Refine Your Search

Topic

Author

Affiliation

Search Results

Technical Paper

“Rigidization-on-Command”™ (ROC) Resin Development for Lightweight Isogrid Booms with MLI

2003-07-07
2003-01-2342
The “Rigidization-on-Command”™ (ROC™) resin development has focused on the development of resin systems that use UV light cure for rigidization. Polymeric sensitizers have been incorporated into the resin formulations to promote cure using Pen-Ray lamps and UV light-emitting diodes (LED's). Formulations containing the polymeric sensitizers were examined by FTIR and DSC. Complete cure was observed after 15 min. exposure with the Pen-Ray lamps. Performance of the Pen-Ray lamps and UV LEDs was thoroughly characterized. Thermal models were developed to optimize the performance of the of the MLI insulation thermal oven used for orbital cure of the boom. Results show that -12°C is the lowest temperature required for cure of the ROC™ resin systems.
Technical Paper

“Model Based Predictive Control of MELISSA Photobioreactors. Steady State Determination”

1994-06-01
941411
Mathematical modeling and control of artificial ecosystems, such as MELISSA, require first the study of physical and biological characteristics in optimal and limiting conditions. Following the previous determination of the stoichiometric equations (Spirulina compartment) and regarding the two phototrophic compartments of MELISSA (Rhodospirillaceae and Spirulina), we have first to focus our control study on the growth kinetics for the light source. In this paper, we recall the theoretical equations of microbial growth kinetics and emphasise the problem of the light transfer in a photobioreactor. We present their adaptations to our pilot plant taking into account technological and biological specifics (lamp spectrum, working illuminated volume, growth rate,…). We then develop the principles and structure of the control system and describe tests of both the hardware and software for several steady state configurations.
Technical Paper

some development problems with Large Cryogenic Propellant Systems

1960-01-01
600022
HEAT TRANSFER causes loading and starting design problems in large missile systems powered by cryogenic propellants. This manifests itself during loading as effective density variation, violent surface conditions, boiloff, and ice formation — problems which may be solved by insulating the tank. During starting it causes overheating and caviation — effects which may be reduced by recirculators and subcooled charge injections. The study described in this paper centers around liquid oxygen and its variations in heat flux rate, which affect liquid density, surface condition, and replenishing requirements. The problem areas are made apparent by consideration of a hypothetical missile system.*
Technical Paper

eROSITA Camera Low Temperature Thermal Control

2008-01-29
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

X-29A Subsystems Integration - An Example for Future Aircraft

1988-10-01
881504
The X-29A is the first X-series experimental aircraft developed in the United States since the mid-sixties. The X-29A is a technology demonstrator aircraft that integrates several different-technologies into one airframe. Among the technologies demonstrated are the aeroservoelastically tailored composite forward swept wings, close coupled canards, discrete variable camber wing, triplex digital flight control system with analog backup, thin supercritical wing, three surface pitch control, large negative static margin and the integration of these technologies into the X-29 airframe. This paper deals with the issue of technology integration of five of the X-29A subsystems and the early design decision to use existing aircraft, components whenever and wherever possible. The subsystems described are the X-29 aircraft Hydraulics System, the Electrical Power System, the Emergency Power System, the Aircraft Mounted Accessory Drive and the Environmental Control System.
Technical Paper

X-29A Forward-Swept-Wing Flight Research Program Status

1987-11-13
872418
The X-29A aircraft is a fascinating combination of integrated technologies incorporated into a unique research aircraft. The X-29A program is a multiple-agency program with management and other responsibilities divided among the National Aeronautics and Space Administration (NASA), the Defense Advanced Research Projects Agency (DARPA), the U.S. Air Force, and the Grumman Corporation. This paper presents an overview of the recently completed X-29A flight research program, the objectives achieved to date, and a discussion of the future of the flight research program. Also discussed are the flight test approach expanding the envelope, typical flight maneuvers performed, X-29A program accomplishments, lessons learned for the Number One aircraft, and future plans with the Number Two aircraft. A schedule for both the Number One and Number Two aircraft is presented.
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, Positioning, and Support Accessories

2020-11-03
CURRENT
AS23190D
AS23190 is a procurement specification that covers a series of plastic and metal components and devices used for the tying, positioning, and supporting cable, cable assemblies, wire, and wire bundles in electrical, electronic, and communication equipment, and in interconnection systems.
Standard

Wiring, Positioning, and Support Accessories

2015-10-01
HISTORICAL
AS23190C
AS23190 is a procurement specification that covers a series of plastic and metal components and devices used for the tying, positioning, and supporting cable, cable assemblies, wire, and wire bundles in electrical, electronic and communication equipment, and in interconnection systems.
Standard

Wiring, Positioning, and Support Accessories

2012-03-07
HISTORICAL
AS23190B
AS23190 is a procurement specification that covers a series of plastic and metal components and devices used for the tying, positioning, and supporting cable, cable assemblies, wire, and wire bundles in electrical, electronic and communication equipment, and in interconnection systems.
Standard

Wiring, Positioning, and Support Accessories

2010-05-12
HISTORICAL
AS23190A
AS23190 is a procurement specification that covers a series of plastic and metal components and devices used for the tying, positioning, and supporting cable, cable assemblies, wire, and wire bundles in electrical, electronic and communication equipment, and in interconnection systems.
Standard

Wiring Aerospace Vehicle

2023-01-13
CURRENT
AS50881H
This specification covers all aspects in Electrical Wiring Interconnection Systems (EWIS) 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.
X