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A perception system for a planetary explorer

To perform planetary exploration without human supervision, a complete autonomous robot must be able to model its environment and to locate itself while exploring its surroundings. For that purpose, the authors propose a modular perception system for an autonomous explorer. The perception system maintains a consistent internal representation of the observed terrain from multiple sensor views. The representation can be accessed from other modules through queries. The perception system is intended to be used by the Ambler, a six-legged vehicle being built at CMU. A partial implementation of the system using a range scanner is presented as well as experimental results on a testbed that includes the sensor, one computer-controlled leg, and obstacles on a sandy surface.

Hebert, M.↗

Mini-rovers for Mars explorations

Rovers are desirable for surface exploration because they allow sampling, and sample returns from several diverse locations on a planet's surface. Unfortunately, the rovers currently being examined for Mars exploration have several undesirable features. These rovers are quite massive (500 kg to one ton), have very complicated operations, and are very expensive. A possible alternative is described to using large rovers for exploring the surface of Mars. The idea of mini-rovers is proposed. Mini-rovers weigh less than 5 kg, are trivial to control from the ground, and can do a more thorough survey of the terrain (per kilogram of mass) than can be obtained by large rovers. By redesigning the Mars sample return mission to accommodate the idea of mini-rovers and small spacecraft, considerable mass and cost savings can be achieved.

Miller, David P.↗

The 1990 update to strategy for exploration of the inner planets

The Committee on Planetary and Lunar Exploration (COMPLEX) has undertaken to review and revise the 1978 report Strategy for Exploration of the Inner Planets, 1977-1987. The committee has found the 1978 report to be generally still pertinent. COMPLEX therefore issues its new report in the form of an update. The committee reaffirms the basic objectives for exploration of the planets: to determine the present state of the planets and their satellites, to understand the processes active now and at the origin of the solar system, and to understand planetary evolution, including appearance of life and its relation to the chemical history of the solar system.

Esposito, Larry W.↗

Small Explorers - Small is beautiful

NASA's Small Explorer Program aims to achieve a flight rate of one mission per year in a program of small scientific satellites launched from small expendable launch vehicles. The Program is developing 3 missions for launch in the early 1990's: the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX), the Submillimeter Wave Astronomy Satellite (SWAS), and the Fast Auroral Snapshot Explorer (FAST). This paper gives an overview of the program, a description of the selected missions, the approach to developing the missions and the plans for the next Announcement of Opportunity.

Gilman, David↗

Exploration Technology Program plans and directions

A summary of the proposed Space Exploration Initiative (SEI) needs that have been identified is presented along with a detailed review of the status of SEI technology planning. Plans are also being formulated to implement an Exploration Technology Program (ETP) that will develop the major technologies required for SEI. The ETP will provide in the near term clear demonstrations of potential exploration technologies, results of research to support SEI architecture decisions, and a foundation of mature technology that is ready to be applied in the first round of SEI missions. A family of functional building blocks has been defined from which both lunar and Mars SEI mission architectures can be constructed.

Aldrich, Arnold↗

Thematic Conference on Remote Sensing for Exploration Geology - Methods, Integration, Solutions, 7th, Calgary, Canada, Oct. 2-6, 1989, Proceedings. Volumes 1 & 2

Recent advances in airborne and satellite remote-sensing technology for application to geological exploration are discussed in reviews and reports. Sections are devoted to basement tectonics and their surface expressions, spectral geology, hydrocarbon exploration applications, radar applications and future systems, engineering and environment issues, geobotanical remote sensing, advanced image processing, data integration and mapping, and mineral exploration. Extensive diagrams, graphs, and sample images are provided.

Source record↗

Human exploration of Mars

Novel approaches to the human exploration of Mars are considered with emphasis on a space suit design, extraterrestrial surface mobility, and water supply. A possible way of transporting personnel on the surface of Mars uses a suborbital rocket that will hop from one site to the next, refuelling each time it lands and giving the Martian explorers effective global mobility. Telepresence could be used to avoid limiting the people on Mars to a small exploration area as a result of a lack of transportation infrastructure. Drawings and photographs are included.

Gwynne, Owen↗

The X-ray Timing Explorer

The capabilities and projected mission objectives of the X-ray Timing Explorer (XTE) are set forth with attention given to the components of the space explorer. The XTE instrument complement is reviewed and specific data and graphic descriptions are presented regarding the large-area proportional counter array, the all-sky monitor, and the high-energy crystal scintillation experiment. The XTE provides low-background continuous 2-200 keV response with large apertures, rapid maneuverability, and detailed energy-resolved studies of phenomena close to neutron stars. The synergism of the mission capabilities is shown to permit a powerful mechanism for timing and broad-band spectral studies after deployment by the NASA Explorer Platform in approximately 1995.

Bradt, H. V.↗

Extreme Ultraviolet Explorer (EUVE): Emergency support

The Extreme Ultraviolet Explorer (EUVE) will conduct a survey of the entire celestial sphere in the extreme ultraviolet (UV) spectrum, 100 to 1000 angstrom units. This survey will be accomplished using four grazing incidence telescopes mounted on a spinning spacecraft whose spin axis is along the Sun line. Data is taken only when the spacecraft is in the Earth's shadow. The EUVE will be placed in a near circular orbit by a Delta expendable launch vehicle. The design orbit is circular at an altitude of 550 km by 28.5 degrees for a period of 96 minutes. The EUVE will be flown on a standardized Explorer Platform (EP) which will be reused for followup Explorer missions. Coverage will be provided by the Deep Space Network (DSN) for EUVE emergencies that would prevent communications via the normal channels of the Tracking and Data Relay Satellite System (TDRSS). Emergency support will be provided by the 26-meter subnet. Data is presented in tabular form for DSN support, frequency assignments, telemetry, and command.

Zayas, H.↗

Planetary protection issues and human exploration of Mars

A key feature of the Space Exploration Initiative involves human missions to Mars. The report describing the initiative cites the search for life on Mars, extant or extinct, as one of the five science themes for such an endeavor. Because of this, concerns for planetary protection (PP) have arisen of two fronts: (1) forward contamination of Mars by spacecraft-borne terrestrial microbes which could interfere with exobiological analyses; and (2) back contamination of Earth by species that may be present in returned Mars samples. The United States is also signatory to an international treaty designed to protect Earth and planets from harmful cross-contamination during exploration. Therefore, it is timely to assess the necessity for, and impact of, PP procedures on the mission set comprising the human exploration of Mars. The ground-rules adopted at a recent workshop which addressed PP questions of this type are presented. In addition, the workshop produced several recommendations for dealing with forward and back contamination concerns for non-scientific perspectives, including public relations, legal, regulatory, international, and environmental.

Devincenzi, D. L.↗

Overview of Ka-band communications technology requirements for the space exploration initiative

In the Space Exploration Initiative, Ka-band frequencies are likely to carry the bulk of the communications traffic both in the vicinity of and on the return links from the moon and Mars. The four exploration architectures identified by the Synthesis Group are examined and Ka-band technology requirements to meet the data traffic needs and schedule are identified. Specific Ka-band technology requirements identified are: transmitters - 0.5 to 200 W with high efficiency; antennas - 5m and 9m diameter, with multiple beams and/or scanning beams; and spacecraft receivers - noise figure of 2 dB. For each component, the current state of technology is assessed and needed technology development programs are identified. It is concluded that to meet the schedules of lunar and Mars precursor missions beginning in approximately the year 2000, aggressive technology development and advanced development programs are required immediately for Ka-band communications systems components. Additionally, the greater data transmission rates for the cargo and piloted phases of the exploration program require further Ka-band communications technology developments targeted for operations beginning in about 2010.

Miller, Edward F.↗

Self-organization via active exploration in robotic applications

We describe a neural network based robotic system. Unlike traditional robotic systems, our approach focussed on non-stationary problems. We indicate that self-organization capability is necessary for any system to operate successfully in a non-stationary environment. We suggest that self-organization should be based on an active exploration process. We investigated neural architectures having novelty sensitivity, selective attention, reinforcement learning, habit formation, flexible criteria categorization properties and analyzed the resulting behavior (consisting of an intelligent initiation of exploration) by computer simulations. While various computer vision researchers acknowledged recently the importance of active processes (Swain and Stricker, 1991), the proposed approaches within the new framework still suffer from a lack of self-organization (Aloimonos and Bandyopadhyay, 1987; Bajcsy, 1988). A self-organizing, neural network based robot (MAVIN) has been recently proposed (Baloch and Waxman, 1991). This robot has the capability of position, size rotation invariant pattern categorization, recognition and pavlovian conditioning. Our robot does not have initially invariant processing properties. The reason for this is the emphasis we put on active exploration. We maintain the point of view that such invariant properties emerge from an internalization of exploratory sensory-motor activity. Rather than coding the equilibria of such mental capabilities, we are seeking to capture its dynamics to understand on the one hand how the emergence of such invariances is possible and on the other hand the dynamics that lead to these invariances. The second point is crucial for an adaptive robot to acquire new invariances in non-stationary environments, as demonstrated by the inverting glass experiments of Helmholtz. We will introduce Pavlovian conditioning circuits in our future work for the precise objective of achieving the generation, coordination, and internalization of sequence of actions.

Ogmen, H.↗

Data exploration systems for databases

Data exploration systems apply machine learning techniques, multivariate statistical methods, information theory, and database theory to databases to identify significant relationships among the data and summarize information. The result of applying data exploration systems should be a better understanding of the structure of the data and a perspective of the data enabling an analyst to form hypotheses for interpreting the data. This paper argues that data exploration systems need a minimum amount of domain knowledge to guide both the statistical strategy and the interpretation of the resulting patterns discovered by these systems.

Greene, Richard J.↗

The Space Exploration Initiative

The goals of the Space Exploration Initiative (SEI) and the content and current status of NASA activities and studies relevant to the SEI are briefly reviewed. The principal way points of the program are discussed with particular reference to lunar exploration, preparations for a Martian mission, habitation, and fuels. Attention is also given to the problem of enhancing energy delivery on earth, the use of asteroids as way points, and activities related to the human exploration of Mars.

Aldrich, Arnold D.↗

Mars Observer as a precursor to intensive exploration of Mars

The Mars Observer Mission, to be launched by the United States in September 1992, is designed to perform an extended orbital study of the Martian surface, atmosphere, climate, and gravitational and magnetic fields using a spacecraft in Mars orbit for one Martian year. This information will add to the global data base that is necessary for increasing scientific understanding of Mars, as well as for planning the next stages of intensive exploration of the planet. Future missions will progress from more specific robotic exploration to eventual human exploration, and will require progressively more detailed engineering information. Mars Observer will provide key basic data including planet shape, gravity field, geodetic framework, topography, characteristics of the surface, atmospheric profiles, dust content of the atmosphere, and wind field. Special data products for engineering purposes could be obtained from the currently planned data return, and additional engineering data could be returned by augmentation to the basic Mars Observer's operation.

Cunningham, Glenn E.↗

Solar system exploration in the 1990's and beyond

Exploration of Venus by Magellan and Pioneer Venus continues. Additionally, Galileo's Venus-earth-earth gravity assist trajectory to Jupiter has already provided targets of opportunity at Venus and at earth. Additional opportunities exist during the October 29, 1991, flyby of the asteroid Gaspra, the second earth gravity assist on December 8, 1992, and the flyby of the asteroid Ida on October 18, 1993. A fully successful mission through entry of the Jupiter atmospheric probe is anticipated in 1995/1996. The buildup of the Mars Observer spacecraft for a September 1992 launch is accelerating, and the development of the CRAF spacecraft and the orbiter for the NASA-ESA Cassini mission to Saturn is proceeding. Strategic plans to continue this ambitious program include early initiation of a phased program to detect other planetary systems; start of a program of low-cost, near-earth missions beginning with a near-earth asteroid rendezvous; continuation of moon-Mars exploration using sequentially launched single experiment Lunar Scouts and clusters of small landers to build up a Mars network of 16 stations; and finally, start of a major mission late in the century to explore Neptune and/or Pluto.

Huntress, Wesley T., Jr.↗

NASA's Small Explorer program

NASA's Small Explorer program, or 'SMEX', was designed to support disciplines heretofore accommodated within NASA's astrophysics/space physics/upper-atmosphere science Explorer program. Under the aegis of SMEX, a principal investigator proposes an entire mission and its experiments; emphasis is placed on the passing of spacecraft-design experience to a new generation of scientists and engineers. The first SMEX mission selected for implementation is the Solar Anomalous and Magnetospheric Particle Explorer, which is scheduled for launch on June, 1992.

Baker, Daniel N.↗

Medical concerns for exploration-class missions

The Space Exploration initiative will challenge life scientists with a diverse set of crew medical risks. The varied sources of this cumulative risk are identified and briefly discussed in terms of risk assessment and preliminary plans for risk management. The roles of Space Station Freedom and other flight programs are discussed in the context of exploration medical objectives. The significant differences between Space Station era (second generation) and exploration medical support systems (third generation) are reviewed.

Stewart, Donald F.↗