Modeling, Stability Analysis, and Testing of a Hybrid Docking Simulator

A hybrid docking simulator is a hardware-in-the-loop (HIL) simulator that includes a hardware element within a numerical simulation loop. One of the goals of performing a HIL simulation at the European Proximity Operation Simulator (EPOS) is the verification and validation of the docking phase in an on-orbit servicing mission.....Comment: 30 papge

Orbiting quarantine facility. The Antaeus report

A mission plan for the Orbiting Quarantine Facility (OQF) is presented. Coverage includes system overview, quarantine and protocol, the laboratory, support systems, cost analysis and possible additional uses of the OQF

Experimental validation of docking and capture using space robotics testbeds

This presentation describes the application of robotic and computer vision systems to validate docking and capture operations for space cargo transfer vehicles. Three applications are discussed: (1) air bearing systems in two dimensions that yield high quality free-flying, flexible, and contact dynamics; (2) validation of docking mechanisms with misalignment and target dynamics; and (3) computer vision technology for target location and real-time tracking. All the testbeds are supported by a network of engineering workstations for dynamic and controls analyses. Dynamic simulation of multibody rigid and elastic systems are performed with the TREETOPS code. MATRIXx/System-Build and PRO-MATLAB/Simulab are the tools for control design and analysis using classical and modern techniques such as H-infinity and LQG/LTR. SANDY is a general design tool to optimize numerically a multivariable robust compensator with a user-defined structure. Mathematica and Macsyma are used to derive symbolically dynamic and kinematic equations

National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program, 1989, volume 1

The 1989 Johnson Space Center (JSC) National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program was conducted by Texas A and M University and JSC. The 10-week program was operated under the auspices of the ASEE. The program at JSC, as well as the programs at other NASA Centers, was funded by the Office of University Affairs, NASA Headquarters, Washington, D.C. The objectives of the program, which began nationally in 1964 and at JSC in 1965, are: (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of participants' institutions; and (4) to contribute to the research objective of the NASA Centers

Tethers in space: Birth and growth of a new avenue to space utilization

The evolution of the ideas of tether applications in space are traced from its origin in the last century past a dormant period of sixty-five years to the mid-seventies. At that time as a consequence of major revival efforts, NASA entered into serious investigations of the theoretical and practical feasibility of a large number of tethered concepts in space. These efforts culminated in the establishment of the Tethered Satellite System Project now at NASA in the advanced development phase. Extensive planning efforts are described, first, through a Tether Applications in Space Workshop which generated additional concepts and provided overall assessments and recommendations to NASA, and then through a NASA inter-center Tether Applications in Space Task Group which generated a four year program plan in the areas of further studies, technology, work and science and applications of tethers in space. An outlook into the future of tether applications that approaches some of the goals of the early visionaries is offered

Tethers in space handbook

The handbook provides a list and description of ongoing tether programs. This includes the joint U.S.-Italy demonstration project, and individual U.S. and Italian studies and demonstration programs. An overview of the current activity level and areas of emphasis in this emerging field is provided. The fundamental physical principles behind the proposed tether applications are addressed. Four basic concepts of gravity gradient, rotation, momentum exchange, and electrodynamics are discussed. Information extracted from literature, which supplements and enhances the tether applications is also presented. A bibliography is appended

System analysis approach to deriving design criteria (loads) for Space Shuttle and its payloads. Volume 1: General statement of approach

Space shuttle, the most complex transportation system designed to date, illustrates the requirement for an analysis approach that considers all major disciplines simultaneously. Its unique cross coupling and high sensitivity to aerodynamic uncertainties and high performance requirements dictated a less conservative approach than those taken in programs. Analyses performed for the space shuttle and certain payloads, Space Telescope and Spacelab, are used a examples. These illustrate the requirements for system analysis approaches and criteria, including dynamic modeling requirements, test requirements control requirements and the resulting design verification approaches. A survey of the problem, potential approaches available as solutions, implications for future systems, and projected technology development areas are addressed

Design and modeling of a space docking mechanism for cooperative on-orbit servicing

This dissertation addresses the design procedure of a docking mechanism for space applications, in particular, on-orbit servicing of cooperative satellites. The mechanism was conceived to comply with the technical specifications of the STRONG mission. The objective of this mission is to deploy satellite platforms using a space tug with electric propulsion. This mission is part of the SAPERE project, which focuses on space exploration and access to space. A docking mechanism is used for recovering the misalignments left by the guidance, navigation, and control system of the servicer satellite when approaching the customer spacecraft. However, most importantly, the mechanism must safely dissipate the energy associated with the relative velocities between the spacecraft upon contact. Five concepts were considered as possible candidates for the docking mechanism: a system based on the Stewart-Gough platform with a position controller, a Stewart-Gough platform with impedance control, a central passive mechanism (probe-drogue), a central active mechanism, and a mechanism equipped with articulated arms. Several trade-off criteria were defined and applied to the concepts. The result of this trade study was the selection of the central passive mechanism as the most balanced solution. This mechanism is composed of a probe and a conical frustum equipped with a socket to capture the probe. It was further developed and tested using mathematical models of the docking maneuver. The results of the simulations showed that the passiveness of the system prevented the docking maneuver from being fully accomplished. Consequently, a second design iteration was performed. In this new iteration, the degrees of freedom of the mechanism were increased by adding two controlled linear axes in series with the degrees of freedom of the preliminary design. The electromechanical actuators and transmissions of this mechanism were selected following the guidelines of The ECSS standards. Also, in this case, numerical models were used to assess the functioning of the docking system. The results produced by these models demonstrated the suitability of the mechanism for completing the docking operation defined by the mission’s specifications. Furthermore, the results also showed the architecture and functioning of the mechanism to be possibly suitable for other cooperative docking operations between small and mid-sized satellites. In addition, the definition of the mechanical details as well as the control architecture led to the complete design of an engineering prototype for laboratory tests. In this regard, the laboratory tests were defined with the scope of verifying the different operating modes of the docking mechanism. The test rig was designed to be equipped with a serial manipulator connected to the female part of the mechanism through a force and torque module. The objective will be to simulate the relative motion between the docking halves using different techniques to generate the trajectory of the manipulator

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 331)

This bibliography lists 129 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during December, 1989. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance