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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 523 records · Page 29
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Impact of space station appendage vibrations on the pointing performance of gimballed payloads

A study of the interface problems between the Space Station Structure (vibrations) and the Payload Pointing Control System was undertaken. A major goal of the study was to identify any bounding factors that might limit the achievement of required pointing accuracies. A major result is that the space station will have a disturbance-rich environment and the background levels will be large enough to impact the pointing of some of the payloads. The need for an interface vibration specification between the structure and the payloads was identified.

Hughes, Robert O.↗
NASA NTRS1987

Contamination assessment for OSSA space station IOC payloads

An assessment is made of NASA/OSSA space station IOC payloads. The report has two main objectives, i.e., to provide realistic contamination requirements for space station attached payloads, serviced payloads and platforms, and to determine unknowns or major impacts requiring further assessment.

Wu, S. T.↗
NASA NTRS1986

Economy of middeck payloads

The utilization of the middeck, designed as the crew quarters, for experiments is examined. The dimensions of the middeck's standard lockers, double lockers, adapter plates, and the galley, which are applicable for experiments, are described. The utilities available for middeck payloads include ac and dc electrical power supply, active and passive cooling, vacuum/vent line connections, and data handling, and four basic payload configurations are possible. The development of a middeck accommodations rack to make payload space more flexible and to enable an optimum number and variety of experiments to be flown is proposed. Diagrams of the orbiter's middeck and experimental designs are provided.

Michel, E. L.↗
NASA NTRS1986

Development and first flight of a sounding rocket payload to investigate the phenomena of rapidly varying space plasma

NASA Goddard Space Flight Center, Wallops Flight Facility has developed, flown, and recovered a unique plasma physics payload. This sounding rocket payload was developed to measure varying aspects of Alfven's critical velocity effect in a space plasma by using conical-shaped barium explosives. These measurements could possibly duplicate conditions that existed in the early solar system. This paper provides details of the payload and subpayload development, with specific emphasis on the extensive dynamic analysis of the barium release modules. Other key elements which are expanded on in the paper are: (1) design, development, and testing acceptance for the science/inertia booms using a viscous damping system for high spin rate deployment; (2) vehicle dynamic analysis; (3) apogee and impact dispersion analysis to satisfy the science and NASA safety requirements; (4) a comparison of predicted versus actual flight events.

Buchanan, R. P.↗
NASA NTRS1986

System concept for the pinhole/occulter facility payload

The results of a study of the systems concept of the Pinhole/Occulter Facility (PDF) to fly on the Shuttle as a Spacelab payload are reported. In particular, attention is given to the POF configuration and structural/mechanical concepts; POF payload structural concept development; POF payload new baseline configuration; POF pointing requirements and the Spacelab Instrument Pointing System capabilities and limitations; and pointing control implementation approach. The discussion also covers POF command and data management system configuration; POF processor software assessment; and thermal design concept.

Srinivas, R.↗
NASA NTRS1987

Analytical formulation of orbiter-payload models coupled by trunnion joints with Coulomb friction

An orbiter and its payload substructure are linked together by five trunnion joints which have thirty degrees-of-freedom. Geometric compatibility conditions require fourteen of the interface physical coordinates of the orbiter and payload to be equal to each other and the remaining sixteen are free to have relative motions under Coulomb friction. The component modes synthesis method using fourteen inertia relief attachment modes for the formulation of the coupled system is presented. The exact nonlinear friction function is derived based on the characteristics of the joints. Formulation is applicable to an orbiter that carries any number of payload substructures.

Liu, Frank C.↗
NASA NTRS1987

Rapid prototyping and AI programming environments applied to payload modeling

This effort focused on using artificial intelligence (AI) programming environments and rapid prototyping to aid in both space flight manned and unmanned payload simulation and training. Significant problems addressed are the large amount of development time required to design and implement just one of these payload simulations and the relative inflexibility of the resulting model to accepting future modification. Results of this effort have suggested that both rapid prototyping and AI programming environments can significantly reduce development time and cost when applied to the domain of payload modeling for crew training. The techniques employed are applicable to a variety of domains where models or simulations are required.

Carnahan, Richard S., Jr.↗
NASA NTRS1987

Expert mission planning and replanning scheduling system for NASA KSC payload operations

EMPRESS (Expert Mission Planning and REplanning Scheduling System) is an expert system created to assist payload mission planners at Kennedy in the long range planning and scheduling of horizontal payloads for space shuttle flights. Using the current flight manifest, these planners develop mission and payload schedules detailing all processing to be performed in the Operations and Checkout building at Kennedy. With the EMPRESS system, schedules are generated quickly using standard flows that represent the tasks and resources required to process a specific horizontal carrier. Resources can be tracked and resource conflicts can be determined and resolved interactively. Constraint relationships between tasks are maintained and can be enforced when a task is moved or rescheduled. The domain, structure, and functionality of the EMPRESS system is briefly designed. The limitations of the EMPRESS system are described as well as improvements expected with the EMPRESS-2 development.

Pierce, Roger↗
NASA NTRS1988

Materials processing in space: An introduction to the G-480 payload

The Space Research and Development Organization at San Jose State University designed and developed a small self-contained payload (designated G-480 by NASA) which will perform four materials science experiments in low Earth orbit aboard the Space Shuttle. These experiments are categorized under two areas of investigation: corrosion and electrodeposition. While none of these experiments have previously been performed in space, both government and industry have expressed great interest in these and related areas of materials processing and engineering. A brief history of the G-480 project development is given along with a description of each experiment, followed by a tour of the G-480 payload. Expected results are discussed along with the function, design and operation of the payload hardware and software.

Butow, Steven J.↗
NASA NTRS1987

A Vibroacoustic Database Management Center for Shuttle and expendable launch vehicle payloads

A Vibroacoustic Database Management Center has recently been established at the Jet Propulsion Laboratory (JPL). The center uses the Vibroacoustic Payload Environment Prediction System (VAPEPS) computer program to maintain a database of flight and ground-test data and structural parameters for both Shuttle and expendable launch-vehicle payloads. Given the launch-vehicle environment, the VAPEPS prediction software, which employs Statistical Energy Analysis (SEA) methods, can be used with or without the database to establish the vibroacoustic environment for new payload components. This paper summarizes the VAPEPS program and describes the functions of the Database Management Center at JPL.

Thomas, Valerie C.↗
NASA NTRS1988

STS safety approval process for small self-contained payloads

The safety approval process established by the National Aeronautics and Space Administration for Get Away Special (GAS) payloads is described. Although the designing organization is ultimately responsible for the safe operation of its payload, the Get Away Special team at the Goddard Space Flight Center will act as advisors while iterative safety analyses are performed and the Safety Data Package inputs are submitted. This four phase communications process will ultimately give NASA confidence that the GAS payload is safe, and successful completion of the Phase 3 package and review will clear the way for flight aboard the Space Transportation System orbiter.

Gum, Mary A.↗
NASA NTRS1988

Acceleration ground test program to verify GAS payload No. 559 structure/support avionics and experiment structural integrity

Acceleration ground tests were conducted on the Get Away Special (GAS) payload 559 to verify the structural integrity of the structure/support avionics and two of the planned three flight experiments. The ITA (Integrated Test Area) Standardized Experiment Module (ISEM) structure was modified to accommodate the experiments for payload 559. The ISEM avionics consisted of a heavy duty sliver zinc power supply, three orthogonal-mounted low range microgravity accelerometers, a tri-axis high range accelerometer, a solid state recorder/programmer sequencer, and pressure and temperature sensors. The tests were conducted using the Gravitational Plant Physiology Laboratory Centrifuge of the University City Science Center in Philadelphia, PA. The launch-powered flight steady state acceleration profile of the shuttle was simulated from lift-off through jettison of the External Tank (3.0 g's). Additional tests were conducted at twice the nominal powered flight acceleration levels (6 g's) and an over-test condition of four times the powered flight loads to 12.6 g's. The present test program has demonstrated the value of conducting ground tests to verify GAS payload experiment integrity and operation before flying on the shuttle.

Cassanto, John M.↗
NASA NTRS1988

Inorganic chemical precipitate formation payload design

The Get Away Special payload to investigate the formation of inorganic precipitates (G-405) utilizes six transparent chemical reaction chambers to actively mix a dry powder with a liquid solution. At predetermined intervals the progress of the precipitate formation is photographed and stored as data. The precipitate particles will also be subject to post-flight analysis. The various tasks performed during the 14 hour duration of the experiment are initiated and monitored by a custom-built digital controller. The payload is currently scheduled as a backup payload for STS-29 with a possible launch date of January, 1989.

Friedrich, Craig↗
NASA NTRS1989

The design and analysis of a double swivel toggle release mechanism for the Orbiter stabilized payload deployment system

The NASA Stabilized Payload Deployment System (SPDS) is discussed. The lightweight and heavy-duty system rolls payloads over the orbiter's side rather than ejecting them upward. The system will enhance the orbiter capability of carrying larger and heavier payloads. The design, function, and analysis of a new three-pin double swivel toggle release mechanism which is crucial to the successful deployment of the SPDS are described.

King, Guy L.↗
NASA NTRS1988

Dual keel Space Station payload pointing system design and analysis feasibility study

A Space Station attached Payload Pointing System (PPS) has been designed and analyzed. The PPS is responsible for maintaining fixed payload pointing in the presence of disturbance applied to the Space Station. The payload considered in this analysis is the Solar Optical Telescope. System performance is evaluated via digital time simulations by applying various disturbance forces to the Space Station. The PPS meets the Space Station articulated pointing requirement for all disturbances except Shuttle docking and some centrifuge cases.

Smagala, Tom↗
NASA NTRS1988

Reaction torque minimization techniques for articulated payloads

Articulated payloads on spacecraft, such as antenna telemetry systems and robotic elements, impart reaction torques back into the vehicle which can significantly affect the performance of other payloads. This paper discusses ways to minimize the reaction torques of articulated payloads through command-shaping algorithms and unique control implementations. The effects of reaction torques encountered on Landsat are presented and compared with simulated and measured data of prototype systems employing these improvements.

Kral, Kevin↗
NASA NTRS1989

Optimal force distribution for payload positioning using a planar dual-arm robot

This paper presents a parameter optimization technique for deciding the force distribution on a payload being transported along a predetermined trajectory using two planar manipulator arms. The methodology begins by transforming the singular dynamics of two-arm transport to an ordinary set of differential equations and then proceeds to obtain a relation between the torques exerted by each arm. This relation is then used in a quadratic torque cost which is subsequently minimized to yield an optimal torque distribution. Significant savings in energy were found to occur when the arms were allowed to interact by transmission of forces through the payload. Even more significant are the savings found over one-arm transport of payloads where the arm torques are fixed by the prescribed trajectory.

Carignan, C. R.↗
NASA NTRS1989

Lessons learned from trend analysis of Shuttle Payload Processing problem reports

In the wake of the Challenger accident, NASA has placed an increasing emphasis on trend analysis techniques. These analyses provide meaningful insights into system and hardware status, and also develop additional lessons learned from historical data to aid in the design and operation of future space systems. This paper presents selected results from such a trend analysis study that was conducted on the problem report data files for the Shuttle Payload Processing activities. Specifically, the results shown are for the payload canister system which interfaces with and transfers payloads from their processing facilities to the orbiter.

Heuser, Robert E.↗