SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS
A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 43, ISSUE 18 - SEPTEMBER 09, 2005
18 SPACECRAFT DESIGN, TESTING AND PERFORMANCE
Includes satellites; space platforms; space stations; spacecraft systems and components such as thermal and environmental controls; and spacecraft control and stability characteristics.
For life support systems see 54 Man/System Technology and Life Support.
For related information see also 05 Aircraft Design, Testing and Performance; 39 Structural Mechanics; and 16 Space Transportation and Safety.
20050205026 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, USA
Capability 6.0 Terminal Descent
Wolf, Aron; Guernsey, Carl; Rivellini, Tom; Mease, Ken; Schmitt, Harrison; Capabilities Roadmap Briefings to the National Research Council; March 1, 2005; 22 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
For human missions, need redundant / backup systems. Fail-safe design, multiple-string (dual? triple?) for system components essential to safe landing, where possible. ‘Launch vehicle-like’ reliability for EDL. More redundancy / less tolerance for mission risk than Apollo s three nines (human risk), ‘two nines’ (mission risk). Abort scenarios are probably fewer and more difficult. Human Mars missions won’t be done in rapid succession like Apollo. Commitment of resources is greater than Apollo. Human risk = mission risk to a greater degree than Apollo. Derived from text
Backups; Fail-Safe Systems; Reliability
20050205030 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, USA
A-Prior Observations, Section 9 Manning, Rob; Capabilities Roadmap Briefings to the National Research Council
March 1, 2005; 13 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
Contents include the following: Capability Description, Benefits, Current State-of-the-Art. Capability Requirements and Assumptions. Maturity Level - Capabilities. Maturity Level - Technologies. Metrics. Roadmap for Capability. Derived from text
Breakdown; Technology Utilization; Robotics; Mars Observer
20050205031 NASA Ames Research Center, Moffett Field, CA, USA
4.0 Hypersonic Systems
Venkatapathy, Ethiraj; Munk, Michelle; Powell, Dick; Arnold, Jim; masciarelli, Jim; Wilcockson, Bill; Congdon, Bill; Cheatwood, Neil; Epp, Chirold; Joosten, Kent, et al.; Capabilities Roadmap Briefings to the National Research Council; March 1, 2005; 28 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
Contents include the following: Capability Description. Some Initial Thoughts. Capability State-of-the-Art, Gaps and Requirements. Capability Roadmap. Candidate Technologies. Metrics. Derived from text
Hypersonics; Flight Envelopes
20050205032 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, USA
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Human Planetary Landing System (HPLS) Capability Roadmap NRC Progress Review
Manning, Rob; Schmitt, Harrison H.; Graves, Claude; Capabilities Roadmap Briefings to the National Research Council; March 1, 2005; 36 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
Capability Roadmap Team. Capability Description, Scope and Capability Breakdown Structure. Benefits of the HPLS. Roadmap Process and Approach. Current State-of-the-Art, Assumptions and Key Requirements. Top Level HPLS Roadmap. Capability Presentations by Leads. Mission Drivers Requirements. ‘AEDL’ System Engineering. Communication & Navigation Systems. Hypersonic Systems. Super to Subsonic Decelerator Systems. Terminal Descent and Landing Systems. A Priori In-Situ Mars Observations. AEDL Analysis, Test and Validation Infrastructure. Capability Technical Challenges. Capability Connection Points to other Roadmaps/Crosswalks. Summary of Top Level Capability. Forward Work. Derived from text
Landing Aids; Planetary Landing; Brakes (For Arresting Motion); Failure
20050205038 NASA, Washington, DC, USA
Capability 9.3 Assembly and Deployment
Dorsey, John; Capabilities Roadmap Briefings to the National Research Council; March 1, 2005; 56 pp.; In English; See also 20050205013; Original contains color illustrations; No Copyright; Avail: CASI; A04, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document
Large space systems are required for a range of operational, commercial and scientific missions objectives however, current launch vehicle capacities substantially limit the size of space systems (on-orbit or planetary). Assembly and Deployment is the process of constructing a spacecraft or system from modules which may in turn have been constructed from sub-modules in a hierarchical fashion. In-situ assembly of space exploration vehicles and systems will require a broad range of operational capabilities, including: Component transfer and storage, fluid handling, construction and assembly, test and verification. Efficient execution of these functions will require supporting infrastructure, that can: Receive, store and protect (materials, components, etc.); hold and secure; position, align and control; deploy; connect/disconnect; construct; join; assemble/disassemble; dock/undock; and mate/demate. Derived from text
Assembling; Construction; Deployment; Large Space Structures; Launch Vehicles
20050205046 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, USA
Advanced Modeling, Simulation and Analysis (AMSA) Capability Roadmap Progress Review
Antonsson, Erik; Gombosi, Tamas; Capabilities Roadmap Briefings to the National Research Council; March 1, 2005; 115 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
Contents include the following: NASA capability roadmap activity. Advanced modeling, simulation, and analysis overview. Scientific modeling and simulation. Operations modeling. Multi-special sensing (UV-gamma). System integration. M and S Environments and Infrastructure. Derived from text
Simulation; Models; Ultraviolet Emission; Gamma Rays
20050205051 NASA Langley Research Center, Hampton, VA, USA
5.0 Aerodynamic and Propulsive Decelerator Systems Cruz, Juan R.; Powell, Richard; Masciarelli, James; Brown, Glenn; Witkowski, Al; Guernsey, Carl; Capabilities Roadmap Briefings to the National Research Council; March 1, 2005; 23 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
Contents include the following: Introduction. Capability Breakdown Structure. Decelerator Functions. Candidate Solutions. Performance and Technology. Capability State-of-the-Art. Performance Needs. Candidate Configurations. Possible Technology Roadmaps. Capability Roadmaps. Derived from text
Aerodynamic Brakes; Deceleration; Performance Tests
20050205848 Arizona State Univ., Tempe, AZ, USA
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MicroPPT-Based Secondary/Backup ACS for a 160-m, 450-kg Solar Sail Spacecraft
Wie, Bong; Murphy, David; May 2005; 14 pp.; In English; 41st AlAA Joint Propulsion Conference, 10-13 Jul. 2005, Tucson, AZ, USA Contract(s)/Grant(s): NNM04AB09C; Copyright; Avail: CASI; A03, Hardcopy
Solar sail tip-mounted, lightweight pulsed plasma thrusters (PPTs) are proposed for a secondary (or backup) attitude control system (ACS) of a 160-m, 450-kg solar sail spacecraft of the Solar Polar Imager (SPI) mission.
A propellantless primary ACS of the SPI sailcraft employs trim control masses running along mast lanyards for pitch/yaw control together with roll stabilizer bars at the mast tips for quadrant tilt (roll) control. The robustness of such a propellantless primary ACS would be further enhanced by a secondary ACS utilizing tip-mounted, lightweight PPTs.
The microPPT-based ACS is intended mainly for attitude recovery maneuvers from various off-nominal conditions that cannot be reliably handled by the propellantless primary ACS. However, it can also be employed for: i) the checkout or standby mode prior to and during sail deployment, ii) the post-deployment transition mode (prior to the propellantless primary ACS mode operation), iii) the solar sailing cruise mode of a trimmed sailcraft, and iv) the spin-stabilized, sun-pointing, safe mode. Although a conventional bus ACS is required for the SPI mission as the sail is jettisoned at the start of its science mission phase, the microPPT-based ACS option promises greater redundancy and robustness for the SPI mission. For other sailing missions, where the sail is never jettisoned, this secondary ACS provides a lower-cost, lower-mass propulsion for deployment control and greater redundancy than any traditional reaction-jet control system.
This paper presents an overview nf the state--of-the--art microPPT technology, the design requirements of microPPTs for solar sail attitude control, and the preliminary ACS design and simulation results. Author
Attitude Control; Pulsed Plasma Thrusters; Solar Sails; Spacecraft Design
20050206169 Optimal Synthesis, Inc., Palo Alto, CA USA
Adaptive Techniques for Multiple Actuator Blending
Menon, P. K.; Iragavarapu, V. R.; Jan. 1998; 28 pp.; In English Contract(s)/Grant(s): N00178-97-C-3005 Report No.(s): AD-A436368; No Copyright; Avail: CASI; A03, Hardcopy
Advanced missiles employ multiple actuators to enhance maneuverability and to improve the intercept probability against highly maneuverable targets. Actuators employed in such missiles include aerodynamic control surfaces and reaction jets. While the usage of aerodynamic surfaces are not generally constrained, reaction jet usage has to be minimized due to the limited amount of fuel available on-board. A blending logic is employed to optimally allocate the actuators in response to commands from the autopilot. This paper discusses the development of a fuel conservative actuator blending logic that provides relatively invariant actuator performance over widely varying flight conditions. The invariant performance is obtained using the model reference adaptive control technique. Multiple adaptation strategies are employed to ensure rapid convergence and stable behavior. The performance of the model reference adaptive actuator blending strategy is illustrated using a realistic missile model. DTIC
Actuators; Aerodynamics; Antimissile Defense; Ballistic Missiles; Control Surfaces; Fuel Systems; Maneuverability; Mixtures; Stability; Weapons
20050206376 Air Force Research Lab., Hanscom AFB, MA, USA
Electrostatic Charging of Mirrors in Space: A Plausible Cause of Solar Panel Anomalies on Satellites
Lai, Shu T.; 18th Space Photovoltaic Research and Technology Conference; April 2005, pp. 252-255; In English; See also 20050206360; Original contains color illustrations; No Copyright; Avail: CASI; A01, Hardcopy
The entire fleet of Boeing Model 702 geosynchronous satellites has suffered from a similar fate: degradation of the solar cell panels. Mirrors flank both sides of the solar cell panels. Degradation, sometimes sudden and stepwise, shortens the lifetime of the solar cells. We suggest that space environment effects play an important role in damaging the solar cells. As a cornerstone in this idea, we expound a theorem that high reflectivity reduces photoemission. With little or no photoemission, mirrors often charge to minus kilovolts in eclipse as well as in sunlight, whenever the space plasma is hot enough. Since the rest of the solar panel does not have this mirror property, differential charging between the mirrors and the rest of the solar panel occurs during eclipse exits. We show the charging data obtained during an eclipse exit on LANL-97A satellite for supporting the idea of differential charging. Finally, we recommend this important mirror charging property to be taken in account in future solar panel designs and in commercial products of spacecraft charging computer codes. Author
Solar Cells; Electrostatics; Photoelectric Emission; Spacecraft Charging; Mirrors; Degradation; Panels
20050207325 NASA Marshall Space Flight Center, Huntsville, AL, USA
Status of the Combustion Devices Injector Technology Program at the NASA MSFC
Jones, Gregg W.; Protz, Christopher; Trinh, Huu; Tucker, Kevin; Nesman, Tomas; Hulka, James; [2005]; 39 pp.; In English; AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 10-14 Jul. 2005, Tucson, AZ, USA; Copyright; Avail: CASI; A03, Hardcopy
Task provide two deliverables: 1. Technological solutions demonstrated by design, fabrication, and test of single element of small scale rocket injector hardware. 2. Improvement in capability and validity to analyze large, multi-element injectors. Derived from text
Combustion; Injectors; Rocket Engines; Scale (Ratio)
20050207347 NASA Kennedy Space Center, Cocoa Beach, FL, USA
STS-114: Discovery Return to Flight: Langley Engineers Anaylsis Briefing
July 10, 2005; In English; 28 min., 35 sec. playing time, in color, with sound; No Copyright; Avail: CASI; V02, Videotape-VHS; B02, Videotape-Beta
This video features a briefing on NASA Langley Research Center (LaRC) contributions to the Space Shuttle fleet’s Return to Flight (RTF). The briefing is split into two sections, which LaRC Shuttle Project Manager Robert Barnes and Deputy Manager Harry Belvin deliver in the form of a viewgraph presentation. Barnes speaks about LaRC contributions to the STS-114 mission of Space Shuttle Discovery, and Belvin speaks about LaRC contributions to subsequent Shuttle missions. In both sections of the briefing, LaRC contributions are in the following areas: External Tank (ET), Orbiter, Systems Integration, and Corrosion/Aging. The managers discuss nondestructive and destructive tests performed on ET foam, wing leading edge reinforced carbon-carbon (RCC) composites, on-orbit tile repair, aerothermodynamic simulation of reentry effects, Mission Management Team (MMT) support, and landing gear tests. The managers briefly answer questions from reporters, and the video concludes with several short video segments about LaRC contributions to the RTF effort. CASI
Space Shuttle Missions; Space Transportation System Flights; Space Transportation System; Space Shuttles; Aerospace Safety; Nondestructive Tests; Destructive Tests; Discovery (Orbiter)
20050207361 Princeton Satellite Systems, Inc., NJ, USA
AOCS Performance and Stability Validation for a 160-m Solar Sail with Control-Structure Interactions
Wie, Bong; Murphy, David; June 2005; 19 pp.; In English; 41st AIAA Joint Propulsion Conference, 10-13 Jul. 2005, Tucson, AZ, USA Contract(s)/Grant(s): NNM04AB09C; Copyright; Avail: CASI; A03, Hardcopy
Future solar sail missions, such as NASA’s Solar Polar Imager Vision, will require sails with dimensions on the order of 50-500 m. We are examining a square sail design with moving mass (trim control mass, TCM) and quadrant rotation primary actuators plus pulsed plasma thrusters (PPTs) at the mast tips for backup attitude control.
Quadrant rotation is achieved via roll stabilizer bars (RSB) at the mast tips. At these sizes, given the gossamer nature of the sail supporting structures, flexible modes may be low enough to interact with the control system, especially as these actuators are located on the flexible structure itself and not on the rigid core. This paper develops a practical analysis of the flexible interactions using state-space systems and modal data from finite element models of the system.
Torsion and bending of the masts during maneuvers could significantly affect the function of the actuators while activation of the membrane modes could adversely affect the thrust vector direction and magnitude. Analysis of the RSB and TCM dynamics for developing high-fidelity simulations is included. For control analysis of the flexible system, standard finite-element models of the flexible sail body are loaded and the modal data is used to create a modal coordinate state-space system. Key parameters include which modes to include, which nodes are of interest for force inputs and displacement outputs, connecting nodes through which external forces and torques are applied from the flex body to the core, any nominal momentum in the system, and any steady rates. The system is linearized about the nominal attitude and rate. The state-space plant can then be analyzed with a state-space controller, and Bode, Nyquist, step and impulse responses generated. The approach is general for any rigid core with a flexible appendage.
This paper develops a compensator for a simple two-mass flex system and extrapolates the results to the solar sail. A finite element model of the 20 m solar sail by ATK Space Systems, recently validated in ground tests, is used to demonstrate the sail analysis approach. Author
Mathematical Models; Solar Sails; NASA Space Programs; Space Missions; Spacecraft Control
20050207380 NASA Marshall Space Flight Center, Huntsville, AL, USA
A Comparative Study of Aerocapture Missions with a Mars Destination
Vaughan, Diane; Miller, Heather C.; Griffin, Brand; James, Bonnie F.; Munk, Michelle M.; April 26, 2005; 16 pp.; In English; 41st AIAA Joint Propulsion Conference and Exhibit, 10-13 Jul. 2005, Tuscon, AZ, USA Contract(s)/Grant(s): NASA Order H-35186-D; No Copyright; Avail: CASI; A03, Hardcopy
Conventional interplanetary spacecraft use propulsive systems to decelerate into orbit. Aerocapture is an alternative approach for orbit capture, in which the spacecraft makes a single pass through a target destination’s atmosphere. Although this technique has never been performed, studies show there are substantial benefits of using aerocapture for reduction of propellant mass, spacecraft size, and mission cost. The In-Space Propulsion (ISP) Program, part of NASA’s Science Mission Directorate, has invested in aerocapture technology development since 2002. Aerocapture investments within ISP are largely driven by mission systems analysis studies, The purpose of this NASA-funded report is to identify and document the fundamental parameters of aerocapture within previous human and robotic Mars mission studies which will assist the community in identifying technology research gaps in human and robotic missions, and provide insight for future technology investments. Upon examination of the final data set, some key attributes within the aerocapture disciplines are identified. Author
Aerocapture; Interplanetary Spacecraft; Mars Missions; Propulsion
20050207383 Lockheed Martin Michoud Space Systems, New Orleans, LA, USA
Shuttle Derived In-Line Heavy Lift Vehicle
Greenwood, Terry; Twichell, Wallace; Ferrari, Daniel; Kuck, Frederick; [2005]; 11 pp.; In English; AIAA Conference, 10-13 Jul. 2005, Tucson, AZ, USA; No Copyright; Avail: CASI; A03, Hardcopy
This paper introduces an evolvable Space Shuttle derived family of launch vehicles. It details the steps in the evolution of the vehicle family, noting how the evolving lift capability compares with the evolving lift requirements. A system description is given for each vehicle. The cost of each development stage is described. Also discussed are demonstration programs, the merits of the SSME vs. an expendable rocket engine (RS-68), and finally, the next steps needed to refine this concept. Author
Launch Vehicles; Spacecraft Launching; Rocket Engines; Space Shuttle Main Engine
20050207385 NASA Marshall Space Flight Center, Huntsville, AL, USA
Marshall Space Flight Center Test Capabilities
Hamilton, Jeffrey T.; [2005]; 17 pp.; In English; 41st AIAA Joint Propulsion Conference, 11-15 Jul. 2005, Tucson, AZ, USA; No Copyright; Avail: CASI; A03, Hardcopy
The Test Laboratory at NASA’s Marshall Space Flight Center has over 50 facilities across 400+ acres inside a secure, fenced facility. The entire Center is located inside the boundaries of Redstone Arsenal, a 40,000 acre military reservation. About 150 Government and 250 contractor personnel operate facilities capable of all types of propulsion and structural testing, from small components to engine systems and structural strength, structural dynamic and environmental testing. We have tremendous engineering expertise in research, evaluation, analysis, design and development, and test of space transportation systems, subsystems, and components. Author
Dynamic Tests; Flight Tests; Laboratories; Structural Design
20050207549 Precision Combustion, Inc., New Haven, CT, USA
Resistively-Heated Microlith-based Adsorber for Carbon Dioxide and Trace Contaminant Removal
Roychoudhury, S.; Walsh, D.; Perry, J.; [2005]; 8 pp.; In English; 35th International Conference on Environmental Systems, 11-14 Jul. 2005, Rome, Italy Contract(s)/Grant(s): NAS8-021082 Report No.(s): SAE-2005-01-2866; Paper 05ICES-470; No Copyright; Avail: CASI; A02, Hardcopy
An integrated sorber-based Trace Contaminant Control System (TCCS) and Carbon Dioxide Removal Assembly (CDRA) prototype was designed, fabricated and tested. It corresponds to a 7-person load. Performance over several adsorption/regeneration cycles was examined. Vacuum regenerations at effective time/temperature conditions, and estimated power requirements were experimentally verified for the combined CO2/trace contaminant removal prototype. The current paper details the design and performance of this prototype during initial testing at CO2 and trace contaminant concentrations in the existing CDRA, downstream of the drier.
Additional long-term performance characterization is planned at NASA. Potential system design options permitting associated weight, volume savings and logistic benefits, especially as relevant for long-duration space flight, are reviewed. The technology consisted of a sorption bed with sorbent- coated metal meshes, trademarked and patented as Microlith by Precision Combustion, Inc. (PCI). By contrast the current CO2 removal system on the International Space Station employs pellet beds. Preliminary bench scale performance data (without direct resistive heating) for simultaneous CO2 and trace contaminant removal was reviewed in SAE 2004-01-2442. In the prototype, the meshes were directly electrically heated for rapid response and accurate temperature control. This allowed regeneration via resistive heating with the potential for shorter regeneration times, reduced power requirement, and net energy savings vs. conventional systems.
A novel flow arrangement, for removing both CO2 and trace contaminants within the same bed, was demonstrated. Thus, the need for a separate trace contaminant unit was eliminated resulting in an opportunity for significant weight savings. Unlike the current disposable charcoal bed, zeolites for trace contaminant removal are amenable to periodic regeneration. Author
Adsorbents; Carbon Dioxide Removal; Trace Contaminants; Time Temperature Parameter; Temperature Control; Coatings
20050207558 NASA Marshall Space Flight Center, Huntsville, AL, USA
Intelligent, Self-Diagnostic Thermal Protection System for Future Spacecraft
Hyers, Robert W.; SanSoucie, Michael P.; Pepyne, David; Hanlon, Alaina B.; Deshmukh, Abhijit; June 15, 2005; 17 pp.; In English; 2005 National Space and Missile Materials Symposium, 27 Jun. - 1 Jul. 2005, Summerlin, NV, USA; Original contains color illustrations Contract(s)/Grant(s): NCC8-222; No Copyright; Avail: CASI; A03, Hardcopy
The goal of this project is to provide self-diagnostic capabilities to the thermal protection systems (TPS) of future spacecraft. Self-diagnosis is especially important in thermal protection systems (TPS), where large numbers of parts must survive extreme conditions after weeks or years in space. In-service inspections of these systems are difficult or impossible, yet their reliability must be ensured before atmospheric entry. In fact, TPS represents the greatest risk factor after propulsion for any transatmospheric mission. The concepts and much of the technology would be applicable not only to the Crew Exploration Vehicle (CEV), but also to ablative thermal protection for aerocapture and planetary exploration. Monitoring a thermal protection system on a Shuttle-sized vehicle is a daunting task: there are more than 26,000 components whose integrity must be verified with very low rates of both missed faults and false positives. The large number of monitored components precludes conventional approaches based on centralized data collection over separate wires; a distributed approach is necessary to limit the power, mass, and volume of the health monitoring system. Distributed intelligence with self-diagnosis further improves capability, scalability, robustness, and reliability of the monitoring subsystem. A distributed system of intelligent sensors can provide an assurance of the integrity of the system, diagnosis of faults, and condition-based maintenance, all with provable bounds on errors. Author
Thermal Protection; Space Shuttles; Systems Engineering
20050207581 NASA Marshall Space Flight Center, Huntsville, AL, USA
Distributed sensing of Composite Over-wrapped Pressure Vessels using Fiber-Bragg Gratings
Grant, Joseph; [2005]; 1 pp.; In English; National Space and Missile Materials Symposium. Betting on Materials: ASureWin, 27 Jun. - 1 Jul. 2005, Las Vegas, NV, USA; No Copyright; Avail: Other Sources; Abstract Only
The increasing use of advanced composite materials in the wide range of applications including Space Structures is a great impetus to the development of smart materials. These materials offer a wide range of possibilities within the space program. But before they can be reliably incorporated into space flight applications, additional understanding is required in the area of damage tolerance of these materials.
Efforts to enhance our understanding of failure modes, mechanical properties, long and short term environmental effects, cyclic damage accumulation and residual strength are needed. Thus we have employed the use of fiber optical sensors which offers an excellent opportunity exploit these materials through monitoring and characterizing their mechanical properties and thus the integrity of structures made from such materials during their life cycle. Use of these optical innovations provides an insight into structures that have not been available in the past, as well as the technology available to provide real time health monitoring throughout its life cycle. The embedded fiber optical sensor shows a clearly detectable sensitivity to changes in the near strain and stress fields of the host structure promoted by mechanical or thermal loading or, in certain conditions, structural damage.
The last ten years have seen a large increase in the use of FBG based monitoring systems in a broad range of applications. Fiber Bragg gratings are use to monitor the structural properties of composite pressure vessels. These gratings optically inscribed into the core of a single mode fiber are used as a tool to monitor the stress strain relation in composite structures. The fiber Bragg sensors are both embedded within the composite laminates and bonded to the surface of the vessel with varying orientations with respect to the carbon fiber in the epoxy matrix. The response of these fiber-optic sensors is investigated by pressurizing the cylinder up to its burst pressure of around 4400 psi. This is done at both ambient and cryogenic temperatures using water and liquid nitrogen.
The recorded response is compared with the response from conventional strain gauge also present on the vessel. Additionally, several vessels were tested that had been damaged to simulate different type of events, such as cut tow, delimitation and impact damage. Author
Pressure Vessels; Composite Structures; Bragg Gratings; Composite Materials; Spacecraft Structures; Damage; Fiber Optics; Failure Modes; Mechanical Properties; Environment Effects; Residual Strength
20050209887 Aerospace Corp., Arlington, VA, USA, NASA Goddard Space Flight Center, Greenbelt, MD, USA
Enabling Exploration Missions Now: Applications of On-Orbit Staging
Folta, David C.; Vaughn, Frank; Westmeyer, Paul; Rawitscher, Gary; Bordi, Francesco; [2005]; 3 pp.; In English; AIAA/AAS Conference, 7-11 Aug. 2005, Lake Tahoe, CA, USA; No Copyright; Avail: CASI; A01, Hardcopy
Future NASA Exploration goals are difficult to meet using current launch vehicle implementations and techniques. We introduce a concept of On-Orbit Staging (OOS) using multiple launches into a Low Earth orbit (LEO) staging area to increase payload mass and reduce overall cost for exploration initiative missions. This concept is a forward-looking implementation of ideas put forth by Oberth and Von Braun to address the total mission design. Applying staging throughout the mission and utilizing technological advances in propulsion efficiency and architecture enable us to show that exploration goals can be met in the next decade. As part of this architecture, we assume the readiness of automated rendezvous, docking, and assembly technology. Author
Mission Planning; Payloads; Propulsion; Launch Vehicles
20050209905 NASA Marshall Space Flight Center, Huntsville, AL, USA
The Business Case for Spiral Development in Heavy Lift Launch Vehicle Systems
Farr, Rebecca A.; Christensen, David L.; Keith, Edward L.; [2005]; 12 pp.; In English; 41st AIAA Joint Propulsion Conference, 11-15 Jul. 2005, Tucson, AZ, USA; Original contains black and white illustrations Report No.(s): AIAA Paper 2005-4181; Copyright; Avail: CASI; A03, Hardcopy
Performance capabilities of a specific combination of the Space Shuttle external tank and various liquid engines in an in-line configuration, two-stage core vehicle with multiple redesigned solid rocket motor strap-ons are reexamined. This concept proposes using existing assets, hardware, and capabilities that are already crew-rated, flight certified, being manufactured under existing contracts, have a long history of component and system ground testing, and have been flown for over 20 yr. This paper goes beyond describing potential performance capabilities of specific components to discuss the overall system feasibility-from end to end, start to finish-describing the inherent cost advantages of the Spiral Development concept, which builds on existing capabilities and assets, as opposed to starting up a ‘fresh sheet’ heavy-lift launch vehicle program from scratch. Author
Heavy Lift Launch Vehicles; Solid Propellant Rocket Engines; External Tanks; Costs
20050209963 NASA Kennedy Space Center, Cocoa Beach, FL, USA
STS-114: Discovery Day 3/Mission Status Briefing
July 28, 2005; In English; 36 min., 21 sec. playing time, in color, with sound; No Copyright; Avail: CASI; V03, Videotape-VHS; B03, Videotape-Beta
Paul Hill, STS-114 Lead Flight Director, and John Shannon, Flight Operations and Integrations Manager for the Space Shuttle Program were present. Paul gave a detailed description of the Orbiter’s performance upon its arrival on the International Space Station, orbital rendezvous and docking was completed, performance was nominal by all measures, and crew is already inside the ISS. He also briefly mentioned the next day crew activities, robotics work and first space walk. John emphasized on ground technical engineering tasks, data gathering and inspection of data, imagery and damage assessment, assessing the performance of the external tank, engineering analysis, and the increase of understanding of the overall condition of the vehicle. Safety of the vehicle, battery lifetime, foam loss, tile damage, post launch analysis were some of the topics discussed with the News Media. CASI
Space Transportation System; Space Transportation System Flights; Spacecraft Docking; Orbital Rendezvous; Docking; International Space Station
20050210080 NASA Glenn Research Center, Cleveland, OH, USA
Advanced Control Surface Seal Development at NASA GRC for Future Space Launch Vehicles
Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; DeMange, Jeffrey J.; March 18, 2003; 16 pp.; In English; First Quarterly Review of the NGLT Vehicle Systems Research and Technology Project, 24-28 Mar. 2003, Hampton, VA, USA Contract(s)/Grant(s): WBS 22-706-85-09; No Copyright; Avail: CASI; A03, Hardcopy
NASA s Glenn Research Center (GRC) is developing advanced control surface seal technologies for future space launch vehicles as part of the Next Generation Launch Technology project (NGLT). New resilient seal designs are currently being fabricated and high temperature seal preloading devices are being developed as a means of improving seal resiliency. GRC has designed several new test rigs to simulate the temperatures, pressures, and scrubbing conditions that seals would have to endure during service. A hot compression test rig and hot scrub test rig have been developed to perform tests at temperatures up to 3000 F. Another new test rig allows simultaneous seal flow and scrub tests at room temperature to evaluate changes in seal performance with scrubbing. These test rigs will be used to evaluate the new seal designs. The group is also performing tests on advanced TPS seal concepts for Boeing using these new test facilities. Author
Control Surfaces; Spacecraft Launching; Sealing; Prestressing; Compression Tests
Source: NASA.
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