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Lunar Space Elevator
A lunar space elevator or lunar spacelift is a proposed transportation system for moving a mechanical climbing vehicle up and down a ribbon-shaped tethered cable that is set between the surface of the Moon "at the bottom" and a docking port suspended tens of thousands of kilometers above in space at the top. It is similar in concept to the better known Earth-based space elevator idea, but since the Moon's surface gravity is much lower than the Earth's, the engineering requirements for constructing a lunar elevator system can be met using materials and technology already available. For a lunar elevator, the cable or tether extends considerably farther out from the lunar surface into space than one that would be used in an Earth-based system. However, the main function of a space elevator system is the same in either case; both allow for a reusable, controlled means of transporting payloads of cargo, or possibly people, between a base station at the bottom of a gravity well and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbit Of The Moon
The Moon orbits Earth in the retrograde and prograde motion, prograde direction and completes one orbital period, revolution relative to the March Equinox, Vernal Equinox and the fixed stars in about 27.3 days (a tropical month and sidereal month), and one revolution relative to the Sun in about 29.5 days (a synodic month). On average, the lunar distance, distance to the Moon is about from Earth's centre, which corresponds to about 60 Earth radii or 1.28 light-seconds. Earth and the Moon orbit about their barycentre (common centre of mass), which lies about from Earth's centre (about 73% of its radius), forming a satellite system called the Earth–Moon system. With a mean orbital speed around the barycentre of , the Moon covers a distance of approximately its diameter, or about half a degree on the celestial sphere, each hour. The Moon differs from most Regular moon, regular satellites of other planets in that its orbital plane (astronomy), orbital plane is closer to the ec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (magazine)
''Science'' is the peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature'' cover the full range of scientific disciplines. According to the '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scripps Institution Of Oceanography
Scripps Institution of Oceanography (SIO) is the center for oceanography and Earth science at the University of California, San Diego. Its main campus is located in La Jolla, with additional facilities in Point Loma. Founded in 1903 and incorporated into the University of California system in 1912, the institution has since broadened its research focus to encompass the physics, chemistry, geology, biology, and climate of the Earth. The institution awards the Nierenberg Prize annually to recognize researchers with exceptional contributions to science in public interest. History Founding Scripps Institution of Oceanography can trace its beginnings back to William Ritter, a biologist originally from Wisconsin. In 1891, Ritter was offered a job teaching biology at the University of California, Berkeley and married Mary Bennett. Their honeymoon and subsequent biological studies took them to San Diego, where Ritter met a local physician and naturalist, Fred Baker, who would ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Dove Isaacs
John Dove Isaacs III (March 28, 1913 – June 6, 1980) was an American engineer and oceanographer. He was known for his research and contributions to the Scripps Institution of Oceanography at the University of California, San Diego. Early life Isaacs was born in Spokane, Washington in 1913. He joined the U.S.Civilian Conservation Corps in 1933 and moved to the Siuslaw National Forest thereafter to work as a service lookout. He moved to Astoria in 1938 to work as a fisherman. Isaacs studied engineering at the University of California, Berkeley and received his Bachelor of Science in 1944. During World War II, he worked alongside Willard Bascom to test DUKWs. Research at Scripps Isaacs joined Scripps in 1948 as an associate oceanographer, working as a consultant to monitor Pacific nuclear tests including Operations Crossroads, Ivy, Castle, Wigwam, and Redwing. In 1952, Isaacs met William Nierenberg on the Mine Advisory Committee and was influential in convincing Nierenberg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pravda
''Pravda'' ( rus, Правда, p=ˈpravdə, a=Ru-правда.ogg, 'Truth') is a Russian broadsheet newspaper, and was the official newspaper of the Central Committee of the Communist Party of the Soviet Union, when it was one of the most influential papers in the country with a newspaper circulation, circulation of 11 million. The newspaper began publication on 5 May 1912 in the Russian Empire but was already extant abroad in January 1911. It emerged as the leading government newspaper of the Soviet Union after the October Revolution. The newspaper was an organ of the Central Committee of the CPSU between 1912 and 1991. After the dissolution of the Soviet Union, ''Pravda'' was sold by the then Russian president Boris Yeltsin to a Greek business family in 1992, and the paper came under the control of their private company Pravda International. In 1996, there was an internal dispute between the owners of Pravda International and some of the ''Pravda'' journalists that led to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yuri Artsutanov
Yuri Nikolaevich Artsutanov (; 5 October 1929 – 1 January 2019) was a Russian engineer born in Leningrad. He was one of the pioneers of the idea of a space elevator. The February issue of the ISEC Newsletter is devoted to his life and place in history and features reminisces and photographs from his colleagues in the West, including his attendance at the 2010 ISEC Space Elevator conference. Biography Artsutanov was a graduate of Leningrad Technological Institute. In 1960, he wrote an article "V Kosmos na Electrovoze (en. ''Into space with the help of an electric locomotive'')", where he discussed the concept of the space elevator as an economic, safe and convenient way to access orbit and facilitate space exploration. Artsutanov developed his idea independently from Konstantin Tsiolkovsky, who in 1895 proposed an idea of building an ''orbital tower''. Artsutanov's concept was based on the linking of geosynchronous satellites to the ground with a cable. He suggested using ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultra-high-molecular-weight Polyethylene
Ultra-high-molecular-weight polyethylene (UHMWPE, UHMW) is a subset of the thermoplastic polyethylene. Also known as high-modulus polyethylene (HMPE), it has extremely long chains, with a molecular mass typically between 2 and 6 million amu. The longer chain serves to transfer load more effectively to the polymer backbone by strengthening intermolecular interactions. This results in a very tough material, with the highest impact strength of any thermoplastic presently made. UHMWPE is odorless, tasteless, and nontoxic. It embodies all the characteristics of high-density polyethylene (HDPE) with the added traits of being resistant to concentrated acids and alkalis, as well as numerous organic solvents. It is highly resistant to corrosive chemicals except oxidizing acids; has extremely low moisture absorption and a very low coefficient of friction; is self-lubricating (see boundary lubrication); and is highly resistant to abrasion, in some forms being 15 times more resistant to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M5 Fiber
M5 fiber (polyhydroquinone-diimidazopyridine or PIPD) is a high-strength synthetic fiber first developed by the Dutch chemical firm AkzoNobel. It is produced in the United States by the Magellan Systems International, which became a division of DuPont. Preparation M5 fiber is prepared by a condensation polymerization between tetraaminopyridine and dihydroxyterephthalic acid using diphosphorus pentoxide as a dehydrating agent. The polymer mixture is then heated and extruded to form brightly blue polymer fibers. The fibers are then washed extensively with water and base in order to remove the phosphoric acid generated by the hydration of diphosphorus pentoxide from the polymer. Next the fiber is heated, to remove water, and exposed to controlled stress, enabling the intermolecular hydrogen bonds to be created, thus increasing the strength of the polymer by aligning the molecular structure of the fiber in a better configuration for tensile and compressive strength. Properties M5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kevlar
Kevlar (para-aramid) is a strong, heat-resistant synthetic fiber, related to other aramids such as Nomex and Technora. Developed by Stephanie Kwolek at DuPont in 1965, the high-strength material was first used commercially in the early 1970s as a replacement for steel in racing tires. It is typically spun into ropes or fabric sheets that can be used as such, or as an ingredient in composite material components. Kevlar has many applications, ranging from bicycle tires and sailcloth#Kevlar, racing sails to bulletproof vests, due to its high Specific strength, tensile strength-to-weight ratio; by this measure it is five times stronger than steel. It is also used to make modern marching drumheads that withstand high impact, and for Mooring, mooring lines and other underwater applications. A similar fiber, Twaron, with the same chemical structure was developed by Akzo in the 1970s. Commercial production started in 1986, and Twaron is manufactured by Teijin Aramid. History Poly- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Nanotube
A carbon nanotube (CNT) is a tube made of carbon with a diameter in the nanometre range ( nanoscale). They are one of the allotropes of carbon. Two broad classes of carbon nanotubes are recognized: * ''Single-walled carbon nanotubes'' (''SWCNTs'') have diameters around 0.5–2.0 nanometres, about 100,000 times smaller than the width of a human hair. They can be idealised as cutouts from a two-dimensional graphene sheet rolled up to form a hollow cylinder. * ''Multi-walled carbon nanotubes'' (''MWCNTs'') consist of nested single-wall carbon nanotubes in a nested, tube-in-tube structure. Double- and triple-walled carbon nanotubes are special cases of MWCNT. Carbon nanotubes can exhibit remarkable properties, such as exceptional tensile strength and thermal conductivity because of their nanostructure and strength of the bonds between carbon atoms. Some SWCNT structures exhibit high electrical conductivity while others are semiconductors. In addition, carbon nanotubes can b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peak Of Eternal Light
A peak of eternal light (PEL) is a hypothetical point on the surface of an astronomical body that is always in sunlight. Such a peak must have high latitude, high elevation, and be on a body with very small axial tilt. The existence of such peaks was first postulated by Beer and Mädler in 1837. The pair said about the lunar polar mountains: "...many of these peaks have (with the exception of eclipses caused by the Earth) eternal sunshine". These polar peaks were later mentioned by Camille Flammarion in 1879, who speculated that there may exist at the poles of the Moon. PELs would be advantageous for space exploration and space colonization, colonization due to the ability of an electrical device located there to receive solar power regardless of the time of day or day of the year, and the relatively stable temperature range. Detailed lunar topography collected by the Lunar Reconnaissance Orbiter (LRO) suggests that no points on the Moon receive perpetual light during both the wint ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
