Search NASA⌕ Search

SEARCH · Search NASA

Results for “service”

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 739 records · Page 41
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

Dexterous Orbital Servicing System (DOSS)

The Dexterous Orbiter Servicing System (DOSS) is a dexterous robotic spaceflight system that is based on the manipulator designed as part of the Flight Telerobotics Servicer program for the Space Station Freedom and built during a 'technology capture' effort that was commissioned when the FTS was cancelled from the Space Station Freedom program. The FTS technology capture effort yielded one flight manipulator and the 1 g hydraulic simulator that had been designed as an integrated test tool and crew trainer. The DOSS concept was developed to satisfy needs of the telerobotics research community, the space shuttle, and the space station. As a flight testbed, DOSS would serve as a baseline reference for testing the performance of advanced telerobotics and intelligent robotics components. For shuttle, the DOSS, configured as a movable dexterous tool, would be used to provide operational flexibility for payload operations and contingency operations. As a risk mitigation flight demonstration, the DOSS would serve the International Space Station to characterize the end to end system performance of the Special Purpose Dexterous Manipulator performing assembly and maintenance tasks with actual ISSA orbital replacement units. Currently, the most likely entrance of the DOSS into spaceflight is a risk mitigation flight experiment for the International Space Station.

Price, Charles R.↗
NASA NTRS1992

NASA-ACEE/Boeing 737 graphite-epoxy horizontal stabilizer service

The 737 graphite-epoxy horizontal stabilizer was developed by Boeing as part of the NASA-ACEE (Aircraft Energy Efficiency) Advanced Composite Structures Program. NASA-ACEE programs challenged large-transport manufacturers to use graphite material in redesigning existing aircraft components. The goal of the program was to develop the necessary data and technology to achieve production commitments to advanced composites. Boeing designed, fabricated, and certified five shipsets of horizontal stabilizers for the 737-200 airframe. The program was initiated in July 1977 and certification was achieved in August 1982. Schedule highlights are shown. The work performed on this program is reported in NASA technical summaries and final reports. Boeing introduced the stabilizer into commercial operation in 1984, and has maintained surveillance for seven years of in-service evaluation. Outstanding performance was demonstrated with no service incidents attributed to the graphite-epoxy structure. Boeing will continue to monitor and support these aircraft, adding to the database of commercial composite experience.

Quinlivan, J. T.↗
NASA NTRS1995

Heterogeneous concurrent computing with exportable services

Heterogeneous concurrent computing, based on the traditional process-oriented model, is approaching its functionality and performance limits. An alternative paradigm, based on the concept of services, supporting data driven computation, and built on a lightweight process infrastructure, is proposed to enhance the functional capabilities and the operational efficiency of heterogeneous network-based concurrent computing. TPVM is an experimental prototype system supporting exportable services, thread-based computation, and remote memory operations that is built as an extension of and an enhancement to the PVM concurrent computing system. TPVM offers a significantly different computing paradigm for network-based computing, while maintaining a close resemblance to the conventional PVM model in the interest of compatibility and ease of transition Preliminary experiences have demonstrated that the TPVM framework presents a natural yet powerful concurrent programming interface, while being capable of delivering performance improvements of upto thirty percent.

Sunderam, Vaidy↗
NASA NTRS1995

Design and simulation of EVA tools and robot end effectors for servicing missions of the HST

The Hubble Space Telescope (HST) was launched into near-earth orbit by the Space Shuttle Discovery on April 24, 1990. The payload of two cameras, two spectrographs, and a high-speed photometer is supplemented by three fine-guidance sensors that can be used for astronomy as well as for star tracking. A widely reported spherical aberration in the primary mirror causes HST to produce images of much lower quality than intended. A Space Shuttle repair mission in January 1994 installed small corrective mirrors that restored the full intended optical capability of the HST. A Second Servicing Mission (SM2) scheduled in 1997 will involve considerable Extra Vehicular Activity (EVA). To reduce EVA time, the addition of robotic capability in the remaining servicing missions has been proposed. Toward that end, two concept designs for a general purpose end effector for robots are presented in this report.

Naik, Dipak↗
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 NTRS1996

International GPS Service for Geodynamics

This 1995 annual report of the IGS International GPS (Global Positioning System) Service for Geodynamics - describes the second operational year of the service. It provides the many IGS contributing agencies and the rapidly growing user community with essential information on current organizational and technical matters promoting the IGS standards and products (including organizational framework, data processing strategies, and statistics showing the remarkable expansion of the GPS monitoring network, the improvement of IGS performance, and product quality). It also introduces important practical concepts for network densification by integration of regional stations and the combination of station coordinate solutions. There are groups of articles describing general aspects of the IGS, the Associate Analysis Centers (AACs), Data Centers, and IGS stations.

Zumberge, J. F.↗
NASA NTRS1998

Photogrammetric Assessment of the Hubble Space Telescope Solar Arrays During the Second Servicing Mission

This report documents the photogrammetric assessment of the Hubble Space Telescope (HST) solar arrays conducted by the NASA c Center Image Science and Analysis Group during Second Servicing Mission 2 (SM-2) on STS-82 in February 1997. Two type solar array analyses were conducted during the mission using Space Shuttle payload bay video: (1) measurement of solar array motion due to induced loads, and (2) measurement of the solar array static or geometric twist caused by the cumulative array loading. The report describes pre-mission planning and analysis technique development activities conducted to acquire and analyze solar array imagery data during SM-2. This includes analysis of array motion obtained during SM-1 as a proof-of-concept of the SM-2 measurement techniques. The report documents the results of real-time analysis conducted during the mission and subsequent analysis conducted post-flight. This report also provides a summary of lessons learned on solar array imagery analysis from SM-2 and recommendations for future on-orbit measurements applicable to HST SM-3 and to the International Space Station. This work was performed under the direction of the Goddard Space Flight Center HST Flight Systems and Servicing Project.

Sapp, C. A.↗
NASA NTRS1998

Transitioning NASA Space Operations to Commercial Services

Major considerations associated with "Transitioning NASA Space Operations to Commercial Services" are presented in viewgraph form. Specific topics include: 1) Government use of commercial frequencies vs. commercial use of commercial frequencies for government use; 2) Commercial use of government frequencies; 3) Government vs commercial: Access techniques, data formats, and modulation and coding; 4) Government need for multiple sources: backup and competition; 5) Government in perceived competition with commercial service providers if TDRSS is used for commercial purposes; and 6) Coordination required among plans for CSOC, NSCP, and satellite industry.

Gilbert, Charlene E.↗
NASA NTRS1999

Design Issues for Traffic Management for the ATM UBR + Service for TCP Over Satellite Networks

This project was a comprehensive research program for developing techniques for improving the performance of Internet protocols over Asynchronous Transfer Mode (ATM) based satellite networks. Among the service categories provided by ATM networks, the most commonly used category for data traffic is the unspecified bit rate (UBR) service. UBR allows sources to send data into the network without any feedback control. The project resulted in the numerous ATM Forum contributions and papers.

Jain, Raj↗
NASA NTRS1999

International VLBI Service for Geodesy and Astrometry: 1999 Annual Report

This volume of reports is the 1999 Annual Report of the International VLBI Service for Geodesy and Astrometry -IVS. The individual reports were contributed by VLBI groups in the international geodetic community who constitute the components of IVS. The 1999 Annual Report documents the work of the IVS components for the year ending March 1, 1999, the official inauguration date of IVS. As the newest of the space technique services, IVS decided to publish this Annual Report as a reference to our organization and its components. The entire contents of this Annual Report also appear on the IVS website at: http://ivscc.gsfc.nasa.gov/pub/arl999. The IVS 1999 Annual Report will be a valuable reference for information about IVS and its components. This Annual Report will serve as a baseline from which we can measure the anticipated progress of IVS in coming years.

Vandenberg, Nancy R.↗
NASA NTRS2000

Service Quality in the U.S. Airline Industry: Variations in Performance Within Airlines and Between Airlines and the Industry

This study examined the service quality of 25 U.S. airlines (1987-1996) using data from the Department of Transportation's Air Travel Consumer Report. After a total quality and total complaint rate was calculated for these airlines, a 95 percent confidence interval was placed around the yearly and company means calculated to examine those cases that were significantly different from the mean. Results indicate that while the major carriers are converging toward a higher level of quality, there continues to be significant yearly variation. The service quality of regional carriers was much lower than major carriers and showed much greater variation.

Rhoades, Dawna L.↗
NASA NTRS2000

The Hubble Space Telescope Servicing Mission 3A Contamination Control Program

After nearly 10 years on-orbit, the Hubble Space Telescope (HST) external thermal control materials and paint have degraded due to exposure to the low Earth orbit environment. This presented a potentially large on-orbit contamination source (particles and/or debris). Contamination mitigation techniques were developed to augment existing on-orbit servicing contamination controls. They encompassed mission management, crew training, and crew aids and tools. These techniques were successfully employed during the HST Servicing Mission 3A, December 1999.

Hansen, Patricia A.↗
NASA NTRS1999

NASA Headquarters/Kennedy Space Center: Organization and Small Spacecraft Launch Services

The objectives of the Kennedy Space Center's (KSC) Expendable Launch Vehicles (ELV) Program are to provide safe, reliable, cost effective ELV launches, maximize customer satisfaction, and perform advanced payload processing capability development. Details are given on the ELV program organization, products and services, foreign launch vehicle policy, how to get a NASA launch service, and some of the recent NASA payloads.

Sierra, Albert↗
NASA NTRS2001

Utilization of KSC Present Broadband Communications Data System For Digital Video Services

This report covers a visibility study of utilizing present KSC broadband communications data system (BCDS) for digital video services. Digital video services include compressed digital TV delivery and video-on-demand. Furthermore, the study examines the possibility of providing interactive video on demand to desktop personal computers via KSC computer network.

Andrawis, Alfred S.↗
NASA NTRS2000

International VLBI Service for Geodesy and Astrometry 2000 Annual Report

This volume of reports is the 2000 Annual Report of the International Very Long Base Interferometry (VLBI) Service for Geodesy and Astrometry (IVS). The individual reports were contributed by VLBI groups in the international geodetic and astrometric community who constitute the permanent components of IVS. The IVS 2000 Annual Report documents the work of the IVS components for the period March 1, 1999 (the official inauguration date of IVS) through December 31, 2000. The reports document changes, activities, and progress of the IVS. The entire contents of this Annual Report also appear on the IVS web site at http://ivscc.gsfc.nasa.gov/publications/ar2000. This book and the web site are organized as follows: (1) The first section contains general information about IVS, a map showing the location of the components, information about the Directing Board members, and the report of the IVS Chair; (2) The second section of Special Reports contains a status report of the IVS Working Group on GPS phase center mapping, a reproduction of the resolution making IVS a Service of the International Astronomical Union (IAU), and a reprint of the VLBI Standard Interface (VSI); (3) The next seven sections hold the component reports from the Coordinators, Network Stations, Operation Centers, Correlators, Data Centers, Analysis Centers, and Technology Development Centers; and (4) The last section includes reference information about IVS: the Terms of Reference, the lists of Member and Affiliated organizations, the IVS Associate Member list, a complete list of IVS components, the list of institutions contributing to this report, and a list of acronyms. The 2000 Annual Report demonstrates the vitality of the IVS and the outstanding progress we have made during our first 22 months.

Vandenberg, N. R.↗
NASA NTRS2002

New Data and Search Features in the NASA ADS Abstract Service

The NASA-ADS Abstract Service provides search capability for literature in Astronomy/Planetary Sciences, Physics/Geophysics, and Instrumentation. Scanned articles are available for many journals and proceedings. The ADS service is free for anybody. Additional information is contained in the original extended abstract.

Eichhorn, G.↗
NASA NTRS1992

Food Service System

The 3M Food Service System 2 employs a "cook/chill" concept for serving food in hospitals. The system allows staff to prepare food well in advance, maintain heat, visual appeal and nutritional value as well as reducing operating costs. The integral heating method, which keeps hot foods hot and cold foods cold, was developed by 3M for the Apollo Program. In the 1970s, the company commercialized the original system and in 1991, introduced Food Service System 2. Dishes are designed to resemble those used at home, and patient satisfaction has been high.

Source record↗