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Yuri Gagarin was the first human in space and the first in Earth orbit, on Vostok 1. 17 July 1962 or 19 July 1963 Either Robert M. White or Joseph A. Walker (depending on the definition of the space border) was the first to pilot a spaceplane, the North American X-15, on 17 July 1962 (White) or 19 July 1963 (Walker). 18 March 1965
Radiation in space usually comes from three main sources: The Van Allen radiation belts; Solar proton events and solar energetic particles; and; Galactic cosmic rays. For long-duration missions, the high doses of radiation can damage electronic components and solar cells.
The exposure of a human body to ionizing radiation has the same harmful effects whether the source of the radiation is a medical X-ray machine, a nuclear power plant, or radiation in space. The degree of the harmful effect depends on the length of exposure and the radiation's energy density .
Space radiation is composed mostly of high-energy protons, helium nuclei, and high-Z high-energy ions (HZE ions). The ionization patterns in molecules , cells , tissues , and the resulting biological harm are distinct from high-energy photon radiation: X-rays and gamma rays , which produce low- linear energy transfer (low-LET) radiation from ...
In human spaceflight, a life-support system is a group of devices that allow a human being to survive in outer space. US government space agency NASA , [ 2 ] and private spaceflight companies use the phrase "environmental control and life-support system" or the acronym ECLSS when describing these systems. [ 3 ]
The characteristic energy with respect to Sun was negative, and MAVEN – instead of heading to infinity – entered an elliptical orbit around the Sun. But the maximal velocity on the new orbit could be approximated to 33.5 km/s by assuming that it reached practical "infinity" at 3.5 km/s and that such Earth-bound "infinity" also moves with ...
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Using the upper limit of the cosmological constant, the vacuum energy of free space has been estimated to be 10 −9 joules (10 −2 ergs), or ~5 GeV per cubic meter. [3] However, in quantum electrodynamics , consistency with the principle of Lorentz covariance and with the magnitude of the Planck constant suggests a much larger value of 10 113 ...