Biological life support for manned missions by ESA.

The anticipated evolution of life support technologies for ESA, considering both the complementary life support system requirements and the missions' characteristics, is presented. Based on these results, promising biological life support technologies for manned space missions have been selected by ESA either for their intrinsic ability and performance in effecting specific tasks for atmosphere-, water-, waste-management versus physico-chemical alternatives and/or for longer-term application to a more ecological concept (CES) focusing ultimately on food production. Actual status and plan for terrestrial and space testing of biological life support presented focusing on the "task specific" decontamination technology of the Biological Air Filter (BAF), and on food reprocessing technologies from biodegradable wastes with the MELISSA microbial ecosystem.     

Wide field cameras for SAX

SAX is an Italian X-ray satellite with a Dutch contribution that will be placed in orbit in 1994. The prime scientific object of SAX is to cover an energy bandwidth that ranges from 0.1 keV up to 200 keV. Among other instruments, SAX will consist of two X-ray Wide Field Cameras built by the Space Research Organisation Netherlands at Utrecht. The WFCs are based on the coded mask principle, the reconstruction of the image takes place on ground. The field of view is 20 degrees square full width at half maximum (FWHM), the angular resolution 5 arcminutes (FWHM) and the energy band ranges from 1.8 to 30 keV with a resolution of 18% at 6 keV. The sensitive area is 200 cm² at 6 keV. The mask pattern is based on a pseudo random array with 255 × 257 elements of 1 mm², 50% of which are transparent.     

Initial ISEE magnetometer results: magnetopause observations

The magnetic field profiles across the magnetopause obtained by the ISEE-1 and -2 spacecraft separated by only a few hundred kilometers are examined for four passes. During one of these passes the magnetosheath field was northward, during one it was slightly southward, and in two it was strongly southward. The velocity of the magnetopause is found to be highly irregular ranging from 4 to over 40 km s^-1 and varying in less time than it takes for a spacecraft to cross the boundary. Thicknesses ranged from 500 to over 1000 km.Clear evidence for reconnection is found in the data when the magnetosheath field is southward. However, this evidence is not in the form of classic rotational discontinuity signatures. Rather, it is in the form of flux transfer events, in which reconnection starts and stops in a matter of minutes or less, resulting in the ripping off of flux tubes from the magnetosphere. Evidence for flux transfer events can be found both in the magnetosheath and the outer magnetosphere due to their alteration of the boundary normal. In particular, their presence at the time of magnetopause crossings invalidates the usual 2-dimensional analysis of magnetopause structure. Not only are these flux transfer events probably the dominant means of reconnection on the magnetopause, but they may also serve as an important source of magnetopause oscillations, and hence of pulsations in the outer magnetosphere. On two days the flux transfer rate was estimated to be of the order of 2 × 10¹² Maxwells per second by the flux transfer events detected at ISEE. Events not detectable at ISEE and continued reconnection after passage of an FTE past ISEE could have resulted in an even greater reconnection rate at these times.     

The human cardiovascular system during space flight

Purpose of the work is to analyze and to summarize the data of investigations into human hemodynamics performed over 20 years aboard orbital stations Salyut-7 and Mir with participation of 26 cosmonauts on space flights (SF) from 8 to 438 days in duration. The ultrasonic techniques and occlusive plethysmography demonstrated dynamics of changes in the cardiovascular system during SF of various durations. The parameters of general hemodynamics, the pumping function of the heart and arterial circulation in the brain remained stable in all the space flights; however, there were alterations in peripheral circulation associated with blood redistribution and hypovolemie in microgravity. The anti-gravity distribution of the vascular tone decayed gradually as unneeded. The most considerable changes were observed in leg vessels, equally in arteries (decrease in resistance) and veins (increase in maximum capacity). The lower body negative pressure test (LBNP) revealed deterioration of the gravity-dependent reactions that changed for the worse as SF duration extended. The cardiovascular deconditioning showed itself as loss of descent acceleration tolerance and orthostatic instability in the postflight period.     

Structural health management technologies for inflatable/deployable structures: Integrating sensing and self-healing

Inflatable/deployable structures are under consideration as habitats for future Lunar surface science operations. The use of non-traditional structural materials combined with the need to maintain a safe working environment for extended periods in a harsh environment has led to the consideration of an integrated structural health management system for future habitats, to ensure their integrity. This article describes recent efforts to develop prototype sensing technologies and new self-healing materials that address the unique requirements of habitats comprised mainly of soft goods. A new approach to detecting impact damage is discussed, using addressable flexible capacitive sensing elements and thin film electronics in a matrixed array. Also, the use of passive wireless sensor tags for distributed sensing is discussed, wherein the need for on-board power through batteries or hardwired interconnects is eliminated. Finally, the development of a novel, microencapuslated self-healing elastomer with applications for inflatable/deployable habitats is reviewed.     

Evaluation of Cyanothece sp. ATCC 51142 as a candidate for inclusion in a CELSS.

Controlled ecological life support systems (CELSS) have been proposed to make long-duration manned space flights more cost-effective. Higher plants will presumably provide food and a breathable atmosphere for the crew. It has been suggested that imbalances between the CO2/O2 gas exchange ratios of the heterotrophic and autotrophic components of the system will inevitably lead to an unstable system, and the loss of O2 from the atmosphere. Ratio imbalances may be corrected by including a second autotroph with an appropriate CO2/O2 gas exchange ratio. Cyanothece sp. ATCC 51142 is a large unicellular N2-fixing cyanobacterium, exhibiting high growth rates under diverse physiological conditions. A rat-feeding study showed the biomass to be edible. Furthermore, it may have a CO2/O2 gas exchange ratio that theoretically can compensate for ratio imbalances. It is suggested that Cyanothece spp. could fulfill several roles in a CELSS: supplementing atmosphere recycling, generating fixed N from the air, providing a balanced protein supplement, and protecting a CELSS in case of catastrophic crop failure.     

Two magnetars: SGR 1627–41 and 1E 1547–5408

We describe the results obtained with Target of Opportunity observations of the galactic sources SGR 1627–41 and 1E 1547–5408. These two transients show several similarities supporting the interpretation of Anomalous X-ray Pulsars and Soft Gamma-ray Repeaters as a single class of strongly magnetized neutron stars.     

Coronal mass ejection detection using wavelets,curvelets and ridgelets: Applications for space weather monitoring

Coronal mass ejections (CMEs) are large-scale eruptions of plasma and magnetic field that can produce adverse space weather at Earth and other locations in the Heliosphere. Due to the intrinsic multiscale nature of features in coronagraph images, wavelet and multiscale image processing techniques are well suited to enhancing the visibility of CMEs and suppressing noise. However, wavelets are better suited to identifying point-like features, such as noise or background stars, than to enhancing the visibility of the curved form of a typical CME front. Higher order multiscale techniques, such as ridgelets and curvelets, were therefore explored to characterise the morphology (width, curvature) and kinematics (position, velocity, acceleration) of CMEs. Curvelets in particular were found to be well suited to characterising CME properties in a self-consistent manner. Curvelets are thus likely to be of benefit to autonomous monitoring of CME properties for space weather applications.