Human Exploration of Mars Design Reference Architecture 5.0 Bret G. Drake NASA Lyndon B. Johnson Space Center Houston, Texas 77058 Stephen J. Hoffman Science Applications International Corporation Houston, Texas 77058 David W. Beaty Jet Propulsion Laboratory Pasadena, California 91109 This paper provides a summary of the 2007 Mars Design • Derive technology research and development plans Reference Architecture 5.0 (DRA 5.0) [1], which is the • Define and prioritize requirements for precursor robotic latest in a series of NASA Mars reference missions. It missions provides a vision of one potential approach to human Mars • Define and prioritize flight experiments and human exploration including how Constellation systems can be exploration mission elements, such as those involving used. The reference architecture provides a common the International Space Station (ISS), lunar surface framework for future planning of systems concepts, systems, and space transportation technology development, and operational testing as well as • Open a discussion with international partners in a Mars robotic missions, research that is conducted on the manner that allows identification of potential interests International Space Station, and future lunar exploration of the participants in specialized aspects of the missions missions. This summary the Mars DRA 5.0 provides an • Provide educational materials at all levels that can be overview of the overall mission approach, surface strategy used to explain various aspects of human interplanetary and exploration goals, as well as the key systems and exploration challenges for the first three human missions to Mars. • Describe to the public, media, other Federal Government organizations the feasible, long-term TABLE OF CONTENTS visions for space exploration 1. HISTORICAL BACKGROUND ..............................................1 2. GOALS AND OBJECTIVES ...................................................1 3. DRA 5.0 OVERVIEW ..........................................................7 Each of these previous architecture studies emphasized one 4. VEHICLE AND SYSTEMS OVERVIEW ................................11 or many aspects that are critical for human exploration to 5. KEY CHALLENGES ...........................................................21 determine basic feasibility and technology needs. Example 6. SUMMARY .......................................................................23 architectural areas of emphasis include the destination, ACKNOWLEDGEMENTS ........................................................24 system reusability, goals and objectives, surface mobility, REFERENCES ........................................................................24 launch vehicles, transportation, LEO assembly, transit BIOGRAPHIES .......................................................................25 modes, surface power, and crew size to name a few. DRA 5.0 examined several of these aspects in an integrated manner. The strategy and results from this study have been reviewed and endorsed by the four NASA headquarters 1. HISTORICAL BACKGROUND mission directorates. A complete copy of this study During the past several years NASA has either conducted or including more details on the results can be found at: sponsored numerous studies of human exploration beyond http://www.nasa.gov/exploration/library/esmd_documents.html low-Earth Orbit (LEO) [2, 3, 4, 5, 6, 7, 8, 9]. These studies have been used to understand requirements for human exploration of the Moon and Mars in the context of other 2. GOALS AND OBJECTIVES space missions and research and development programs. Each of these exploration architectures provides an end-to- The goals for the initial human exploration of Mars can best end mission reference against which other mission and be organized under the following taxonomy: technology concepts can be compared. The results from the architecture studies are used by NASA to • Goals I-III: The traditional planetary science goals from the Mars Exploration Program Analysis Group (MEPAG) [10] for understanding Mars Life (Goal I), processes are likely to be partially complete. In addition to Climate (Goal II), and Geology/Geophysics (Goal III). continuing long-term observations, our scientific questions Goal IV: Preparation for the first human explorers, as seem likely to evolve in the following directions. Note in defined by MEPAG (revision in work). particular that if there is no robotic mission to one of the Goal IV+: Preparation for sustained human presence. polar caps, the priority of that science is likely to be Goal V (Ancillary Science): This includes all scientific significantly more important than it is today because of the objectives that are unrelated to Mars, including those influence of polar ice on the climate system. that are related to astrophysics, observations of the Sun, Earth, Moon, and the interplanetary environment. Note • Quantitative understanding of global atmospheric that these objectives may be important during the dynamics. transit phase for missions to and from Mars. • Understand microclimates – range of variation, how and why they exist. • Perform weather prediction. Goal I. Determine Whether Life Ever Arose on Mars • Understand the large-scale evolution of the polar caps including the modern energy balance, links with dust, The results of the robotic missions between now and 2025 carbon dioxide (CO2), and H2O cycles, changes in will answer some of the questions about Mars on our deposition and erosion patterns, flow, melting, age, and current horizon, which would therefore be removed and links between the two caps. would be replaced by new questions; this is the scientific process. Although our ability to predict the results of these future missions and the kinds of new questions that will Goal III: Determine the Evolution of the Surface and come up is partial, we do know the kinds of data that will be Interior of Mars collected and the kinds of questions that these data are capable of answering. Thus, we can make some general As of 2006, there were two primary objectives within this projections of the state of knowledge as of 2025. goal: (1) Determine the nature and evolution of the geologic processes that have created and modified the martian crust By 2025, our assessments of habitability potential will be and surface, and (2) characterize the structure, composition, well advanced for some environments, particularly those dynamics, and evolution of the martian interior. These are that have been visited by the Mars Sample Return (MSR) or broadly enough phrased that they are likely to still be valid by major in-situ rovers with life-related experiments. in 2025. These two objectives, for example, currently apply However, it is likely that the habitability of the martian to the study of the Earth, even after more than 200 years of subsurface will be almost completely unexplored other than geologic study by thousands of geologists. Given the by geophysical methods. The objective relating to carbon anticipated robotic missions leading up to the first human cycling is likely to be partially complete, but in particular as missions, the first objective is likely to evolve in the related to subsurface environments. For the purpose of this following direction: planning, we assume that the investigations through 2025 have made one or more discoveries that are hypothesized as • Quantitatively characterize the different components of being related to ancient life (by analogy with the Allen Hills the martian geologic system (at different parts of meteorite story, this is a particularly likely outcome of martian geologic history), and understand how these MSR). We should then be prepared for the following new components relate to each other. objectives: • Understand the field context of the various martian features of geologic interest at both regional and local Characterize the full suite of biosignatures for ancient scale. life to confirm the past presence of life. Interpret its life • Test specific hypotheses. processes and the origin of such life. • Perform comparative planetology. Assess protected environmental niches that may serve as refugia for extant life forms that may have survived to the present. Find the life, measure its life processes. Goal IV: Preparing for Human Exploration of Mars In earliest martian rocks, characterize the pre-biotic chemistry. Goal IV addresses the precursor measurements of Mars needed to reduce the risk of the first human mission to Mars. MEPAG is currently updating Goal IV objectives as Goal II: Understanding the Processes and History of derived from Mars DRA 5.0. Since this process in still Climate on Mars underway, the results of this reformulation cannot be discussed here. By 2025, our objectives related to characterization of the Mars atmosphere and its present and ancient climate Goal IV+: Preparing for Sustained Human Presence Initial Human Exploration of Mars Objectives Related to Goals I-III Goal IV+ specifically focuses on Mars human habitability, exploration systems development, and long-duration space Geology Scientific Objectives— Some of the most important mission operations necessary for sustained human presence. questions about Goals I through III involve the relationship Goal IV+ focuses on the objectives for the first three human of H2O to martian geologic and biologic processes as a Mars missions that would support the performance of function of geologic time. Mars has apparently evolved human Mars missions four through ten. The scope