Rocky 7 - Mojave Desert Field Experiments MOJAVE FIELD EXPERIMENT PLANS FOR JPL PROTOTYPE MARS ROVERS

CONTENTS

1. SUMMARY
2. INTRODUCTION
3. BACKGROUND DISCUSSION
4. FIELD EXPERIMENT PLANS
5. LONG RANGE ROVER TASK GROUP
6. SCIENCE ADVISORY GROUP
7. EXPECTED RESULTS

1. SUMMARY

The Rocky series of prototype Mars rovers, developed by the Jet Propulsion Laboratory (JPL), is the subject of a set of field experiments in the Mojave Desert to test rover operations, measurements, and sample collection technologies to be used on Mars rover missions. This project has been undertaken jointly by the JPL Long Range Science Rover Task Group, led by Dr. Samad Hayati of JPL, and the Science Advisory Group for Rover Field Experiments, led by Dr. Raymond Arvidson of Washington University. This document presents the five-year plan for Mojave field deployments and associated experiments.

Objectives for each deployment are focused on traverses, measurements, and sample collection approaches designed to better understand how to conduct rover missions on Mars. The Mojave is used because of its proximity to JPL and because the area includes sites that are analogs for primary rover targets on Mars, especially sites with landforms and deposits indicative of past wet climatic regimes and extensive alteration of rocks by hydrothermal processes.

Deployments build on the December 1996 (initial field check out studies) and May 1997 (1 km traverse) experiments with Rocky 7 at Lavic Lake, a dry lake bed, and surrounding lava flows and alluvial fans. The 1998 deployment with Rocky 7 will be to Silver Lake and associated ancient shoreline deposits. A 5 km traverse will occur during the 1998 deployment, using multispectral imaging, a point spectrometer bore sighted with the imager, and perhaps an arm mounted Raman Spectrometer. Some sample manipulation will take place, using an arm capable of acquiring soil samples and turning over and pushing rocks. In 1999 a site will be visited using remote sensing instrumentation and a sample acquisition system capable of breaking and or drilling into rocks and caching samples. The 2000 deployment will be a rehearsal of the 2001 rover mission to Mars. In all cases, the test sites will be examined by a science team using orbital and airborne remote sensing data sets that simulate acquisition of morphologic, mineralogic, and descent imaging data for Mars. Tests will be conducted in a blind mode where possible, simulating the "data-limited" environment expected during Mars rover missions. Results from all field experiments, including data, interpretations, and lessons learned (quantitative and qualitative) are archived with the Planetary Data System (PDS) and posted for general access on this Web site (http://wundow.wustl.edu/rocky7/). The overall efforts are guided by the Science Advisory Group that reports to the Mars Surveyor Program Office and Advanced Technology Program Office (TAP).

2. INTRODUCTION

The Mars Surveyor Program is embarking on a plan for Mars rovers to be launched during the 2001 and 2003 opportunities. The rovers will traverse 10 or more kilometers, making imaging, mineralogic and chemical measurements in terrains selected to test the idea that Mars once supported fluvial and lacustrine environments and/or that hydrothermal systems may have sequestered volatile species. The rovers will also collect and cache samples for a return mission to be launched in 2005.

This document describes a series of field experiments in the Mojave Desert in California. The purpose of these field experiments is to use selected sites over the next five years to test rover operations, key navigation, surface and sample measurements, and sample collection and caching technologies before they are used on Mars. The efforts are coordinated by a Science Advisory Group that reports to the Mars Surveyor Program Office and the Advanced Technology Program Office (TAP). Work began in December 1996 in the Lavic Lake area with testing of basic rover operations, using Rocky 7. Further tests occurred in May 1997 in the same area with more extensive science and engineering objectives.

3. BACKGROUND DISCUSSION

Important challenges are associated with the Mars Surveyor Program rover and sample return missions. At the rover level, experiments in natural environments are needed to test the ability of the vehicle to traverse many kilometers. The extent to which orbital and descent imaging should be used to define traverses needs to be evaluated. The ability to conduct field geology from the data-limited environment of rovers needs to be explored, including the partitioning of measurements that focus on imaging and point spectroscopy as opposed to in-situ measurements of chemistry and mineralogy. Methods must be developed for selecting, manipulating, and storing samples for eventual return to Earth. The work can be done in part in laboratory settings and in the JPL Mars Yard; however, field experiments in which the systems are tested together, under mission-like conditions, are important for learning how to best accomplish rover objectives on Mars.

The Mojave Desert is conveniently close to JPL and offers numerous sites suitable for prototype Mars rover operations. Although the area is currently dry, it once supported interconnected lakes during the Pleistocene glacial periods. The abundance of sites with lacustrine deposits (including ancient shorelines), relict fluvial and alluvial surfaces, basaltic volcanism, and aeolian materials makes the area an excellent analog for the types of surfaces expected on Mars. The Desert also contains areas that have been subjected to extensive hydrothermal activity. All these sites are useful for making the types of measurements needed to test hypotheses related to climatic changes and the extent to which hydrothermal systems have operated on Mars.

4. FIELD EXPERIMENT PLANS

Table 1 summarizes the objectives and scope of the field experiments. The sites and instrumentation beyond the spring 1998 field tests will be selected after consultation with the 2001 rover science team and the Science Advisory Group.

TABLE 1-SUMMARY OF MOJAVE EXPERIMENT PLANS

5. LONG RANGE ROVER TASK GROUP

The Long Range Rover Task Group at JPL, led by Dr. Samad Hayati, builds and operates Rocky rovers. They are in charge of rover operations during the field experiments. They also decide whether or not a given instrument or system can be integrated with the rover as opposed to making measurements apart from the rover during the field experiments. The efforts are under the TAP Program managed by Charles Weisbin.

6. SCIENCE ADVISORY GROUP

The Science Advisory Group for Rover Field Experiments is led by Dr. Raymond Arvidson, Interdisciplinary Scientist for the Mars Surveyor Program and head of the Planetary Data System Geosciences Node. It includes a small group of scientists (Table 2) and reports to R. Stephen Saunders as the In Situ Study Scientist, JPL, on behalf of Daniel McCleese, Mars Surveyor Program Scientist and to Charles Weisbin, head of the TAP Program. On a practical basis it provides advice to the Long Range Rover Task Group for field experiments. It also forms science teams composed of instrumentation investigators to conduct field experiments. It selects instrumentation for field experiments based on relevance to specific field objectives and directions defined by the Mars Surveyor and TAP Programs.

TABLE 2-SCIENCE ADVISORY GROUP

7. EXPECTED RESULTS

The results of the Mojave Desert Field Experiments will include (1) advice on key technologies to pursue to meet the Mars rover science objectives; (2) rigorous tests of the rovers and instrumentation in the field; (3) reports published on the Web and in hard copy that document field experiment plans and results; and (4) delivery of documented archives to the PDS for distribution to the science community. The PDS Geosciences Node at Washington University is responsible for archiving and posting plans, archives, and results on this Web site (http://wundow.wustl.edu/rocky7/).

Specific advice and tasks to be provided by the Science Advisory Group include:

• Orbital and descent imaging requirements for traverse definition and for operations
• The appropriate balance of measurements from rovers that focus on imaging and point spectroscopy as opposed to in situ measurements of chemistry and mineralogy
• Methods by which samples for eventual return to Earth are selected, manipulated, and stored
• Development of Mars surface operations strategies
• Training of rover science flight teams