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Reuven Ramaty High Energy Solar Spectroscopic Imager
Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI, originally High Energy Solar Spectroscopic Imager or HESSI or Explorer 81) was a NASA solar flare observatory. It was the sixth mission in the Small Explorer program (SMEX), selected in October 1997 and launched on 5 February 2002, at 20:58:12 UTC. Its primary mission was to explore the physics of particle acceleration and energy release in solar flares. Spacecraft HESSI was renamed to RHESSI on 29 March 2002 in honor of Dr. Ramaty, a pioneer in the area of high energy solar physics. RHESSI was the first space mission named after a NASA scientist. RHESSI was built by Spectrum Astro for Goddard Space Flight Center and was operated by the Space Sciences Laboratory in Berkeley, California. The principal investigator from 2002 to 2012 was Robert Lin, who was succeeded by Säm Krucker. The entire spacecraft rotated to provide the necessary signal modulation. The four, fixed solar panels were designed to provide enou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Observatory
A solar observatory is an observatory that specializes in monitoring the Sun. As such, they usually have one or more solar telescopes. The Einstein Tower was a solar observatory in the Albert Einstein Science Park in Potsdam, Germany. Solar observatories study phenomena associated with the Sun. The Sun, being the closest star to earth, allows a unique chance to study stellar physics with high-resolution. It was, until the 1990s, the only star whose surface had been resolved. General topics that interest a solar astronomer are its 11-year periodicity (i.e., the Solar Cycle), sunspots, magnetic field activity (see solar dynamo), solar flares, coronal mass ejections, differential rotation, and plasma physics. Some examples * Huairou Solar Observing Station * Solar observatories in space * National Solar Observatory See also * Coronagraph * Heliometer * Helioscope * List of solar telescopes * Spectroheliograph * Spectrohelioscope * Solar astronomy * Solar tower (astronomy) A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Flare
A solar flare is an intense localized eruption of electromagnetic radiation in the Sun's atmosphere. Flares occur in active regions and are often, but not always, accompanied by coronal mass ejections, solar particle events, and other solar phenomena. The occurrence of solar flares varies with the 11-year solar cycle. Solar flares are thought to occur when stored magnetic energy in the Sun's atmosphere accelerates charged particles in the surrounding plasma. This results in the emission of electromagnetic radiation across the electromagnetic spectrum. High-energy electromagnetic radiation from solar flares is absorbed by the daylight side of Earth's upper atmosphere, in particular the ionosphere, and does not reach the surface. This absorption can temporarily increase the ionization of the ionosphere which may interfere with short-wave radio communication. The prediction of solar flares is an active area of research. Flares also occur on other stars, where the term ''stellar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Battery Types ...
This list is a summary of notable electric battery types composed of one or more electrochemical cells. Three lists are provided in the table. The primary (non-rechargeable) and secondary (rechargeable) cell lists are lists of battery chemistry. The third list is a list of battery applications. Battery cell types See also * Baghdad Battery * Battery nomenclature * Carnot battery * Comparison of commercial battery types * History of the battery * List of battery sizes * List of energy densities * ''Search for the Super Battery'' (2017 PBS film) * Fuel cell References {{Battery sizes * Battery Battery most often refers to: * Electric battery, a device that provides electrical power * Battery (crime), a crime involving unlawful physical contact Battery may also refer to: Energy source *Automotive battery, a device to provide power t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite Bus
A satellite bus (or spacecraft bus) is the main body and structural component of a satellite or spacecraft, in which the payload and all scientific instruments are held. Bus-derived satellites are opposed to specially produced satellites. Bus-derived satellites are usually customized to customer requirements, for example with specialized sensors or transponders, in order to achieve a specific mission. They are commonly used for geosynchronous satellites, particularly communications satellites, but are also used in spacecraft which occupy lower orbits, occasionally including low Earth orbit missions. Examples Some satellite bus examples include: * Boeing DS&S 702 * Lockheed Martin Space Systems A2100 * Alphabus * INVAP ARSAT-3K * Airbus D&S Eurostar * ISRO's I-1K, I-2K, I-3K, I-4K, I-6K, and Indian Mini Satellite bus * NASA Ames MCSB * SSL 1300 * Orbital ATK GEOStar * Mitsubishi Electric DS2000 * Spacecraft bus of the James Webb Space Telescope * SPUTNIX TabletSat * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoelectric Effect
The photoelectric effect is the emission of electrons when electromagnetic radiation, such as light, hits a material. Electrons emitted in this manner are called photoelectrons. The phenomenon is studied in condensed matter physics, and solid state and quantum chemistry to draw inferences about the properties of atoms, molecules and solids. The effect has found use in electronic devices specialized for light detection and precisely timed electron emission. The experimental results disagree with classical electromagnetism, which predicts that continuous light waves transfer energy to electrons, which would then be emitted when they accumulate enough energy. An alteration in the intensity of light would theoretically change the kinetic energy of the emitted electrons, with sufficiently dim light resulting in a delayed emission. The experimental results instead show that electrons are dislodged only when the light exceeds a certain frequency—regardless of the light's intensity or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germanium
Germanium is a chemical element with the symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid in the carbon group that is chemically similar to its group neighbors silicon and tin. Like silicon, germanium naturally reacts and forms complexes with oxygen in nature. Because it seldom appears in high concentration, germanium was discovered comparatively late in the discovery of the elements. Germanium ranks near fiftieth in relative abundance of the elements in the Earth's crust. In 1869, Dmitri Mendeleev predicted its existence and some of its properties from its position on his periodic table, and called the element ekasilicon. In 1886, Clemens Winkler at Freiberg University found the new element, along with silver and sulfur, in the mineral argyrodite. Winkler named the element after his country, Germany. Germanium is mined primarily from sphalerite (the primary ore of zinc), though germanium is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Attitude Control
Attitude control is the process of controlling the orientation of an aerospace vehicle with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc. Controlling vehicle attitude requires sensors to measure vehicle orientation, actuators to apply the torques needed to orient the vehicle to a desired attitude, and algorithms to command the actuators based on (1) sensor measurements of the current attitude and (2) specification of a desired attitude. The integrated field that studies the combination of sensors, actuators and algorithms is called guidance, navigation and control (GNC). Aircraft attitude control An aircraft's attitude is stabilized in three directions: ''Yaw (rotation), yaw'', nose left or right about an axis running up and down; ''pitch'', nose up or down about an axis running from wing to wing; and ''roll'', rotation about an axis running from nose to tail. Elevator (aeronautics), Elevat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Panels On Spacecraft
Spacecraft operating in the inner Solar System usually rely on the use of power electronics-managed photovoltaic solar panels to derive electricity from sunlight. Outside the orbit of Jupiter, solar radiation is too weak to produce sufficient power within current solar technology and spacecraft mass limitations, so radioisotope thermoelectric generators (RTGs) are instead used as a power source.NASA JPL Publication: Basics of Space Flight, Chapter 11. Typical Onboard Systems, Electrical Power Supply and Distribution Subsystems, History The first practical silicon-based solar cells were introduced by Bell Labs in April 1954. They were initially about 6% efficient, but improvements began to raise this number almost immediately. Bell had been interested in the idea as a system to provide power at remote telephone repeater stations, but the cost of the devices was far too high to be practical in this role. Aside from small experimental kits and uses, the cells remained largely unus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Lin
Robert Peichung Lin (; January 24, 1942 – November 17, 2012) was Chinese-born American astrophysicist. He was a professor and director of the Space Sciences Laboratory (1998–2008) at the University of California, Berkeley. As a pioneer of gamma-ray astronomy and of particle detection in space, his research was fundamental to the development of our knowledge in solar physics, the physics of the solar wind and of the magnetosphere. He was the principal investigator for the Reuven Ramaty High Energy Solar Spectroscopic Imager. Early life and education Robert Lin was the son of Tung Hua Lin. He was born in Guangxi, China on January 24, 1942, and moved to London as a child and then to Michigan. He earned a Bachelor of Science degree in physics from the California Institute of Technology in 1962 and a Ph.D. from the University of California, Berkeley in 1967. Career Lin remained at his PhD institution, the University of California, Berkeley, for his entire career, and was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principal Investigator
In many countries, the term principal investigator (PI) refers to the holder of an independent grant and the lead researcher for the grant project, usually in the sciences, such as a laboratory study or a clinical trial. The phrase is also often used as a synonym for "head of the laboratory" or "research group leader". While the expression is common in the sciences, it is used widely for the person or persons who make final decisions and supervise funding and expenditures on a given research project. A co-investigator (Co-I) assists the principal investigator in the management and leadership of the research project. There may be a number of co-investigators supporting a PI. Federal funding In the context of United States federal funding from agencies such as the National Institutes of Health (NIH) or the National Science Foundation (NSF), the PI is the person who takes direct responsibility for completion of a funded project, directing the research and reporting directly to the fun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berkeley, California
Berkeley ( ) is a city on the eastern shore of San Francisco Bay in northern Alameda County, California, United States. It is named after the 18th-century Irish bishop and philosopher George Berkeley. It borders the cities of Oakland and Emeryville to the south and the city of Albany and the unincorporated community of Kensington to the north. Its eastern border with Contra Costa County generally follows the ridge of the Berkeley Hills. The 2020 census recorded a population of 124,321. Berkeley is home to the oldest campus in the University of California System, the University of California, Berkeley, and the Lawrence Berkeley National Laboratory, which is managed and operated by the university. It also has the Graduate Theological Union, one of the largest religious studies institutions in the world. Berkeley is considered one of the most socially progressive cities in the United States. History Indigenous history The site of today's City of Berkeley was the territo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goddard Space Flight Center
The Goddard Space Flight Center (GSFC) is a major NASA space research laboratory located approximately northeast of Washington, D.C. in Greenbelt, Maryland, United States. Established on May 1, 1959 as NASA's first space flight center, GSFC employs approximately 10,000 civil servants and contractors. It is one of ten major NASA field centers, named in recognition of American rocket propulsion pioneer Robert H. Goddard. GSFC is partially within the former Goddard census-designated place; it has a Greenbelt mailing address.CENSUS 2000 BLOCK MAP: GODDARD CDP " . Retrieved on September 1, 2018. 1990 Census map of Prince ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
