Engineering topics
Publications and source records attributed to Friedman, L..
Students 18 years of age and younger were invited to propose experiments that were consistent with MECA's Mission: to help us better understand how humans will be able to live on Mars.
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Explore the source record for details and available documents.
As scientists and engineers primarily employed by the public, we have a responsibility to "communicate the results of our research so that the average American could understand that NASA is an investment in our future...". Not only are we employed by the public, but they are also the source of future generations of scientists and engineers. Teachers typically don't have the time or expertise to research recent advances in space science and reduce them to a form that students can absorb. Teachers are also often intimidated by both the subject and the researchers themselves. Therefore, the burden falls on us - the space scientists and engineers of the world - to communicate our findings in ways both teachers and students can understand. Student Nanoexperiments for Outreach and Observational Planetary InquirY (SNOOPY) provides just such an opportunity to directly involve our customers in planetary science missions.
Scientific inquiry into the nature of the universe beyond Earth and exploration of the Sun's solar system have to date been enterprises carried out primarily by the United States, the former Soviet Union, and only a few other industrialized states.
Tests on a prototype engineering model of the Russian Mars 96 Rover were conducted by an international team in and near Death Valley in the United States in late May, 1992. These tests were part of a comprehensive design and testing program initiated by the three Russian groups responsible for the rover development. The specific objectives of the May tests were: (1) evaluate rover performance over different Mars-like terrains; (2) evaluate state-of-the-art teleoperation and autonomy development for Mars rover command, control and navigation; and (3) organize an international team to contribute expertise and capability on the rover development for the flight project. The range and performance that can be planned for the Mars mission is dependent on the degree of autonomy that will be possible to implement on the mission. Current plans are for limited autonomy, with Earth-based teleoperation for the nominal navigation system. Several types of television systems are being investigated for inclusion in the navigation system including panoramic camera, stereo, and framing cameras. The tests used each of these in teleoperation experiments. Experiments were included to consider use of such TV data in autonomy algorithms. Image processing and some aspects of closed-loop control software were also tested. A micro-rover was tested to help consider the value of such a device as a payload supplement to the main rover. The concept is for the micro-rover to serve like a mobile hand, with its own sensors including a television camera.
New algorithms for diagnosing problems in electromechanical systems based on artificial intelligence techniques used to locate faults with minimal human intervention. After given information on system architecture, electrical connections, types of parts, and failure modes, algorithms apply "reasoning" processes patterned after those of humans.
To prevent a repetition of the lack of reporting and dissemination of the data obtained during the 1910 observations of Comet Halley, a mechanism is proposed for coordinating the work of scientists and amateurs, including government, industrials, and academic personnel during the 1985-86 apparition of Comet Halley. Specialists from each discipline, in consultation with other experts in the field, would recommend specific objectives, standards, data format, and priorities for observations in that discipline. Following time for individual publication, scientists would be invited to contribute results to a multivolume compilation containing as complete as possible a record of the apparition. It is suggested that the discipline specialists be selected jointly by the IHW leader an by an international steering group with members from COSPAR, the IAU, etc., perhaps in response to some form of international announcement of opportunity.
Topics are presented on navigation systems, inner planets, comets and asteroids, outer planets, earth orbital applications, and computational methods. Individual subjects include an overview of the Navstar Global Positioning System and the Navy Navigation Satellite System, the solar probe mission, Uranus mission options, as well as a study of lifetimes of geosynchronous transfer orbits, and the price of oil in the year 2000.
A new logic is developed which permits continuously variable strength of belief in the truth of assertions. Four inference rules result, with formal logic as a limiting case. Quantification of belief is defined. Propagation of belief to linked assertions results from dependency-based techniques of truth maintenance so that local consistency is achieved or contradiction discovered in problem solving. Rules for combining, confirming, or disconfirming beliefs are given, and several heuristics are suggested that apply to revising already formed beliefs in the light of new evidence. The strength of belief that results in such revisions based on conflicting evidence are a highly subjective phenomenon. Certain quantification rules appear to reflect an orderliness in the subjectivity. Several examples of reasoning by plausible inference are given, including a legal example and one from robot learning. Propagation of belief takes place in directions forbidden in formal logic and this results in conclusions becoming possible for a given set of assertions that are not reachable by formal logic.
Scientific study of Mars after Viking will focus on the following areas: planetary formation from the solar nebula, internal development, interaction with its atmosphere and with the interplanetary medium, and biological history (if any). Four basic measurement modes are outlined to pursue these areas of investigation. They are: orbital, especially polar orbits with wide area surface, atmospheric, and magnetospheric studies; in situ, which include bio-, geo-, and meteorological surface ground stations; network, using separated ground stations and, possibly, RPV aircraft; and sample-return. Various vehicle concepts for the different study modes are described.
The practicability of using solar sails as a means of spacecraft propulsion is discussed with reference to a Haley's comet rendezvous mission in 1981. Two types of sails are examined: square and heliogyro. Because of ease of deployment (release into space from a space shuttle, and unfolding of the blades through solar radiation pressure) the latter is preferred. Structural and mission parameters are given for the heliogyro configuration, with attention to operational temperature limits and material coefficients. A cranking orbit is described, where a sail-powered spacecraft flies first toward the sun, and then away from it in order to achieve rendezvous with a comet. Other missions using solar sails, including a back-up mission to Encke's comet in 1983, are also discussed.
A model of robot learning is described that associates previously unknown perceptions with the sensed known consequences of robot actions. For these actions, both the categories of outcomes and the corresponding sensory patterns are incorporated in a knowledge base by the system designer. Thus the robot is able to predict the outcome of an action and compare the expectation with the experience. New knowledge about what to expect in the world may then be incorporated by the robot in a pre-existing structure whether it detects accordance or discrepancy between a predicted consequence and experience. Errors committed during plan execution are detected by the same type of comparison process and learning may be applied to avoiding the errors.