Status Report

Science Planning for Exploring Mars

By SpaceRef Editor

July 1, 2001

Filed under Jet Propulsion Laboratory, Mars, US

JPL Publication 01-7

Note: Full report online in Adobe Acrobat format.

Foreword

This document is a collection of three white papers that capture the development of
NASA’s science strategy for exploring Mars using robotic spacecraft. These papers are
products of three science working groups chartered by NASA between 1996Ð2001. The
present collection captures the continuing refinement of NASA’s vision of Mars
exploration and the emergence of Mars as an international focus for space exploration.
The white papers are also sources of science requirements that are levied on missions to
Mars.

The strategy for exploring Mars described here is realized in a series of spacecraft that
carry instruments judged by NASA and the science community to be likely to unlock the
key questions relating to the origin and evolution of the planet and its potential for
harboring life. Specific investigations are chosen, in part, based upon the extent to which
they address questions of high priority described in the three white papers collected here.
Central to those priority questions is whether water was ever persistent on the surface of
Mars and whether, therefore, the planet was ever habitable. Simply stated, these
questions are:

When was water present on the surface of Mars?
Did water persist at the surface long enough for life to have developed?
How much and where was the water?
Where did the water go that formed the fluvial features evident on the surface
of modern Mars?

By following the history of water, robotic missions may find the environments and
specific surface sites where life might have originated and evolved.

Mars Expeditions Strategy Group

Immediately following the announcement by McKay et al. (Science 1996 August 16;
273: 924-930) that the Mars meteorite ALH 84001 appeared to exhibit signatures of past
life, NASA Administrator, Mr. Dan Goldin, asked a group of scientists to formulate a
science strategy for exploring Mars. Explicit in Mr. Goldin’s charge to the Mars
Expeditions Strategy Group (MESG) was the challenge to create a strategy that would
determine whether life had ever existed on Mars. MESG membership included some 20
scientists from biology, geology, and climatology, as well as several engineers and
technologists. The group presented its strategic plan in the first of the papers reproduced
here. In this plan, MESG outlined a program consisting of global reconnaissance and in
situ measurements of the surface, followed by bringing samples of Mars to Earth. MESG
also identified specific classes of surface sites for detailed study Ð ancient sites of
groundwater, ancient sites of surface water, and modern sites of groundwater.

Mars Exploration Payload Analysis Group

In the course of planning and executing missions to Mars it became evident that another
step of strategic planning was needed. The goals of the NASA’s Mars Exploration
Program needed to be more directly linked to specific investigations and then to
measurements that can be made by science payloads aboard spacecraft or conducted in
Earth-based laboratories. In response to this need the Mars Exploration Payload Analysis
Group (MEPAG) created Òinvestigation pathwaysÓ that link the program’s strategic goals
to specific prioritized measurements. Investigations are described by MEPAG in terms
of measurement methodologies, together with instrument specifications such as spectral
and spatial resolutions.

Mars Sampling Advisory Group

No investigation is more crucial to the strategy of MESG and to the investigation
pathways of MEPAG than the analysis of Martian rock, soil, and atmosphere in the best
laboratories on Earth. Indeed, the scientific value of sample analysis is such that this
objective has emerged as the cornerstone of an international program to explore Mars.
To elucidate the characteristics of early sample return, MEPAG formed a special sub-group.
In the third paper, the MEPAG Mars Sample Advisory Group set forth the
anticipated knowledge to be gained from the first returned samples. Sample return,
because of its importance and the difficulty of achieving it, currently dominates much of
the scientific and technological planning of the Mars Exploration Program.

Table of Contents

Foreword

Part 1: “The Search for Evidence of Life on Mars”, Mars Expeditions Strategy Group Report, Chair, Dan McCleese

Part 2: “Scientific Goals, Objectives, Investigations, and Priorities”, Mars Exploration Payload Assessment Group Report, Chair, Ron Greeley

Part 3: “The First Returned Martian Samples: Science Opportunities”, Mars Sampling Advisory Group Report, Chair, Glenn MacPherson

Appendix 1: Group Member Lists