MER 2003 Slide 1

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Mars Exploration Rover Project Science
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Comparison MER Rover and Pathfinder Sojourner
Rover
185 kg, 157 cm tall cameras 154 cm above
surface 9 cameras (1024x1024) 3 spectrometers
11 kg, 32 cm tall cameras 25 cm above the
ground 3 cameras (768 x 484) 1 spectrometer
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Key Features

• Two identical landers launched in May-July 2003
• Targeted to two sites on Mars, landings in
  January 2004
• Delivered to the Martian surface using Mars
  Pathfinder lander architecture
• Each delivers a highly capable rover carrying the
  Athena payload
• On a mast
• Camera and infrared spectrometer
• On a 5-degree-of-freedom robotic arm
• Spectrometers, Microscopic Imager, Rock Abrasion
  Tool
• On the rover
• Magnet array, calibration targets
• Two surface missions of 90 Martian days each

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Mission Overview

• MER-A
• Launch on a Delta II 7925 Launch Window May
  30 to June 16, 2003
• Arrive January 4, 2004
• Latitude band 15S to 5N
• MER-B
• Launch on a Delta II 7925H Launch Window June
  25 to July 12, 2003
• Arrive January 25, 2004
• Latitude band 10S to 10N
• Mass (each)
• Launch 1063 kg, Rover 185 kg, Payload 15 kg (not
  including arm, mobility)
• Capability per mission
• 90 sols of science operations (after landing sol)
• 600 meter odometer traverse (system qualified
  to 1000 meters)
• 4 distinct locations (including landing
  location)
• 6 targets one soil, five rockone of which is
  abraded
• 3 Gbits total data return (more for MER-A)
• Your mileage may vary

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Science Objectives

• Search for and characterize a diversity of rocks
  and soils that hold clues to past water activity
• Investigate landing sites which have a high
  probability of containing physical and/or
  chemical evidence of the action of liquid water
• Determine the distribution and composition of
  minerals, rocks, and soils
• Determine the nature of local surface geologic
  processes
• Calibrate and validate orbital remote sensing
  data and assess the heterogeneity
• Identify and quantify iron-bearing minerals
  indicating aqueous processes
• Characterize mineral assemblages and textures in
  the geologic context
• Extract clues related to past environmental
  conditions and assess whether past environments
  were conducive for life

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How the Objectives are Met
Choose a landing site that shows clear evidence
for the action of liquid water, and use the
instruments to search for and characterize a
diversity of rocks and soils that hold clues to
past aqueous activity and biological potential at
the site. Use color images and hyperspectral
mid-IR panoramas to study the sites geology, and
to select targets whose mineralogy and texture
are most likely to yield clues to processes of
formation and alteration. Drive the rover to
those targets and examine them in detail using
the full suite of instruments.
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Potential Landing Site Candidates
Coarse-grained hematite identified by TES, likely
formed by an aqueous process Possible water-lain
sediments in the valley floor of Valles
Marineris Possible sedimentary lakebeds in
craters
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Science Payload

• Multicolor images and infrared spectroscopic
  panoramas reveal the diversity of materials
  around the rover, and provide geologic context.
  These remote sensing data are used to select the
  most promising rock and soil targets for closer
  examination.
• Panoramic imager (Pancam)
• Panoramic mid-infrared spectrometer (Mini-TES)
• Then, the rover drives to selected targets and
  investigates them in more detail with the full
  instrument set, including close-up examination
  using instruments on the robotic arm. A rock
  abrasion tool can expose fresh rock surfaces.
• Mössbauer Spectrometer (MB)
• Alpha Particle X-Ray Spectrometer (APXS)
• Microscopic Imager (MI)
• Rock Abrasion Tool (RAT)
• The science instruments also analyze the magnetic
  components of the dust.
• Magnet Array

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Remote Sensing Payload Elements

• Panoramic Camera (Pancam)
• Geologic context, rock and soil texture,
  iron-bearing mineralogy
• 15 color filters, visible to near-infrared (0.4
  1.1 mm)
• 1024?1024 CCDs
• Field of view 16º x 16º, 0.28 mrad/pixel (3?
  higher resolution than Mars Pathfinder imager)
• Mini Thermal Emission Spectrometer (Mini-TES)
• Mineralogy (silicates, clays, carbonates, salts,
  etc.)
• Panoramic point infrared spectrometer
• 5-29 µm, 10 cm-1 spectral resolution
• 8 and 20 mrad angular resolution modes

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Using Pancam and Mini-TES Together
Pancam Image Panorama
Hi-resolution, local Mini-TES coverage
Lo-res, wide-area Mini-TES coverage
Full spectrum for each Mini-TES pixel
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Payload Elements on the Robotic Arm

• Mössbauer Spectrometer
• Identify iron-bearing minerals
• Determine Fe2 /Fe3
• 1.5 cm FOV
• Alpha Particle X-ray Spectrometer (APXS)
• Elemental composition
• 4 cm FOV
• Microscopic Imager
• Microscale texture
• 1024?1024 CCD, 30 ?m/pixel resolution
• Focus by taking images at different distances

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Payload Elements on the Robotic Arm, contd.

• Rock Abrasion Tool (RAT)
• Exposes fresh rock over an area 4.5 cm in
  diameter, to a depth of 0.5 cm
• Mechanical grinding teeth and self-contained
  actuation
• Robotic arm provides fixed placement of RAT
  against a rock with a small (several newtons)
  preload force
• Grinds through hard volcanic rock in about 2
  hours

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Instrument Deployment Device
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Data From MER Flight Instruments
Pancam image mosaic
Pancam color image
Mini-TES mineralogy image
Mössbauer spectrum (hematite)
Mini-TES spectrum (limestone)
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Interpreting the Data
Together, composition and morphology reveal the
environmental conditions under which rocks and
soils were formed and altered Specific minerals
require distinct environmental conditions and
chemical pathways for their formation and
alteration (e.g., temperature, pressure, presence
of liquid water) Elemental chemistry constrains
mineral proportions and rock type, and provides
clues to the conditions of formation and
alteration. Fine-scale textures also yield
information on environmental conditions.
For example, size, angularity, sorting, and shape
of grains in aqueous sediments reveal conditions
of transport and deposition. Geologic context
from panoramic sensors ties it all
together. Identification of past environmental
conditions allows assessment of former climate,
water activity, and biological potential.
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Mars Exploration Rover Firsts

• Much greater mobility capability on the surface
  than weve had before
• First remote sensing spectrometer on the surface
  A high spatial spectral resolution mid-infrared
  panoramic spectrometer
• Stereo color panorama at 3x higher spatial
  resolution than ever before
• First look at mineralogy, texture, and
  composition of the interiors of rocks and
  comparison to their exteriors
• First hand lens on Mars Examination of rocks
  and soils on Mars at 10x higher spatial
  resolution than ever before
• First unambiguous in-situ identification of
  Fe-bearing minerals (Mössbauer spectrometer)
• First high-quality elemental analysis (APXS)
• First in-situ ground-truth mineral identification
• First determination of mineralogy of the magnetic
  component of the airborne dust