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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Preliminary maintenance experience for DSS 13 unattended operations demonstration

The maintenance data base collected for 15 weeks of recent unattended and automated operation of DSS 13 is summarized. During this period, DSS 13 was receiving spacecraft telemetry while being controlled remotely from JPL in Pasadena. Corrective and preventive maintenance manhours are reported by subsystem for DSS 13 including the equipment added for the automation demonstration. The corrective and preventive maintenance weekly manhours at DSS 13 averaged 22 and 40, respectively. The antenna hydraulic and electronic systems accounted for about half of the preventive and corrective maintenance manhours for a comparable attended DSN station, DSS 11.

Remer, D. S.↗
NASA NTRS1972

Space shuttle maintenance program planning document

A means for developing a space shuttle maintenance program which will be acceptable to the development centers, the operators (KSC and AF), and the manufacturer is presented. The general organization and decision processes for determining the essential scheduled maintenance requirements for the space shuttle orbiter are outlined. The development of initial scheduled maintenance programs is discussed. The remaining maintenance, that is non-scheduled or non-routine maintenance, is directed by the findings of the scheduled maintenance program and the normal operation of the shuttle. The remaining maintenance consists of maintenance actions to correct discrepancies noted during scheduled maintenance tasks, nonscheduled maintenance, normal operation, or condition monitoring.

Brown, D. V.↗
NASA NTRS1982

Space station preliminary design report

The results of a 3 month preliminary design and analysis effort is presented. The configuration that emerged consists of a very stiff deployable truss structure with an overall triangular cross section having universal modules attached at the apexes. Sufficient analysis was performed to show feasibility of the configuration. An evaluation of the structure shows that desirable attributes of the configuration are: (1) the solar cells, radiators, and antennas will be mounted to stiff structure to minimize control problems during orbit maintenance and correction, docking, and attitude control; (2) large flat areas are available for mounting and servicing of equipment; (3) Large mass items can be mounted near the center of gravity of the system to minimize gravity gradient torques; (4) the trusses are lightweight structures and can be transported into orbit in one Shuttle flight; (5) the trusses are expandable and will require a minimum of EVA; and (6) the modules are anticipated to be structurally identical except for internal equipment to minimize cost.

Source record↗
NASA NTRS1994

Expert System Detects Power-Distribution Faults

Autonomous Power Expert (APEX) computer program is prototype expert-system program detecting faults in electrical-power-distribution system. Assists human operators in diagnosing faults and deciding what adjustments or repairs needed for immediate recovery from faults or for maintenance to correct initially nonthreatening conditions that could develop into faults. Written in Lisp.

Walters, Jerry L.↗
NASA NTRS2016

Hypergol Maintenance Facility Hazardous Waste South Staging Areas, SWMU 070 Corrective Measures Implementation

This document presents the Corrective Measures Implementation (CMI) Year 10 Annual Report for implementation of corrective measures at the Hypergol Maintenance Facility (HMF) Hazardous Waste South Staging Areas at Kennedy Space Center, Florida. The work is being performed by Tetra Tech, Inc., for the National Aeronautics and Space Administration (NASA) under Indefinite Delivery Indefinite Quantity (IDIQ) NNK12CA15B, Task Order (TO) 07. Mr. Harry Plaza, P.E., of NASA's Environmental Assurance Branch is the Remediation Project Manager for John F. Kennedy Space Center. The Tetra Tech Program Manager is Mr. Mark Speranza, P.E., and the Tetra Tech Project Manager is Robert Simcik, P.E.

CMI↗
NASA NTRSDate not supplied

Optimized Trajectory Correction Burn Placement for NRHO Orbit Maintenance

NASA's future Artemis missions plan to utilize a near rectilinear halo orbit (NRHO) in the lunar vicinity to facilitate access to the lunar surface and place other critical assets to support human exploration. This exploration architecture requires a vehicle to remain in the NRHO for long periods of time ranging from several days, to weeks, to months, and even years. Consequently, periodic orbit maintenance burns become essential to ensure the spacecraft follows the desired reference trajectory in an efficient yet effective manner despite crew activity, navigation uncertainty, maneuver execution errors, disturbance accelerations, orbit insertion dispersions, and other system limitations. This work introduces a targeting algorithm that can be utilized to analyze a variety of targeting constraints and parameters that maximizes overall performance. Techniques associated with robust trajectory optimization are used to identify the optimized number and placement for NRHO trajectory correction (NTC) burns that accounts for the mission schedule, both a primary and backup navigation system, targeting strategies and burn plan configurations, vehicle venting, thruster selection, and integrated GN\&C performance. A notional scenario extracted from the NASA Artemis III mission is used to motivate and demonstrate these concepts and performance results.

Linear Covariance Analysis↗
NASA NTRS1995

Hubble Space Telescope - First Servicing Mission: Down to Earth Logistics - From GSFC to KSC and Back

The Hubble Space Telescope First Servicing Mission is a major accomplishment for NASA and has drawn world-wide attention and interest. The extravehicular servicing and repair activities performed by the STS-61 crew were the most ambitious ever undertaken. Their unprecedented success in performing on-orbit repair and maintenance, particularly in correcting the aberration in the primary mirror, has enabled the HST to provide sensational images and the anticipation of exciting scientific discoveries. Although the whole world watched the televised logistics activities (on-orbit maintenance) that took place in space, few are aware of the time and effort that went into planning and executing the space logistics that takes place with our feet on the ground. This paper addresses a major part of that effort - the packaging, handling, and transportation (PH&T) activities required to ship the GSFC HST space flight hardware and ground support equipment to KSC for launch and the post launch return to GSFC. It addresses the logistics and transportation planning for the containers for the Solar Array Carrier, the Orbital Replacement Unit Carrier, and the Flight Support System and their transporters, and the over land and water portions of the shipments.

Kubicko, Richard M.↗
NASA NTRS1993

The Space Station Freedom Reliability and Maintainability Assessment Tool

The Reliability and Maintainability Assessment Tool is a stochastic, event-oriented simulation model that has been developed to analyze the functional reliability, availability, and maintainability characteristics of the Space Station Freedom. This tool simulates failures and performs corrective and preventive maintenance tasks, utilizing user-specified maintenance resources, including crewmembers and/or robotics, and accommodates the growth of the station. The model dynamically interfaces with minimal cut sets derived from reliability block diagrams to assess functional status and to determine queuing priorities.

Blumentritt, Will↗
NASA NTRS1996

STS-78 Flight Day 6

On this sixth day of the STS-78 mission, the flight crew, Cmdr. Terence T. Henricks, Pilot Kevin R. Kregel, Payload Cmdr. Susan J. Helms, Mission Specialists Richard M. Linnehan, Charles E. Brady, Jr., and Payload Specialists Jean-Jacques Favier, Ph.D. and Robert B. Thirsk, M.D., are shown performing status checks on the life and microgravity experiments and conducting a brief maintenance procedure to correct an electrical circuit problem in the Bubble Drop Particle Unit. On this day, the crew is given four hours off to relax after five days of work with the life and microgravity science investigation being conducted on board.

Source record↗
NASA NTRS2003

Prognostics Methodology for Complex Systems

An automatic method to schedule maintenance and repair of complex systems is produced based on a computational structure called the Informed Maintenance Grid (IMG). This method provides solutions to the two fundamental problems in autonomic logistics: (1) unambiguous detection of deterioration or impending loss of function and (2) determination of the time remaining to perform maintenance or other corrective action based upon information from the system. The IMG provides a health determination over the medium-to-longterm operation of the system, from one or more days to years of study. The IMG is especially applicable to spacecraft and both piloted and autonomous aircraft, or industrial control processes.

Gulati, Sandeep↗
NASA NTRS1980

Maintenance of NASTRAN (R) as a state-of-the-art computer program

The maintenance requirements for a large, general purpose, finite element computer program are presented. The program is maintained as state-of-the-art on three computer systems (IBM, CDC, and UNIVAC) with respect to both finite element and computer technology. There are four primary areas involved in the maintenance effort: (1) error correction; (2) incorporation of advances in technology; (3) documentation; and (4) new level generation. The complexity of the maintenance effort is compounded by the sizes of the program (400,000 lines of code) and the documentation (7000 pages divided into seven manuals).

Rogers, J. L., Jr.↗
NASA NTRSDate not supplied

Assessment of ProgPy - An Open-Source Condition Monitoring and Diagnostics Tool

Traditional maintenance programs, such as corrective and preventive strategies, may lead to high costs and operational inefficiencies. Condition Monitoring and Diagnostics (CM&D) aims to improve these maintenance strategies by enabling timely insights into equipment health and performance. However, implementation of CM&D can be challenging without a robust framework that manages data efficiently, supports interoperability and simplifies integration. To address these challenges ProgPy, an open-source Python-based prognostics tool developed by NASA Ames Research Center, offers a structured solution for broader Prognostics and Health Management (PHM) applications. Ongoing research is assessing the feasibility of implementing ProgPy as a Condition Monitoring and Diagnostics (CM&D) solution by comparing its framework to the guidelines for open CM&D systems recommended in the ISO 13374-2 standard. This evaluation aims to highlight ProgPy’s strengths and identify opportunities for improvement, thereby, contributing to its advancement as an effective tool for Prognostics and Health Management (PHM). This paper presents the results of an initial assessment of the ProgPy toolbox through a gearbox case study using open-source datasets.

Condition-Monitoring, Diagnostics, Failure, Gearbo↗
NASA NTRS1994

Does software design complexity affect maintenance effort?

The design complexity of a software system may be characterized within a refinement level (e.g., data flow among modules), or between refinement levels (e.g., traceability between the specification and the design). We analyzed an existing set of data from NASA's Software Engineering Laboratory to test whether changing software modules with high design complexity requires more personnel effort than changing modules with low design complexity. By analyzing variables singly, we identified strong correlations between software design complexity and change effort for error corrections performed during the maintenance phase. By analyzing variables in combination, we found patterns which identify modules in which error corrections were costly to perform during the acceptance test phase.

Epping, Andreas↗
NASA NTRS1994

Time maintenance system for the BMDO MSX spacecraft

The Johns Hopkins University Applied Physics Laboratory (APL) is responsible for designing and implementing a clock maintenance system for the Ballistic Missile Defense Organizations (BMDO) Midcourse Space Experiment (MSX) spacecraft. The MSX spacecraft has an on-board clock that will be used to control execution of time-dependent commands and to time tag all science and housekeeping data received from the spacecraft. MSX mission objectives have dictated that this spacecraft time, UTC(MSX), maintain a required accuracy with respect to UTC(USNO) of +/- 10 ms with a +/- 1 ms desired accuracy. APL's atomic time standards and the downlinked spacecraft time were used to develop a time maintenance system that will estimate the current MSX clock time offset during an APL pass and make estimates of the clock's drift and aging using the offset estimates from many passes. Using this information, the clock's accuracy will be maintained by uplinking periodic clock correction commands. The resulting time maintenance system is a combination of offset measurement, command/telemetry, and mission planning hardware and computing assets. All assets provide necessary inputs for deciding when corrections to the MSX spacecraft clock must be made to maintain its required accuracy without inhibiting other mission objectives. The MSX time maintenance system is described as a whole and the clock offset measurement subsystem, a unique combination of precision time maintenance and measurement hardware controlled by a Macintosh computer, is detailed. Simulations show that the system estimates the MSX clock offset to less than+/- 33 microseconds.

Hermes, Martin J.↗
NASA NTRS2020

2019 Corrective Measures Implementation and Intermim Measures Annual Status Report: Summary of Biosparge System Operation and Maintenance, and Interim Groundwater Monitoring Mobile Launch Platform / Vehicle Assembly Building Area (SWMU 056) Kennedy Space Center, Florida

This report presents a summary of the Corrective Measures Implementation (CMI) and Interim Measure (IM) implementation activities that occurred from May 2019 through December 2019 at the Mobile Launch Platform/Vehicle Assembly Building (MLPV) Area, Solid Waste Management Unit 056 (SWMU 056), located at the John F. Kennedy Space Center, Florida.

MOBILE LAUNCH PLATFORM / VEHICLE ASSEMBLY BUILDING↗
NASA NTRS2022

2021 Corrective Measures Implementation and Interim Measures Annual Status Report: Summary of Biosparge System Operation and Maintenance, and Interim Groundwater Monitoring Mobile Launch Platform Rehabilitation Sites / Vehicle Assembly Building Area (SWMU 056) Kennedy Space Center, Florida

This report presents a summary of the Corrective Measures Implementation (CMI) and Interim Measure (IM) implementation activities that occurred from January 2021 through December 2021 at the Mobile Launch Platform Rehabilitation Sites (MLP)/Vehicle Assembly Building (VAB) Area, Solid Waste Management Unit 056 (SWMU 056), located at the John F. Kennedy Space Center, Florida. The following summaries briefly describe areas within SWMU 056 identified by historical site investigation activities where groundwater monitoring and remedial actions have been implemented to date.

Randall K. Sillan↗