Automated resupply of consumables: Enhancement of space commercialization opportunities

This paper addresses work performed at Rockwell International's Space Systems Division to investigate the feasibility of, and develop concepts for, automated and/or robotic resupply of consumables on orbit. The work focuses on the resupply of satellites and is described in five sections. First, the various problems relating the resupply on orbit are discussed: for example, economic concerns, fuel handling problems, and safety issues. Next major methods of effecting fuel transfer on orbit are summarized, together with their advantages and disadvantages. Direct fuel exchange is emphasized as the most feasible technique. Third, guidelines are developed for automated/robotic refueling mechanisms to accomplish on-orbit consumable resupply. For example, the guidelines cover safety, reliability, maintainability, alignment, induced loads, thermal protection, leaks, extravehicular activity (EVA) interface, and so on. The fourth part of the paper covers the development of design concepts for satellite resupply robotic interfaces that comply with the guidelines. Concepts include servicer fluid transfer system and satellite propulsion system, and a combined docking/umbilical device. Last, future technical development in these areas are discussed

Paper Session I-B - Nuclear Thermal Rocket Propulsion Application to Mars Missions

This paper discusses vehicle configuration options using nuclear thermal rocket (NTR) propulsion application to Mars missions. A reference mission in 2016 using an opposition-class Mars transfer trajectory is assumed. The total mission duration is 435 days. A single 75,000-lb-thrust nuclear engine is used for all major propulsive maneuvers. The studies indicate that three perigee kick burns upon leaving Earth result in the lowest stage weights required in low Earth orbit (LEO). The stay time on Mars is assumed to be 30 days. On the interplanetary return leg en route to Earth, a gravity assist by Venus is employed. The reference mission assumes that the nuclear engine delivers a specific impulse of 925 s with an engine thrust-to-weight ratio of 4. The total stage thrust-to-weight ratio was 0.06. To determine which engine parameters were most critical to good mission performance, calculations were performed over arange of specific impulses and thrust-to-weight ratios. One of the major conclusions resulting from this study is that engine specific impulse is the single most important engine parameter in reducing overall stage weight, provided the engine thrust-to-weight ratio is above approximately 4. Lower engine thrust-to-weight ratios were found to incur severe performance penalties

Whitney coverings and the tent spaces T1,q(γ)T^{1,q}(\gamma) for the Gaussian measure

We introduce a technique for handling Whitney decompositions in Gaussian harmonic analysis and apply it to the study of Gaussian analogues of the classical tent spaces $T^{1,q}$ of Coifman, Meyer and Stein.Comment: 13 pages, 1 figure. Revised version incorporating referee's comments. To appear in Arkiv for Matemati

Pen shell Pinna nobilis L. (Mollusca: Bivalvia) from different peculiar environments: adaptive mechanisms of osmoregulation and neurotransmission

The pen shell Pinna nobilis (Linnaeus, 1758) is the largest endemic bivalve mollusc of the Mediterranean Sea, listed as an endangered species in the European Union. Because no information is available about the adaptation of pen shells to different habitats, herein the fundamental conditions of adaptation of P. nobilis to peculiar natural environments, such as the Strait of Messina (SM) and the meromictic Faro Lake (FL; Sicily, Italy), were explored by assessing the morphology, mucous production, osmoregulation and neurotransmission of their gills. Although gills of the pen shells from both sites exhibited a regular morphology, a higher presence of acid mucous cells was detected in P. nobilis from FL than SM, as well as higher levels of osmolytes but without interfering the osmoregulatory processes. About the functioning of gills, the cholinergic (i.e. acetylcholine and AChE) neuronal system was unaltered between individuals from the two sites, whereas the GABAergic neurotransmission (i.e. 4-aminobutyrate or GABA) was significantly augmented in gills of P. nobilis from FL than SM. This may be an adaptive response to hypoxic conditions in FL, as supported by the increased hypoxia-inducible factor (HIF-1α) in gills of pen shells from FL than SM. Noteworthy, this study reports for the first time the presence of the GABA neurotransmitter within the metabolite profile, obtained by application of a protonic Nuclear Magnetic Resonance (1H NMR)-based metabolomics approach, of a marine bivalve. Therefore, GABA may be suggested as a metabolite biomarker in pen shells. Overall, findings from this study provide new insights on the behavioural and adaptive responses of the pen shell Pinna nobilis settled in different peculiar environments

Paper Session I-B - Autonomous Robotic Systems For SEI Tasks

On the 20th anniversary, in 1989, of our country\u27s triumphant first landing on the surface of our moon, the President of the United States once again challenged the nation to excel in space. Since that time, a series of outreach efforts was initiated by NASA to the aerospace industry, federal agencies, and the public. In addition, the Vice President of the United States chartered an Advisory Committee on the Future of the U.S. Space Program. At this writing, the AIAA has submitted a report on their canvass of the aerospace community, and the Advisory Committee report has been published. The synthesis group is in the conclusion preparation phase and should have the report completed by the time of this conference. Although each of these groups has taken different approaches, a consensus does appear that agrees with the President\u27s objectives. Whether the schedule or architectures agree, they all recommend a ...\u27 \u27balanced Space Program for America. We will, within budgetary limits, reenergize our country\u27s thrust into space through a renewed dedication toward the long-term magnet for the manned space program ... the human exploration of Mars. This, of course, is the long-term goal coupled with the science, mission-to-planet Earth, expanded technology and development of a robust space transportation system that make up the balanced program recommended. The authors do not disagree with the goals, objectives, or recommendations of the two reports published to date nor will we differ with the synthesis conclusions after they become apparent. We will briefly summarize the results of an .analysis conducted by McDonnell Douglas and Eagle Engineering in the second and third quarters of CY9Q. The results will show the benefits of space programs and suggest an overall approach to space architecture that could help maximize the world benefits of space while still meeting the overall objectives of the three sets of recommendations mentioned above. We acknowledge the work of the con- \u27 tributors to the AIAA report and to numerous NASA studies of specific endeavors such as the Lunar Energy Enterprise study. This paper is a much shortened version of the entire treatment. A more complete presentation will be available from the authors at the conference if desired

Paper Session I-C - Robotics for Interstellar Missions

This paper discusses the requirements for robotics in future interstellar missions and describes the various robotic development activities at NASA KSC that are laying the basis for the robotics of the future. The first longduration interstellar missions, which might occur at the end of the 21 st century, would probably be preceded by trips to outer planets in the Solar System and by near-Solar interstellar probe missions. The time span, dangers, and uncertainties involved would almost certainly decree that the first missions be unmanned. If an interstellar mission involved a surface landing, all initial exploration would be performed by robots or other autonomous devices. These robots of the next century must possess true autonomy: onboard intelligence; sensor systems to provide information on the visual scene, temperature, radiation, task forces, and torques; stable locomotion; self-maintenance and repair capabilities; and so on. The varied sensor data must be integrated into an intelligent understanding of the environment to support decisions concerning that environment—for example, avoiding collisions or other dangers, or selecting areas of interest for exploration. The capability to store and transmit data, and to modify behavior based on experience, would also be required. Many of these capabilities are in their infancy today. However, NASA is expanding the state-of-the-art of robotics in directions which, while supporting near-term endeavors, will eventually lay the necessary foundation for the interstellar missions of the next century. For instance, the NASA KSC robotics program is making very meaningful contributions in areas of robot mobility, collision avoidance, vision systems, and special endeffectors. One example of this activity concerns the KSC Thermal Protection System robot, which provides an autonomous mobile platform and special end-effectors and vision systems for navigation, inspection, and positioning tasks. The robot can also store task data for downloading at a later date. Other developments at KSC include special mechanisms and controls for robotic space vehicle cleaning and component inspection, and the development of self-diagnostics for automated systems. In summary, while we are presently a long way from achieving the robotics capabilities to support interstellar missions, present-day robotics development activities at KSC and at other NASA centers are laying the groundwork for these exciting future endeavors

The surgical treatment of mandibular peripheral calcifying epithelial odontogenic tumour (pindborg tumor) with Er,Cr:YSGG laser: a case report.\u201d

The aim of this case report was to propose a new treatment modality of peripheral calcifying epithelial odontogenic tumour (CEOT) using Er, Cr: YSGG laser

Prevenzione e management odontoiatrico dei pazienti oncologici a rischio di osteonecrosi delle ossa mascellari da farmaci

non disponibil