Vibrations of a shell with the discretely attached dynamic subsystem

A problem on low vibrations of a thin spherical shell is considered. A solid of finite dimensions is discretely attached to the shell by means of an elastic rod system. The calculation examples are presented.     

A capillary-driven root module for plant growth in microgravity.

A new capillary-driven root module design for growing plants in microgravity was developed which requires minimal external control. Unlike existing systems, the water supply to the capillary-driven system is passive and relies on root uptake and media properties to develop driving gradients which operate a suction-induced flow control valve. A collapsible reservoir supplies water to the porous membrane which functions to maintain hydraulic continuity. Sheet and tubular membranes consisting of nylon, polyester and sintered porous stainless steel were tested. While finer pore sized membranes allow greater range of operation, they also reduce liquid flux thereby constraining system efficiency. Membrane selection should consider both the maximum anticipated liquid uptake rate and maximum operating matric head (suction) of the system. Matching growth media water retention characteristics to the porous membrane characteristics is essential for supplying adequate liquid flux and gas exchange. A minimum of 10% air-filled porosity (AFP) was necessary for adequate aeration. The capillary-driven module maintained hydraulic continuity and proper gas exchange rates for more than 80 days in a plant growth experiment.     

The APT on the Polar Orbiting Weather Satellites

The receipt of the Pioneer Award has given me a chance to look back over my professional life and the opportunity to take stock of how I helped shape a small part of the world. While I hope this process entertains my contemporaries, more importantly, I hope it stimulates those that are engaged in actively shaping the present. To describe the need for automatic picture transmission (APT), I must retrace the historical development of meteorological satellites. The idea for weather observations from a satellite originated with a small group of meteorologists at the U.S. Army Signal Corps Research and Development Lab. at Ft. Monmouth, N.J., and resulted in the design of Vanguard II. The Tiros and TOS series of satellites, and the design of Nimbus, followed soon thereafter. However, a faster picture dissemination than was available at that time was needed, and it was this necessity that sparked the development of APT. Nimbus was originally intended to be an operational system, but the advent of simpler, less costly stabilization systems made the Tiros evolution the clear winner. The geosynchronous weather satellites started nearly a decade later and evolved from the NASA Application Technology Satellite (ATS) series. All three systems, existing polar orbiting weather satellites, APT, and geosynchronous weather satellites, have changed meteorology and the reliability of weather forecasting profoundly.     

Simultaneous measurement of multiple radiation-induced protein expression profiles using the Luminex(TM) system.

Space flight results in the exposure of astronauts to a mixed field of radiation composed of energetic particles of varying energies, and biological indicators of space radiation exposure provides a better understanding of the associated long-term health risks. Current methods of biodosimetry have employed the use of cytogenetic analysis for biodosimetry, and more recently the advent of technological progression has led to advanced research in the use of genomic and proteomic expression profiling to simultaneously assess biomarkers of radiation exposure. We describe here the technical advantages of the Luminex(TM) 100 system relative to traditional methods and its potential as a tool to simultaneously profile multiple proteins induced by ionizing radiation. The development of such a bioassay would provide more relevant post-translational dynamics of stress response and will impart important implications in the advancement of space and other radiation contact monitoring.     

On the structure and dynamics of the thermosphere

Thermospheric temperature, composition and wind measurements from the Dynamics Explorer satellite (DE-2) are interpreted using a three dimensional, multiconstituent spectral model. The analysis accounts for tides driven by the absorbed solar radiation as well as energy and momentum coupling involving the magnetosphere and lower atmosphere. We discuss phenomena associated with the annual tide, polar circulation, magnetic storms and substorms.     

The biological clock of Neurospora in a microgravity environment.

The circadian rhythm of conidiation in Neurospora crassa is thought to be an endogenously derived circadian oscillation; however, several investigators have suggested that circadian rhythms may, instead, be driven by some geophysical time cue(s). An experiment was conducted on space shuttle flight STS-9 in order to test this hypothesis; during the first 7-8 cycles in space, there were several minor alterations observed in the conidiation rhythm, including an increase in the period of the oscillation, an increase in the variability of the growth rate and a diminished rhythm amplitude, which eventually damped out in 25% of the flight tubes. On day seven of flight, the tubes were exposed to light while their growth fronts were marked. Some aspect of the marking process reinstated a robust rhythm in all the tubes which continued throughout the remainder of the flight. These results from the last 86 hours of flight demonstrated that the rhythm can persist in space. Since the aberrant rhythmicity occurred prior to the marking procedure, but not after, it was hypothesized that the damping on STS-9 may have resulted from the hypergravity pulse of launch. To test this hypothesis, we conducted investigations into the effects of altered gravitational forces on conidiation. Exposure to hypergravity (via centrifugation), simulated microgravity (via the use of a clinostat) and altered orientations (via alterations in the vector of a 1 g force) were used to examine the effects of gravity upon the circadian rhythm of conidiation.     

History of monopulse radar in the USSR

Monopulse radars have played an important role in air and missile defense systems since the development of the monopulse technique in the late 1940s. This paper outlines the application of monopulse radars in Russian defense systems, starting with the Moscow ABM system and continuing in instrumentation and air defense radars now widely deployed in Russia and elsewhere     

In situ measurements to determine if Phobos is layered

The complex system of linear features on Phobos—the inner moon of Mars—found by the Viking Orbiters in 1976, can be classified morphologically into three types according to their appearance as well as their geometrical distribution on the surface. One kind of grooves appears to form arcs of small circles normal to the Phobos-Mars direction. We propose that these grooves are the surface manifestation of layering within Phobos[4–6] which could have been formed when Phobos was a part of a much larger and geologically active parent planet.Here we suggest some measurements to observe whether Phobos has a layered structure or not. The suggestion contains remote sensing measurements (particularly determination of the magnetic field by magnetometer and by electron reflection method) by a spacecraft orbiting around Mars as well as surface measurements (active seismic reflection experiment) by a landing module on Phobos.     

Innovations for competitiveness: European views on “better-faster-cheaper”

The paper elaborates on “ lessons learned” from two recent ESA workshops, one focussing on the role of Innovation in the competitiveness of the space sector and the second on technology and engineering aspects conducive to better, faster and cheaper space programmes. The paper focuses primarily on four major aspects, namely:

1. a) the adaptations of industrial and public organisations to the global market needs;

2. b) the understanding of the bottleneck factors limiting competitiveness;

3. c) the trends toward new system architectures and new engineering and production methods;

4. d) the understanding of the role of new technology in the future applications.

Under the pressure of market forces and the influence of many global and regional players, applications of space systems and technology are becoming more and more competitive. It is well recognised that without major effort for innovation in industrial practices, organisations, R&D, marketing and financial approaches the European space sector will stagnate and loose its competence as well as its competitiveness. It is also recognised that a programme run according to the “better, faster, cheaper” philosophy relies on much closer integration of system design, development and verification, and draws heavily on a robust and comprehensive programme of technology development, which must run in parallel and off-line with respect to flight programmes.

A company's innovation capabilities will determine its future competitive advantage (in time, cost, performance or value) and overall growth potential. Innovation must be a process that can be counted on to provide repetitive, sustainable, long-term performance improvements. As such, it needs not depend on great breakthroughs in technology and concepts (which are accidental and rare). Rather, it could be based on bold evolution through the establishment of know-how, application of best practices, process effectiveness and high standards, performance measurement, and attention to customers and professional marketing. Having a technological lead allows industry to gain a competitive advantage in performance, cost and opportunities. Instrumental to better competitiveness is an R&D effort based on the adaptation of high technology products, capable of capturing new users, increasing production, decreasing the cost and delivery time and integrating high level of intelligence, information and autonomy. New systems will have to take in to account from the start what types of technologies are being developed or are already available in other areas outside space, and design their system accordingly. The future challenge for “faster, better, cheaper” appears to concern primarily “cost-effective”, performant autonomous spacecraft, “cost-effective”, reliable launching means and intelligent data fusion technologies and robust software serving mass- market real time services, distributed via EHF bands and Internet.

In conclusion, it can be noticed that in the past few years new approaches have considerably enlarged the ways in which space missions can be implemented. They are supported by true innovations in mission concepts, system architecture, development and technologies, in particular for the development of initiatives based on multi-mission mini-satellites platforms for communication and Earth observation missions. There are also definite limits to cost cutting (such as lowering heads counts and increasing efficiency), and therefore the strategic perspective must be shifted from the present emphasis on cost-driven enhancement to revenue-driven improvements for growth. And since the product life-cycle is continuously shortening, competitiveness is linked very strongly with the capability to generate new technology products which enhance cost/benefit performance.