The data from the R3DE instrument of ESA’s EXPOSE-E mission outside the ISS at the European Technological Expose Facility (EuTEF) on the ESA Columbus module shows that the docking of the Space Shuttle with the International Space Station (ISS) decreased the South-Atlantic Anomaly (SAA) maxima dose rates from about 1500 Gy h-1 down to 600-700 Gy h-1 or by factor of 2. The dose rate data at the same time from another Bulgarian built instrument (R3DR) of the EXPOSE-R mission outside the Russian “Zvezda” module showed that: 1) before the Space Shuttle docking, the SAA dose rates measured with R3DR were higher (2500 Gy h-1) than the R3DE data; 2) The relative decrease of the SAA dose rates after the shuttle docking was only by a factor of 1.25. These differences are explained by the smaller shielding of R3DR from the body of ISS and by the larger distance of it from the body of Space Shuttle. Very similar data, but with smaller dose rates were obtained with a third Bulgarian built instrument (Liulin-5) inside Russian “Pirs” module. The analysis of the ascending/descending SAA dose rate maxima of the three instruments shows that the effect can be simply explained by the additional shielding against the 30 to 150 MeV protons of the SAA, provided by the 78 tons Shuttle to the instruments and by changing of the ISS 3D mass distribution when the ISS rotates.
We present the catalog of high Galactic-latitude (|b| > 10◦) X-ray sources detected in the first 37-month data of Monitor of All-sky X-ray Image (MAXI) / Gas Slit Camera (GSC). To achieve the best sensitivity, we develop a background model of the GSC that well reproduces the data based on the detailed on-board calibration. Source detection is performed through image fit with the Poisson likelihood algorithm. The catalog contains 500 objects detected in the 4–10 keV band with significance of sD,4−10keV ≥ 7. The limiting sensitivity is ≈ 7.5 × 10−12 ergs cm−2 s−1 (≈ 0.6 mCrab) in the 4–10 keV band for 50% of the survey area, which is the highest ever achieved as an all-sky survey mission covering this energy band. We summarize the statistical properties of the catalog and results from cross matching with the Swift/BAT 70-month catalog, the meta- catalog of X-ray detected clusters of galaxies, and the MAXI/GSC 7-month catalog. Our catalog lists the source name (2MAXI), position and its error, detection significances and fluxes in the 4–10 keV and 3–4 keV bands, their hardness ratio, and basic information of the likely counterpart available for 296 sources.
Characterisation of Growth and Ultrastructural Effects of the Xanthoria elegans Photobiont After 1.5 Years of Space Exposure on the International Space Station
The lichen Xanthoria elegans has been exposed to space and simulated Mars-analogue environment in the Lichen and Fungi Experiment (LIFE) on the EXPOSE-E facility at the International Space Station (ISS). This long-term exposure of 559 days tested the ability of various organisms to cope with either low earth orbit (LEO) or Mars-analogue conditions, such as vacuum, Mars-analogue atmosphere, rapid temperature cycling, cosmic radiation of up to 215 +/- 16 mGy, and insolation of accumulated doses up to 4.87 GJm(-2), including up to 0.314 GJm(-2) of UV irradiation. In a previous study, X. elegans demonstrated considerable resistance towards these conditions by means of photosynthetic activity as well as by post-exposure metabolic activity of 50-80 % in the algal and 60-90 % in the fungal symbiont (Brandt et al. Int J Astrobiol 14(3):411-425, 2015). The two objectives of the present study were complementary: First, to verify the high post-exposure viability by using a qualitative cultivation assay. Second, to characterise the cellular damages by transmission electron microscopy (TEM) which were caused by the space and Mars-analogue exposure conditions of LIFE. Since the algal symbiont of lichens is considered as the more susceptible partner (de Vera and Ott 2010), the analyses focused on the photobiont. The study demonstrated growth and proliferation of the isolated photobiont after all exposure conditions of LIFE. The ultrastructural analysis of the algal cells provided an insight to cellular damages caused by long-term exposure and highlighted that desiccation-induced breakdown of cellular integrity is more pronounced under the more severe space vacuum than under Mars-analogue atmospheric conditions. In conclusion, desiccation-induced damages were identified as a major threat to the photobiont of X. elegans. Nonetheless, a fraction of the photobiont cells remained cultivable after all exposure conditions tested in LIFE.
We report on the initial results of the NanoRocks experiment on the ISS, which simulates collisions in protoplanetary disks and planetary ring systems. The objective of the NanoRocks experiment is to study low-energy collisions inside systems of multiple mm- sized particles of different shapes and materials. In September 2014, NanoRocks reached ISS as part of the NanoRacks platform. First video data from the experiment operations on ISS allows for the measurement of energy damping inside multi-particle systems and the observation of the formation of clusters.
The paper presents observation of relativistic electrons. Data are collected by the Radiation Risk Radiometer-Dosimeters (R3D) B2/B3 modifications during the flights of Foton M2/M3 satellites in 2005 and 2007 as well as by the R3DE instrument at the European Technology Exposure Facility (EuTEF) on the Columbus External Payload Adaptor at the International Space Station (ISS) in the per- iod February 20 – April 28, 2008. On the Foton M2/M3 satellites relativistic electrons are observed more frequently than on the ISS because of higher (62.8°) inclination of the orbit. At both Foton satellites the usual duration of the observations are a few minutes long. On the ISS the duration usually is about 1 min or less. The places of observations of high doses due to relativistic electrons are distributed mainly at latitudes above 50° geographic latitude in both hemispheres on Foton M2/M3 satellites. A very high maximum is found in the southern hemisphere at longitudinal range 0°–60°E. At the ISS the maximums are observed between 45° and 52° geographic latitude in both hemispheres mainly at longitudes equatorward from the magnetic poles. The measured absolute maximums of dose rates generated by relativistic electrons are found to be as follows: 304 lGy h 1 behind 1.75 g cm 2 shielding at Foton M2, 2314 lGy h 1 behind 0.71 g cm 2 shielding at Foton M3 and 19,195 lGy h 1 (Flux is 8363 cm 2 s 1) behind les than 0.4 g cm 2 shielding at ISS.
The Human Genome Project changed everything—or did it? Although un-deniably a scientific tour de force, the Genome Project’s outcome posed more questions than it answered, and molecular biology has been working assiduously ever since to answer those questions.
Mesodinium rubrum is a globally distributed nontoxic ciliate that is known to produce intense red-colored blooms using enslaved chloroplasts from its algal prey. Although frequent enough to have been observed by Darwin, blooms of M. rubrum are notoriously difficult to quantify because M. rubrum can aggregate into massive clouds of rusty-red water in a very short time due to its high growth rates and rapid swimming behavior and can disaggregate just as quickly by vertical or horizontal dispersion. A September 2012 hyperspectral image from the Hyperspectral Imager for the Coastal Ocean sensor aboard the International Space Station captured a dense red tide of M. rubrum (10(6) cells per liter) in surface waters of western Long Island Sound. Genetic data confirmed the identity of the chloroplast as a cryptophyte that was actively photosynthesizing. Microscopy indicated extremely high abundance of its yellow fluorescing signature pigment phycoerythrin. Spectral absorption and fluorescence features were related to ancillary photosynthetic pigments unique to this organism that cannot be observed with traditional satellites. Cell abundance was estimated at a resolution of 100 m using an algorithm based on the distinctive yellow fluorescence of phycoerythrin. Future development of hyperspectral satellites will allow for better enumeration of bloom-forming coastal plankton, the associated physical mechanisms, and contributions to marine productivity.
EVALUATION OF MARINE VECTOR WINDS OBSERVED BY RAPIDSCAT ON THE INTERNATIONAL SPACE STATION USING STATISTICAL DISTRIBUTION
Statistical distribution of marine surface wind speeds and directions observed by RapidScat (RSCAT) on the International Space Station (ISS) over the global oceans were assessed to validate the vector wind products. Comparisons with buoy data and assessments of global histograms of wind speeds and directions showed that quality of the wind data observed by RSCAT is comparable to that of the previous scatterometer missions. It is confirmed that systematic errors in the wind speed and direction were not significant.
The Automatic Identification System (AIS) is based on VHF radio transmissions of ships’ identity, position, speed and heading, in addition to other key parameters. In 2004, the Norwegian Defence Research Establishment (FFI) undertook studies to evaluate if the AIS signals could be detected in low Earth orbit. Since then, the interest in Space-Based AIS reception has grown significantly, and both public and private sector organizations have established programs to study the issue, and demonstrate such a capability in orbit. FFI is conducting two such programs. The objective of the first program was to launch a nano-satellite equipped with an AIS receiver into a near polar orbit, to demonstrate Space-Based AIS reception at high latitudes. The satellite was launched from India 12th July 2010. Even though the satellite has not finished commissioning, the receiver is operated with real-time transmission of received AIS data to the Norwegian Coastal Administration. The second program is an ESA-funded project to operate an AIS receiver on the European Columbus module of the International Space Station. Mounting of the equipment, the NORAIS receiver, was completed in April 2010. Currently, the AIS receiver has operated for more than three months, picking up several million AIS messages from more than 60 000 ship identities. In this paper, we will present experience gained with the space-based AIS systems, highlight aspects of tracking ships throughout their voyage, and comment on possible contributions to port security.
Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station
Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.