Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Checkout”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12

Test plan/procedure for the checkout of the USA cable communications test configuration for the electromagnetic compatibility (EMC) tests

A series of electromagnetic compatibility (EMC) tests were conducted in May, 1975 in the Soviet Union. The purpose of the EMC tests was to determine the effects of the operating environment of the Soviet aircraft, Soyuz, upon the electrical performance of the USA's cable communications equipment located in Soyuz. The test procedures necessary to check out the cable communications test configuration in preparation for the EMC tests are presented.

Perry, J. C.↗

On-orbit checkout study

The spaceborne testing equipment carried by the orbiter and the measuring equipment onboard the satellite (telemetry) is tested to verify that each is operating satisfactorily. The satellite command system is also checked. Thermal stabilization with the satellite in the orbiter shadow is achieved in six to eight hours. Satellite subsystem tests are run, and thermal control by heaters is checked. Thermal stabilization with the satellite exposed to the sun (when the orbiter is in sunlight) is again achieved in an estimated six to eight hours. Subsystem tests are again run in the hot condition, and heat rejection tests are made.

Pritchard, E. I.↗

TRASYS: Checkout of accuracy of direct irradiation calculations for discs, trapezoids, cones, and circular paraboloids

Results of the direct irradiation link of the TRASYS program are evaluated. Several surface configurations were investigated. The accuracy of the results was examined for simple cases where the answers were analytically known. By varying an accuracy factor in the program, the amount of computer time needed to achieve different degress of accuracy was determined.

Mackeen, R. C.↗

Fuseholders allow fast system checkout

Technique involves modifying fuseholder cap with drilled hole to allow each circuit to be connected to automatic circuit analyzer. Tester is commercially-available continuity device used for checking out wiring harnesses that sequentially steps from one circuit to the next automatically. Test results are printed.

Wooters, R. L.↗

Spacecraft subsystem checkout by minicomputer

The minicomputer, with its large capacity in a small and inexpensive package, can be an important component in special-purpose test equipment. The Voyager spacecraft flight data subsystem support equipment is an example of computer-based test gear. The subsystem to be tested is a major control and data acquisition element of the Voyager spacecraft, with a large number of interfaces to several other onboard subsystems. This equipment was designed to meet spacecraft subsystem testing requirements while making maximum use of off-the-shelf commercial components. Careful consideration was given to design tradeoffs in the areas of commercial versus specially built hardware and hardware versus software problem solutions. The resulting system is an integrated package of commercial and special-purpose hardware plus software.

Andersen, R. W.↗

Installation and checkout of the DOE/NASA Mod-1 2000-kW wind turbine generator

The paper describes the DOE/NASA Mod-1 wind turbine generator, its assembly and testing, and its installation at Boone, North Carolina. The paper concludes with performance data taken during the initial tests conducted on the machine. The successful installation and initial operation of the Mod-1 wind turbine generator has had the following results: (1) megawatt-size wind turbines can be operated satisfactorily on utility grids; (2) the structural loads can be predicted by existing codes; (3) assembly of the machine on top of the tower presents no major problem; (4) large blades 100 ft long can be transported long distances and over mountain roads; and (5) operating experience and performance data will contribute substantially to the design of future low-cost wind turbines.

Puthoff, R. L.↗

Thematic Mapper Image Production in the Engineering Checkout Phase

Thematic Mapper data processing during LANDSAT 4's first year was performed on an engineering evaluation basis. Fully corrected products were created for some 282 scenes during this period using software and systems based upon the intended full production systems to become operational following the evaluation period. The engineering systems included substantial software and procedures for assessing spacecraft, instrument and ground processing algorithmic behavior. The data systems are described in terms of performance objectives, processing organization and data flow, quality assurance measurements and achievement of goals. The a priori implementation of TM radiometric and geometric corrections is described. Changes to processing suggested by or implemented on the basis of on-orbit data analysis are discussed. Spacecraft, instrument and algorithmic performance are evaluated.

Fischel, D.↗

Ground man-machine interfaces for orbiter checkout

The challenge of the concept of a reusable, cargo carrying space vehicle, and how those challenges were met for the Space Shuttle are discussed. The complexity of the vehicle, the ground support systen, the onboard computer system, ramifications of a reusable vehicle, and the turn around objectives for Shuttle flights are outlined. The Apollo and the space transportation system (STS) are compared.

Blackmon, F. H.↗

Integrated design checkout of shuttle payload avionics interfaces

Orbiter/payload avionics integration testing in the shuttle program are discussed. Payloads show extensive orbiter interfaces. The three testing modes used to verify orbiter/payload avionics interfaces are described. These modes consist of orbiter testing using generic payload simulators, payload testing utilizing the actual payload and a high fidelity orbiter simulator, and interface testing with the actual orbiter and payload. Several special avionics techniques, such as the split flight computer technique were developed for this testing. Experience from the first six shuttle cargoes is reviewed and problems found in testing that would have hampered mission success are emphasized.

Muratore, J. F.↗

Large space structures ground experiment checkout

NASA Marshall Space Flight Center has developed a facility in which closed loop control of Large Space Structures (LSS) can be demonstrated and verified. The main objective of the facility is to verify LSS control system techniques so that on-orbit performance can be ensured. The facility consists of an LSS test article or payload which is connected to a 3-axis angular pointing mount assembly that provides control torque commands. The angular pointing mount assembly is attached to a base excitation system which will simulate disturbances most likely to occur for Orbiter and DOD payloads. The control computer contains the calibration software, the reference systems, the alignment procedures, the telemetry software, and the control algorithms. The total system is suspended in such a fashion that the LSS test article has the characteristics common to all LSS.

Waites, Henry B.↗

Computer system evolution requirements for autonomous checkout of exploration vehicles

This study, now in its third year, has had the overall objective and challenge of determining the needed hooks and scars in the initial Space Station Freedom (SSF) system to assure that on-orbit assembly and refurbishment of lunar and Mars spacecraft can be accomplished with the maximum use of automation. In this study automation is all encompassing and includes physical tasks such as parts mating, tool operation, and human visual inspection, as well as non-physical tasks such as monitoring and diagnosis, planning and scheduling, and autonomous visual inspection. Potential tasks for automation include both extravehicular activity (EVA) and intravehicular activity (IVA) events. A number of specific techniques and tools have been developed to determine the ideal tasks to be automated, and the resulting timelines, changes in labor requirements and resources required. The Mars/Phobos exploratory mission developed in FY89, and the Lunar Assembly/Refurbishment mission developed in FY90 and depicted in the 90 Day Study as Option 5, have been analyzed in detailed in recent years. The complete methodology and results are presented in FY89 and FY90 final reports.

Davis, Tom↗

Hardware independence checkout software

ACSI has developed a program utilizing CLIPS to assess compliance with various programming standards. Essentially the program parses C code to extract the names of all function calls. These are asserted as CLIPS facts which also include information about line numbers, source file names, and called functions. Rules have been devised to establish functions called that have not been defined in any of the source parsed. These are compared against lists of standards (represented as facts) using rules that check intersections and/or unions of these. By piping the output into other processes the source is appropriately commented by generating and executing parsed scripts.

Cameron, Barry W.↗

Solar Thermal Upper Stage Cryogen System Engineering Checkout Test

The Solar Thermal Upper Stage technology (STUSTD) program is a solar thermal propulsion technology program cooperatively sponsored by a Boeing led team and by NASA MSFC. A key element of its technology program is development of a liquid hydrogen (LH2) storage and supply system which employs multi-layer insulation, liquid acquisition devices, active and passive thermodynamic vent systems, and variable 40W tank heaters to reliably provide near constant pressure H2 to a solar thermal engine in the low-gravity of space operation. The LH2 storage and supply system is designed to operate as a passive, pressure fed supply system at a constant pressure of about 45 psia. During operation of the solar thermal engine over a small portion of the orbit the LH2 storage and supply system propulsively vents through the enjoy at a controlled flowrate. During the long coast portion of the orbit, the LH2 tank is locked up (unvented). Thus, all of the vented H2 flow is used in the engine for thrust and none is wastefully vented overboard. The key to managing the tank pressure and therefore the H2 flow to the engine is to manage and balance the energy flow into the LH2 tank with the MLI and tank heaters with the energy flow out of the LH2 tank through the vented H2 flow. A moderate scale (71 cu ft) LH2 storage and supply system was installed and insulated at the NASA MSFC Test Area 300. The operation of the system is described in this paper. The test program for the LH2 system consisted of two parts: 1) a series of engineering tests to characterize the performance of the various components in the system: and 2) a 30-day simulation of a complete LEO and GEO transfer mission. This paper describes the results of the engineering tests, and correlates these results with analytical models used to design future advanced Solar Orbit Transfer Vehicles.

Olsen, A. D↗