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Technical Paper

‘Bigelow Aerospace® Life Support Laboratory - Planning and Status’

2004-07-19
2004-01-2474
This Life Support Laboratory consists of a simulator of the spacecraft called Nautilus, which houses Air Revitalization Subsystem, Atmospheric Control and Supply, and Fire Detection and Suppression in the Equipment Area. There are supporting facilities including a Human Metabolic Simulator, simulated Low and Moderate Temperature Coolant Loop, chemical analysis bench, purified water supply, vacuum and gas supplies. These facilities are scheduled to be completed and start to operate for demonstration purposes by March 2005. There are an ARES Ground Model (AGM) and a Trace Contaminant Control Assembly in the ARS. The latter will be integrated with the AGM and a Condensing Heat Exchanger. The unit of AGM is being engineered, built, and will be delivered in early 2005 by EADS Space Division. These assemblies will be operated for sensitivity analysis, integration and optimization studies. The main goal is the achievement for optimal recovery of oxygen.
Technical Paper

eROSITA Camera Low Temperature Thermal Control

2008-06-29
2008-01-1957
eROSITA (extended ROentgen Survey with an Imaging Telescope Array) is a powerful X-ray telescope under development by the Max-Planck-Institut für extraterrestrische Physik (MPE) in Garching, Germany. eROSITA is the core instrument on the Russian SRG1 mission which is planned for launch in 2011. It comprises seven nested Wolter-I grazing incidence telescopes, each equipped with its own CCD camera. The mirror modules have to be maintained at 20°C while the cameras are operated at -80°C. Both, mirrors and CCDs have to be kept within tight limits. The CCD cooling system consists of passive thermal control components only: two radiators, variable conductance heat pipes (VCHP) and two special thermal storage units. The orbit scenario imposes severe challenges on the thermal control system and also on the attitude control system.
Technical Paper

considerations of some JET-DEFLECTION PRINCIPLES for - - directional control - - lift

1958-01-01
580062
THE performance characteristics of various devices applicable for jet directional control, lift augmentation, and VTOL-STOL studied at the NACA Lewis Laboratory are discussed, including jet deflection devices applicable to the conventonal round nozzle and novel nozzle configurations. The results indicate that many of the deflection devices applicable to conventional nozzles can readily be used for directional control or lift augmentation. Other deflection devices, such as movable plug, internal flap, cylindrical thrust reverser, swiveled primary with fixed shroud, and 90 deg side-bleed nozzle, are limited in application to jet directional control or aircraft trim because the loss in axial thrust for a given deflection force is prohibitive or the maximum deflected force obtainable is limited.
Technical Paper

Zero-Venting, Regenerable, Lightweight Heat Rejection for EVA Suits

2005-07-11
2005-01-2974
Future space exploration missions will require a lightweight spacesuit that expends no consumables. This paper describes the design and performance of a prototype heat rejection system that weighs less than current systems and vents zero water. The system uses regenerable LiCl/water absorption cooling. Absorption cooling boosts the heat absorbed from the crew member to a high temperature for rejection to space from a compact, non-venting radiator. The system is regenerated by heating to 100°C for two hours. The system provides refrigeration at 17°C and rejects heat at temperatures greater than 50°C. The overall cooling capacity is over 100 W-hr/kg.
Technical Paper

X-Wing: A Low Disc-Loading V/STOL for the Navy

1985-10-01
851772
The X-Wing concept employs a single lifting system for all modes of flight. The lifting system is comprised of four very rigid, circulation control wings with blowing for lift modulation and control. For hover and low speed flight, the wings rotate such as the rotor of a helicopter. For high speed flight, the wings are stopped in an “X” configuration across the fuselage - from which the name of the concept is derived - with two forward-swept wings and two aft-swept wings. Such a vehicle is also envisioned to have an integrated gas turbine propulsive system for all flight modes. At low speeds, the gas generators) would drive a shaft to turn the wings and the circulation control compressor as well as a set of propulsive fans. For high-speed flight, the shaft would drive only the compressor and accessories as the fans propel the vehicle. The X-Wing concept has been underdevelopment for over 15 years.
Standard

Wrench, Spanner

2013-05-28
CURRENT
AS6018
This SAE Aerospace Standard (AS) covers adjustable and non-adjustable spanner wrenches generally used for aerospace machinery maintenance and for tightening and loosening hose couplings and hydrant caps. Inclusion of dimensional data in this document is not intended to imply all of the products described therein are stock production sizes. Consumers are requested to consult with manufacturers concerning lists of stock production sizes.
Technical Paper

Working Out of Heat Pipes for Low Temperature Radiative Cooling Systems for Space Optic Sensors

1996-07-01
961603
The substantiation of heat pipe usage in passive radiative cooling systems on temperature level (190…240) K for space optical sensors is presented. Heat pipes can be sound practice like heat conducting lines between sensor and radiator particularly at distances more 0.2 m and irreplaceable at distances (0.5…2) m. Embedding heat pipe with radiator allows to create the uniform temperature basis in case of several sensors connection to single radiator and to improve radiator efficiency. It is analyzed approach to design of thermocontrol and cooling radiative systems with heat pipes to reduce sensitiveness to external light disturbances and to enlarge area of radiative system application. The results of design, thermovacuum test and flight operation of thermocontrol radiative system samples are under discussion as well.
Technical Paper

Working Fluid De-freezing in Radiator on Base of LHP

2007-07-09
2007-01-3199
Selection of working fluid is one of the main criterions for designing of heat pipes thermal control systems (TCS) for space application. In this paper we will describe how we solved the task of development of the TCS with working fluid of high thermal physical properties. In 2004-2006 we developed the Engineering model of Deployable Radiator based on Loop Heat Pipe by CAST purchase order. It was developed for qualification tests. Ammonia application as LHP working fluid is stipulated by its high thermal physical properties. However Ammonia freezing temperature is of minus 77ºC. Such fact impedes Ammonia application when operation temperatures of LHP Radiator are lower than this value, for example, It takes several tens of hours to orbit a spacecraft and prepare it for work (at that moment the spacecraft is out of power supply) and the working fluid can be frozen in a condenser-radiator when the spacecraft being in the shadow over a long period of time.
Standard

Wiring Aerospace Vehicle

2006-10-05
HISTORICAL
AS50881C
This specification covers all aspects from the selection through installation of wiring and wiring devices and optical cabling and termination devices used in aerospace vehicles. Aerospace vehicles include manned and unmanned airplanes, helicopters, lighter-than- air vehicles, missiles and external pods.
Standard

Wiring Aerospace Vehicle

2010-07-15
HISTORICAL
AS50881D
This specification covers all aspects from the selection through installation of wiring and wiring devices and optical cabling and termination devices used in aerospace vehicles. Aerospace vehicles include manned and unmanned airplanes, helicopters, lighter-than- air vehicles, missiles and external pods.
Technical Paper

Weathering of Thermal Control Coatings

2007-07-09
2007-01-3020
Spacecraft radiators reject heat to their surroundings. Radiators can be deployable or mounted on the body of the spacecraft. NASA's Crew Exploration Vehicle is to use body mounted radiators. Coatings play an important role in heat rejection. The coatings provide the radiator surface with the desired optical properties of low solar absorptance and high infrared emittance. These specialized surfaces are applied to the radiator panel in a number of ways, including conventional spraying, plasma spraying, or as an appliqué. Not specifically designed for a weathering environment, little is known about the durability of conventional paints, coatings, and appliqués upon exposure to weathering and subsequent exposure to solar wind and ultraviolet radiation exposure. In addition to maintaining their desired optical properties, the coatings must also continue to adhere to the underlying radiator panel.
Technical Paper

WORKING FLUIDS FOR HIGH TEMPERATURE, RANKINE CYCLE, SPACE POWER PLANTS

1961-01-01
610065
An analysis is presented of the relative suitability of sodium, potassium, rubidium, and cesium as working fluids in a high temperature, Rankine Cycle, space power plant. Turbine inlet temperatures of from 1800 to 2000 F with corresponding condensing temperatures of from 1240 to 1530 F are considered. The criteria by which the fluids are evaluated are the thermodynamic cycle characteristics, heat transfer and fluid friction characteristics, metallurgical compatibility, and the influence of the fluids on the design of the turbine, bearings, radiator, generator, and pump. The turbogenerator unit is thought to be the most critical component and it is found that the working fluid will determine the required number of turbine stages and will therefore establish the turbogenerator bearing arrangement. It is not known whether blade erosion will be a problem.
Technical Paper

Vought Ground Effects and Transition Tests of a Tandem Fan Medium Speed V/STOL Configuration

1983-10-03
831547
Vought has participated with the Navy and NASA in studies of various subsonic and supersonic V/STOL aircraft. From these studies, a unique propulsion concept, the Tandem Fan, has been developed. A. 11 scale subsonic V/STOL Tandem Fan model has recently been tested in Vought's large ground effects facility (LGEFF) and Vought's 7 × 10 ft low speed wind tunnel. The Vought large ground effects facility, provides V/STOL testing at hover in the presence of 0 to 30 knots winds in a free circulation environment. The Tandem Fan tests in this facility consisted of over 100 runs to evaluate both attitude and control effects. Individual fan thrust modulation was tested to evaluate pitch and roll control effectiveness, and exhaust nozzle perturbations were tested for yaw control. The model was then installed in the Vought 7 × 10 ft. low speed wind tunnel to evaluate the cruise and upper transition flight regions.
Technical Paper

Volantor* - A Powered Lift Aircraft for Personal Use

2005-10-03
2005-01-3183
This paper describes a class of “powered lift” aircraft called volantors that utilize multiple ducted fans for generating thrust. Thrust is directed vertically for lift during vertical takeoff and landing and horizontally during cruise. The change in thrust direction is accomplished by partially rotating the ducted fans and partially redirecting the airflow at the duct exit through a series of variable camber vanes. This arrangement avoids the potential of duct leading edge stall during transition that arises if the thrust is re-directed solely by rotating the ducts through 90°. In addition to the above fundamental design arrangement this paper discusses the technical issues and developments that need to be addressed in order to provide a volantor that is practical enough for large scale personal use.
Technical Paper

Vibratory Response of a Cylindrical Shell with Fixed Ends Subjected to a Unit Step Change of Pressure

1985-10-01
851984
The solution to the problem of establishing the value of the maximum stress in a uniform cylinder with fixed ends, subjected to a unit step change in pressure is presented. It is shown that the ratio of the maximum transient stress to the steady-state stress is a monotonically decreasing function of the damping ratio of the shell. The stress ratio approaches a value of 2 as the damping ratio and the parameter ψ, defined as
Technical Paper

Ventilation Transport Trade Study for Future Space Suit Life Support Systems

2008-06-29
2008-01-2115
A new and advanced portable life support system (PLSS) for space suit surface exploration will require a durable, compact, and energy efficient system to transport the ventilation stream through the space suit. Current space suits used by NASA circulate the ventilation stream via a ball-bearing supported centrifugal fan. As NASA enters the design phase for the next generation PLSS, it is necessary to evaluate available technologies to determine what improvements can be made in mass, volume, power, and reliability for a ventilation transport system. Several air movement devices already designed for commercial, military, and space applications are optimized in these areas and could be adapted for EVA use. This paper summarizes the efforts to identify and compare the latest fan and bearing technologies to determine candidates for the next generation PLSS.
Technical Paper

Various COMPRESSORS for Types of SUPERCHARGING

1945-01-01
450231
WHILE the centrifugal supercharger is excellently suited to aviation service and to relatively constant-speed, diesel-engine service, Mr. Pigott states, it is not of value for cases of considerable variation in speed where full boost is required at all speeds. The Roots-type blower, the author says further, has had a justified development for low-pressure boost, but is not valuable for compression ratios much in excess of 1.6 because it has no adiabatic compression. The vane-type supercharger, while it has an adiabatic compression, as so far developed appears to the author to be somewhat complex in structure, requires internal lubrication, and has not yet shown satisfactory efficiency compared to other types. The Elliott-Lysholm screw-type and the new P. L. internal-gear type appear to him, however, to give great promise for satisfactory supercharging at the higher pressures beyond the range of the Roots type, and appear to be the best present line of development.
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