IP@SS - Integrated Passenger Security Solutions

Integrated Passenger Security Solutions (IP@SS) was developed to meet the present challenge faced by the aviation security industry, particularly in view of the audacious, unprecedented terrorist attacks carried out in the USA on September 11, 2001, which have changed aviation security threats beyond recognition. IP@SS is an integrated system which comprises several innovative technological sensors, databases, and advanced analysis methods aimed at accelerating passenger processing transactions and enhancing the level of security.     

Simplified parametric cost trade-offs in satellite system design

In this paper, a parametric cost model for the space segment of a meteorological satellite system is derived and exercised to provide insight into the major economic trade-offs affecting the choice of the satellite's design life and replacement strategy. Trade-offs involving replacement strategy include launch via an expendable booster versus launch via the Space Shuttle; and recovery, repair, and reuse of a failed satellite versus simple replacement with no reuse.

The sensitivities of space segment costs to design life, launch costs, replacement costs, and refurbishment costs are examined with explicit inclusion of nonrecurring and recurring costs.

The results from an application of the model indicate that routine spacecraft retrieval and reuse of a modestly expensive spacecraft is not a significant economic benefit and that design lifetimes of three or four years are the best choice.     

Dynamic compensator design in nonlinear aerospace systems

Based on differential algebraic results, dynamic controllers are proposed for the feedback regulation of typical aerospace systems. Fliess's generalized observability canonical form (GOCF) is used for specifying a dynamic compensator that smoothly regulates the plant dynamics. The synthesis approach used is also applicable to the design of nonlinear pulsewidth-modulation (PWM) controllers, as well as to sliding-mode control strategies. The three underlying nonlinear control techniques, explored with the aid of illustrative examples, are commonly encountered in aerospace control system design problems. Simulations are also included     

Laboratory experiments on spacecraft charging and its neutralization

Simulation experiments on spacecraft charging in space plasma and its neutralization are performed in relation to the electron beam experiment (SEPAC) on Space Shuttle Spacelab 1. A spacecraft simulator or a spherical probe is immersed in a magnetized plasma and a positive high voltage with respect to the plasma is externally applied to it. The current-voltage characteristics follow quite well with the theoretical model of Parker and Murphy [1] in the low voltage, low pressure region. When the voltage rises to more than the ionization potential of the surrounding neutral gas, it departs from the model and the effect of plasma production by the electron current becomes very important. The same kind of ionization effect as this has also been observed in our rocket experiments with an electron beam. The enhancement of the ionization effect by an additional neutral gas injection causes a considerable suppression of the potential rise of a spacecraft emitting an electron beam. This is demonstrated with the SEPAC accelerators in a large space chamber experiment.     

High-energy gamma-astronomy with large underground detectors

Large underground (underwater) detectors (such as ‘Baikal’ and DUMAND) are discussed for their possible use as gamma-ray telescopes. The signal is caused by high-energy muons (E _μ ? 30–100 TeV) produced by the primary gamma-radiation in the Earth's atmosphere. The production of gamma-rays in the source through the reaction p + p → π ⁰ + X is calculated for a low density target of arbitrary thickness taking the electromagnetic cascade into account. The muon production by gamma-rays in the Earth's atmosphere is calculated using three processes: (i) photoproduction of π- and K-mesons followed by decay to muons, (ii) the direct production of μ⁺ μ^?-pairs: γ + Z → Z + μ ⁺ + μ^?, and (iii) photoproduction of charmed particles. It is shown that for thin sources with a flat spectrum (integral exponent γ = 1.1) a large (S = 0.1 km²) underground detector can detect both neutrinos and gamma-quanta generated by the source. Finally we compare the performances of underground detectors with S = 0.1 km² for the search of gamma sources at E = 100 TeV with those of the previously proposed 1 km² EAS array.     

Calcium gradient in plant cells with polarized growth in simulated microgravity.

Plant cells characterized by apical growth, for example, root hairs and apical cells of moss protonema, are a convenient model to address the problem of gravity response mechanisms including initiation of cell polarity. The fluorescent calcium probe, chlorotetracycline, allowed us to display the calcium distribution gradient in these cells. Irradiation by red light led to a sharp decrease in the Ca2+ ion activity in cells. During clinostatting in darkness the pattern of calcium influx and distribution changes inconsiderably as compared with control; in root hairs calcium is detected mainly in their apices and bases as in control. Addition of chlorpromazine to the medium probably increases the influx and accumulation of Ca2+ ions. Under data obtained confirm speculations on the Ca2+ ion functional role for the apical growth of plant cells and may suggest the participation of gravity in redistribution or activation of ion channels, calcium channels included, in the plasmalemma.     

Simultaneous Response of the Mid-Latitude Ionosphere to a Sudden Commencement of Strong Magnetic Storms

Using the new technology of global GPS detection of ionospheric disturbances (GLOBDET), it is found that a sharp increase of the time derivative of the magnetic field strength during magnetic storms is accompanied by a simultaneous decrease of the mid-latitude total electron content (TEC) over the entire dayside of the globe. The corresponding negative correlation coefficient is no less than 0.8, and the delay relative to the sudden commencement of magnetic storm is about 3–10 min. The effect is especially clearly pronounced for magnetic storms with sudden commencements (SSC). The analysis is carried out for a set of 90 to 300 GPS stations for 10 days (January 6 and April 23, 1998; April 6, June 8, July 13, 14, and 15, 2000; March 31, April 4 and 11, 2001) with various levels of geomagnetic activity (D _st and K _p varied from –6 to –295 nT and from 0 to 9, respectively). The amplitude of the response in the total electron content for the events considered was 0.1–0.4 × 10¹⁶ m^–2 (which is a deviation of 0.2–2.6% from the TEC background value). The velocity of the disturbance motion from the dayside to the nightside was about 10–20 km/s. The results obtained agree with the data of ionospheric parameter measurements conducted earlier by methods with high temporal resolution.     

Changes in symbiotic and associative interrelations in a higher plant-bacterial system during space flight.

The miniature cenosis consisting of the water fern Azolla with its associated symbiotic nitrogen-fixing cyanobacterium Anabaena and the concomitant bacteria was investigated. Ecological closure was shown to produce sharp quantitative and qualitative changes in the number and type of concomitant bacteria. Changes in the distribution of bacterial types grown on beef-extract broth after space flight were recorded. Anabaena azollae underwent the most significant changes under spaceflight conditions. Its cell number per Azolla biomass unit increased substantially. Thus closure of cenosis resulted in a weakening of control over microbial development by Azolla. This tendency was augmented by spaceflight factors. Reduction in control exerted by macro-organisms over development of associated micro-organisms must be taken into account in constructing closed ecological systems in the state of weightlessness.