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At least 451 records · Page 25

Integrated operations/payloads/fleet analysis (executive summary)

The Integrated Operations/Payloads/Fleet Analysis predicts total national space program costs and launch vehicle traffic assuming either an expendable, a partially reusable or a fully reusable launch vehicle fleet. The payload system costs are estimated and reported for each payload program at the subsystem level, payload program level, user level and national level, providing complete system cost traceability. The analysis determines the primary changes to be expected for space payload programs and space operations in the space shuttle era. When the space shuttle becomes fully operational, not only will launch costs be reduced but refurbished satellite units will be flown instead of new units and maintenance will be performed on failing satellites. It is possible to implement the concepts of satellite refurbishment and maintenance because of the space shuttle's capability to retrieve and return payloads to the earth's surface. The two-way satellite transportation capability is extended to high energy orbits by use of the space shuttle/space tug combination.

Source record↗

Analysis of space tug operating techniques. Volume 2: Study results

The design requirements for space tug systems and cost analysis of the refurbishment phases are discussed. The vehicle is an integral propulsion stage using liquid hydrogen and liquid oxygen as propellants and is capable of operating either as a fully or a partially autonomous vehicle. Structural features are an integral liquid hydrogen tank, a liquid oxygen tank, a meteoroid shield, an aft conical docking and structural support ring, and a staged combustion main engine. The vehicle is constructed of major modules for ease of maintenance. Line drawings and block diagrams are included to explain the maintenance requirements for the subsystems.

Source record↗

The real-time operations of the Space Shuttle Orbiter during rendezvous and proximity operations

The Space Shuttle Orbiter is the only U.S. spacecraft in operation today that routinely performs an orbital rendezvous with another spacecraft. The trajectory planning and training of both flight crews and ground operations personnel required to achieve a 100 percent success rate is considerable. The preflight planning and training can be reduced through very simple design considerations of a new space vehicle.

Dougherty, Andrew↗

A Simulation Based Investigation of High Latency Space Systems Operations

This study was the first in a series of planned tests to use physics-based subsystem simulations to investigate the interactions between a spacecraft's crew and a ground-based mission control center for vehicle subsystem operations across long communication delays. The simulation models the life support system of a deep space habitat. It contains models of an environmental control and life support system, an electrical power system, an active thermal control systems, and crew metabolic functions. The simulation has three interfaces: 1) a real-time crew interface that can be use to monitor and control the subsystems; 2) a mission control center interface with data transport delays up to 15 minute each way; and 3) a real-time simulation test conductor interface used to insert subsystem malfunctions and observe the interactions between the crew, ground, and simulated vehicle. The study was conducted at the 21st NASA Extreme Environment Mission Operations (NEEMO) mission. The NEEMO crew and ground support team performed a number of relevant deep space mission scenarios that included both nominal activities and activities with system malfunctions. While this initial test sequence was focused on test infrastructure and procedures development, the data collected in the study already indicate that long communication delays have notable impacts on the operation of deep space systems. For future human missions beyond cis-lunar, NASA will need to design systems and support tools to meet these challenges. These will be used to train the crew to handle critical malfunctions on their own, to predict malfunctions and assist with vehicle operations. Subsequent more detailed and involved studies will be conducted to continue advancing NASA's understanding of space systems operations across long communications delays.

Li, Zu Qun↗

Space Station material life considerations

Space Station life requirements for the overall system are currently stated as thirty years of constant space operation. This aspect of constant in-space operation and long life brings in environmental compatibility requirements which place severe new constraints on material selection. Activities within the United States are currently addressing many of these material selection issues including development of coatings and other space-durable materials, material selection methodology, and life certification methodology. A summary of these activities is presented.

Leger, L. J.↗

A Simulation Based Investigation of High Latency Space Systems Operations

This study was the first in a series of planned tests to use physics-based subsystem simulations to investigate the interactions between a spacecraft's crew and a ground-based mission control center for vehicle subsystem operations across long communication delays. The simulation models the life support system of a deep space habitat. It contains models of an environmental control and life support system, an electrical power system, an active thermal control system, and crew metabolic functions. The simulation has three interfaces: 1) a real-time crew interface that can be use to monitor and control the subsystems; 2) a mission control center interface with data transport delays up to 15 minute each way; and 3) a real-time simulation test conductor interface used to insert subsystem malfunctions and observe the interactions between the crew, ground, and simulated vehicle. The study was conducted at the 21st NASA Extreme Environment Mission Operations (NEEMO) mission. The NEEMO crew and ground support team performed a number of relevant deep space mission scenarios that included both nominal activities and activities with system malfunctions. While this initial test sequence was focused on test infrastructure and procedures development, the data collected in the study already indicate that long communication delays have notable impacts on the operation of deep space systems. For future human missions beyond cis-lunar, NASA will need to design systems and support tools to meet these challenges. These will be used to train the crew to handle critical malfunctions on their own, to predict malfunctions, and to assist with vehicle operations. Subsequent more detailed and involved studies will be conducted to continue advancing NASA's understanding of space systems operations across long communications delays.

Li, Zu Qun↗

Operationally efficient propulsion system study (OEPSS) data book: Space Transfer Propulsion Operational Efficiency Study Task of OEPSS - Volume 6

This document is the final report for the Space Transfer Propulsion Operational Efficiency Study Task of the Operationally Efficient Propulsion System Study (OEPSS) conducted by the Rocketdyne Division of Rockwell International. This Study task studied, evaluated and identified design concepts and technologies which minimized launch and in-space operations and optimized in-space vehicle propulsion system operability.

Harmon, Timothy J.↗

Future Vision for NASA Ground Systems

The NASA Space Operations System (NSOS) is defined as the people (organization), processes, services, tools, amd physical elements that do space operations for NASA Missions.

network control center low earth orbit network dee↗

Review of laser and RF systems for space proximity operations

The development of ranging and tracking systems for NASA space missions is discussed. Among the systems described are: rendezvous and docking (RAD) radar systems for the Gemini and Apollo programs; the Shuttle Rendezvous Ku-band radar system; and laser and TV docking systems RAD sensors systems for the Space Station. A multi-target microwave tracking system for Shuttle applications in the future is also described.

Krishen, K.↗

Modeling and Design of an Electro-Rheological Fluid Based Haptic System for Tele-Operation of Space Robots

For many years, the robotic community sought to develop robots that can eventually operate autonomously and eliminate the need for human operators. However, there is an increasing realization that there are some tasks that human can perform significantly better but, due to associated hazards, distance, physical limitations and other causes, only robot can be employed to perform these tasks. Remotely performing these types of tasks requires operating robots as human surrogates. While current "hand master" haptic systems are able to reproduce the feeling of rigid objects, they present great difficulties in emulating the feeling of remote/virtual stiffness. In addition, they tend to be heavy, cumbersome and usually they only allow limited operator workspace. In this paper a novel haptic interface is presented to enable human-operators to "feel" and intuitively mirror the stiffness/forces at remote/virtual sites enabling control of robots as human-surrogates. This haptic interface is intended to provide human operators intuitive feeling of the stiffness and forces at remote or virtual sites in support of space robots performing dexterous manipulation tasks (such as operating a wrench or a drill). Remote applications are referred to the control of actual robots whereas virtual applications are referred to simulated operations. The developed haptic interface will be applicable to IVA operated robotic EVA tasks to enhance human performance, extend crew capability and assure crew safety. The electrically controlled stiffness is obtained using constrained ElectroRheological Fluids (ERF), which changes its viscosity under electrical stimulation. Forces applied at the robot end-effector due to a compliant environment will be reflected to the user using this ERF device where a change in the system viscosity will occur proportionally to the force to be transmitted. In this paper, we will present the results of our modeling, simulation, and initial testing of such an electrorheological fluid (ERF) based haptic device.

Mavroidis, Constantinos↗

Assessment of possible environmental effects of space shuttle operations

The potential of shuttle operations to contribute to atmospheric pollution is investigated. Presented in this interim report are results of the study to date on rocket exhaust inventory, exhaust interactions, dispersion of the ground cloud, detection and measurement of hydrochloric acid and aluminum oxide, environmental effects of hydrochloric acid and aluminum oxide, stratospheric effects of shuttle effluents, and mesospheric and ionospheric effects of orbiter reentry. The results indicate space shuttle operation will not result in adverse environmental effects if appropriate launch constraints are met.

Cicerone, R. J.↗

How Long Can the Hubble Space Telescope Operate Reliably?

Total ionizing dose exposure of electronic parts in the Hubble Space Telescope is analyzed using 3-D ray trace and Monte Carlo simulations. Results are discussed along with other potential failure mechanisms for science operations.

Mechanical Structure↗

Conjunction Assessment at NASA

The number of objects in orbit is growing exponentially The space environment today is very different from a decade ago and continues to evolve very rapidly - Historically, space operations were domain of large governmental entities. - Commercial space operators are becoming commonplace and have different business models than government actors - CubeSats are cost effective and accessible for everyone, even down to elementary schools - Challenge in educating new space actors on best practices and availability of data and tools Technology enabling this access has rapidly evolved, while no regulatory framework has been established to ensure that space can be used safely by all.

Conjunction Assessment↗

Information for Lateral Aircraft Spacing Enabling Closely-Spaced Runway Operations During Instrument-Weather Conditions

In an effort to increase airport capacity, the U.S. plans on investing nearly $6 billion a year to properly maintain and improve the nation's major airports. Current FAA standards however, require a reduction in terminal operations during instrument-weather conditions at many airports, causing delays and reducing airport capacity. NASA, in cooperation with the FAA, has developed the Terminal Area Productivity Program to achieve clear-weather capacity in instrument- weather conditions for all phases of flight. This paper describes a series of experiments planned to investigate the conceptual design of different systems that provide information to flight crews regarding nearby traffic during the approach phase of flight. The purpose of this investigation is to identify and evaluate different display and auditory interfaces to the crew for use in closely-spaced parallel runway operations. Three separate experiments are planned for the investigation. The first two experiments will be conducted using part-task flight simulators located at the MIT Aeronautical Systems Laboratory and at NASA Ames. The third experiment will be conducted in the Advanced Concepts Flight Simulator, a generic "glass-cockpit" simulator at NASA Ames. Subjects for each experiment will be current glass-cockpit pilots from major U.S. air carriers. Subject crews will fly several experimental scenarios in which pseudo-aircraft are "blundered" into the subject aircraft simulation. Runway spacing, longitudinal aircraft separation, aircraft performance and traffic information will be varied. Analyses of the subject reaction times in evading the blundering aircraft and the resulting closest points of approach will be conducted. This paper presents a preliminary examination of the data recorded during the part-task experiments. The impact of traffic information on closely-spaced parallel runway operations is discussed, cockpit displays to aid these operations are examined, and topics for future research are suggested.

Thrush, Trent↗

Does NASA's Constellation Architecture Offer Opportunities to Achieve Multiple Additional Goals in Space?

Every major NASA human spaceflight program in the last four decades has been modified to achieve goals in space not incorporated within the original design goals: the Apollo Applications Program, Skylab, Space Shuttle, and International Space Station. Several groups in the US have been identifying major future science goals, the science facilities necessary to investigate them, as well as possible roles for augmented versions of elements of NASA's Constellation program. Specifically, teams in the astronomy community have been developing concepts for very capable missions to follow the James Webb Space Telescope that could take advantage of - or require - free-space operations by astronauts and/or robots. Taking as one example, the Single-Aperture Far-InfraRed (SAFIR) telescope with a approx. 10+ m aperture proposed for operation in the 2020 timeframe. According to current NASA plans, the Ares V launch vehicle (or a variant) will be available about the same time, as will the capability to transport astronauts to the vicinity of the Moon via the Orion Crew Exploration Vehicle and associated systems. [As the lunar surface offers no advantages - and major disadvantages - for most major optical systems, the expensive system for landing and operating on the lunar surface is not required.] Although as currently conceived, SAFIR and other astronomical missions will operate at the Sun-Earth L2 location, it appears trivial to travel for servicing to the more accessible Earth-Moon L1,2 locations. Moreover. as the recent Orbital Express and Automated Transfer Vehicle missions have demonstrated, future robotic capabilities should offer capabilities that would (remotely) extend human presence far beyond the vicinity of the Earth. In addition to multiplying the value of NASA's architecture for future human spaceflight to achieve the goals multiple major stakeholders. if humans one day travel beyond the Earth-Moon system - say, to Mars - technologies and capabilities for operating for long periods in free space must be developed. The engineering, management. and operational successes of the Space Station have demonstrated that international collaboratio~i is possible. However, there is a danger that the hard-won lessons of cLul+sent programs will be lost without continuing development of in-space operations. A program to achieve. for example. major astronomical goals in space using astronauts and robots will sustain international capabilities. produce highly visible achievements. and appeal to a11 additional broad community of stakeholders not currently involved with missions to the lunar surface.

Thronson, Harley↗

Does NASA's Constellation Architecture Offer Opportunities to Achieve Multiple Additional Goals in Space?

Every major NASA human spaceflight program in the last four decades has been modified to achieve goals in space not incorporated within the original design goals: the Apollo Applications Program, Skylab, Space Shuttle, and International Space Station. Several groups in the US have been identifying major future science goals, the science facilities necessary to investigate them, as well as possible roles for augmented versions of elements of NASA's Constellation program. Specifically, teams in the astronomy community have been developing concepts for very capable missions to follow the James Webb Space Telescope that could take advantage of - or require - free-space operations by astronauts and/or robots. Taking as one example, the Single-Aperture Far-InfraRed (SAFIR) telescope with a approx.10+ m aperture proposed for operation in the 2020 timeframe. According to current NASA plans, the Ares V launch vehicle (or a variant) will be available about the same time, as will the capability to transport astronauts to the vicinity of the Moon via the Orion Crew Exploration Vehicle and associated systems. [As the lunar surface offers no advantages - and major disadvantages - for most major optical systems, the expensive system for landing and operating on the lunar surface is not required.] Although as currently conceived, SAFIR and other astronomical missions will operate at the Sun-Earth L2 location, it appears trivial to travel for servicing to the more accessible Earth-Moon L1,2 locations. Moreover, as the recent Orbital Express and Automated Transfer Vehicle missions have demonstrated, future robotic capabilities should offer capabilities that would (remotely) extend human presence far beyond the vicinity of the Earth. In addition to multiplying the value of NASA's architecture for future human spaceflight to achieve the goals multiple major stakeholders, if humans one day travel beyond the Earth-Moon system - say, to Mars - technologies and capabilities for operating for long periods in free space must be developed. The engineering. management, and operational successes of the Space Station have demonstrated that international collaboration is possible. However, there is a danger that the hard-won lessons of current programs will be lost without continuing development of in-space operations. A program to achieve. for example, major astronomical goals in space using astronauts and robots will sustain international capabilities, produce highly visible achievements, and appeal to an additional broad community of stakeholders not currently involved with missions to the lunar surface.

Thronson, Harley A.↗

Rapid Turnaround of Costing/Designing of Space Missions Operations

The Ground Segment Team (GST), at NASA's Jet Propulsion Laboratory in Pasadena, California, provides high-level mission operations concepts and cost estimates for projects that are in the formulation phase. GST has developed a tool to track costs, assumptions, and mission requirements, and to rapidly turnaround estimates for mission operations, ground data systems, and tracking for deep space and near Earth missions. Estimates that would often take several weeks to generate are now generated in minutes through the use of an integrated suite of cost models. The models were developed through interviews with domain experts in areas of Mission Operations, including but not limited to: systems engineering, payload operations, tracking resources, mission planning, navigation, telemetry and command, and ground network infrastructure. Data collected during interviews were converted into parametric cost models and integrated into one tool suite. The tool has been used on a wide range of missions from small Earth orbiters, to flagship missions like Cassini. The tool is an aid to project managers and mission planners as they consider different scenarios during the proposal and early development stages of their missions. The tool is also used for gathering cost related requirements and assumptions and for conducting integrated analysis of multiple missions.

Cost estimation↗

Influence of a new generation of operations support systems on current spacecraft operations philosophy: The users feedback

Current trends in the spacecraft mission operations area (spacecraft & mission complexity, project duration, required flexibility are requiring a breakthrough for what concerns philosophy, organization, and support tools. A major evolution is related to space operations 'informationalization', i.e adding to existing operations support & data processing systems a new generation of tools based on advanced information technologies (object-oriented programming, artificial intelligence, data bases, hypertext) that automate, at least partially, operations tasks that used be performed manually (mission & project planning/scheduling, operations procedures elaboration & execution, data analysis & failure diagnosis). All the major facets of this 'informationalization' are addressed at MATRA MARCONI SPACE, operational applications were fielded and generic products are becoming available. These various applications have generated a significant feedback from the users (at ESA, CNES, ARIANESPACE, MATRA MARCONI SPACE), which is now allowing us to precisely measure how the deployment of this new generation of tools, that we called OPSWARE, can 'reengineer' current spacecraft mission operations philosophy, how it can make space operations faster, better, and cheaper. This paper can be considered as an update of the keynote address 'Knowledge-Based Systems for Spacecraft Control' presented during the first 'Ground Data Systems for Spacecraft Control' conference in Darmstadt, June 1990, with a special emphasis on these last two years users feedback.

Darroy, Jean Michel↗