586 research outputs found

    Exobiology and Future Mars Missions

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    Scientific questions associated with exobiology on Mars were considered and how these questions should be addressed on future Mars missions was determined. The mission that provided a focus for discussions was the Mars Rover/Sample Return Mission

    International exploration of Mars. A special bibliography

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    This bibliography lists 173 reports, articles, and other documents introduced into the NASA Scientific and Technical Information Database on the exploration of Mars. Historical references are cited for background. The bibliography was created for the 1991 session of the International Space University

    Enabling technologies for the subsurface exploration of the solar system

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    Future robotic exploration missions within the Solar System, focussing on either scientific discovery or the emerging field of In-Situ Resource Utilisation (ISRU), shall require the development of technologies which are capable of exploring to ever-greater depths beneath the planetary surface. In order to achieve these ambitious goals, advances in the existing state of the art in robotic sampling are required. This Ph.D. presents findings on the development of novel solutions within this field. The development of the Ultrasonic Planetary Core Drill (UPCD), a system based upon the ultrasonic-percussive drill technique, was designed with a Mars Sample Return (MSR) objective at the core of the development. Breakthroughs in autonomous control and the robotic assembly of drill strings were required in order to meet the requirements set. The system was tested at Coal Nunatak, Antarctica, in December 2016. A rotary-percussive drilling system for use in extracting subglacial bedrock samples from Earth’s Polar Regions was developed. Making use of technologies devised in the UPCD project, this collaboration with the British Antarctic Survey (BAS) required a low resource approach to the problem in order to ensure compatibility with existing BAS systems and logistical constraints. Building upon technologies developed and confidence generated in previous systems, the subglacial bedrock was industrialised into what became the Percussive Rapid Access Isotope Drill (P-RAID). This system underwent initial field trials at the Skytrain Ice Rise, Antarctica in January 2019 with the intention to further develop the system for full deployment

    Development of a robust mating system for use in the autonomous assembly of planetary drill strings

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    Volume-constrained robotic missions seeking to obtain samples from beneath a planetary subsurface may wish to use a rigid drill string consisting of multiple, individual drill bit sections connected together, as opposed to a single, lengthy drill bit. To ensure that drill strings can be assembled and disassembled reliably, it is essential that a robust connection system be used. The authors propose a geometry that seeks to address the requirements of such a mating interface. The proposed solution is based on the bayonet interface, using L- and T-shaped so-called female grooves and male studs connected and disconnected together through a series of clockwise and counterclockwise rotations and single-point clamping events. This routine allows the transfer of both percussion through the drill string and torque in both directions of rotation, while permitting the accurate disconnection of individual drills bits at the required location. Sustained laboratory and field drilling operations suggest that bayonet-style connections offer a reliable solution to the problem of autonomous assembly and disassembly of drill strings in a planetary exploration setting. This paper discusses the development of such a connection system, based on the bayonet connection, which has been implemented in the overall architecture of the Ultrasonic Planetary Core Drill (UPCD). The design trade-off study, which sought to evaluate the use of the bayonet system in comparison with the more conventional screw thread interface, will be discussed, alongside experimental results from percussion transmission testing and drill string assembly testing

    BDS GNSS for Earth Observation

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    For millennia, human communities have wondered about the possibility of observing phenomena in their surroundings, and in particular those affecting the Earth on which they live. More generally, it can be conceptually defined as Earth observation (EO) and is the collection of information about the biological, chemical and physical systems of planet Earth. It can be undertaken through sensors in direct contact with the ground or airborne platforms (such as weather balloons and stations) or remote-sensing technologies. However, the definition of EO has only become significant in the last 50 years, since it has been possible to send artificial satellites out of Earth’s orbit. Referring strictly to civil applications, satellites of this type were initially designed to provide satellite images; later, their purpose expanded to include the study of information on land characteristics, growing vegetation, crops, and environmental pollution. The data collected are used for several purposes, including the identification of natural resources and the production of accurate cartography. Satellite observations can cover the land, the atmosphere, and the oceans. Remote-sensing satellites may be equipped with passive instrumentation such as infrared or cameras for imaging the visible or active instrumentation such as radar. Generally, such satellites are non-geostationary satellites, i.e., they move at a certain speed along orbits inclined with respect to the Earth’s equatorial plane, often in polar orbit, at low or medium altitude, Low Earth Orbit (LEO) and Medium Earth Orbit (MEO), thus covering the entire Earth’s surface in a certain scan time (properly called ’temporal resolution’), i.e., in a certain number of orbits around the Earth. The first remote-sensing satellites were the American NASA/USGS Landsat Program; subsequently, the European: ENVISAT (ENVironmental SATellite), ERS (European Remote-Sensing satellite), RapidEye, the French SPOT (Satellite Pour l’Observation de laTerre), and the Canadian RADARSAT satellites were launched. The IKONOS, QuickBird, and GeoEye-1 satellites were dedicated to cartography. The WorldView-1 and WorldView-2 satellites and the COSMO-SkyMed system are more recent. The latest generation are the low payloads called Small Satellites, e.g., the Chinese BuFeng-1 and Fengyun-3 series. Also, Global Navigation Satellite Systems (GNSSs) have captured the attention of researchers worldwide for a multitude of Earth monitoring and exploration applications. On the other hand, over the past 40 years, GNSSs have become an essential part of many human activities. As is widely noted, there are currently four fully operational GNSSs; two of these were developed for military purposes (American NAVstar GPS and Russian GLONASS), whilst two others were developed for civil purposes such as the Chinese BeiDou satellite navigation system (BDS) and the European Galileo. In addition, many other regional GNSSs, such as the South Korean Regional Positioning System (KPS), the Japanese quasi-zenital satellite system (QZSS), and the Indian Regional Navigation Satellite System (IRNSS/NavIC), will become available in the next few years, which will have enormous potential for scientific applications and geomatics professionals. In addition to their traditional role of providing global positioning, navigation, and timing (PNT) information, GNSS navigation signals are now being used in new and innovative ways. Across the globe, new fields of scientific study are opening up to examine how signals can provide information about the characteristics of the atmosphere and even the surfaces from which they are reflected before being collected by a receiver. EO researchers monitor global environmental systems using in situ and remote monitoring tools. Their findings provide tools to support decision makers in various areas of interest, from security to the natural environment. GNSS signals are considered an important new source of information because they are a free, real-time, and globally available resource for the EO community

    NASA's supercomputing experience

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    A brief overview of NASA's recent experience in supercomputing is presented from two perspectives: early systems development and advanced supercomputing applications. NASA's role in supercomputing systems development is illustrated by discussion of activities carried out by the Numerical Aerodynamical Simulation Program. Current capabilities in advanced technology applications are illustrated with examples in turbulence physics, aerodynamics, aerothermodynamics, chemistry, and structural mechanics. Capabilities in science applications are illustrated by examples in astrophysics and atmospheric modeling. Future directions and NASA's new High Performance Computing Program are briefly discussed

    The 1990 Johnson Space Center bibliography of scientific and technical papers

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    Abstracts are presented of scientific and technical papers written and/or presented by L. B. Johnson Space Center (JSC) authors, including civil servants, contractors, and grantees, during the calendar year of 1990. Citations include conference and symposium presentations, papers published in proceedings or other collective works, seminars, and workshop results, NASA formal report series (including contractually required final reports), and articles published in professional journals

    A Localized Autonomous Control Algorithm For Robots With Heterogeneous Capabilities In A Multi-Tier Architecture

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    This dissertation makes two contributions to the use of the Blackboard Architecture for command. The use of boundary nodes for data abstraction is introduced and the use of a solver-based blackboard system with pruning is proposed. It also makes contributions advancing the engineering design process in the area of command system selection for heterogeneous robotic systems. It presents and analyzes data informing decision making between centralized and distributed command systems and also characterizes the efficacy of pruning across different experimental scenarios, demonstrating when it is effective or not. Finally, it demonstrates the operations of the system, raising the technology readiness level (TRL) of the technology towards a level suitable for actual mission use. The context for this work is a multi-tier mission architecture, based on prior work by Fink on a “tier scalable” architecture. This work took a top-down approach where the superior tiers (in terms of scope of visibility) send specific commands to craft in lower tiers. While benefitting from the use of a large centralized processing center, this approach is limited in responding to failures and interference. The work presented herein has involved developing and comparatively characterizing centralized and decentralized (where superior nodes provide information and goals to the lower-level craft, but decisions are made locally) Blackboard Architecture based command systems. Blackboard Architecture advancements (a solver, pruning, boundary nodes) have been made and tested under multiple experimental conditions

    H-SPACE 2016

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