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

Sensor systems testbed for telerobotic navigation

A testbed has been developed for the study of sensor systems to be used in telerobotic operations. The program, conducted in conjunction with Johnson Space Center of NASA, addresses the navigational problems associated with target acquisition and rendezvous for teleoperated robotic work stations. The program will utilize a mobile platform which will support various sensor systems during their development and testing in an earth-based environment. The testbed has been developed in support of a program to develop sensor systems that will aid in rendezvous and docking operations to be conducted as a part of the space station program. A mobile platform has been used to permit testing of these components in a conventional laboratory environment with consequent savings in cost and complexity. The sensor systems, while representative of devices currently in use for robotic applications, are not considered prototypical of the ones that will be used in the final applications. The test program provided information that will support the design of system augmentations and will lead to a comprehensive test program for sensor development

Asymptotic properties of the Dirac quantum cellular automaton

We show that the Dirac quantum cellular automaton [A. Bisio, G. M. D'Ariano, and A. Tosini, Ann. Phys. (N. Y.) 354, 244 (2015)] shares many properties in common with the discrete-time quantum walk. These similarities can be exploited to study the automaton as a unitary process that takes place at regular time steps on a one-dimensional lattice, in the spirit of general quantum cellular automata. In this way, it becomes an alternative to the quantum walk, with a dispersion relation that can be controlled by a parameter that plays a similar role to the coin angle in the quantum walk. The Dirac Hamiltonian is recovered under a suitable limit. We provide two independent analytical approximations to the long-term probability distribution. It is shown that, starting from localized conditions, the asymptotic value of the entropy of entanglement between internal and motional degrees of freedom overcomes the known limit that is approached by the quantum walk for the same initial conditions and is similar to the ones achieved by highly localized states of the Dirac equation

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

Testing of an End-Point Control Unit Designed to Enable Precision Control of Manipulator-Coupled Spacecraft

This paper presents an end-point control concept designed to enable precision telerobotic control of manipulator-coupled spacecraft. The concept employs a hardware unit (end-point control unit EPCU) that is positioned between the end-effector of the Space Shuttle Remote Manipulator System and the payload. Features of the unit are active compliance (control of the displacement between the end-effector and the payload), to allow precision control of payload motions, and inertial load relief, to prevent the transmission of loads between the end-effector and the payload. This paper presents the concept and studies the active compliance feature using a simulation and hardware. Results of the simulation show the effectiveness of the EPCU in smoothing the motion of the payload. Results are presented from initial, limited tests of a laboratory hardware unit on a robotic arm testbed at the l Space Flight Center. Tracking performance of the arm in a constant speed automated retraction and extension maneuver of a heavy payload with and without the unit active is compared for the design speed and higher speeds. Simultaneous load reduction and tracking performance are demonstrated using the EPCU

Conservation physiology can inform threat assessment and recovery planning processes for threatened species

Conservation physiology has emerged as a discipline with many success stories. Yet, it is unclear how it is currently integrated into the activities of the IUCN and other bodies which undertake international, national, or regional species threat assessments and work with partners to develop recovery plans. Here we argue that conservation physiology has much to offer for the threat assessment process and we outline the ways in which this can be operationalized. For instance, conservation physiology is effective in revealing causal relationships and mechanisms that explain observed patterns, such as population declines. Identifying the causes of population declines is a necessary precursor to the design of actions to reverse or mitigate such threats. Conservation physiology can also identify complex interactions and support modeling activities that consider emerging threats. When a population or species is deemed threatened and recovery plans are needed, physiology can be used to predict how organisms will respond to the conservation intervention and future threats. For example, if a recovery plan was focused on translocation, understanding how to safely translocate organisms would be necessary, as would ensuring that the recipient habitat provides the necessary environmental characteristics to meet the fundamental physiological needs/tolerances of that organism. Our hope is that this paper will clarify ways in which physiological data can make an important contribution to the conservation activities of bodies like the IUCN that are engaged in threat assess

Quantum walks: a comprehensive review

Quantum walks, the quantum mechanical counterpart of classical random walks, is an advanced tool for building quantum algorithms that has been recently shown to constitute a universal model of quantum computation. Quantum walks is now a solid field of research of quantum computation full of exciting open problems for physicists, computer scientists, mathematicians and engineers. In this paper we review theoretical advances on the foundations of both discrete- and continuous-time quantum walks, together with the role that randomness plays in quantum walks, the connections between the mathematical models of coined discrete quantum walks and continuous quantum walks, the quantumness of quantum walks, a summary of papers published on discrete quantum walks and entanglement as well as a succinct review of experimental proposals and realizations of discrete-time quantum walks. Furthermore, we have reviewed several algorithms based on both discrete- and continuous-time quantum walks as well as a most important result: the computational universality of both continuous- and discrete- time quantum walks.Comment: Paper accepted for publication in Quantum Information Processing Journa