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U.S. Government Reports
Prospero 9/1/2008 | 0 (0) | 18 | 0 | 0 | English
NASA Marshall; During routine inspections of the Space Shuttle's Main Propulsion System (MPS) Liquid Oxygen (LO2) pre-valve, the mechanism provided to maintain the valve in the open position was found cracked. The mechanism is a Vespel roller held against the valve visor by a stack of Belleville springs. The roller has been found cracked 3 times. All three instances were in the same valve in the same location. ... more>>
Prospero 9/1/2008 | 0 (0) | 24 | 2 | 0 | English
NASA Marshall; The United States (U.S.) is charting a renewed course for lunar exploration, with the fielding of a new human-rated space transportation system to replace the venerable Space Shuttle, which will be retired after it completes its missions of building the International Space Station (ISS) and servicing the Hubble Space Telescope. Powering the future of space-based scientific exploration will be the Ares I Crew Launch Vehicle, which will transport the Orion Crew Exploration Vehicle to orbit where it will rendezvous with the Altair Lunar Lander, which will be delivered by the Ares V Cargo Launch Vehicle. Marshall Space Flight Center is working with the Constellation Program and its project offices to streamline ground operations concepts by designing for operability, which reduces lifecycle costs and promotes sustainable space exploration. ... more>>
Prospero 9/1/2008 | 0 (0) | 17 | 0 | 0 | English
NASA Glenn; An apparatus is disclosed that includes a carrier structure and an optical coupling arrangement. The carrier structure is made of a silicon material and allows for the packaging and integrating of microphotonic devices onto a single chip. The optical coupling mechanism enables laser light to be coupled into and out of a microphotonic resonant disk integrated on the carrier. The carrier provides first, second and third cavities that are dimensioned so as to accommodate the insertion and snug fitting of the microphotonic resonant disk and first and second prisms that are implemented by the optical coupling arrangement to accommodate the laser coupling. ... more>>
Prospero 9/1/2008 | 0 (0) | 9 | 0 | 0 | English
ASME Turbo Expo 2008 Berlin 9-13 Jun. 2008; NASA Glenn; In this paper, an enhanced on-line diagnostic system which utilizes dual-channel sensor measurements is developed for the aircraft engine application. The enhanced system is
composed of a nonlinear on-board engine model (NOBEM), the hybrid Kalman filter (HKF) algorithm, and fault detection and isolation (FDI) logic. The NOBEM provides the analytical third channel against which the dual-channel measurements are compared. The NOBEM is further utilized as part of the HKF algorithm which estimates measured engine parameters. Engine parameters obtained from the dual-channel
measurements, the NOBEM, and the HKF are compared against each other. When the discrepancy among the signals exceeds a
tolerance level, the FDI logic determines the cause of discrepancy. Through this approach, the enhanced system achieves the following objectives: 1) anomaly detection, 2) component fault detection, and 3) sensor fault detection and
isolation. The performance of the enhanced system is evaluated in a simulation environment using faults in sensors and components, and it is compared to an existing baseline system. ... more>>
Prospero 9/1/2008 | 0 (0) | 30 | 2 | 0 | English
Prospero 9/1/2008 | 0 (0) | 17 | 0 | 0 | English
Prospero 9/1/2008 | 0 (0) | 19 | 0 | 0 | English
Prospero 9/1/2008 | 0 (0) | 11 | 0 | 0 | English
Prospero 9/1/2008 | 0 (0) | 17 | 0 | 0 | English
Prospero 9/1/2008 | 0 (0) | 24 | 0 | 0 | English
ProfessionalDocument 8/22/2008 | 0 (0) | 95 | 2 | 0 | English
ProfessionalDocument 8/19/2008 | 0 (0) | 28 | 0 | 0 | English
August 2008
Highlights
Highlights of GAO-08-791, a report to congressional committees
Accountability Integrity Reliability
COMMONWEALTH OF THE NORTHERN MARIANA ISLANDS
Managing Potential Economic Impact of Applying U.S. Immigration Law Requires Coordinated Federal Decisions and Additional Data
Why GAO Did This Study
The United States enacted le ... more>>
ProfessionalDocument 8/19/2008 | 0 (0) | 25 | 0 | 0 | English
July 2008
BORDER SECURITY
Highlights
Highlights of GAO-08-1006, a report to the Subcommittee on Government Management, Organization, and Procurement, Committee on Oversight and Government Reform, House of Representatives
Accountability Integrity Reliability
State Department Is Taking Steps to Meet Projected Surge in Demand for Visas and Passpor ... more>>
ProfessionalDocument 8/19/2008 | 0 (0) | 38 | 0 | 0 | English
ProfessionalDocument 8/19/2008 | 0 (0) | 28 | 0 | 0 | English
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