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At least 1,117 records · Page 62

Space engine safety system

A rocket engine safety system is designed to initiate control procedures which will minimize damage to the engine and vehicle or test stand in the event of an engine failure. This report describes the features and the implementation issues associated with rocket engine safety systems. Specific concerns of safety systems applied to a space-based engine and long duration space missions are discussed. Examples of safety system features and architectures are given from recent safety monitoring investigations conducted for the Space Shuttle Main Engine and for future liquid rocket engines. Also, a general design and implementation process for rocket engine safety systems is presented.

Maul, William A.↗

Increase of stagnation pressure and enthalpy in shock tunnels

High stagnation pressures and enthalpies are required for the testing of aerospace vehicles such as aerospace planes, aeroassist vehicles, and reentry vehicles. Among the most useful ground test facilities for performing such tests are shock tunnels. With a given driver gas condition, the enthalpy and pressure in the driven tube nozzle reservoir condition can be varied by changing the driven tube geometry and initial gas fill pressure. Reducing the driven tube diameter yields only very modest increases in reservoir pressure and enthalpy. Reducing the driven tube initial gas fill pressure can increase the reservoir enthalpy significantly, but at the cost of reduced reservoir pressure and useful test time. A new technique, the insertion of a converging section in the driven tube is found to produce substantial increases in both reservoir pressure and enthalpy. Using a one-dimensional inviscid full kinetics code, a number of different locations and shapes for the converging driven tube section were studied and the best cases found. For these best cases, for driven tube diameter reductions of factors of 2 and 3, the reservoir pressure can be increased by factors of 2.1 and 3.2, respectively and the enthalpy can be increased by factors of 1.5 and 2.1, respectively.

Bogdanoff, David W.↗

Thermal coatings for titanium-aluminum alloys

Titanium aluminides and titanium alloys are candidate materials for use in hot structure and heat-shield components of hypersonic vehicles because of their good strength-to-weight characteristics at elevated temperature. However, in order to utilize their maximum temperature capability, they must be coated to resist oxidation and to have a high total remittance. Also, surface catalysis for recombination of dissociated species in the aerodynamic boundary layer must be minimized. Very thin chemical vapor deposition (CVD) coatings are attractive candidates for this application because of durability and very light weight. To demonstrate this concept, coatings of boron-silicon and aluminum-boron-silicon compositions were applied to the titanium-aluminides alpha2 (Ti-14Al-21Nb), super-alpha2 (Ti-14Al-23-Nb-2V), and gamma (Ti-33Al-6Nb-1Ta) and to the titanium alloy beta-21S (Ti-15Mo-3Al-3Nb-0.2Si). Coated specimens of each alloy were subjected to a set of simulated hypersonic vehicle environmental tests to determine their properties of oxidation resistance, surface catalysis, radiative emittance, and thermal shock resistance. Surface catalysis results should be viewed as relative performance only of the several coating-alloy combinations tested under the specific environmental conditions of the LaRC Hypersonic Materials Environmental Test System (HYMETS) arc-plasma-heated hypersonic wind tunnel. Tests were also conducted to evaluate the hydrogen transport properties of the coatings and any effects of the coating processing itself on fatigue life of the base alloys. Results are presented for three types of coatings, which are as follows: (1) a single layer boron silicon coating, (2) a single layer aluminum-boron-silicon coating, and (3) a multilayer coating consisting of an aluminum-boron-silicon sublayer with a boron-silicon outer layer.

Cunnington, George R.↗

Task 4 supporting technology. Part 2: Detailed test plan for thermal seals. Thermal seals evaluation, improvement and test. CAN8-1, Reusable Launch Vehicle (RLV), advanced technology demonstrator: X-33. Leading edge and seals thermal protection system technology demonstration

The objective is to develop the advanced thermal seals to a technology readiness level (TRL) of 6 to support the rapid turnaround time and low maintenance requirements of the X-33 and the future reusable launch vehicle (RLV). This program is divided into three subtasks: (1) orbiter thermal seals operation history review; (2) material, process, and design improvement; and (3) fabrication and evaluation of the advanced thermal seals.

Hogenson, P. A.↗

Dynamic Inlet Distortion Prediction with a Combined Computational Fluid Dynamics and Distortion Synthesis Approach

A procedure has been developed for predicting peak dynamic inlet distortion. This procedure combines Computational Fluid Dynamics (CFD) and distortion synthesis analysis to obtain a prediction of peak dynamic distortion intensity and the associated instantaneous total pressure pattern. A prediction of the steady state total pressure pattern at the Aerodynamic Interface Plane is first obtained using an appropriate CFD flow solver. A corresponding inlet turbulence pattern is obtained from the CFD solution via a correlation linking root mean square (RMS) inlet turbulence to a formulation of several CFD parameters representative of flow turbulence intensity. This correlation was derived using flight data obtained from the NASA High Alpha Research Vehicle flight test program and several CFD solutions at conditions matching the flight test data. A distortion synthesis analysis is then performed on the predicted steady state total pressure and RMS turbulence patterns to yield a predicted value of dynamic distortion intensity and the associated instantaneous total pressure pattern.

Norby, W. P.↗

X-34 Program Status

The National Aeronautics and Space Administration (NASA) initiated the current X-34 program in 1996 as part of the U.S. space agency's effort to dramatically reduce the cost of access to space. The X-34 is the first in a series of "Pathfinder" vehicles designed to conduct flight testing of key launch vehicle technologies at low cost. The X-34 program has moved rapidly from the drawing board to hardware build-up, with the first flight scheduled for 1999. The development of the X-34 has been accomplished by a unique blend of industry and government organizations and personnel working closely together. The program will provide rocket powered winged vehicles that can fly sub-orbital missions in support of advanced reusable launch vehicle technology development. In addition, the X-34 vehicles will represent a hypersonic test bed for advanced experiments in the aeronautical sciences.

London, John R., III↗

International Space Station General Resource Reel

The construction and evolution of the International Space Station (ISS) is seen through various clips. Live footage shows the following: (1) the Zarya Module under construction and during launch preparations; (2) the Unity Module under construction, during launch preparations, and being lowered into the payload canister; (3) STS-88 Mission Specialists Jerry Ross and Jim Newman during training for their spacewalks, including activities in the Neutral Buoyancy Laboratory (NBL); (4) Zarya and Unity docking to the Service Module; (5) the Expedition 1 crew (William Shepherd, Yuri Gidzenko, and Sergei Krikalev) during emergency escape training in the Black Sea and during water survival training at Johnson Space Center; (6) the X-38 Crew Return Vehicle Drop Test; and (7) the US Destiny Laboratory Module, Pressurized Mating Adapter (PMA), Service Module, Italian Multi-Purpose Logistics Module, US Airlock, and US Habitation Module under construction. Computerized animations show the following: (1) an ISS fly-around; (2) the STS-88 Space Shuttle as it docks with Zarya and attaches Zarya to the Unity Module; (3) the Space Shuttle as it docks with ISS and installs the Z1 truss segment and PMA; (4) the Soyuz spacecraft as it docks with ISS; (5) interior and exterior views of the Columbus Attached Pressurized Module; and (6) a Transhab animation showing the interior and exterior and marking the components.

Source record↗

Technology for Smoother Transit

Langley Research Center has developed a portable, self contained ride quality meter for accessing ride quality during vehicle operation. System is applicable to air, sea, road, or track vehicles for estimating passenger ride comfort in the presence of complex vibrations and interior noise. Meter has three components: a package of three vibration sensors, a microphone, and a computer. Installed on the floor of the vehicle being tested, sensors measure vibrations in five different axes, microphone measures noise level, and computer processes input from both and gives user a printed readout including a number of options for assessing ride quality.

Source record↗

A Ground-Based Research Vehicle for Base Drag Studies at Subsonic Speeds

A ground research vehicle (GRV) has been developed to study the base drag on large-scale vehicles at subsonic speeds. Existing models suggest that base drag is dependent upon vehicle forebody drag, and for certain configurations, the total drag of a vehicle can be reduced by increasing its forebody drag. Although these models work well for small projectile shapes, studies have shown that they do not provide accurate predictions when applied to large-scale vehicles. Experiments are underway at the NASA Dryden Flight Research Center to collect data at Reynolds numbers to a maximum of 3 x 10(exp 7), and to formulate a new model for predicting the base drag of trucks, buses, motor homes, reentry vehicles, and other large-scale vehicles. Preliminary tests have shown errors as great as 70 percent compared to Hoerner's two-dimensional base drag prediction. This report describes the GRV and its capabilities, details the studies currently underway at NASA Dryden, and presents preliminary results of both the effort to formulate a new base drag model and the investigation into a method of reducing total drag by manipulating forebody drag.

Diebler, Corey↗

An Overview of the NASA Sounding Rocket and Balloon Programs

The U.S. National Aeronautics and Space Administration (NASA) Sounding Rockets and Balloon Programs conduct a total of 50 to 60 missions per year in support of the NASA scientific community. These missions support investigations sponsored by NASA's Offices of Space Science, Life and Microgravity Sciences & Applications, and Earth Science. The Goddard Space Flight Center has management and implementation responsibility for these programs. The NASA Sounding Rockets Program provides the science community with payload development support, environmental testing, launch vehicles, and launch operations from fixed and mobile launch ranges. Sounding rockets continue to provide a cost-effective way to make in situ observations from 50 to 1500 km in the near-earth environment and to uniquely cover the altitude regime between 50 km and 130 km above the Earth's surface. New technology efforts include GPS payload event triggering, tailored trajectories, new vehicle configuration development to expand current capabilities, and the feasibility assessment of an ultra high altitude sounding rocket vehicle. The NASA Balloon Program continues to make advancements and developments in its capabilities for support of the scientific ballooning community. The Long Duration Balloon (LDB) is capable of providing flight durations in excess of two weeks and has had many successful flights since its development. The NASA Balloon Program is currently engaged in the development of the Ultra Long Duration Balloon (ULDB), which will be capable of providing flight times up to 100-days. Additional development efforts are focusing on ultra high altitude balloons, station keeping techniques and planetary balloon technologies.

Eberspeaker, Philip J.↗

Investigation of the Static Longitudinal and Lateral Stability Characteristics of a 0.10-Scale Model of a Three-Stage Configuration of the Scout Research Vehicle at Mach Numbers of 2.29, 2.96, 3.96, and 4.65

An investigation w a s made i n the Langley Unitary Plan wind tunnel o determine the effects of fin area and the effects of antennas and w iring tunnels on the static longitudinal and lateral stability of a 0 .10- scale model of a three- stage configuration of the Scout vehicle. The tests were performed at Mach numbers of 2.29, 2.96, 3.96, and 4. 65 6 and at Reynolds numbers of about 3.5 X 10 per foot.

Jernell, Lloyd S.↗

Glenn Refractory Adhesive for Bonding and Exterior Repair (GRABER) Developed for Repairing Shuttle Damage

Advanced in-space repair technologies for reinforced carbon/carbon composite (RCC) thermal protection system (TPS) structures are critically needed for the space shuttle Return To Flight (RTF) efforts. These technologies are also critical for the repair and refurbishment of thermal protection system structures of future Crew Exploration Vehicles of space exploration programs. The Glenn Refractory Adhesive for Bonding and Exterior Repair (GRABER) material developed at the NASA Glenn Research Center has demonstrated capabilities for repair of small cracks and damage in RCC leading-edge material. The concept consists of preparing an adhesive paste of desired ceramic in a polymer/phenolic resin matrix with appropriate additives, such as surfactants, and then applying the paste into the damaged or cracked area of the RCC composite components with caulking guns. The adhesive paste cures at 100 to 120 C and transforms into a high-temperature ceramic during simulated vehicle reentry testing conditions.

Singh, Mrityunjay↗

CBGA/PBGA Package Planarity and Assembly Reliability

Jet Propulsion Laboratory (JPL) is currently assessing the use of Ball Grid Arrays (BGAs) for National Aeronautics and Space Administration (NASA) spaceflight applications. This work is being funded through NASA Headquarters, Code Q. The objectives are to demonstrate the robustness, quality and reliability of BGAs technology, and to assist in the development of the repidly growing infastructure for this technology.

BGAs ball grid arrays test vehicles plastic and ce↗

Crew Launch Vehicle (CLV) Avionics and Software Integration Overview

On January 14, 2004, the President of the United States announced a new plan to explore space and extend a human presence across our solar system. The National Aeronautics and Space Administration (NASA) established the Exploration Systems Mission Directorate (ESMD) to develop and field a Constellation Architecture that will bring the Space Exploration vision to fruition. The Constellation Architecture includes a human-rated Crew Launch Vehicle (CLV) segment, managed by the Marshall Space Flight Center (MSFC), comprised of the First Stage (FS), Upper Stage (US), and Upper Stage Engine (USE) elements. The CLV s purpose is to provide safe and reliable crew and cargo transportation into Low Earth Orbit (LEO), as well as insertion into trans-lunar trajectories. The architecture's Spacecraft segment includes, among other elements, the Crew Exploration Vehicle (CEV), managed by the Johnson Space Flight Center (JSC), which is launched atop the CLV. MSFC is also responsible for CLV and CEV stack integration. This paper provides an overview of the Avionics and Software integration approach (which includes the Integrated System Health Management (ISHM) functions), both within the CLV, and across the CEV interface; it addresses the requirements to be met, logistics of meeting those requirements, and the roles of the various groups. The Avionics Integration and Vehicle Systems Test (ANST) Office was established at the MSFC with system engineering responsibilities for defining and developing the integrated CLV Avionics and Software system. The AIVST Office has defined two Groups, the Avionics and Software Integration Group (AVSIG), and the Integrated System Simulation and Test Integration Group (ISSTIG), and four Panels which will direct trade studies and analyses to ensure the CLV avionics and software meet CLV system and CEV interface requirements. The four panels are: 1) Avionics Integration Panel (AIP), 2) Software Integration Panel, 3) EEE Panel, and 4) Systems Simulation and Test Panel. Membership on the groups and panels includes the MSFC representatives from the requisite engineering disciplines, the First Stage, the Upper Stage, the Upper Stage Engine projects, and key personnel from other NASA centers. The four panels will take the results of trade studies and analyses and develop documentation in support of Design Analysis Cycle Reviews and ultimately the System Requirements Review.

Monell, Donald W.↗

Remotely Piloted Vehicles for Experimental Flight Control Testing

A successful flight test and training campaign of the NASA Flying Controls Testbed was conducted at Naval Outlying Field, Webster Field, MD during 2008. Both the prop and jet-powered versions of the subscale, remotely piloted testbeds were used to test representative experimental flight controllers. These testbeds were developed by the Subsonic Fixed Wing Project s emphasis on new flight test techniques. The Subsonic Fixed Wing Project is under the Fundamental Aeronautics Program of NASA's Aeronautics Research Mission Directorate (ARMD). The purpose of these testbeds is to quickly and inexpensively evaluate advanced concepts and experimental flight controls, with applications to adaptive control, system identification, novel control effectors, correlation of subscale flight tests with wind tunnel results, and autonomous operations. Flight tests and operator training were conducted during four separate series of tests during April, May, June and August 2008. Experimental controllers were engaged and disengaged during fully autonomous flight in the designated test area. Flaps and landing gear were deployed by commands from the ground control station as unanticipated disturbances. The flight tests were performed NASA personnel with support from the Maritime Unmanned Development and Operations (MUDO) team of the Naval Air Warfare Center, Aircraft Division

Motter, Mark A.↗

Modeling the Launch Abort Vehicle's Subsonic Aerodynamics from Free Flight Testing

An investigation into the aerodynamics of the Launch Abort Vehicle for NASA's Constellation Crew Launch Vehicle in the subsonic, incompressible flow regime was conducted in the NASA Langley 20-ft Vertical Spin Tunnel. Time histories of center of mass position and Euler Angles are captured using photogrammetry. Time histories of the wind tunnel's airspeed and dynamic pressure are recorded as well. The primary objective of the investigation is to determine models for the aerodynamic yaw and pitch moments that provide insight into the static and dynamic stability of the vehicle. System IDentification Programs for AirCraft (SIDPAC) is used to determine the aerodynamic model structure and estimate model parameters. Aerodynamic models for the aerodynamic body Y and Z force coefficients, and the pitching and yawing moment coefficients were identified.

Hartman, Christopher L.↗