# Presentation: 716406

## Mars Exploration Rover

- Project Science

## Comparison: MER Rover and Pathfinder Sojourner Rover

- 11 kg, 32 cm tall
- cameras  25 cm above the ground
- 3 cameras (768 x 484)
- 1 spectrometer

- 185 kg, 157 cm tall
- cameras 154 cm above surface
- 9 cameras (1024x1024)
- 3 spectrometers

## 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**

## Mission Overview

**MER-A**
**Launch on a Delta II 7925    Launch Window: May 30 to June 16, 2003**
**Arrive January 4, 2004**
**Latitude band 15°S to 5°N**
**MER-B**
**Launch on a Delta II 7925H    Launch Window: June 25 to July 12, 2003**
**Arrive January 25, 2004**
**Latitude band 10°S to 10°N**
**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 rock—one of which is abraded**
**~ 3 Gbits total data return (more for MER-A)**
**Your mileage may vary**

## 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

## 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 site’s 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.

## 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**

## 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**

## 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 m)
- 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

## Using Pancam and Mini-TES Together

- Pancam Image Panorama

- Lo-res, wide-area Mini-TES coverage

- Hi-resolution,
- local
- Mini-TES
- coverage

- Full spectrum for each
- Mini-TES pixel

## 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

## Payload Elements on the Robotic Arm, cont’d.

**	****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

## Instrument Deployment Device

## Data From MER Flight Instruments

**Data From MER Flight Instruments**

- Mini-TES spectrum
- (limestone)

- Mössbauer spectrum
- (hematite)

- Mini-TES
-  mineralogy image

- Pancam
- image mosaic

- Pancam
- color image

## 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.**

## Mars Exploration Rover “Firsts”

- Much greater mobility capability on the surface than we’ve 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