SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 43, ISSUE 18 - SEPTEMBER 09, 2005

19 SPACECRAFT INSTRUMENTATION AND ASTRIONICS
Includes the design, manufacture, or use of devices for the purpose of measuring, detecting, controlling, computing, recording, or processing data related to the operation of space vehicles or platforms.

For related information see also 06 Avionics and Aircraft Instrumentation; for spaceborne instruments not integral to the vehicle itself see 35 Instrumentation and Photography; for spaceborne telescopes and other astronomical instruments see 89 Astronomy.

20050205034 NASA, USA

Robotic Access to Planetary Surfaces Capability Roadmap Capabilities Roadmap Briefings to the National Research Council

March 1, 2005; 120 pp.; In English; See also 20050205013; Original contains color illustrations; No Copyright; Avail: CASI; A06, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document

A set of robotic access to planetary surfaces capability developments and supporting infrastructure have been identified. Reference mission pulls derived from ongoing strategic planning. Capability pushes to enable broader mission considerations. Facility and flight test capability needs. Those developments have been described to the level of detail needed for high-level planning. Content and approach. Readiness and metrics. Rough schedule and cost. Connectivity to mission concepts. Derived from text
Robotics; Schedules; Flight Tests; Management Planning

20050205050 NASA Johnson Space Center, Houston, TX, USA

2.0 AEDL Systems Engineering

Graves, Claude; Capabilities Roadmap Briefings to the National Research Council; March 1, 2005; 33 pp.; In English; See also 20050205013; Original contains color illustrations; No Copyright; Avail: CASI; A03, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document

Some engineering topics:

Some Initial Thoughts.

Capability Description.

Capability State-of-the-Art.

Capability Requirements.

Systems Engineering.

Capability Roadmap.

Capability Maturity.

Candidate Technologies.

Metrics.

Derived from text

Architecture (Computers); Systems Engineering

20050206347 Boeing Aerospace Co., USA

Reliability Improvements in Liquid Rocket Engine Instrumentation

Hill, A.; Acosta, E.; [2005]; 1 pp.; In English; AIAA Conference, 10 Jul. 2005, Tucson, AZ, USA Contract(s)/Grant(s): NAS8-01140; No Copyright; Avail: Other Sources; Abstract Only

Instrumentation hardware is often the weak link in advanced liquid fueled propulsion systems. The development of the Space Shuttle Main Engine (SSME) was no exception. By sheer necessity, a reusable, high energy, low weight engine system often relegates the instrumentation hardware to the backseat in the critical hardware development process. This produces less than optimum hardware constraints; including size, location, mounting, redundancy, and signal conditioning. This can negatively affect the development effort and ultimately the system reliability. The challenge was clear, however, the outcome was less certain. Unfortunately, the SSME hardware development culminated in series of measurement failures, most significant of which was the premature engine shutdown during the launch of STS-51F on July 29, 1985. The Return to Flight activities following the Challenger disaster redoubled our efforts to eliminate, once and for all, sensor malfunctions as the determining factor in overall engine reliability. This paper describes each phase of this effort in detail and includes discussion of the tasks related to improving measurement reliability. Author

Space Shuttle Main Engine; Hardware; Liquid Propellant Rocket Engines; Propulsion System Configurations; Failure

20050207487 Hamilton Sundstrand Space Systems International, Inc., USA

Flight Hydrogen Sensor for Use in the ISS Oxygen Generation Assembly

MSadoques, George, Jr.; Makel, Darby B.; [2005]; 9 pp.; In English; International Conference on Environmental Systems, 11-15 Jul. 2005, Rome, Italy; Original contains color illustrations; Copyright; Avail: CASI; A02, Hardcopy

This paper provides a description of the hydrogen sensor Orbital Replacement Unit (ORU) used on the Oxygen Generation Assembly (OGA), to be operated on the International Space Station (ISS). The hydrogen sensor ORU is being provided by Makel Engineering, Inc. (MEI) to monitor the oxygen outlet for the presence of hydrogen. The hydrogen sensor ORU is a triple redundant design where each sensor converts raw measurements to actual hydrogen partial pressure that is reported to the OGA system controller. The signal outputs are utilized for system shutdown in the event that the hydrogen concentration in the oxygen outlet line exceeds the specified shutdown limit. Improvements have been made to the Micro-Electro-Mechanical Systems (MEMS) based sensing element, screening, and calibration process to meet OGA operating requirements. Two flight hydrogen sensor ORUs have successfully completed the acceptance test phase. This paper also describes the sensor s performance during acceptance testing, additional tests planned to extend the operational performance calibration cycle, and integration with the OGA system. Author

Microelectromechanical Systems; Hydrogen; Partial Pressure; Controllers; Oxygen Production; Gas Detectors

20050210022 NASA Marshall Space Flight Center, Huntsville, AL, USA

A Novel Repair Technique for the Internal Thermal Control System Dual-Membrane Gas Trap

Leimkuehler, Thomas O.; Patel, Vipul; Reeves, Daniel R.; Holt, James M.; [2005]; 5 pp.; In English; 2005 International Conference on Environmental Systems, 11-14 Jul. 2005, Rome, Italy Report No.(s): SAE-2005-01-3079; Copyright; Avail: CASI; A01, Hardcopy

A dual-membrane gas trap is currently used to remove gas bubbles from the Internal Thermal Control System (ITCS) coolant on board the International Space Station (ISS). The gas trap consists of concentric tube membrane pairs, comprised of outer hydrophilic tubes and inner hydrophobic fibers. Liquid coolant passes through the outer hydrophilic membrane, which traps the gas bubbles. The inner hydrophobic fiber allows the trapped gas bubbles to pass through and vent to the ambient atmosphere in the cabin. The gas trap was designed to last for the entire lifetime of the ISS, and therefore was not designed to be repaired. However, repair of these gas traps is now a necessity due to contamination from the on-orbit ITCS fluid and other sources on the ground as well as a limited supply of flight gas traps. This paper describes a novel repair technique that has been developed that will allow the refurbishment of contaminated gas traps and their return to flight use. Author

Vapor Traps; Temperature Control; Membranes; Hydrophobicity; Coolants; International Space Station

Source: NASA.