverse accuracy – Closed-loop navigation system to respond to sensed variations in atmospheric density (Squyres 2004, personal communication) Vd. G: ISME - July 2004 9

Hale Landing • Feasible – Smaller error ellipse – Increased rover range Vd. G: ISME - July 2004 Edgett et al. 2003 10

The Rovers • Science payloads identical • Both have slope-climbing abilities • Powered by RTGs – Eliminates low-latitude and nighttime operations as a hazard – Heavier spacecraft, but increases operational parameters • Digging scoop – depth 1 m in regolith Vd. G: ISME - July 2004 11

Instrumentation • Main body – Pancam copy, Mini mid IR TES (MMIRTES) – Raman analysis and multi-range sensing package (up to 100 m) – GCMS • rock-crushing package – Circular Dichroism Filter Set Spectrometer – 96 well culture plates, geared towards autotrophic methanogens Vd. G: ISME - July 2004 12

Instrumentation • Manipulator arm – Microscope with fluorescence capabilities – Raman Capabilities (via fibre optics) – Mössbauer – APXS with micron sized mapping – Sample manipulation Vd. G: ISME - July 2004 13

Raman • Complements MMIRTES • Organics • Minerals Vd. G: ISME - July 2004 Ellery & Wynn-Williams 14 2003

GCMS NAP Signs of Life, Moldowan Vd. G: ISME - July 2004 15

H 2/CO 2 atmosphere shielded from martian surface radiation Moveable 100 x microscope 500 u. L media: Combinations of organic rich, organic poor, nitrates, and phosphates Tiny Mars rock (~1 mm) DAPI, (gradual sonication) Light source (for microscopy) Vd. G: ISME - July 2004 16

Summary • Precursor methane localization • Twin Rovers – Meridiani & Hale Crater gullies • Rovers – Climbing capabilities – Enhanced power – Enhanced instrument package (Raman, GCMS, Fluorescence) • Dual biological and geological payload Vd. G: ISME - July 2004 17