Mars Pathfinder Mission Research Articles

Lander and rover histories of dust accumulation on and removal from solar arrays on Mars

The degradation in electrical output of solar arrays on Mars landers and rovers is reviewed. A loss of 0.2% per Sol is typical, although observed rates of decrease in ‘dust factor’ vary between 0.05% and 2% per Sol. 0.2%/Sol has been observed throughout the first 800 Sols of the ongoing InSight mission, as well as the shorter Mars Pathfinder and Phoenix missions. This rate was also evident for much of the Spirit and Opportunity missions, but the degradation there was episodically reversed by cleaning events due to dust devils and gusts. The enduring success of those rover missions may have given an impression of the long-term viability of solar power on the Martian surface that is not globally-applicable: the occurrence of cleaning events with an operationally-useful frequency seems contingent upon local meteorological circumstances. The conditions for significant cleaning events have apparently not been realized at the InSight landing site, where, notably, dust devils have not been detected in imaging. Optical obscuration by dust deposition and removal has also been observed by ultraviolet sensors on Curiosity, with a similar (but slightly higher) degradation rate. The observations are compared with global circulation model (GCM) results: these predict a geographically somewhat uniform dust deposition rate, while there is some indication that the locations where cleaning events were more frequent may be associated with weaker background winds and a deeper planetary boundary layer. The conventional Dust Devil Activity metric in GCMs does not effectively predict the different dust histories.

Mars precession rate determined from radiometric tracking of the InSight Lander

The Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport (InSight) mission has provided an opportunity to improve our knowledge of Mars’ interior via the Rotation and Interior Structure Experiment (RISE). RISE provides information on the rotation of Mars by measuring the Doppler shift of radio transmissions from InSight to NASA’s Deep Space Network (DSN) on Earth. Through the combination of one year of Doppler data from InSight with previous data from the Viking-1 lander, Mars Pathfinder, and Opportunity missions, data spanning 43 years from 1976 to 2019 are used to estimate the Mars precession rate as −7605 ​± ​3 milliarcseconds per year. This result is consistent with the precession rate estimated from Doppler tracking of previous landers and orbiters alone.

Extraterrestrial Soils and Space Agriculture

Extraterrestrial Soils and Space Agriculture

Simulation and Spacecraft Design: Engineering Mars Landings.

A key issue in history of technology that has received little attention is the use of simulation in engineering design. This article explores the use of both mechanical and numerical simulation in the design of the Mars atmospheric entry phases of the Viking and Mars Pathfinder missions to argue that engineers used both kinds of simulation to develop knowledge of their designs' likely behavior in the poorly known environment of Mars. Each kind of simulation could be used as a warrant of the other's fidelity, in an iterative process of knowledge construction.

Three-layer intelligence of planetary exploration wheeled mobile robots: Robint, virtint, and humint

The great success of the Sojourner rover in the Mars Pathfinder mission set off a global upsurge of planetary exploration with autonomous wheeled mobile robots (WMRs), or rovers. Planetary WMRs are among the most intelligent space systems that combine robotic intelligence (robint), virtual intelligence (virtint), and human intelligence (humint) synergetically. This article extends the architecture of the three-layer intelligence stemming from successful Mars rovers and related technologies in order to support the R&D of future tele-operated robotic systems. Double-layer human-machine interfaces are suggested to support the integration of humint from scientists and engineers through supervisory (Mars rovers) or three-dimensional (3D) predictive direct tele-operation (lunar rovers). The concept of multilevel autonomy to realize robint, in particular, the Coupled-Layer Architecture for Robotic Autonomy developed for Mars rovers, is introduced. The challenging issues of intelligent perception (proprioception and exteroception), navigation, and motion control of rovers are discussed, where the terrains’ mechanical properties and wheel-terrain interaction mechanics are considered to be key. Double-level virtual simulation architecture to realize virtint is proposed. Key technologies of virtint are summarized: virtual planetary terrain modeling, virtual intelligent rover, and wheel-terrain interaction mechanics. This generalized three-layer intelligence framework is also applicable to other systems that require human intervention, such as space robotic arms, robonauts, unmanned deep-sea vehicles, and rescue robots, particularly when there is considerable time delay.

The final frontier-on your phone [Resources_App Watch

In 1997, the website for NASA's Mars Pathfinder mission became an Internet sensation. But as the world has shifted from computers to smart gadgets, NASA has been increasingly using apps to reach the public. Some are tied to individual missions, while others educate users about scientific or engineering topics.

Introduction to autonomous mobile robots

Mobile robots range from the Mars Pathfinder mission's teleoperated Sojourner to the cleaning robots in the Paris Metro. This text offers students and other interested readers an introduction to the fundamentals of mobile robotics, spanning the mechanical, motor, sensory, perceptual, and cognitive layers the field comprises. The text focuses on mobility itself, offering an overview of the mechanisms that allow a mobile robot to move through a real world environment to perform its tasks, including locomotion, sensing, localization, and motion planning. It synthesizes material from such fields as kinematics, control theory, signal analysis, computer vision, information theory, artificial intelligence, and probability theory. The book presents the techniques and technology that enable mobility in a series of interacting modules. Each chapter treats a different aspect of mobility, as the book moves from low-level to high-level details. It covers all aspects of mobile robotics, including software and hardware design considerations, related technologies, and algorithmic techniques.] This second edition has been revised and updated throughout, with 130 pages of new material on such topics as locomotion, perception, localization, and planning and navigation. Problem sets have been added at the end of each chapter. Bringing together all aspects of mobile robotics into one volume, Introduction to Autonomous Mobile Robots can serve as a textbook or a working tool for beginning practitioners.

Autonomy for Mars Rovers: Past, Present, and Future

The vehicles used to explore the Martian surface require a high degree of autonomy to navigate challenging and unknown terrain, investigate targets, and detect scientific events. Increased autonomy will be critical to the success of future missions. In July 1997, as part of NASA's Mars Pathfinder mission, the Sojourner rover became the first spacecraft to autonomously drive on another planet. The twin Mars Exploration Rovers (MER) vehicles landed in January 2004, and after four years Spirit had driven more than four miles and Opportunity more than seven miles-lasting well past their projected three-month lifetime and expected distances traveled. The newest member of the Mars rover family will have the ability to autonomously approach and inspect a target and automatically detect interesting scientific events. In fall 2009, NASA plans to launch the Mars Science Laboratory (MSL) rover, with a primary mission of two years of surface exploration and the ability to acquire and process rock samples. In the near future, the Mars Sample Return (MSR) mission, a cooperative project of NASA and the European Space Agency, will likely use a lightweight rover to drive out and collect samples and bring them back to an Earth return vehicle. This rover will use an unprecedented level of autonomy because of the limited lifetime of a return rocket on the Martian surface and the desire to obtain samples from distant crater walls.

Modeling of airborne dust accumulation on solar cells at the Martian surface

An adsorption/desorption model of airborne dust on solar cell panels was proposed. This theoretical model successfully explained the time evolution of solar cell performance associated with dust accumulation in the Mars Pathfinder Mission. This model can be used to predict the long-term cell performance evolution simply by fitting two parameters to an initial-stage data. The saturation output power loss was estimated to be 15% for the solar cell used in the Mars Pathfinder, which indicates the potential of solar cells as a long-life power source on Mars.

Dust deposition on the Mars Exploration Rover Panoramic Camera (Pancam) calibration targets

The Panoramic Camera (Pancam) on the Mars Exploration Rover mission has acquired in excess of 20,000 images of the Pancam calibration targets on the rovers. Analysis of this data set allows estimates of the rate of deposition and removal of aeolian dust on both rovers. During the first 150–170 sols there was gradual dust accumulation on the rovers but no evidence for dust removal. After that time there is ample evidence for both dust removal and dust deposition on both rover decks. We analyze data from early in both rover missions using a diffusive reflectance mixing model. Assuming a dust settling rate proportional to the atmospheric optical depth, we derive spectra of optically thick layers of airfall dust that are consistent with spectra from dusty regions on the Martian surface. Airfall dust reflectance at the Opportunity site appears greater than at the Spirit site, consistent with other observations. We estimate the optical depth of dust deposited on the Spirit calibration target by sol 150 to be 0.44 ± 0.13. For Opportunity the value was 0.39 ± 0.12. Assuming 80% pore space, we estimate that the dust layer grew at a rate of one grain diameter per ∼100 sols on the Spirit calibration target. On Opportunity the rate was one grain diameter per ∼125 sols. These numbers are consistent with dust deposition rates observed by Mars Pathfinder taking into account the lower atmospheric dust optical depth during the Mars Pathfinder mission.

From 2D Images to 3D Tangible Models: Autostereoscopic and Haptic Visualization of Martian Rocks in Virtual Environments

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.

Colonialism and Place Creation in Mars Pathfinder Media Coverage

This paper addresses the representation of the planet Mars during the 1997 Mars Pathfinder mission through a content analysis of major U.S. newspapers as well as transcripts of television and radio news shows. Content analysis identified three threads of representation: scientific advance and the search for life, the naming of Martian places, and the Earth analogy. Together these converge in a language of colonialism that both advances the economic goals of the media and the National Aeronautics and Space Administration and represents Mars as a space fit for human colonization. This article focuses on how the Sojourner rover technology simulated human activity on the surface of Mars and led to the constitution of Mars as a place of social activity, thereby enabling the language of colonialism.

Preliminary analysis of the MER magnetic properties experiment using a computational fluid dynamics model

Motivated by questions raised by the magnetic properties experiments on the NASA Mars Pathfinder and Mars Exploration Rover (MER) missions, we have studied in detail the capture of airborne magnetic dust by permanent magnets using a computational fluid dynamics (CFD) model supported by laboratory simulations. The magnets studied are identical to the capture magnet and filter magnet on MER, though results are more generally applicable. The dust capture process is found to be dependent upon wind speed, dust magnetization, dust grain size and dust grain mass density. Here we develop an understanding of how these parameters affect dust capture rates and patterns on the magnets and set bounds for these parameters based on MER data and results from the numerical model. This results in a consistent picture of the dust as containing varying amounts of at least two separate components with different physical properties.

Frontiers of space exploration

From the first experimentation with rocket technology in the early 20th century to the Mir space station and the Mars Pathfinder mission of 1997, this one-stop guide to space exploration provides a wealth of information for student researchers. Combining narrative description, analytical essays, a timeline, biographical profiles, and the text of key primary documents, Roger D. Launius, Chief Historian of NASA, provides the latest information and analysis on all aspects of space exploration. Four essays give a historical overview of space exploration and up-to-date examinations of the race to the moon, exploration of the solar system, space stations and space shuttles, and U.S.-Soviet cooperative ventures. Ready reference features include: a timeline of key events; biographical profiles of 24 American and Soviet space pioneers; the text of 20 key primary documents relating to space exploration initiatives; a table of American space flight since 1961; and an annotated bibliography of works on space history. The essays are designed to be understandable and to capture the human drama as well as the scientific accomplishments of space exploration. Biographical profiles include not only astronauts and cosmonauts, but also American and Soviet pioneers in the science of space exploration, NASA leaders, and the Challenger crew. Key documents include presidential speeches and directives on the creation of the space program and the decision to go to the moon, official statements on U.S.-Soviet cooperation in space, the text of the Apollo creW's radio broadcast from space on the first moon landing, recollections of Apollo astronauts who first landed on the moon, policy directives on the decision to build the space shuttle, the radio transcript of the last words from the space shuttle Challenger disaster, and a speech from Robert Zubrin, member of the National Space Society Board of Directors, addressing the promise of space exploration in the 21st century. A selection of photos complements the text.

Sojourner: an insider's view of the Mars Pathfinder mission

Sojourner: an insider's view of the Mars Pathfinder mission

Simulation of the Martian dust aerosol at low wind speeds

Performing realistic simulations is crucial for developing, testing, and subsequently analyzing results of experiments sent to the surface of Mars. A wind tunnel has been constructed, in which the atmospheric conditions of pressure and wind speed are controlled to match those observed by the Pathfinder mission to Mars. Injection into the wind tunnel of an analogue dust from Salten Skov in Denmark allows simulation of the Martian aerosol. Here experiments can be tested in preparation for a planned mission to the planet (Mars Exploration Rovers to be launched in 2003). Observations of adhesion and cohesion effects have been made in the wind tunnel, which are relevant to particle transport and of significance for validating the performance of specific experiments on Mars. Preliminary studies have been made, at Mars atmospheric pressure, of dust capture on magnet arrays similar to those flown on the Mars Pathfinder mission.

Genetic Planning Method and its Application to Planetary Exploration

This paper describes a genetic algorithm planning method for autonomous robots in unstructured environments. It presents the approach and demonstrates its application to a laboratory planetary exploration problem. The method represents activities of the robot with discrete actions, or action modules. The action modules are assembled into an action plan with a Genetic Algorithm (GA). A successful plan allows the robot to complete the task without violating any physical constraints. Plans are developed that explicitly consider constraints such as power, actuator saturation, wheel slip, and vehicle stability. These are verified using analytical models of the robot and environment. The methodology is described in the context of planetary exploration similar to the NASA Mars Pathfinder mission. More aggressive missions are planned where rovers will explore scientifically important areas that are difficult to reach (e.g., ravines, craters, dry riverbeds, and steep cliffs). The proposed approach is designed for such areas.

Goldin Era Ends at NASA, Canada Picks New Space Chief

Dan Goldin, NASA’s longest-serving chief administrator, announced his resignation in mid-October, just days before the results of an investigation into cost overruns of the International Space Station (ISS) were made public. In November, he joined the Council on Competitiveness, a group based in Washington, DC, that promotes American economic and business leadership.Goldin is widely credited with revitalizing enthusiasm for space science exploration both within NASA and among the public (see April 2001, page 25). He was instrumental in getting NASA to consider innovative technological solutions in an agency that was still reeling from the aftereffects of the 1986 Challenger disaster. But he’s probably best known for his mantra “faster, cheaper, better,” which translates into a push to switch from costly spacecraft that took years to develop to smaller, more focused missions that could be launched for under $500 million within 18 months of receiving funding approval. The Lunar Prospector, Deep Space 1, and the 1997 Mars Pathfinder missions are examples.Goldin’s departure comes on the cusp of NASA’s biggest-ever financial crisis. The ISS is projected to be $4.8 billion over budget, the human spaceflight program faces a $1 billion shortfall in its budget for next year, and a $500 million overrun in NASA’s 1999 budget was discovered this fall. In response, this year NASA slashed 40% from the ISS science budget and reduced the space station’s crew from seven to three.Further fixes will follow from the ISS management and cost evaluation task force report, ordered by Goldin this past July to get the ISS back on track without new money. The task force recommends that NASA slash jobs and, to avoid future cost overruns, that the agency adopt strict accounting methods.NASA’s top job is proving hard to fill—by early November, an appointment by President Bush had been imminent for months. It was well known that Goldin didn’t want to leave NASA, but the Bush administration had given him no indication that it wanted him to stay. Courtney Stadd, one of Goldin’s possible successors and NASA’s chief of staff, is temporarily running the day-to-day operations.Meanwhile, north of the border, Marc Garneau has been appointed president of the Canadian Space Agency. Garneau, Canada’s first astronaut, has a bachelor’s degree in engineering physics and a PhD in engineering. The CSA’s annual budget of Can$300 million ($188 million) is just 1.5% of NASA’s. Since 1999 the CSA has emphasized terrestrial applications, such as remote sensing, and closer strategic links among government, academia, and industry. Garneau succeeds Mac Evans, who retired after 35 years at the agency. Garneau CSAPPT|High resolution© 2001 American Institute of Physics.

Mars: Uncovering the Secrets of the Red Planet

Riding on the tidal wave of interest in Mars sparked by the highly successful Mars Pathfinder mission, Mars: Uncovering the Secrets of the Red Planet was first published in hardback in August 1998. The book, now available in paperback edition's loaded with more than 125 spectacular photographs from every successful mission to Mars from Mariner and Viking to Mars Pathfinder and Mars Global Surveyor. Raeburn portrays both the drama and the human history of the exploration of Mars in seven chapters.While the text is technically accurate from both engineering and geology viewpoints, its potential dryness is also frequently enlivened by anecdotes that provide a unique personal perspective on more than 30 years of Mars exploration. The players discussed rank among the most distinguished members of planetary science, including Copernicus, Kepler, Galileo, Lowell, Sagan, and many more currently active scientists too numerous to mention here. The foreword provided by Matt Golombek, the project scientist for Mars Pathfinder at NASA's Jet Propulsion Laboratory, sets the stage by outlining some of the major issues in the exploration of Mars. These key issues include the history of water at and below the surface, the possibility of life on Mars and its possible preservation in the Allan Hills meteorite (ALH 84001), and the role of future human exploration in finding some answers.

Special Issue on Advanced Space Robotics

Toward the turn of the century, several missions to explore deep space such as the moon, Mars, asteroids, and comets are being planned for scientific observation. Recently, many researchers have studied and developed lunar or planetary rovers for unmanned planet surface exploration. Microrover missions have received much attention. In July 1997, NASA/JPL succeeded in the Mars Pathfinder mission and the Sojourner rover moved over the Martian surface gathering and transmitting voluminous amounts of data back to the Earth. NASA plans to send robots to Mars in 2003 and 2005 Missions. In Japan, the Institute of Space and Astronautical Science (ISAS) launched the Nozomi, a Mars's orbiter. ISAS plans to send Lunar-A spacecraft with penetrators to the moon and is also promoting the MUSES-C mission for asteroid sample return. ISAS and the National Space Development Agency (NASDA) are cooperatively promoting the SELENE mission, whose major objectives are to acquire scientific data on lunar origin and evolution, and to develop technology for future lunar exploration. NASDA launched the ETS-VII satellite in 1997 for rendezvous docking and orbital robotics experiments. The International Space Station (ISS) is under construction by international cooperation. We will shortly start robotics activities onboard the Japanese Experimental Module (JEM) named KIBOU for the ISS. Space robotics including Al is a key technology for planetary exploration. Space robotics is expected to support space activities, such as external vehicular activities (EVA) and internal vehicular activities (IVA) for future space utilization. Future space projects will require space robotics technology to construct, repair and maintain satellites and space structures in orbit. This special issue on advanced space robotics introduces updated mission results and advanced research activities of space organizations, institutes, and universities, although it does not include all. We hope that this special issue will be useful to readers as an introduction to advanced space robotics in Japan, and that more robotics and Al researchers and engineers will become interested in space robotics and participate in space missions. We thank those researchers who have contributed their advanced research activities to this special issue, and deeply appreciate their earnest efforts.