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Mars exploration planning is discussed which is based on three scientific objectives: to understand Mars' geologic and geophysical evolution; to understand the present state and past evolution of Martian climate, and to determine the state of present biological activity and past life. The plan assumes a 25-year planning horizon, from 1995-2020, and includes both broad-scale and local exploration capabilities.
This January, the Mars Exploration Rovers "Spirit" and "Opportunity" are starting their fifth year of exploring the surface of Mars, well over ten times their nominal 90-day design lifetime. This lecture discusses the Mars Exploration Rovers, presents the current mission status for the extended mission, some of the most results from the mission and how it is affecting our current view of Mars, and briefly presents the plans for the coming NASA missions to the surface of Mars and concepts for exploration with robots and humans into the next decade, and beyond.
A year-long NASA-wide study effort has led to the development of an innovative strategy for the human exploration of Mars. The latest Mars Exploration Study Workshop 2 advanced a design reference mission (DRM) that significantly reduces the perceived high costs, complex infrastructure, and long schedules associated with previous Mars scenarios. This surface-oriented philosophy emphasizes the development of high-leveraging surface technologies in lieu of concentrating exclusively on space transportation technologies and development strategies. As a result of the DRM's balanced approach to mission and crew risk, element commonality, and technology development, human missions to Mars can be accomplished without the need for complex assembly operations in low-Earth orbit. This report, which summarizes the Mars Exploration Study Workshop held at the Ames Research Center on May 24-25, 1993, provides an overview of the status of the Mars Exploration Study, material presented at the workshop, and discussions of open items being addressed by the study team. The workshop assembled three teams of experts to discuss cost, dual-use technology, and international involvement, and to generate a working group white paper addressing these issues. The three position papers which were generated are included in section three of this publication.
The Mars Program Planning Group (MPPG) under the direction of Dr. Orlando Figueroa, was chartered to develop options for a program-level architecture for robotic exploration of Mars consistent with the objective to send humans to Mars in the 2030's. Scientific pathways were defined for future exploration, and multiple architectural options were developed that meet current science goals and support the future human exploration objectives. Integral to the process was the identification of critical technologies which enable the future scientific and human exploration goals. This paper describes the process for technology capabilities identification and examines the critical capability needs identified in the MPPG process. Several critical enabling technologies that have been identified to support the robotic exploration goals and with potential feedforward application to human exploration goals. Potential roadmaps for the development and validation of these technologies are discussed, including options for subscale technology demonstrations of future human exploration technologies on robotic missions.
The U.S. Mars Exploration Program comprises at least on Discovery mission (Mars Pathfinder), and Mars Surveyor Program, plus sample return missions and other missions to prepare for possible human expeditions to Mars. The original themes of the Mars Surveyor Program (which are still the official program goals) are to understand Life, Climate and Resources on Mars, with these themes tied together by the common thread of Water. The ability to move about the Martian surface is key to the Mars Exploration Program. This paper addresses the overall Mars Exploration Program strategy, with an emphasis of the role of rovers in the program. Specifically, the need for improvements in rover performance is addressed.
Mars Exploration Rover Enhanced Telemetry Extraction and Reporting System (METERS) is software that generates a human-readable representation of the state of the mobility and arm-related systems of the Mars Exploration Rover (MER) vehicles on each Martian solar day (sol). Data are received from the MER spacecraft in multiple streams having various formats including text messages, sparsely-sampled engineering quantities, images, and individual motor-command histories.
NASA and ESA have established an international network of Mars orbiters, outfitted with relay communications payloads, to support robotic exploration of the red planet. Starting in January, 2004, this network has provided the Mars Exploration Rovers with telecommunications relay services, significantly increasing rover engineering and science data return while enhancing mission robustness and operability. Augmenting the data return capabilities of their X-band direct-to-Earth links, the rovers are equipped with UHF transceivers allowing data to be relayed at high rate to the Mars Global Surveyor (MGS), Mars Odyssey, and Mars Express orbiters. As of 21 July, 2004, over 50 Gbits of MER data have been obtained, with nearly 95% of that data returned via the MGS and Odyssey UHF relay paths, allowing a large increase in science return from the Martian surface relative to the X-band direct-to-Earth link. The MGS spacecraft also supported high-rate UHF communications of MER engineering telemetry during the critical period of entry, descent, and landing (EDL), augmenting the very low-rate EDL data collected on the X-band direct-to-Earth link. Through adoption of the new CCSDS Proximity-1 Link Protocol, NASA and ESA have achieved interoperability among these Mars assets, as validated by a successful relay demonstration between Spirit and Mars Express, enabling future interagency cross-support and establishing a truly international relay network at Mars.
The Mars Exploration Program is pioneering a series of better, faster, cheaper missions to Mars over at least the next 10 years, and possibly well into the 21st century.
The Ingenuity Mars Helicopter is a technology demonstrator. The hope is that Ingenuity will one day lead to future generations of ever-more capable rotorcraft and other aerial vehicles for Mars exploration and other planetary science missions. This paper builds upon nearly twenty-four years of Mars rotorcraft and planetary aerial vehicle work at NASA Ames Research Center. It is posited that a spectrum of different Mars aerial vehicle mission concepts and capabilities could be developed over the next couple of decades – all of which are now potentially enabled by Ingenuity. A series of technology challenges or problems are also detailed in this paper. These problems are presented as an aid in helping establish a nascent planetary rotorcraft or planetary aerial vehicle research community as well as, maybe, helping realize some of the vehicle/mission concepts discussed in the paper.
Over the past several years, a number of candidate scenarios for the human exploration of Mars have been advanced. These have had a range of mission objectives, scope, scale, complexity and probable cost. The Exploration Programs Office (ExPO) has developed a reference Mars exploration program and a means of comparing it to other proposed Mars programs. The reference program was initiated in a workshop of Mars exploration advocates which defined two objectives of equal importance for early Mars exploration - understanding Mars and understanding the potential of Mars to support humans. These goals were used to define a set of transportation and surface elements that could carry out a robust exploration program. The approach to comparing alternate architectures has three principal parts: (1) Bringing the architectures into rough commonality in terms of surface mission objectives and hardware capabilities; (2) Providing a common level of human support for flights to and from Mars; and (3) Comparing the complexity of the elements needed to carry out the program and using partial redundancy to approximate the same statistical probability of mission success. This top-level approach has been applied to the ExPO reference program, the 'Mars Directs strategy (Zubrin, 1991) and the Stanford International Mars Mission (Lusignan, 1992).
Mars is an exciting target for the human exploration; the next destination toward the ultimate human colonization of the solar system. But the price of proposed missions to Mars is a daunting barrier. Expensive missions make it a slow and difficult process to achieve the political consensus to make a commitment to exploration. In today's deficit-conscious era (and what era is not?), it is as difficult-- perhaps impossible-- task to justify to a skeptical and cost-conscious public the need to invest in exploration. It seems far too easy to postpone exploration into a future that never seems to arrive. It would be terrific to explore Mars in small steps, where each step makes progress toward human exploration and settlement, and each step also is not only exciting to the public, but also justifiable on its own scientific merits.
Mars-bound rovers such as the Mars Exploration Rover (MER) endure strict planetary protection implementation campaigns to assess bioburden. The objective of this study is to identify cultivable microorganisms isolated by the NASA Standard Assay from spacecraft during pre-launch and evaluate their potential to survive conditions on the Martian surface. Of approximately 350 isolates collected from the MER spacecraft archive, 171 microorganisms were reconstituted for characterization via 16S rRNA fingerprinting. Alignment of 16S sequences revealed high levels of sequence similarity to spore-forming species, overwhelmingly of the genera Bacillus (73.7%) and Paenibacillus (14.0%). Samples underwent phenotype characterization employing multiple carbon sources and ion concentrations in an automated microarray format using the Omnilog system. Working and stock cultures were prepared to address the immediate needs for day-to-day culture utilization and long-term preservation, respectively. Results from this study produced details about the microbes that contaminate surfaces of spacecraft, as well as a preliminary evaluation of a rapid biochemical ID method that also provides a phenotypic assessment of contaminants. The overall outcome of this study will benefit emerging cleaning and sterilization technologies for preventing forward contamination that could negatively impact future life detection or sample return missions.
Surface features associated with aeolian (wind) processes at the Mars Exploration Rover (MER) landing sites for Spirit (Gusev crater) and Opportunity (Sinus Meridiani) were observed from the surface and from orbit through coordinated observations by the rovers and the Mars Express orbiter High Resolution Stereo Camera and compared with features seen in other orbiter data and with wind vectors predicted by a numerical mesoscale model of the atmosphere.
Rovers will play a critical role in the exploration of Mars. Near-term mission plans call for long traverses over unknown terrain, robust navigation and instrument placement, and reliable operations for extended periods of time. Longer-term missions may visit multiple science sites in a single day and perform opportunistic science data collection, as well as complex scouting, construction, and maintenance tasks in preparation for an eventual human presence. The Pathfinder mission demonstrated the potential for robotic Mars exploration but at the same time indicated the need for more rover autonomy. The highly ground-intensive control with infrequent communication and high latency limited the effectiveness of the Sojourner rover. When failures occurred, Sojourner often sat idle for extended periods of time, awaiting further commands from earth. In future missions, the tasks will be more complex and extended; hence there will be even more situations where things do not go exactly as planned. Significant advances in rover autonomy are needed to cope with increasing task complexity and greater execution uncertainty. Towards this end, we have designed an on-board executive architecture that incorporates robust operation, resource utilization, and failure recovery. In addition, we have designed ground tools to produce and refine contingent schedules that take advantage of the on-board architecture's flexible execution characteristics. Together, the on-board executive and the ground tools constitute an integrated rover autonomy architecture. This work draws from our experience with the Deep Space One autonomy experiment, with enhancements to ensure robust operation in the face of the unpredictable, complex environment that the rover will encounter on Mars. The rover autonomy architecture is currently being developed and deployed on the Marsokhod rover platform at NASA Ames Research Center. The capabilities of the rover autonomy architecture to support autonomous operations will be demonstrated concretely in upcoming field tests.
Highly propellant-efficient electric propulsion is being combined with advanced solar power technology to provide a non-nuclear transportation option for the human exploration of Mars. By virtue of its high specific impulse, electric propulsion offers a greater change in spacecraft velocity for each pound of propellant than do conventional chemical rockets. As a result, a mission to Mars based on solar electric propulsion (SEP) would require fewer heavy-lift launches than a traditional all-chemical space propulsion scenario would. Performance, as measured by mass to orbit and trip time, would be comparable to the NASA design reference mission for human Mars exploration, which utilizes nuclear thermal propulsion; but it would avoid the issues surrounding the use of nuclear reactors in space.
The active Heat Rejection System designed for Mars Pathfinder was modified for the Mars Exploration Rover mission and will be used to remove excess heat from the Rover electronics during the cruise part of the mission. This paper addresses the lessons learned from the performance testing, and potential changes to improve the HRS performance.
The Mars Exploration Rover (MER) mission will send two 185 kg rovers to Mars in 2003 to continue the scientific community's search for evidence of past water on Mars. These twin robotic vehicles will carry harmonic drives and their performance will be characterized at various temperatures, speeds and loads.
The Mars Exploration Rovers Spirit and Opportunity landed at Gusev crater and Meridiani Planum. The Alpha Particle X-ray Spectrometer (APXS) is part of the instrument suite on both rovers. It is equipped with six 244Cm sources which provide x-ray excitation with alpha-particles (PIXE) and x-ray radiation (XRF). This combination allows x-ray spectroscopy of elements from Na to Br in the energy range of 0.9 to 16 keV. X-ray detectors with a high energy resolution of 160 eV at Fe K allow us to separate even closely spaced energy peaks, such as Na, Mg, Al and Si. The APXS is attached to the rover s arm and provides in-situ measurements of the chemical composition of soils, surfaces of rocks and outcrops and their abraded surfaces. This abstract gives an overview of APXS results obtained during the first year of operation on both landing sites.