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Abstract High-accuracy, autonomous and reliable navigation systems are important foundations for Mars rovers to achieve exploration missions successfully. Based on the motion characteristics and working environment of the rover, the paper shows a high-accuracy strapdown inertial navigation system/visual navigation system/celestial navigation system (SINS/VNS/CNS) integrated navigation scheme suitable for the rover with long-time and long-distance motion. According to the feature point positions in the camera frame at adjacent time obtained by the binocular visual odometry, its velocity in the camera frame and the attitude are calculated, then a subsystem model of SINS/VNS integrated navigation is established. In addition, using the star vectors measured by the large field-of-view star sensor, a high-accuracy attitude matrix of the rover in the inertial frame can be obtained, and a SINS/CNS subsystem model is established. Furthermore, in order to make full use of the complementary advantages of the two subsystems in attitude and position estimation, an interacting multiple model filter is developed. By updating the model probabilities of the subsystems separately in real time, the filter can output accurate navigation information of the rover. Simulation results show that the proposed navigation scheme can significantly improve the estimation accuracy of attitude, position and velocity simultaneously. Highlights • A high-accuracy SINS/VNS/CNS integrated navigation scheme is proposed for Mars rovers. • SINS/VNS and SINS/CNS subsystem models are deduced and established. • In order to make full use of the complementary advantages of two subsystems, the IMM filter is developed. • The proposed scheme achieves high-accuracy and high-reliability autonomous navigation. [ABSTRACT FROM AUTHOR]

The article presents information on several space missions during summer 2012. The Mars Science Laboratory (MSL) will approach Mars and arrive at the planet by August 6, 2012. The Dragon spacecraft will deliver cargo to the International Space Station (ISS) in July, 2012. The Cassini orbiter will begin its seventh year of orbiting Saturn on July 1, 2012.

Physiological and methodological principles of the organization of physical training (PT) and its computerization during a space flight to Mars under the conditions of autonomous activity of the crew, including interaction with onboard medical systems, self-maintenance of health, preventive measures, diagnostic examinations, and, if necessary, treatment, are discussed. The conditions of unusually long-term autonomous space flights make the ground-based monitoring of the state of health of crew members substantially more difficult, which calls for computerization of the control over the crew members’ health, including prophylactic measures. The situation is further complicated because it is impossible to receive the necessary information from, and transmit it to, the spacecraft in a real-time mode or to quickly return the crew to Earth in case of an emergency. Under these conditions, physical prevention should be based on an onboard automated expert system ensuring the control over the activities of all crew members aimed at optimizing their psychophysical state. The problems of the control of training, including the use of an onboard automated expert system, are discussed. [ABSTRACT FROM AUTHOR]

This study investigates the performance and feasibility of a new entry, descent, and landing architecture on Mars, termed Smart Divert, for landing in one of a number of small safe zones surrounded by hazardous terrain. Smart Divert consists of a ballistic entry followed by supersonic parachute deployment. After parachute release, the vehicle diverts to one of many predefined, fuel-optimal safe zone sites. The Smart Divert concept does not require hypersonic guidance or real-time terrain recognition. Instead, it relies on a priori orbital observations to identify small, multiple safe zones within a larger hazardous region and additional terminal descent propellant to land at the fuel-optimal safe zone. Before launch, mission designers could trade the number and size of the safe zones as part of the landing site selection process. Reasonable propellant mass fractions of 0.3 can be achieved by initiating the divert at 5 km altitude, providing a 10 km horizontal divert capability. The number of safe zones is shown to be a function of landing ellipse size. Assuming Mars Science Laboratory state-of-the-art interplanetary navigation, four safe zone sites, randomly placed throughout the landing ellipse to simulate unknown destinations of future minions, require a propellant mass fraction less than 0.3 for 97% of the cases analyzed. The unconstrained optimal arrangement of four safe zone sites within the same landing ellipse reduced the required propellant mass fraction from 0.3 to 0.22. The propellant mass fraction may be further reduced as the number of safe zone sites is increased. An example scenario using rock count data for the Phoenix landing site region demonstrates that Smart Divert can be implemented to land in previously unreachable terrain for a propellant mass fraction of 0.2. [ABSTRACT FROM AUTHOR]

Abstract: Plans for interplanetary manned space missions imply significant risks arising from human''s exposure to the hostile space environment. Thus the design of reliable protection systems against the ionizing cosmic radiation becomes one of the most relevant issues. In this paper the composition and magnitude of the atmospheric radiation on the planetary surface and for typical interplanetary transfer configurations have been analyzed. The investigation based on prior NASA and ESA mission results, using a manned mission to planet Mars as a case study. According to this, the time-dependent character of the consistency of cosmic radiation has been taken into account, which is justified by the interdependence of the radiation magnitude to the solar cycle. With regard to this paper it implies even solar particle events. The results have been compared to the protective character of different materials potentially usable as a habitat''s structural shell and for interplanetary spacecrafts. The investigation aimed on particle energy degradation rates and reduction of secondary particle production. In this regard the physical process of absorbing effectiveness against particle radiation has been examined by analytical calculation and given scientific results, depending on thickness and molecular composition of the materials. The most suitable materials have been used for shield design proposals using different configurations, evaluating the use of aluminium, water tanks and polyethylene bricks. [Copyright &y& Elsevier]

Abstract: The Polar Balloon Atmospheric Composition Experiment (P-BACE) is a new generation of neutral gas mass spectrometer based on the time-of-flight principle. P-BACE is the scientific experiment on the Mars Environment Analog Platform (MEAP) flown successfully on a balloon mission in summer 2008. The MEAP mission was flown with a 334,000m3 helium balloon in the stratosphere on a semicircular trajectory from northern Sweden around the North Pole to Canada using the summer northern hemispheric wind current. The atmospheric conditions at an atmospheric altitude of 35–40km are remarkably similar to those on the surface of Mars and thus the balloon mission was an ideal testbed for our mass spectrometer P-BACE. Originally this instrument was designed for in situ measurements of the chemical composition of the Martian atmosphere. P-BACE has a unique mass range from 0 to 1000amu/q with a mass resolution m/Δm (FWHM)>1000, and the dynamic range is at least six orders of magnitude. During this experiment, the acquisition of one mass spectrum is a sum of 65,535 single spectra, recorded in a time frame of 66s. The balloon mission lasted 5 days and had successfully demonstrated the functionality of the P-BACE instrument during flight conditions. We had recorded more than 4500 mass spectra. With little modifications, P-BACE can be used on a planetary mission for Mars, but for example also for Venus or Mercury, if placed on a satellite. [Copyright &y& Elsevier]

The article reports on the study and exploration of Mars using robots, including orbiters, landers and rovers, to collect observation from orbit and on the ground to better understand the Martian environment. It reveals the similarities and differences between the plant and Earth which are the subject of the said study and exploration. It discusses the key components of any exploration including deciding where to go and determining what pictures to take and what to send home. It offers information on three key technologies for autonomous navigation which include real-time stereo analysis of navigation images, traversability map computation and obstacle avoidance. It reveals the detection of dust devils in Mars.

Abstract: An effective program for Mars exploration should proceed in steps. The best strategy for the initial human missions to Mars may be to put the humans into Mars orbit and explore the surface by telerobotic operation. This could provide the benefits of human exploration at greatly reduced risk and cost. Telecontrol of Mars surface robots from a Mars-orbital habitat would give human nearly “real time” virtual presence with minimum time delay, allowing high-fidelity virtual exploration of the surface. It is a cheaper, simpler, and safer way to explore, and hence it will be a faster way to investigate a wide variety of locations, from the polar caps to near-equatorial canyon regions. Teleoperation also enhances planetary protection in both directions, protecting Mars from contamination by Earth life and keeping humans from exposure to possible Mars microbes, and has the potential for valuable spin-off technologies. [Copyright &y& Elsevier]

The Mars Exploration Rover mission successfully landed two rovers "Spirit" and "Opportunity" on Mars on January 4th and 25th of 2004, respectively. In this paper, the trajectory analysis performed to define the entry, descent, and landing (EDL) scenario is described. The entry requirements and constraints are presented, as well as uncertainties used in a Monte Carlo dispersion analysis to statistically assess the robustness of the entry design to off-nominal conditions. In the analysis, six-degree-of-freedom and three-degree-of-freedom trajectory results are compared to assess the entry characteristics of the capsule. Comparison of the pre entry results to preliminary post-landing reconstruction data shows that all EDL parameters were within the requirements. In addition, the final landing locations for both Spirit and Opportunity were within 15 km from the target. [ABSTRACT FROM AUTHOR]

Abstract: NASA''s plans for Mars exploration demand increasing telecommunications capabilities in the coming decades. Ambitious robotic missions will deploy high-rate instruments in Mars orbit and on the Martian surface, with increasing spatial, spectral, and temporal resolution. Orbiters will require high-performance direct-to-Earth links, while landed missions will benefit from energy-efficient communications through relay-equipped orbiters to increase data return while minimizing landed mass. The Mars Reconnaissance Orbiter and the Mars Exploration Rovers define the current state-of-the-art for Martian orbiters and landers, respectively. Even with respect to these capabilities, however, significant growth appears to be very feasible based on infusion of relatively mature technologies. Deployable spacecraft antennas, high-power traveling wave tube amplifiers, and migration to Ka-band provide a path to much higher spacecraft equivalent isotropic radiated power. When combined with proposed upgrades to the Deep Space Network, future orbiters can envision downlink rates more than two orders of magnitude beyond current capability. Similar growth can be achieved on relay links between landers and relay orbiters, based on improved relay capabilities which can be infused into the current generation of Electra software-defined relay radios, and by migration to high-frequency directional relay links. [Copyright &y& Elsevier]

Abstract: Before humans trek the mountains and canyons of Mars, a key event must happen. That vital undertaking will be to fly a roundtrip mission to Mars for acquiring representative surface materials and returning them to Earth. Mars sample return has also been a premier objective of planetary scientists for more than four decades. In the meantime, the Stardust mission has returned dust grains from a comet, and Genesis has collected and returned solar wind. Yet at this time, Mars sample return is no longer an official project in any space agency. Inestimable value would also accrue for engineering the systems needed for future human missions. Sample return from the surface will validate our collective ability to successfully accomplish such a roundtrip to Mars in absence of the ability for end-to-end testing on Earth. Embarking on a historic Mars surface sample return mission will provide the confirming signal that a space program is ready, willing, and capable to achieve the next major engineering challenge for exploration of our solar system. Beginning serious development of the missing critical link, the Mars Ascent Vehicle, will signal the beginning of this undertaking. [Copyright &y& Elsevier]

A planetary rover acquires a large collection of images while exploring its surrounding environment. For example, 2D stereo images of the Martian surface captured by the lander and the Sojourner rover during the Mars Pathfinder mission in 1997 were transmitted to Earth for scientific analysis and navigation planning. Due to the limited memory and computational power of the Sojourner rover, most of the images were captured by the lander and then transmitted to Earth directly for processing. If these images were merged together at the rover site to reconstruct a 3D representation of the rover's environment using its on-board resources, more information could potentially be transmitted to Earth in a compact manner. However, construction of a 3D model from multiple views is a highly challenging task to accomplish even for the new generation rovers (Spirit and Opportunity) running on the Mars surface at the time this article was written. Moreover, low transmission rates and communication intervals between Earth and Mars make the transmission of any data more difficult. We propose a robust and computationally efficient method for progressive transmission of multi-resolution 3D models of Martian rocks and soil reconstructed from a series of stereo images. For visualization of these models on Earth, we have developed a new multimodal visualization setup that integrates vision and touch. Our scheme for 3D reconstruction of Martian rocks from 2D images for visualization on Earth involves four main steps: a) acquisition of scans: depth maps are generated from stereo images, b) integration of scans: the scans are correctly positioned and oriented with respect to each other and fused to construct a 3D volumetric representation of the rocks using an octree, c) transmission: the volumetric data is encoded and progressively transmitted to Earth, d) visualization: a surface model is reconstructed from the transmitted data on Earth and displayed to a user through a new autostereoscopic visualization table and a haptic device for providing touch feedback. To test the practical utility of our approach, we first captured a sequence of stereo images of a rock surface from various viewpoints in JPL MarsYard using a mobile cart and then performed a series of 3D reconstruction experiments. In this paper, we discuss the steps of our reconstruction process, our multimodal visualization system, and the tradeoffs that have to be made to transmit multiresolution 3D models to Earth in an efficient manner under the constraints of limited computational resources, low transmission rate, and communication interval between Earth and Mars. [ABSTRACT FROM AUTHOR]

The Mars Exploration Rover Opportunity has spent more than 2 years exploring Meridiani Planum, traveling ∼8 kilometers and detecting features that reveal ancient environmental conditions. These include well-developed festoon (trough) cross-lamination formed in flowing liquid water, strata with smaller and more abundant hematite-rich concretions than those seen previously, possible relict ‘hopper crystals’ that might reflect the formation of halite, thick weathering rinds on rock surfaces, resistant fracture fills, and networks of polygonal fractures likely caused by dehydration of sulfate salts. Chemical variations with depth show that the siliciclastic fraction of outcrop rock has undergone substantial chemical alteration from a precursor basaltic composition. Observations from microscopic to orbital scales indicate that ancient Meridiani once had abundant acidic groundwater, arid and oxidizing surface conditions, and occasional liquid flow on the surface. [ABSTRACT FROM AUTHOR]

Abstract: NASA''s space exploration initiative envisions a return to the moon by 2020, the construction of inhabited lunar bases and manned missions to Mars. Such an ambitious program harbours increased risks, both logistical and physical (particularly that of trauma) within the context of a microgravity environment. This paper also discusses the cellular response to microgravity and the potential scientific and technological benefits of Space exploration. [Copyright &y& Elsevier]

Abstract: Mars is a compelling astrobiological target, and a human mission would provide an opportunity to collect immense amounts of scientific data. Exploration alone, however, cannot justify the increased risk. Instead, three factors drive a human mission: economics, education, and exploration. A human mission has a unique potential to inspire the next generation of young people to enter critically needed science and engineering disciplines. A mission is economically feasible, and the research and development program put in place for a human mission would propel growth in related high-technology industries. The main hurdles are human physiological responses to 1–2 years of radiation and microgravity exposure. However, enabling technologies are sufficiently mature in these areas that they can be developed within a few decade timescale. Hence, the decision of whether or not to undertake a human mission to Mars is a political decision, and thus, educational and economic benefits are the crucial factors. [Copyright &y& Elsevier]

We present a new European Mars mission proposal to build on the UK-led Beagle2 Mars mission and continue its astrobiology-focussed investigation of Mars. The small surface element to be delivered to the Martian surface—Vanguard—is designed to be carried by a Mars Express-type spacecraft bus to Mars and adopts a similar entry, descent and landing system as Beagle2. The surface element comprises a triad of robotic devices—a lander, a micro-rover of the Sojourner class for surface mobility, and three ground-penetrating moles mounted onto the rover for sub-surface penetration to 5 m depth. The major onboard instruments on the rover include a Raman spectrometer/imager, a laser plasma spectrometer, an infrared spectrometer—these laser instruments provide the basis for in situ “remote” sensing of the sub-surface Martian environment within a powerful scientific package. The moles carry the instruments’ sensor head array to the sub-surface. The moles are thus required to undergo a one-way trip down the boreholes without the need for recovery of moles or samples, eliminating much of the robotic complexity invoked by such operations. [Copyright &y& Elsevier]

The alpha particle x-ray spectrometer on the Spirit rover determined major and minor elements of soils and rocks in Gusev crater in order to unravel the crustal evolution of planet Mars. The composition of soils is similar to those at previous landing sites, as a result of global mixing and distribution by dust storms. Rocks (fresh surfaces exposed by the rock abrasion tool) resemble volcanic rocks of primitive basaltic composition with low intrinsic potassium contents. High abundance of bromine (up to 170 parts per million) in rocks may indicate the alteration of surfaces formed during a past period of aqueous activity in Gusev crater. [ABSTRACT FROM AUTHOR]

The Mars Exploration Rover Spirit has traversed a fairly flat, rock-strewn terrain whose surface is shaped primarily by impact events, although some of the landscape has been altered by eolian processes. Impacts ejected basaltic rocks that probably were part of locally formed lava flows from at least 10 meters depth. Some rocks have been textured and/or partially buried by windblown sediments less than 2 millimeters in diameter that concentrate within shallow, partially filled, circular impact depressions referred to as hollows. The terrain traversed during the 90-sol (martian solar day) nominal mission shows no evidence for an ancient lake in Gusev crater. [ABSTRACT FROM AUTHOR]

Panoramic Camera images at Gusev crater reveal a rock-strewn surface interspersed with high- to moderate-albedo fine-grained deposits occurring in part as drifts or in small circular swales or hollows. Optically thick coatings of fine-grained ferric iron-rich dust dominate most bright soil and rock surfaces. Spectra of some darker rock surfaces and rock regions exposed by brushing or grinding show near-infrared spectral signatures consistent with the presence of mafic silicates such as pyroxene or olivine. Atmospheric observations show a steady decline in dust opacity during the mission, and astronomical observations captured solar transits by the martian moons, Phobos and Deimos, as well as a view of Earth from the martian surface. . [ABSTRACT FROM AUTHOR]

The Mars Exploration Rover Spirit and its Athena science payload have been used to investigate a landing site in Gusev crater. Gusev is hypothesized to be the site of a former lake, but no clear evidence for lacustrine sedimentation has been found to date. Instead, the dominant lithology is basalt, and the dominant geologic processes are impact events and eolian transport. Many rocks exhibit coatings and other characteristics that may be evidence for minor aqueous alteration. Any lacustrine sediments that may exist at this location within Gusev apparently have been buried by lavas that have undergone subsequent impact disruption. [ABSTRACT FROM AUTHOR]

The article discusses the results of space exploration of astronauts to Mars and Venus. Results of experiments show that Venus is covered with cold, dense clouds, whose hydrocarbon components make the cover something like a very dense Los Angeles smog. In Mars an Italian astronomer discovered dark markings on its buff-ochre surface which he called cannali or canals, astronomers have noted that the canals and larger, dark gray equatorial regions change color with the seasons. The results of these experiments and other investigations will undoubtedly lead to special designs for the human environment astronauts of the future will occupy on their explorations.

The article focuses on the reaction of many planetary researchers regarding the decision of Alan Stern, science chief at the U.S. National Aeronautics and Space Administration (NASA), to back off NASA's mission to collect rocks and soil from Mars. According to the author, many planetary scientists were dismayed. Also, the 2009 budget request for NASA's spending in Mars has been cut by half over the next five years. As a result, many Mars researchers fear that NASA is giving up a carefully plotted exploration on the Red Planet. In response, Stern assures that no space missions have been canceled.