Safe on Mars: Precursor Measurements Necessary to Support Human Operations on the Martian Surface (2002)

NASA is actively pursuing a Mars exploration program. It is a “science-driven, technology-enabled effort to characterize and understand Mars, including its current environment, climate, and geological history and biological potential.”¹ Every 2 years from 2001 to 2011, with the dates dictated by launch windows, another spacecraft, launched by NASA and/or NASA's international partners, is intended to visit Mars. Some spacecraft will orbit the planet, while others will land on the Martian surface. The NASA Mars Exploration Program Office (within the NASA headquarters Office of Space Science) has established the Mars Exploration Program/Payload Analysis Group (MEPAG), consisting of more than 110 individuals from the Mars community, with representatives from universities, research centers and organizations, industry, and international partners. The MEPAG participants propose the objectives, investigations, and measurements needed for the eventual exploration of Mars, focusing on four principal exploration goals (Greeley, 2001). These goals fall under four broad categories:

• Life&—determine if life ever arose on Mars.

• Climate&—determine the climate on Mars.

• Geology&—determine the evolution of the surface and interior of Mars.

• Prepare for the eventual human exploration of Mars.

While there is currently no funded human mission to Mars, nor even a baseline reference human mission, one of the goals of the MEPAG is to ensure that sufficient information is developed in a timely manner to support such a mission, once it has been funded.

NASA commissioned this study from the NRC to examine what measurements must be made on Mars prior to the first human mission. These measurements would provide information about the risks to humans so that NASA scientists and engineers can design systems that will protect astronauts on the surface of Mars.

The principal objective of the study was to examine how robotic exploration missions sent to Mars could aid NASA in assessing the risks to astronauts posed by possible environmental, chemical, and biological agents on the planet. Of critical importance is whether it will be necessary to return Martian soil and/or air-borne dust samples to Earth prior to the first human mission to Mars to assure astronaut health and safety. The entire statement of task is contained in Appendix A. The statement of task includes a list of relevant reports that were reviewed during the course of the study.

To respond to this task, NRC's Aeronautics and Space Engineering Board, together with the Space Studies Board, established the Committee on Precursor Measurements Necessary to Support Human Operations on the Surface of Mars. Brief biographies of the 10 committee members are included in Appendix B. Members were carefully chosen to reflect the expertise needed to address the environmental, chemical, and biological risks to the first humans to set foot on Mars.

The committee held three full committee meetings, all of them open to the public. The first meeting was held in Washington, D.C., in May 2001. At the first 2-day meeting, NASA presented its overall strategy for future Mars exploration and the current status of the program. From that initial briefing the committee then determined that it would need to hear further details of specific NASA technical capabilities and hazards on Mars. The second meeting took place over 3 days at the Lunar and Planetary Institute in Houston, Texas, during early August 2001. Representatives from NASA's Lyndon B. Johnson Space Center in Houston and from the Jet Propulsion Laboratory (JPL) in Pasadena provided information on surface operations, space suits and equipment, detection of life on Mars, radiation health effects, lunar dust experience, Martian soil, and in situ instrumentation capability. The issue of whether or not there is need for a soil or airborne dust sample to be returned to Earth from Mars was also discussed.

Subsequently, the committee determined that further information was needed on the Mars robotic program. Three committee members, accompanied by NRC staff, visited JPL in late August 2001, when they were briefed on current research and development efforts in robotics.

The third and final meeting was held in Washington, D.C., in early September 2001; at that meeting the committee finalized the findings and recommendations contained in this report.

To ensure that it was including all previously identified hazards in its study, the Committee on Precursor Measurements Necessary to Support Human Operations on the Surface of Mars referred to the most recent MEPAG report (Greeley, 2001). The committee concluded that the requirements identified in the present report are indeed the only ones essential for NASA to pursue in order to mitigate potential hazards to the first human missions to Mars.

Chapter 2 presents the context in which this study was conceived and conducted. Chapters 3, 4, and 5 address the physical, chemical, and biological hazards likely to be encountered by the first human visitors to the Martian surface. Each of these chapters addresses the risks associated with potential hazards. In each chapter there is a section that details what precursor measurements, if any, should to be made prior to the first human landing on Mars. Appendix C lists the acronyms and abbreviations used in this report.

As a general rule, the committee made recommendations only when it determined that a precursor mission to Mars is required to provide information critical for the safety of the first human missions. The exception to this rule is the first recommendation, which deals with the establishment of risk standards, because the risk standard adopted has the potential to greatly affect the need for precursor missions. The committee presented findings if, in its judgment, there are ways of ensuring the safety of astronauts without carrying out a robotic precursor mission to Mars.

Greeley, R., ed. 2001. Scientific Goals, Objectives, Investigations, and Priorities, Mars Exploration Program/Payload Analysis Group (MEPAG), March 2. Also known as Jet Propulsion Laboratory (JPL) Publication 01-7 (2001). JPL, Pasadena, Calif.