Virtual presence: one step beyond reality

The capabilities and applications of the Dextrous Anthropomorphic Robotic Testbed (DART) in geologic exploration on the Moon and Mars are described. The article also describes a simulation of planetary exploration using a DART robot and Full Immersion Telepresence Testbed (FITT) gear worn by a human. The FITT apparatus allows a human "master" to control movement in the DART "slave". The simulation focused on the robot's ability to use fine motor coordination to manipulate geologic field tools.     

Calculation of a safety factor of damaged composite main rotor blade according to limit equilibrium theory

Safety factors of the Ansat helicopter main rotor blade are determined in the root section at various flight modes with taking into account the possible damages.     

Theory and Modeling for the Magnetospheric Multiscale Mission

The Magnetospheric Multiscale (MMS) mission will provide measurement capabilities, which will exceed those of earlier and even contemporary missions by orders of magnitude. MMS will, for the first time, be able to measure directly and with sufficient resolution key features of the magnetic reconnection process, down to the critical electron scales, which need to be resolved to understand how reconnection works. Owing to the complexity and extremely high spatial resolution required, no prior measurements exist, which could be employed to guide the definition of measurement requirements, and consequently set essential parameters for mission planning and execution. Insight into expected details of the reconnection process could hence only been obtained from theory and modern kinetic modeling. This situation was recognized early on by MMS leadership, which supported the formation of a fully integrated Theory and Modeling Team (TMT). The TMT participated in all aspects of mission planning, from the proposal stage to individual aspects of instrument performance characteristics. It provided and continues to provide to the mission the latest insights regarding the kinetic physics of magnetic reconnection, as well as associated particle acceleration and turbulence, assuring that, to the best of modern knowledge, the mission is prepared to resolve the inner workings of the magnetic reconnection process. The present paper provides a summary of key recent results or reconnection research by TMT members.     

The properties of alamethicin incorporated into planar lipid bilayers under the influence of microgravity.

During evolution, life on earth had adapted to the gravity of 1g. Due to space flight, in the last decades the question arose what happens to the brain under microgravity on the molecular level. Ion channels among others are the molecular basis of brain function. Therefore, the investigation of ion channel function under microgravity seems to be a promising approach to gather knowledge on brain function during space flight. In a first step, the ion channel forming peptide Alamethicin was used as a model channel in an artificial membrane. It is well suitable for this kind of investigation, since its properties are well described under standard gravity. For that reason, changes due to microgravity can be detected easily. All experiments were performed in the German drop tower at ZARM-FAB, Bremen. A special set-up was constructed based on the bilayer technique introduced by Mueller and Rudin. All functions of this set-up can be observed and controlled remotely. In the first set of experiments, a dramatic change of electrical properties of Alamethicin under microgravity could be observed. Mainly, the pore frequency is significantly reduced.     

Prediction of solar particle event proton doses using early dose rate measurements

A methodology for predicting solar particle event doses using Bayesian inference is being developed. As part of this development, we have tested criteria for categorization of new solar particle events (SPE) using calculated asymptotic doses and dose rates for the 22 SPEs that occurred in 2001. In 9 out of 22 events, our criteria for categorization would have over-predicted the range of asymptotic doses in which the tested events would have fallen. In two cases, our methodology under-predicted the dose range in which the event would have fallen. In order to better predict a new event's group category and thus, to better restrict the Bayesian inference predictive model parameter space, we have reexamined our dose rate criteria for categorization of new events. We report the updating of the grouping criteria using data from the 22 SPEs of 2001, as well as five additional SPEs. Using the revised grouping criteria, we present an analysis of group categorization prediction results for the first ten SPEs of 2002.     

Infrared sensor for hot spot recognition for a small satellite mission

High temperature events strongly influence the environmental processes. Therefore, their observation is an important constituent of the global monitoring network. Unfortunately the current remote sensing systems are not able to deliver the necessary information about the world wide burn out of vegetation and its consequences. For global observations a dedicated system of small satellites is required. The main components of the corresponding instrumentation are the infrared channels. The proposed HSRS (HOT SPOT RECOGNITION SENSOR) has to demonstrate the possibilities of an such instrumentation and its feasibility for small satellites. The main drawbacks of the HSRS design are the handling of the hot spot recognition in the subpixel area and of the saturation in the case of larger hot areas by a suitable signal processing hardware.     

STARDUST: finessing expensive cometary sample returns

The STARDUST Discovery mission will collect samples of cometary coma and interstellar dust and return them to Earth. Five years after launch in February 1999, coma dust in the 1- to 100-micrometers size range will be captured by impact into ultra-low-density silica aerogel during a 6 kms-1 flyby of Comet Wild 2. The returned samples will be investigated at laboratories where the most critical information on these primitive materials is retained. The Jet Propulsion Laboratory will provide project management with Lockheed Martin Astronauts as the spacecraft industrial partner. STARDUST management will aggressively and innovatively achieve cost control through the use of Total Quality Management principles, the chief of which will be organization in a Project Engineering and Integration Team that "flattens" the traditional hierarchical structure by including all project elements from the beginning, in a concurrent engineering framework focusing on evolving Integrated Mission Capability.     

Inductive interaction of electroconductive bodies with ionospheric and interplanetary plasma

The hypersonic hyperalfvèn plasma flow around electroconductive bodies is considered and electromagnetic inductive plasma-body interaction is analyzed. The possible applications of results obtained in this analysis to body motion in ionosphere and interplanetary plasma are discussed.     

Chemical aspects in shock ignition of fuel drops

The behavior, in an oxygen atmosphere, of shocked drops of nitromethane, 1- and 2- nitropropane, ethyl and propyl nitrate, decane, and heptane was studied. Results suggest a new mode of ignition for nitrates at high incident shock Mach numbers (M 3.7). At the high incident shock strengths ignition occurs in the boundary layer, but no blast wave develops as is the case for lower shock strengths. Since ignition delay times are very short under these conditions, the absence of blast waves is attributed to the lack of time for the accumulation of fuel in the wake. Gas phase studies of the shock decomposition of fuel molecules were undertaken to determine if gas phase data could be used to explain the trends in the drop ignition observations. Nitromethane and the nitrates were mainly used in this effort. Alternative explanations for the role of gas phase kinetics in the ignition of drops are presented.     

Consideration of space activities by the UN general assembly

The thirty-ninth session of the United Nations General Assembly affirmed ‘that complete and general disarmament warrants that outer space should be used exclusively for peaceful purposes and that it shall not become an arena for an arms race’.This text appears in the first of two important resolutions concerning outer space adopted by the General Assembly during its last session. Also in the first resolution, entitled ‘Prevention of an Arms Race in Outer Space’ (A/39/59 of 12 December 1984), the Assembly called upon all states, particularly those with major space capabilities, to contribute actively to the objective of the peaceful uses of outer space and to take immediate measures to prevent an arms race in outer space in the interest of maintaining international peace and security and promoting international cooperation and understanding.