Deutsche Airbus flight test of Rosemount smart probe fordistributed air data systems

Deutsche Aerospace Airbus (division of DASA) and Rosemount Aerospace Inc. Jointly sponsored a flight test program to evaluate in-flight performance of distributed multifunction air data smart probes. The probes measure pitot pressure, static pressure, and angle of attack. The tests were conducted at the DLR Flight Test Center, near Braunschweig, Germany. Two smart probes were installed on the DLR VFW 614 ATTAS Flight Test Aircraft and tested between June of 1992 and January of 1993. Flight test results are presented together with suggested air data system architectures, including ARINC 738, that can be used with the distributed smart probe concept. New architectures are developed for future commercial aircraft. The smart probe concept offers several advantages including reduced weight and size, reduced number of line replaceable units (LRUs), and increased reliability. Overall cost of ownership is significantly lowered     

Assessment of safety in space power wiring systems

Wiring system failures have resulted from arc propagation in the wiring harnesses of many aircraft and space vehicles. These failures occur when the insulation becomes conductive upon the initiation of an arc. In some cases, the conductive path of the carbon arc track displays a high enough resistance such that the current is limited, and therefore may be difficult to detect using conventional circuit protection. Often, such wiring failures are not simply the result of insulation failure but are due to a combination of wiring system factors. Inadequate circuit protection, unreliable system designs, and careless maintenance procedures can contribute to a wiring system failure. This paper approaches the problem with respect to the overall wiring system, in order to determine what steps can be taken to improve the reliability, maintainability, and safety of space power systems. Power system technologies, system designs, and maintenance procedures which have contributed to past wiring system failures are discussed. New technologies, design processes, and management techniques which may lead to improved wiring system safety are introduced     

Fluence-related risk coefficients using the Harderian gland data as an example.

The risk of radiation-induced cancer to space travelers outside the earth's magnetosphere will be of concern on missions to the Moon and beyond to Mars. High energy galactic cosmic rays with high charge (HZE particles) will penetrate the spacecraft and the bodies of the astronauts, sometimes fragmenting into nuclear secondary species of lower charge but always ionizing densely, thus causing cellular damage which may lead to malignant transformation. To quantitate this risk, the concept of dose equivalent (in which a quality factor Q as a function of LET is assumed) may not be adequate, since different particles of the same LET may have different efficiencies for tumor induction. Also, RBE values on which quality factors are based depend on response to low-LET radiation at low doses, a very difficult region for which to obtain reliable experimental data. Thus, we introduce a new concept, a fluence-related risk coefficient (F), which is the risk of a cancer per unit particle fluence and which we call the risk cross section. The total risk is the sum of the risk from each particle type: sigma i integral Fi(Li) phi i(Li) dLi, where Li is the LET and phi i(Li) is the fluence-LET spectrum of the ith particle type. As an example, tumor prevalence data in mice are used to estimate the probability of mouse Harderian gland tumor induction per year on an extra-magnetospheric mission inside an idealized shielding configuration of a spherical aluminum shell 1 g/cm2 thick. The combined shielding code BRYNTRN/GCR is used to generate the LET spectra at the center of the sphere. Results indicate a yearly prevalence at solar minimum conditions of 0.06, with 60% of this arising from charge components with Z between 10 and 28, and two-thirds of the contribution arising from LET components between 10 and 200 keV/micrometers.     

The interaction of high-voltage spheres with the ionosphere

The interaction of a high-voltage sphere with both magnetized and unmagnetized plasmas was studied with an electrostatic fluid code. Simulations were conducted for a wide range of sphere and plasma parameters. Depending on the conditions, one can observe a propagating spherical double layer, an electron ringing, a stable rapidly-rotating electron density torus, as well as spherical and toroidal discharges.     

A GPS/GLONASS/INS test program

Under contract of different German Ministries a test program investigating the combinations of GPS, GLONASS, and Inertial Navigation has been carried out since 1991. Besides other goals, the aim of the project is to investigate the capabilities of GLONASS in comparison to GPS, to realize a combined GLONASS/INS solution and to perform joint processing of GPS and GLONASS raw data. The paper describes the test procedures and presents some of the results. This includes the comparison of DGPS with stand-alone GLONASS and GLONASS/INS under different dynamic situations, e.g., driving tests, flight tests, and also the presentation of results of combined GPS/GLONASS data processing, which was successfully achieved in March '93 for the first time. The results show the potential of the non-SA-degraded GLONASS and the advantage of using both, GPS and GLONASS for combined solutions     

Digital air/ground communications for air traffic control

The early 1990's communications for air traffic control (ATC) uses analog single channel radios with conventional amplitude modulation (AM) in the very high frequency (VHF) band. To overcome eventual saturation of the current system, a sample “next generation” ATC communications system has been designed to increase capabilities and provide a graceful transition from the current system. The new ATC communication system must address problems with the modulation format and a balance between increased channel capacity and overall cost. The controller/pilot workloads can be reduced in that the information segments allow for either semi-automatic or fully automatic handoff or frequency change. The principal performance factor is the addition of data, fully integrated with voice, while offering an increase in throughput. The architecture is structured to put priority on the uplink voice messages while offering significant information capacity capabilities for external data sources. When digital data and voice communication systems mature in the ATC environment, a natural evolution to more data traffic and less voice will occur. At that time, a simple restructuring of the channel assignments and priorities could offer increased throughput for connection to ground based data sources such as high capacity routers     

Proximate nutritional composition of CELSS crops grown at different CO2 partial pressures.

Two CELSS candidate crops, soybean (Glycine max) and potato (Solanum tuberosum), were grown hydroponically in controlled environments maintained at carbon dioxide (CO2) partial pressures ranging from 0.05 to 1.00 kPa (500 to 10,000 ppm at 101 kPa atmospheric pressure). Plants were harvested at maturity (90 days for soybean and 105 days for potato) and all tissues analyzed for proximate nutritional composition (i.e. protein, fat, carbohydrate, crude fiber, and ash content). Soybean seed ash and crude fiber were higher and carbohydrate was lower than values reported for field-grown seed. Potato tubers showed little difference from field-grown tubers. With the exception of increased crude fiber of soybean seed with increased CO2, no trends were apparent with regard to CO2 effects on proximate composition of soybean seed and potato tubers. Crude fiber of soybean stems and leaves increased with increased CO2, as did soybean leaf protein (total nitrogen). Potato leaf and stem (combined) protein levels also increased with increased CO2, while leaf and stem carbohydrates decreased. Values for leaf and stem protein and ash were higher than values generally reported for field-grown plants for both species. Results suggest that CO2 partial pressure should have little influence on proximate composition of potato tubers or soybean seed, but that high ash and protein levels might be expected from leaves and stems of crops grown in controlled environments of a CELSS.     

Communications-based signaling: advanced capability for mainlinerailroads

Train control has three major functions: (1) protection; (2) operation; and (3) supervision. These functions of train control have been (and still are) implemented both manually and automatically at various railways. The first of these functions, train protection, prevents trains from traveling onto sections of track where they could collide with another train or derail due to switch positions. It also prevents trains from exceeding the safe operating speed, as determined by the vehicle type and track geometry (curves and gradients). The second function, train operation, involves the guidance of a single train in motion and at rest, when it is operating within the train protection function. Finally, train supervision involves guiding and recording the progress of multiple trains in an effort to provide economies to, or assign priorities throughout, the overall railway     

Effects of heavy ions on visual function and electrophysiology of rodents: the ALTEA-MICE project.

ALTEA-MICE will supplement the ALTEA project on astronauts and provide information on the functional visual impairment possibly induced by heavy ions during prolonged operations in microgravity. Goals of ALTEA-MICE are: (1) to investigate the effects of heavy ions on the visual system of normal and mutant mice with retinal defects; (2) to define reliable experimental conditions for space research; and (3) to develop animal models to study the physiological consequences of space travels on humans. Remotely controlled mouse setup, applied electrophysiological recording methods, remote particle monitoring, and experimental procedures were developed and tested. The project has proved feasible under laboratory-controlled conditions comparable in important aspects to those of astronauts' exposure to particle in space. Experiments are performed at the Brookhaven National Laboratories [BNL] (Upton, NY, USA) and the Gesellschaft für Schwerionenforschung mbH [GSI]/Biophysik (Darmstadt, FRG) to identify possible electrophysiological changes and/or activation of protective mechanisms in response to pulsed radiation. Offline data analyses are in progress and observations are still anecdotal. Electrophysiological changes after pulsed radiation are within the limits of spontaneous variability under anesthesia, with only indirect evidence of possible retinal/cortical responses. Immunostaining showed changes (e.g. increased expression of FGF2 protein in the outer nuclear layer) suggesting a retinal stress reaction to high-energy particles of potential relevance in space.