Microbial fuel cells applied to the metabolically based detection of extraterrestrial life

Since the 1970s, when the Viking spacecrafts carried out experiments to detect microbial metabolism on the surface of Mars, the search for nonspecific methods to detect life in situ has been one of the goals of astrobiology. It is usually required that a methodology detect life independently from its composition or form and that the chosen biological signature point to a feature common to all living systems, such as the presence of metabolism. In this paper, we evaluate the use of microbial fuel cells (MFCs) for the detection of microbial life in situ. MFCs are electrochemical devices originally developed as power electrical sources and can be described as fuel cells in which the anode is submerged in a medium that contains microorganisms. These microorganisms, as part of their metabolic process, oxidize organic material, releasing electrons that contribute to the electric current, which is therefore proportional to metabolic and other redox processes. We show that power and current density values measured in MFCs that use microorganism cultures or soil samples in the anode are much larger than those obtained with a medium free of microorganisms or sterilized soil samples, respectively. In particular, we found that this is true for extremophiles, which have been proposed as potential inhabitants of extraterrestrial environments. Therefore, our results show that MFCs have the potential to be used for in situ detection of microbial life.     

Comparative survival analysis of Deinococcus radiodurans and the haloarchaea Natrialba magadii and Haloferax volcanii exposed to vacuum ultraviolet irradiation

The haloarchaea Natrialba magadii and Haloferax volcanii, as well as the radiation-resistant bacterium Deinococcus radiodurans, were exposed to vacuum UV (VUV) radiation at the Brazilian Synchrotron Light Laboratory. Cell monolayers (containing 10(5) to 10(6) cells per sample) were prepared over polycarbonate filters and irradiated under high vacuum (10(-5) Pa) with polychromatic synchrotron radiation. N. magadii was remarkably resistant to high vacuum with a survival fraction of (3.77±0.76)×10(-2), which was larger than that of D. radiodurans (1.13±0.23)×10(-2). The survival fraction of the haloarchaea H. volcanii, of (3.60±1.80)×10(-4), was much smaller. Radiation resistance profiles were similar between the haloarchaea and D. radiodurans for fluences up to 150?J m(-2). For fluences larger than 150?J m(-2), there was a significant decrease in the survival of haloarchaea, and in particular H. volcanii did not survive. Survival for D. radiodurans was 1% after exposure to the higher VUV fluence (1350?J m(-2)), while N. magadii had a survival lower than 0.1%. Such survival fractions are discussed regarding the possibility of interplanetary transfer of viable microorganisms and the possible existence of microbial life in extraterrestrial salty environments such as the planet Mars and Jupiter's moon Europa. This is the first work to report survival of haloarchaea under simulated interplanetary conditions.     

触动古老的喜悦一个西班牙人的洛带客家年体验

中国人是个不善于外露情绪、性格内敛的民族,这次在洛带过了一次真正的中国年,近距离体验了古老中国的春节民俗,让我触动到了这个民族那种古老的喜悦,那开放的、热烈的、真诚的、平凡的,我为之感动的精神内核。     

Ricardo Dyrgalla (1910–1970), pioneer of rocket development in Argentina

One of the most important developers of liquid propellant rocket engines in Argentina was Polish-born Ricardo Dyrgalla. Dyrgalla immigrated to Argentina from the United Kingdom in 1946, where he had been studying German weapons development at the end of the Second World War. A trained pilot and aeronautical engineer, he understood the intricacies of rocket propulsion and was eager to find practical applications to his recently gained knowledge.Dyrgalla arrived in Argentina during Juan Perón's first presidency, a time when technicians from all over Europe were being recruited to work in various projects for the recently created Argentine Air Force.Shortly after immigrating, Dyrgalla proposed to develop an advanced air-launched weapon, the Tábano, based on a rocket engine of his design, the AN-1. After a successful development program, the Tábano was tested between 1949 and 1951; however, the project was canceled by the government shortly after. Today, the AN-1 rocket engine is recognized as the first liquid propellant rocket to be developed in South America. Besides the AN-1, Dyrgalla also developed several other rockets systems in Argentina, including the PROSON, a solid-propellant rocket launcher developed by the Argentine Institute of Science and Technology for the Armed Forces (CITEFA). In the late 1960s, Dyrgalla and his family relocated to Brazil due mostly to the lack of continuation of rocket development in Argentina. There, he worked for the Institute of Aerospace Technology (ITA) until his untimely death in 1970. Ricardo Dyrgalla deserves to be recognized among the world's rocket pioneers and his contribution to the science and engineering of rocketry deserves a special place in the history of South America's rocketry and space flight advocacy programs.     

Magnetohydrodynamics in solar and space physics

Because of its proximity, our Sun provides a unique opportunity to perform high resolution observations of its outer layers throughout the whole electromagnetic spectrum. We can also theoretically model most of the fascinating physical phenomena taking place on the Sun, as well as their impact on the solar system.     

World Space Observatory-Ultraviolet: ISSIS,the imaging instrument

The Imaging and Slitless Spectroscopy Instrument (ISSIS) will be flown as part of the science instrumentation in the World Space Observatory-Ultraviolet (WSO-UV). ISSIS will be the first UV imager to operate in a high Earth orbit from a 2 m class space telescope. In this contribution, the science driving the ISSIS design and the main characteristics of this instrument are presented.     

REMS: The Environmental Sensor Suite for the Mars Science Laboratory Rover

The Rover Environmental Monitoring Station (REMS) will investigate environmental factors directly tied to current habitability at the Martian surface during the Mars Science Laboratory (MSL) mission. Three major habitability factors are addressed by REMS: the thermal environment, ultraviolet irradiation, and water cycling. The thermal environment is determined by a mixture of processes, chief amongst these being the meteorological. Accordingly, the REMS sensors have been designed to record air and ground temperatures, pressure, relative humidity, wind speed in the horizontal and vertical directions, as well as ultraviolet radiation in different bands. These sensors are distributed over the rover in four places: two booms located on the MSL Remote Sensing Mast, the ultraviolet sensor on the rover deck, and the pressure sensor inside the rover body. Typical daily REMS observations will collect 180 minutes of data from all sensors simultaneously (arranged in 5 minute hourly samples plus 60 additional minutes taken at times to be decided during the course of the mission). REMS will add significantly to the environmental record collected by prior missions through the range of simultaneous observations including water vapor; the ability to take measurements routinely through the night; the intended minimum of one Martian year of observations; and the first measurement of surface UV irradiation. In this paper, we describe the scientific potential of REMS measurements and describe in detail the sensors that constitute REMS and the calibration procedures.     

HW/SW Co-design of the Instrument Control Unit for the Energetic Particle Detector on-board Solar Orbiter

ESA’s medium-class Solar Orbiter mission is conceived to perform a close-up study of our Sun and its inner heliosphere to better understand the behaviour of our star. The mission will provide the clues to discover how the Sun creates and controls the solar wind and thereby affects the environments of all the planets. The spacecraft is equipped with a comprehensive suite of instruments. The Energetic Particle Detector (EPD) is one of the in-situ instruments on-board Solar Orbiter. EPD is composed of five different sensors, all of them sharing the Instrument Control Unit or ICU that is the sole interface with the spacecraft. This paper emphasises on how the hardware/software co-design approach can lead to a decrease in software complexity and highlights the versatility of the toolset that supports the development process. Following a model-driven engineering approach, these tools are capable of generating the high-level code of the software application, as well as of facilitating its configuration control and its deployment on the hardware platforms used in the different stages of the development process. Moreover, the use of the Leon2ViP virtual platform, with fault injection capabilities, allows an early software-before-hardware verification and validation and also a hardware–software co-simulation. The adopted solutions reduce development time without compromising the whole process reliability that is essential to the EPD success.