Determination of <Emphasis Type="Italic">Foton M-2</Emphasis> satellite attitude motion by the data of microacceleration measurements

The results of reconstruction of uncontrolled attitude motion of the Foton M-2 satellite using measurements with the accelerometer TAS-3 are presented. The attitude motion of this satellite has been previously determined by the measurement data of the Earth’s magnetic field and the angular velocity. The TAS-3 data for this purpose are used for the first time. These data contain a well-pronounced additional component which made impossible their direct employment for the reconstruction of the attitude motion and whose origin was unknown several years ago. Later it has become known that the additional component is caused by the influence of the Earth’s magnetic field. The disclosure of this fact allowed us to take into account a necessary correction in processing of TAS-3 data and to use them for the reconstruction of the attitude motion of Foton M-2. Here, a modified method of processing TAS-3 data is described, as well as results of its testing and employing. The testing consisted in the direct comparison of the motion reconstructed by the new method with the motion constructed by the magnetic measurements. The new method allowed us to find the actual motion of Foton M-2 in the period June 9, 2005–June 14, 2005, when no magnetic measurements were carried out.     

Venus Express—Science observations experience at Venus

The Venus Express mission is the European Space Agency's (ESA) first spacecraft at Venus. It was launched in November 2005 by a Soyuz–Fregat launcher and arrived at Venus in April 2006. The mission covers a broad range of scientific goals including physics, chemistry, dynamics and structure of the atmosphere as well as atmospheric interaction with the surface and several aspects of the surface itself. Furthermore, it investigates the plasma environment and interaction of the solar wind with the atmosphere and escape processes.One month after the arrival at Venus the Venus Express spacecraft started routine science operations. Since then Venus Express has been observing Venus every day for more than one year continuously making new discoveries.In order to ensure that all the science objectives are fulfilled the Venus Express Science Operations Centre (VSOC) has the task of coordinating and implementing the science operations for the mission. During the first year of Venus observations the VSOC and the experiment teams gained a lot of experience in how to make best use of the observation conditions and payload capabilities. While operating the spacecraft in orbit we also acquired more knowledge on the technical constraints and more insight in the science observations and their results.As the nominal mission is coming to an end, the extended mission will start from October 2007. The Extended Science Mission Plan was developed taking into account the lessons learned. At the same time new observations were added along with specific fine-tuned observations in order to complete the science objectives of the mission.This paper will describe how the previous observations influence the current requirements for the observations around Venus today and how they influence the observations in the mission extension. Also it will give an overview of the Extended Science Mission Plan and its challenges for the future observations.     

Autonomic function testing aboard the ISS using “PNEUMOCARD”

Investigations of blood pressure, heart rate (HR), and heart rate variability (HRV) during long term space flights on board the “ISS” have shown characteristic changes of autonomic cardiovascular control. Therefore, alterations of the autonomic nervous system occurring during spaceflight may be responsible for in- and post-flight disturbances. The device “Pneumocard” was developed to further investigate autonomic cardiovascular and respiratory function aboard the ISS. The hard-software diagnostic complex “Pneumocard” was used during in-flight experiment aboard ISS for autonomic function testing. ECG, photoplethysmography, respiration, transthoracic bioimpedance and seismocardiography were assessed in one male cosmonaut (flight lengths six month). Recordings were made prior to the flight, late during flight, and post-flight during spontaneous respiration and controlled respiration at different rates.HR remained stable during flight. The values were comparable to supine measurements on earth. Respiratory frequency and blood pressure decreased during flight. Post flight HR and BP values increased compared to in-flight data exceeding pre-flight values. Cardiac time intervals did not change dramatically during flight. Pulse wave transit time decreased during flight. The maximum of the first time derivative of the impedance cardiogram, which is highly correlated with stroke volume was not reduced in-flight.Our results demonstrate that autonomic function testing aboard the ISS using “Pneumocard” is feasible and generates data of good quality. Despite the decrease in BP, pulse wave transit time was found reduced in space as shown earlier. However, cardiac output did not decrease profoundly in the investigated cosmonaut.Autonomic testing during space flight detects individual changes in cardiovascular control and may add important information to standard medical control. The recent plans to support a flight to Mars, makes these kinds of observations all the more relevant and compelling.     

India's EO infrastructure for disaster reduction: Lessons and perspectives

India has established a ‘critical mass’ in terms of EO infrastructure for disaster management. Starting from IRS 1A in 1980s to the most recent CARTOSAT-2, India's EO series of satellites are moving away from the generic to thematic constellations. The series of RESOURCESAT, CARTOSAT, OCEANSAT and forthcoming Radar Imaging Satellite (RISAT) satellites exemplifies the thematic characters of the EO missions. These thematic constellations, characterized with multi-platform, multi-resolution and multi-parameter EO missions, are important assets for disaster reduction. In the more specific term, these constellations in conjunction with contemporary EO missions address the critical observational gaps in terms of capturing the catastrophic events, phenomena or their attributes on real/near real time basis with appropriate spatial and temporal attributes.Using conjunctively the data primarily emanating these thematic constellations and all weather radar data from aerial platform and also from RADARSAT as gap-fillers has been a part of India's EO strategy for disaster management. The infrastructure has been addressing the observational needs in disaster management. The high resolution imaging better than one-meter spatial resolution and also Digital Elevation Models (DEM) emanating from Cartosat series are providing valuable inputs to characterize geo-physical terrain vulnerability. Radar Imaging Satellite, with all weather capability missions, is being configured for disaster management. At present, the current Indian EO satellites cover the whole world every 40 h (with different resolutions and swaths), and the efforts are towards making it better than 24 h. The efforts are on to configure RESOURCESAT 3 with wider swath of 740 km with 23 m spatial resolution and also to have AWiFS type of capability at geo-platform to improve the observational frequencies for disaster monitoring.India's EO infrastructure has responded comprehensively to all the natural disasters the country has faced in the recent times. As a member of International Charter on Space and Major Disasters, India has also been instrumental in promoting the related UN initiatives viz., RESAP of UN ESCAP, SPIDER of UN OOSA, Sentinel Asia of JAXA initiative and also of GEOSS initiative. The paper intends to illustrate India's EO strategy for disaster reduction.     

Thyrotropin receptor and membrane interactions in FRTL-5 thyroid cell strain in microgravity

The aim of this work was to analyze the possible alteration of thyrotropin (TSH) receptors in microgravity, which could explain the absence of thyroid cell proliferation in the space environment. Several forms of the TSH receptor are localized on the plasma membrane associated with caveolae and lipid rafts. The TSH regulates the fluidity of the cell membrane and the presence of its receptors in microdomains that are rich in sphingomyelin and cholesterol. TSH also stimulates cyclic adenosine monophosphate (cAMP) accumulation and cell proliferation. Reported here are the results of an experiment in which the FRTL-5 thyroid cell line was exposed to microgravity during the Texus-44 mission (launched February 7, 2008, from Kiruna, Sweden). When the parabolic flight brought the sounding rocket to an altitude of 264?km, the culture media were injected with or without TSH in the different samples, and weightlessness prevailed on board for 6 minutes and 19 seconds. Control experiments were performed, in parallel, in an onboard 1g centrifuge and on the ground in Kiruna laboratory. Cell morphology and function were analyzed. Results show that in microgravity conditions the cells do not respond to TSH treatment and present an irregular shape with condensed chromatin, a modification of the cell membrane with shedding of the TSH receptor in the culture medium, and an increase of sphingomyelin-synthase and Bax proteins. It is possible that real microgravity induces a rearrangement of specific sections of the cell membrane, which act as platforms for molecular receptors, thus influencing thyroid cell function in astronauts during space missions.     

Microperturbations on the <Emphasis Type=Italic>International Space Station</Emphasis> during physical exercises of the crew

The results of a preliminary analysis of microperturbations on the International Space Station during physical exercises of the crew are presented. The goal of this paper is to identify the parameters of perturbations when physical exercises are performed. The results of measurements by sensors of microaccelerations of both Russian and American segments during physical exercises in the service module of the Russian segment are analyzed.     

Stellar coronagraph using the principle of achromatic null-interferometer

In order to observe exoplanets we propose a space-based achromatic stellar coronagraph combined with a 0.8–1.5 m telescope. We develop an achromatic common path interferometer for observing an exoplanet (a faint off-axis source) on the background of a hoste star (bright axial source). An image of the star and its copy acquire an achromatic phase shift by 180° and interfere in antiphase. The achromatic phase shift is caused by geometric phase in the scheme of a three-dimensional interferometer. The interference process divides spatially the dark and light fields of the star image redirecting them to the opposite sides of a beam splitter. The interference process does not weaken the image of a planet, with equal intensities it is redirected to both sides of a beam splitter. The suggested scheme of common path interferometer ensures mechanical stability. The background signal is experimentally demonstrated to be reduced by six orders of magnitude.     

Identification of failures in a set of sensors of a spacecraft

A method to find and identify failures in a spacecraft’s set of sensitive elements that measure vector quantities of different nature is discussed.     

Statistical study of interplanetary condition effect on geomagnetic storms: 2. Variations of parameters

We investigate the behavior of mean values of the solar wind’s and interplanetary magnetic field’s (IMF) parameters and their absolute and relative variations during the magnetic storms generated by various types of the solar wind. In this paper, which is a continuation of paper [1], we, on the basis of the OMNI data archive for the period of 1976–2000, have analyzed 798 geomagnetic storms with D _st ≤ −50 nT and their interplanetary sources: corotating interaction regions CIR, compression regions Sheath before the interplanetary CMEs; magnetic clouds MC; “Pistons” Ejecta, and an uncertain type of a source. For the analysis the double superposed epoch analysis method was used, in which the instants of the magnetic storm onset and the minimum of the D _st index were taken as reference times. It is shown that the set of interplanetary sources of magnetic storms can be sub-divided into two basic groups according to their slowly and fast varying characteristics: (1) ICME (MC and Ejecta) and (2) CIR and Sheath. The mean values, the absolute and relative variations in MC and Ejecta for all parameters appeared to be either mean or lower than the mean value (the mean values of the electric field E _y and of the B _z component of IMF are higher in absolute value), while in CIR and Sheath they are higher than the mean value. High values of the relative density variation sN/〈N〉 are observed in MC. At the same time, the high values for relative variations of the velocity, B _z component, and IMF magnitude are observed in Sheath and CIR. No noticeable distinctions in the relationships between considered parameters for moderate and strong magnetic storms were observed.