PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011

Contact: Diane Ainsworth

February 26, 1997


      Thirteen participating scientists and a six-member team of experts dedicated to studying the atmosphere and weather on Mars will enhance the scope of scientific investigations as new members of NASA's Mars Pathfinder mission.

      The scientists, selected from about 60 proposals submitted to NASA in response to an announcement of opportunity, will augment the existing science teams, direct new investigations not covered by the present teams, and perform interdisciplinary investigations using one or more instruments onboard the lander and rover.

      "The purpose of the Participating Scientist Program is to allow the expansion of existing principal investigator teams as they enter the active period of mission operations, data collection, analysis and archival activities," said Dr. Matthew Golombek, Pathfinder project scientist at NASA's Jet Propulsion Laboratory. "These newcomers have a variety of interdisciplinary interests and areas of expertise that will augment our first direct studies of Mars in more than 20 years."

      Mars Pathfinder, launched from Cape Canaveral, FL, on Dec. 4, 1996, is currently en route to the red planet and scheduled to land in an ancient flood basin called Ares Vallis on Independence Day. The lander carries a small rover that will roll off and explore its surroundings, and science instruments that will measure the composition of surface materials in a landing area that is hundreds of square meters in size. Direct measurements on the ground will establish what scientists call "ground truth," or validation of geologic features that will be studied from space by a companion orbiter, known as Mars Global Surveyor, and future orbiters.

      Pathfinder's science instruments include a stereo imager called IMP, or Imager for Mars Pathfinder, mounted on an extendible mast on the lander, with 12 spectral filters for each "eye," an alpha proton X-ray spectrometer on the rover, and an atmospheric structure instrument and meteorology package. In addition, the rover carries forward stereo cameras and a rear color camera and performs a variety of technology and mobility experiments so that future rovers may be developed to more effectively navigate the surface.

      Using these instruments, the newly selected investigators will carry out a variety of studies along with the existing imaging and spectrometry teams to understand more about the composition of the Martian surface, the structure of the Martian atmosphere and prevailing weather patterns on this planetary neighbor.

      The science and technology investigations will be used to better understand:
      - Mars surface morphology and geology at the scale of centimeters and meters, such as soils, rocks and hills, as well as their size and distributions on the surface.
      - The composition and mineralogy of rocks, soil and surface materials using the spectral filters of the lander imager and the alpha proton X-ray spectrometer measurements.
      - Basic soil mechanics and the magnetic properties of Martian dust. Soil mechanics such as cohesion, angles of internal friction and slippage will be determined by the rover. A series of magnets placed on the spacecraft will be imaged to determine the magnetic properties of dust that adheres to the wheels.
      - The structure of the Martian atmosphere will be measured during entry and descent to understand variations in temperature, pressure and density with respect to altitude.

      After landing, a meteorology package will tell scientists about the weather on Mars. Imaging wind socks will show the wind profile up to a meter above the surface. Imaging the atmosphere will determine aerosol characteristics, such as size and shape of airborne dust and water vapor abundance.

      Tracking of lander telemetry signals will allow measurements of Pathfinder's location in space and the location of the pole of Mars. After a few months of tracking, scientists will be able to infer the interior structure of the planet and whether Mars possesses a metallic core.

      In addition to the 13 new science members, six atmospheric scientists will become part of the Facility Instrument Science Team, which was selected to conduct instrument investigations to optimize operations and the science return from Pathfinder's Atmospheric Structure Instrument/Meteorology Package (ASI/MET) experiment. They will conduct the initial scientific analyses of data and produce calibrated, referenced data that can be used by the entire scientific community.

      A complete list of selected scientists from all over the United States and Europe, including the names of their investigations and the scientists' home institutions, follows. Additional information about the Pathfinder mission is available on the World Wide Web at

      The Jet Propulsion Laboratory manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C.

2/18/97 DEA

Participating Scientists Program

Rock and boulder populations study, M. Malin, Malin Space Science Systems, Inc., San Diego, CA.

Mars Pathfinder wind sock experiment: Characterization of aeolian processes at the landing site, R. Sullivan, Arizona State University, Tempe.

Normative mineralogy of Mars Pathfinder rocks, H. McSween, University of Tennessee, Knoxville.

Mineralogy of the Mars Pathfinder landing site, J. Bell, Cornell University, Ithaca, NY.

Rover science and exploration, H. J. Moore, US Geological Survey, Menlo Park, CA.

Geological implications of the Pathfinder magnetic experiments, R. Hargraves, Princeton University, Princeton, NJ.

Tracking Pathfinder to study Martian interior and climate, W. Folkner, NASA Jet Propulsion Laboratory, Pasadena, CA.

Geologic investigations using lander imager photographs of Phobos and Deimos, S. Murchie, Applied Physics Laboratory, Laurel, MD.

Virtual reality on Mars Pathfinder, C. Stoker, NASA Ames Research Center, Mountain View, CA.

Mars Pathfinder: Photogrammetric characterization of the landing site and geoscientific evaluation of imaging data, R. Jaumann, DLR Institute for Planetary Exploration, Berlin, Germany.

Investigation of Mars atmosphere structure, A. Seiff, NASA Ames Research Center, Mountain View, CA.

Comparison between Mars and Earth atmospheric surface boundary layers, S. Larsen, Risoe National Laboratory, Roskilde, Denmark.

Mars atmosphere thermal tidal studies, R. Haberle, NASA Ames Research Center, Mountain View, CA.

Atmospheric Structure Instrument/Meteorology Package (ASI/MET) Facility Instrument Science Team

Meteorological variability in the Martian subtropics, J. Barnes, Oregon State University, Corvallis, OR.

An investigation of the structure of the upper atmosphere of Mars, J.T. Schofield, NASA Jet Propulsion Laboratory, Pasadena, CA.

Pathfinder ASI/MET thermal balance experiment, D. Crisp, NASA Jet Propulsion Laboratory, Pasadena, CA.

Studies of the Martian boundary layer: Heat and momentum fluxes, G. Wilson, Arizona State University, Tempe.

Reduction and analysis of Mars Pathfinder atmospheric structure data, J. Magalhaes, NASA Ames Research Center, Mountain View, CA.

Diurnal variations in Mars Pathfinder meteorology data, J. Murphy, NASA Ames Research Center, Mountain View, CA.

Primary Pathfinder Science Teams

Imaging Team: Drs. Peter Smith, principal investigator, and co- investigators D. Britt, L. Soose, R. Singer and M. Tomasko, University of Arizona, Tucson; R. Greeley, Arizona State University, Tempe, who provided the wind socks; H.E. Keller, Max Planck Institute for Aeronomie, Germany, who provided the charged couple device and associated electronics; F. Gliem, Technical University of Braunchweig, Germany, who provided the image compression software; J.M. Knudsen, University of Copenhagen, Denmark, who provided the magnets; and L. Soderblom, U.S. Geological Survey, Flagstaff, AZ.

Alpha Proton X-Ray Spectrometer Team:

Drs. Rudolf Rieder, principal investigator, and co- investigator H. Waenke, both of the Max Planck Institute for Chemistry, Germany; and co-investigator T. Economou, University of Chicago, who is providing the x-ray portion of the instrument.