vdg:isme - july 20040 vasco da gama in situ mars explorer

VdG:ISME - July 2004 1

Vasco da Gama

In Situ Mars Explorer


Scientific Goals

• Follow the Carbon– Methane, Other Organics– Possible association with water

• Link carbon and geological features to possible extant and extinct life


Roadmap

• Precursor Mission & Assumptions• Landing site discussion

– Scientific and Technical Justifications

• Rover concept• Payload package

– Bioscience and Geochemical Science

• Summary


Precursor mission

• Spaced-based remote sensing (in development)– Avoids terrestrial atmospheric extinction

– Spatially resolved measurements of atmospheric CH4 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 VdG:ISME landing sites


Landing Sites

• Equatorial Meridiani – Relatively near

Opportunity

• Hale Crater Gullies– 35o S, 324o E


Landing Sites


Scientific Justification: Meridiani

• Atmospheric CH4 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)


Hale Crater Gullies

• Again, assumed CH4 (although very tentative “current-day” detections indicate equatorial presence)

• Possible water signatures (possible carbonates)

• Natural surface excavation

• Possible hydrothermal alteration


GulliesMalin and Edgett 2000


Technical Justification-Landing

• Landing error ellipse shrunk to 5km x 10km– 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)


Hale Landing

• Feasible– Smaller error

ellipse– Increased

rover range

Edgett et al. 2003


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 1m in regolith


Instrumentation

• Main body– Pancam copy, Mini mid IR TES (MMIRTES)– Raman analysis and multi-range sensing

package (up to 100m)– GCMS

• rock-crushing package

– Circular Dichroism Filter Set Spectrometer– 96 well culture plates, geared towards

autotrophic methanogens


Instrumentation

• Manipulator arm– Microscope with fluorescence capabilities– Raman Capabilities (via fibre optics)– Mössbauer– APXS with micron sized mapping– Sample manipulation


Raman

Ellery & Wynn-Williams 2003

• Complements MMIRTES• Organics• Minerals


GCMS

NAP Signs of Life, Moldowan


DAPI, (gradual sonication)

500uL media: Combinations of organic rich, organic poor, nitrates, and phosphates

H2/CO2 atmosphere shielded from martian surface radiation

Moveable 100x microscope

Light source (for microscopy)

Tiny Mars rock (~1mm)


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

vdg:isme - july 20040 vasco da gama in situ mars explorer

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