Group dynamics in a long-term blind endeavor on Earth: An analog for space missions (Lewis & Clark Expedition group dynamic analysis)

In 1803, President Thomas Jefferson set fourth a military expedition led by Captains M. Lewis and W. Clark (Lewis and Clark Expedition) on an exploration that would become an everlasting part of US national history and pride. Looking back at the events of this exploration, there are many similarities to the experiences future human space explorers will face as we look to colonize the Moon and travel to Mars and beyond (NASA Vision for Space Exploration, 2004):

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The Lewis and Clark Expedition lasted almost three years and involved a crew of 43 men traveling up the Missouri River to explore the unknown lands and a possible water route to the Pacific Ocean;     

Host–parasite interactions in closed and open microbial cultivation system

The study addresses interaction of bacteria and phages in the host–parasite system in batch and continuous cultures. The study system consists of the auxotrophic strain of Brevibacterium – Brevibacterium sp. 22L – and the bacteriophage of Brevibacterium sp., isolated from the soil by the enrichment method.

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Closed system. In the investigation of the relationship between the time of bacterial lysis and multiplicity of phage infection it has been found that at a lower phage amount per cell it takes a longer time for the lysis of the culture to become discernible. Another important factor determining cytolysis in liquid medium is the physiological state of bacterial population. Specific growth rate of bacteria at the moment of phage infection has been chosen as an indicator of the physiological state of bacteria. It has been shown that the shortest latent period and the largest output of the phage are observed during the logarithmic growth phase of bacteria grown under favorable nutrient conditions. In the stationary phase, bacterial cells become “a bad host” for the phage, whose reproduction rate decreases, and the lysis either slows down significantly or does not occur at all.     

The PAMELA experiment: A space-borne observatory for heliospheric phenomena

PAMELA is a multi-purpose apparatus composed of a series of scintillator counters arranged at the extremities of a permanent magnet spectrometer to provide charge, time-of-flight and rigidity information. Lepton/hadron identification is performed by a silicon–tungsten calorimeter and a Neutron detector placed at the bottom of the device. An Anticounter system is used offline to reject false triggers coming from the satellite. The device was put into orbit on June 15th 2006 in a pressurized container on board the Russian Resurs-DK1 satellite. The satellite is flying along a high inclination (70°), low Earth orbit (350–600 km), allowing to perform measurements in different points and conditions of the geomagnetosphere. PAMELA main goal is a precise measurement of the antimatter ( 80 MeV–190 GeV, e⁺ 50 MeV–270 GeV) and matter (p 80–700 GeV, e⁻ 50 MeV–400 GeV) component of the galactic cosmic rays. In this paper we focus on the capabilites of observations of heliospheric cosmic rays: trapped and semi-trapped particles in the proton and electron belts, solar particle events, Jovian electrons will be studied in the three years of expected mission.     

Multi-spacecraft tracing of turbulent boundary layer

Multi-spacecraft tracing of the high latitude magnetopause (MP) and boundary layers and Interball-1 statistics indicate that:

1. (a) The turbulent boundary layer (TBL) is a persistent feature in the region of the cusp and ‘sash’, a noticeable part of the disturbances weakly depends on the interplanetary magnetic field By component; TBL is a major site for magnetosheath (MSH) plasma penetration inside the magnetosphere through percolation and local reconnection.

2. (b) The TBL disturbances are mainly inherent with the characteristic kinked double-slope spectra and, most probably, 3-wave cascading. The bi-spectral phase coupling indicates self-organization of the TBL as the entire region with features of the non-equilibrium multi-scale and multi-phase system in the near-critical state.

3. (c) We've found the different outer cusp topologies in summer/winter periods: the summer cusp throat is open for the decelerated MSH flows, the winter one is closed by the distant MP with a large-scale (several Re) diamagnetic ‘plasma ball’ inside the MP; the ‘ball’ is filled from MSH through patchy merging rather than large-scale reconnection.

4. (d) A mechanism for the energy release and mass inflow is the local TBL reconnection, which operates at the larger scales for the average anti-parallel fields and at the smaller scales for the nonlinear fluctuating fields; the latter is operative throughout the TBL. The remote from TBL anti-parallel reconnection seems to happen independently.

Navigation for balloon payloads: Recent experience with OMEGA in the US and a new slant range system

The replacement of OMEGA station G from Trinidad to Australia has recently caused some problems for balloon navigation in the United States. We report on recent experience with OMEGA during a balloon flight of the hard X-ray astronomy payload HEXE¹⁾ from Palestine, Texas on September 28/29, 1981. In this flight three different OMEGA receivers were used. In view of the degraded receiving conditions for OMEGA we have developed a simple slant range system which may easily be adapted to other standard PCM systems. We show that a combination of range, azimuth and one OMEGA line of position (e.g. C-D) provides reasonably accurate balloon positions.     

Gamma rays from accreting matter onto collapsed objects

In the spherical accretion onto massive objects, the matter may be heated up to temperatures as high as 10¹² °K. In such a hot plasma, the thermal bremsstrahlung (e-e and e-p) and π° decay from inelastic collisions of protons are the main γ-ray sources. We determined the γ -ray production spectra from the π° decay and from bremsstrahlung for different temperatures. The expected γ-ray spectra were evaluated too in order to fit experimental data. We have fitted COS B data from 3C 273 using a two temperatures plasma model. The best fit is for

Full-size image (1K)

(M₈ is the black hole mass in 10⁸ M) which gives . The hard X-ray measurements do not contradict the bremsstrahlung spectrum.     

A 3NM-64_He added to LARC for Solar Extreme Event studies during solar cycle 24

The Antarctic Laboratory for Cosmic Rays (LARC, acronym for Laboratorio Antartico per i Raggi Cosmici or Laboratorio Antártico para Rayos Cósmicos) operates on King George Island (South Shetlands). Since January 1991 a standard 6NM-64 detector has been recording continuous cosmic ray measurements and several Ground-Level Enhancements have been registered. Here we describe the different phases performed in Italy for the realization of a 3NM-64_³He detector, which started its measurements during the Italian XXII Antarctic Summer Campaign. Data recorded during solar activity cycle 24 will furnish an useful research tool for the next Solar Extreme Events.