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881.
Aleksashkin S. N. Bobylev A. V. Vlasenko O. V. Pichkhadze K. M. Terterashvili A. V. Yaroshevsky V. A. 《Cosmic Research》2003,41(3):280-284
The possibility of using an inflatable braking device for controlled descent in the Martian atmosphere of large-capacity cargoes is analyzed. The most complicated version of the trajectory control problem is considered, namely, the injection of a spacecraft at hyperbolic velocity into a parking orbit after braking in the atmosphere. 相似文献
882.
On the base of the laser altimetry results obtained using the orbital altimeter MOLA (the MGS mission) and the data of radio occultation experiments of transionospheric sounding of the Mars ionosphere, a method for interpretation of the planet radar sounding data is developed. The proposed method includes a program package for numerical simulation of the process of radiowave propagation through the media under study. 相似文献
883.
Central and regional hemodynamics in prolonged space flights. 总被引:1,自引:0,他引:1
This paper presents the results of measuring central and regional (head, forearm, calf) hemodynamics at rest and during provocative tests by the method of tetrapolar rheography in the course of Salyut-6-Soyuz and Salyut-7-Soyuz missions. The measurements were carried out during short-term (19 man-flights of 7 days in duration) and long-term (21 man-flights of 65-237 days in duration) manned missions. At rest, stroke volume (SV) and cardiac output (CO) as well as heart rate (HR) decreased insignificantly (in short-term flights) or remained essentially unchanged (in long-term flights). In prolonged flights CO increased significantly in response to exercise tests due to an increase in HR and the lack of changes in SV. After exercise tests SV and CO decreased as compared to the preflight level. During lower body negative pressure (LBNP) tests HR and CO were slightly higher than preflight. Changes in regional hemodynamics included a distinct decrease of pulse blood filling (PBF) of the calf, a reduction of the tone of large vessels of the calf and small vessels of the forearm. Head examination (in the region of the internal carotid artery) showed a decrease of PBF of the left hemisphere (during flight months 2-8) and a distinct decline of the tone of small vessels, mainly, in the right hemisphere. During LBNP tests the tone of pre- and postcapillary vessels of the brain returned to normal while PBF of the right and left hemisphere vessels declined. It has been shown that regional circulation variations depend on the area examined and are induced by a rearrangement of total hemodynamics of the human body in microgravity. This paper reviews the data concerning changes in central and regional circulation of men in space flights of different duration. 相似文献
884.
C. Murakami Y. Ohkami O. Okamoto A. Nakajima M. Inoue J. Tsuchiya K. Yabu-uchi S. Akishita T. Kida 《Acta Astronautica》1984,11(9):613-619
A new type of magnetically suspended gimbal momentum wheel utilizing permanent magnets is described. The bearing was composed of four independent thrust actuators which control the rotor thrust position and gimbal angles cooperatively, so that the bearing comes to have a simple mechanism with high reliability and light weight. The high speed instability problem due to the internal damping was easily overcome by introducing anisotropic radial stiffness. A momentum flywheel with the 3-axis controlled magnetic bearing displays good performance for attitude control of satellite with biased momentum. 相似文献
885.
Blood volume regulating hormones response during two space related simulation protocols: four-week confinement and head-down bed-rest 总被引:1,自引:0,他引:1
Maillet A Gauquelin G Gunga HC Fortrat JO Kirsch K Guell A Bizollon ChA Gharib C 《Acta Astronautica》1995,35(8):547-552
The volume of regulating hormones (renin, aldosterone, arginine vasopressin and atrial natriuretic factor), electrolytes and creatinine concentrations, and blood pressure were measured in two different four-week experimental protocols: respectively -6 degrees head-down bed-rest (5 subjects) and confinement (6 subjects). We observed a significant increase (P < 0.01 at D2 vs D-5) of systolic blood pressure during confinement and a different level of response for some hormones, especially for arginine vasopressin (300% increase during confinement instead of 50% during bed-rest). The renin-angiotensin-aldosterone system was enhanced during confinement and head-down bed-rest. In both conditions, we obtained a similar pattern of response for blood volume regulating hormones. During confinement, two main factors were inactivity and stress activation of the sympathetic nervous system. In the bed-rest study the response is principally due to the fluid shift and blood volume adaptation but it is not possible to exclude the role of inactivity and stress. 相似文献
886.
In September 1995, NASA-Goddard held a workshop on low-cost access to space for science missions. The workshop provided briefings on balloons, sounding rockets, Shuttle payloads, and low-cost free-flyer concepts, to provide options of getting experiments into space. This report is the result of a panel session organized with the aim of generating new ideas beyond those presented in the workshop. In addition to the authors, Orlando Figueroa and Paul Ondrus of NASA-Goddard and Richard Zwirnbaum of Computer Sciences Corp. participated in the discussions. The ideas presented do not necessarily reflect the current thinking of NASA managers. Although the panel discussion was focused on the kinds of science missions usually funded by NASA, most of the ideas that were generated are relevant to military and commercial missions as well. 相似文献
887.
O. G. Gazenko E. A. Ilyin 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1986,6(12):101-106
The program of the 7-day flight of the biosatellite Cosmos-1667 launched in July 1985 included experiments on two rhesus monkeys, ten Wistar SPF rats, ten newts, Drosophila flies, maize seedlings, lettuce sprouts, and unicellular organisms - Tetrahymena. The primate study demonstrated that transition to orbital flight was accompanied by a greater excitability of the vestibular apparatus and an increased linear blood flow velocity in the common carotid artery. The rat studies showed that atrophy of antigravity muscles and osteoporosis of limb bones developed even during short-term exposure to microgravity. The experiments on other living systems revealed no microgravity effects on the cell division rate, proliferative activity of cells of regenerating tissues and organs, energy metabolism of developing insects, structure or chemical composition of higher plant seedlings. 相似文献
888.
H. Steinle H. Bloemen W. Collmar R. Diehl W. Hermsen G. Lichti M. McConnell J. Ryan V. Schnfelder G. Stacy A. W. Strong B. N. Swanenburg M. Varendorff O. R. Williams 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1993,13(12):731-734
During the first part of the COMPTON Gamma Ray Observatory sky survey, COMPTEL has detected the quasars 3C273 and 3C279 and the radio galaxy Centaurus A. This paper summarizes the preliminary findings and gives an upper limit on the MeV flux of the Seyfert galaxy NGC4151. 相似文献
889.
A. N. Parmar G. Hasinger M. Arnaud X. Barcons D. Barret H. Bhringer A. Blanchard M. Cappi A. Comastri T. Courvoisier A. C. Fabian F. Fiore I. Georgantopoulos P. Grandi R. Griffiths A. Hornstrup N. Kawai K. Koyama K. Makishima G. Malaguti K. O. Mason C. Motch M. Mendez T. Ohashi F. Paerels L. Piro T. Ponman J. Schmitt S. Sciortino G. Trinchieri M. van der Klis M. Ward 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2004,34(12):2623
Europe is one of the major partners building the International Space Station (ISS) and European industry, together with ESA, is responsible for many station components including the Columbus Orbital Facility, the Automated Transport Vehicle, two connecting modules and the European Robotic Arm. Together with this impressive list of contributions there is a strong desire within the ESA Member States to benefit from this investment by utilizing the unique capabilities of the ISS to perform world-class science. XEUS is one of the astronomical applications being studied by ESA to utilize the capabilities of the ISS. XEUS will be a long-term X-ray observatory with an initial mirror area of 6 m2 at 1 keV that will be expanded to 30 m2 following a visit to the ISS. The 1 keV spatial resolution is expected to be 2–5″ half-energy-width. XEUS will consist of separate detector and mirror spacecraft (MSC) aligned by active control to provide a focal length of 50 m. A new detector spacecraft, complete with the next generation of instruments, will also be added after visiting the ISS. The limiting 0.1–2.5 keV sensitivity will then be 4 × 10−18 erg cm−2 s−1, around 200 times better than XMM-Newton, allowing XEUS to study the properties of the hot baryons and dark matter at high redshift. 相似文献
890.
E. Marsch E. Antonucci P. Bochsler J. -L. Bougeret B. Fleck R. Harrison Y. Langevin R. Marsden O. Pace R. Schwenn J. -C. Vial 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2002,29(12):135-2040
The scientific rationale of the Solar Orbiter is to provide, at high spatial (35 km pixel size) and temporal resolution, observations of the solar atmosphere and unexplored inner heliosphere. Novel observations will be made in the almost heliosynchronous segments of the orbits at heliocentric distances near 45 R and out of the ecliptic plane at the highest heliographic latitudes of 30° – 38°. The Solar Orbiter will achieve its wide-ranging aims with a suite of sophisticated instruments through an innovative design of the orbit. The first near-Sun interplanetary measurements together with concurrent remote observations of the Sun will permit us to determine and understand, through correlative studies, the characteristics of the solar wind and energetic particles in close linkage with the plasma and radiation conditions in their source regions on the Sun. Over extended periods the Solar Orbiter will deliver the first images of the polar regions and the side of the Sun invisible from the Earth. 相似文献