On Advanced Mobility Concepts for Intelligent Planetary Surface Exploration

Surface exploration by wheeled rovers on Earth's Moon (the two Lunokhods) and Mars (Nasa's Sojourner and the two MERs) have been followed since many years already very suc-cessfully, specifically concerning operations over long time. However, despite of this success, the explored surface area was very small, having in mind a total driving distance of about 8 km (Spirit) and 21 km (Opportunity) over 6 years of operation. Moreover, ESA will send its ExoMars rover in 2018 to Mars, and NASA its MSL rover probably this year. However, all these rovers are lacking sufficient on-board intelligence in order to overcome longer dis-tances, driving much faster and deciding autonomously on path planning for the best trajec-tory to follow. In order to increase the scientific output of a rover mission it seems very nec-essary to explore much larger surface areas reliably in much less time. This is the main driver for a robotics institute to combine mechatronics functionalities to develop an intelligent mo-bile wheeled rover with four or six wheels, and having specific kinematics and locomotion suspension depending on the operational terrain of the rover to operate. DLR's Robotics and Mechatronics Center has a long tradition in developing advanced components in the field of light-weight motion actuation, intelligent and soft manipulation and skilled hands and tools, perception and cognition, and in increasing the autonomy of any kind of mechatronic systems. The whole design is supported and is based upon detailed modeling, optimization, and simula-tion tasks. We have developed efficient software tools to simulate the rover driveability per-formance on various terrain characteristics such as soft sandy and hard rocky terrains as well as on inclined planes, where wheel and grouser geometry plays a dominant role. Moreover, rover optimization is performed to support the best engineering intuitions, that will optimize structural and geometric parameters, compare various kinematics suspension concepts, and make use of realistic cost functions like mass and consumed energy minimization, static sta-bility, and more. For self-localization and safe navigation through unknown terrain we make use of fast 3D stereo algorithms that were successfully used e.g. in unmanned air vehicle ap-plications and on terrestrial mobile systems. The advanced rover design approach is applica-ble for lunar as well as Martian surface exploration purposes. A first mobility concept ap-proach for a lunar vehicle will be presented

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 346)

This bibliography lists 134 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during Jan. 1991. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

System of Systems conceptual design methodology for space exploration

The scope of the research is to identify and develop a design methodology for System-of-System (a set of elements and sub-elements able to interact and cooperate in order to complete a mission), based on models, methods and tools, to support the decision makers during the space exploration scenarios design and evaluation activity in line with the concurrent design philosophy. Considering all combinations of system parameters (such as crew size, orbits, launchers, spacecraft, ground and space infrastructures), a large number of mission concept options are possible, even though not all of them are optimal or even feasible. The design methodology is particularly useful in the first phases of the design process (Phase 0 and A) to choose rationally and objectively the best mission concepts that ensure the higher probability of mission success in compliance with the high level requirements deriving from the “user needs”. The first phases of the project are particularly critical for the success of the entire mission because the results of this activity are the starting point of the more costly detailed design phases. Thus, any criticality in the baseline design will involve inevitably into undesirable and costly radical system redesigns during the advanced design phases. For this reason, it is important to develop reliable mathematical models that allow prediction of the system performances notwithstanding the poorly defined environment of very high complexity. In conjunction with the development of the design methodology for system-of-systems and in support of it, a software tool has been developed. The tool has been developed into Matlab environment and provides users with a useful graphical interface. The tool integrates the model of the mission concept, the models of the space elements at system and subsystem level, the cost-effectiveness model or value, the sensitivity and multi-objective optimization analysis. The tool supports users to find a system design solution in compliance with requirements and constraints, such as mass budgets and costs, and provides them with information about cost-effectiveness of the mission. The developed methodology has been applied for the design of several space elements (Man Tended Free Flyer, Cargo Logistic Vehicle, Rover Locomotion System) and several mission scenarios (Moon surface infrastructure support, Cis-Lunar infrastructure delivering, Cis-Lunar infrastructure logistic support), in order to assess advantages and disadvantages of the proposed method. The results of the design activity have been discussed and accepted by the European Space Agency (ESA) and have also been compared and presented to the scientific community. Finally, in a particular case, the study of the locomotion system of a lunar rover, the results of the methodology have been verified through the production and testing of the same system