Search results for "Spaceflight"
showing 10 items of 27 documents
Blood flow in the internal jugular veins during the spaceflight - Is it actually bidirectional?
2020
Recently intriguing results of the research performed on astronauts of the International Space Station have been published. Unexpectedly, in some crew members a stagnant and bidirectional flow in the internal jugular vein was found, and in one of the astronauts this vein seemed to be totally thrombosed. If it actually were the case that in the settings of weightlessness there is a substantial risk of jugular vein thrombosis, any long-term human space missions would be extremely dangerous. Yet, we interpret these findings differently. In our opinion, what has been explained as bidirectional flow, actually represented the flow separation, and what has been described as occluded vein was rathe…
Understanding the Origins of Problem Geomagnetic Storms Associated with "Stealth" Coronal Mass Ejections.
2021
Geomagnetic storms are an important aspect of space weather and can result in significant impacts on space- and ground-based assets. The majority of strong storms are associated with the passage of interplanetary coronal mass ejections (ICMEs) in the near-Earth environment. In many cases, these ICMEs can be traced back unambiguously to a specific coronal mass ejection (CME) and solar activity on the frontside of the Sun. Hence, predicting the arrival of ICMEs at Earth from routine observations of CMEs and solar activity currently makes a major contribution to the forecasting of geomagnetic storms. However, it is clear that some ICMEs, which may also cause enhanced geomagnetic activity, cann…
Preservation of Multiple Mammalian Tissues to Maximize Science Return from Ground Based and Spaceflight Experiments.
2016
Background Even with recent scientific advancements, challenges posed by limited resources and capabilities at the time of sample dissection continue to limit the collection of high quality tissues from experiments that can be conducted only infrequently and at high cost, such as in space. The resources and time it takes to harvest tissues post-euthanasia, and the methods and duration of long duration storage, potentially have negative impacts on sample quantity and quality, thereby limiting the scientific outcome that can be achieved. Objectives The goals of this study were to optimize methods for both sample recovery and science return from rodent experiments, with possible relevance to b…
Sensorimotor adaptation of point-to-point arm movements after spaceflight: the role of internal representation of gravity force in trajectory plannin…
2011
International audience; After an exposure to weightlessness, the central nervous system operates under new dynamic and sensory contexts. To find optimal solutions for rapid adaptation, cosmonauts have to decide whether parameters from the world or their body have changed and to estimate their properties. Here, we investigated sensorimotor adaptation after a spaceflight of 10 days. Five cosmonauts performed forward point-to-point arm movements in the sagittal plane 40 days before and 24 and 72 h after the spaceflight. We found that, whereas the shape of hand velocity profiles remained unaffected after the spaceflight, hand path curvature significantly increased 1 day after landing and return…
Effects of a 21 days space flight on the mechanical performance and the EMG power spectrum of the leg muscles
2002
Reconstruction of the Parker spiral with the Reverse in situ data and MHD APproach - RIMAP
2021
The reconstruction of plasma parameters in the interplanetary medium is very important to understand the interplanetary propagation of solar eruptions and for Space Weather application purposes. Because only a few spacecraft are measuring in situ these parameters, reconstructions are currently performed by running complex numerical Magneto-hydrodynamic (MHD) simulations starting from remote sensing observations of the Sun. Current models apply full 3D MHD simulations of the corona or extrapolations of photospheric magnetic fields combined with semi-empirical relationships to derive the plasma parameters on a sphere centered on the Sun (inner boundary). The plasma is then propagated in the i…
A solar storm observed from the Sun to Venus using the STEREO, Venus Express, and MESSENGER spacecraft
2009
The suite of SECCHI optical imaging instruments on the STEREO-A spacecraft is used to track a solar storm, consisting of several coronal mass ejections (CMEs) and other coronal loops, as it propagates from the Sun into the heliosphere during May 2007. The 3-D propagation path of the largest interplanetary CME (ICME) is determined from the observations made by the SECCHI Heliospheric Imager (HI) on STEREO-A (HI-1/2A). Two parts of the CME are tracked through the SECCHI images, a bright loop and a V-shaped feature located at the rear of the event. We show that these two structures could be the result of line-of-sight integration of the light scattered by electrons located on a single flux rop…
How Do We Know If There’s a Message?
2010
As we have seen, radio waves can be excellent candidates for interplanetary communication, due to the fact that our galaxy is transparent to them. The problem lies in properly identifying the origin – artificial or natural – of an arriving signal. When we tune a radio receiver and we turn the antenna toward the cosmos, we gather hundreds of different signals. Even some of the natural signals are quite suggestive, and one can be tempted to consider them emissions from other civilizations.
Photobiology in space: An experiment on Spacelab I
1984
The joint European/US Spacelab Mission I, scheduled for October 1983 for a 9 day lasting Earth-orbiting flight, provides a laboratory system for various disciplines of science, including exobiology. On the pallet, in the experiment ES 029 "Microorganisms and Biomolecules in Space Hard Environment" 316 dry samples of Bacillus subtilis spores will be exposed to space vacuum and/or selected wavelenghs of solar UV radiation. After recovery action spectra of inactivation, mutation induction, reparability and photochemical damage in DNA and protein will be determined. The results will contribute to the understanding of the mechanism of the increased UV sensitivity of bacterial spores in vacuo and…
FRIPON: a worldwide network to track incoming meteoroids
2020
Context. Until recently, camera networks designed for monitoring fireballs worldwide were not fully automated, implying that in case of a meteorite fall, the recovery campaign was rarely immediate. This was an important limiting factor as the most fragile - hence precious - meteorites must be recovered rapidly to avoid their alteration. Aims. The Fireball Recovery and InterPlanetary Observation Network (FRIPON) scientific project was designed to overcome this limitation. This network comprises a fully automated camera and radio network deployed over a significant fraction of western Europe and a small fraction of Canada. As of today, it consists of 150 cameras and 25 European radio receiver…