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MINERVA (spacecraft)
MINERVA (MIcro-Nano Experimental Robot Vehicle for Asteroid) are a series of rovers developed by the Japanese space agency JAXA for the purpose of exploring asteroid surfaces. The first MINERVA was part of the ''Hayabusa'' mission, and MINERVA-II are a series of three rovers for ''Hayabusa2''. On 12 November 2005, MINERVA rover was deployed from Hayabusa orbiter with aim to land on asteroid 25143 Itokawa. However, the landing failed as MINERVA missed the asteroid and ended up on heliocentric orbit. On 21 September 2018, first two MINERVA-II rovers successfully landed on asteroid 162173 Ryugu.They Made It! Japan's Two Hopping Rovers Successfully Land on Asteroid Ryugu Meghan Bartels, ''Space.com''. 22 September 2018. The third MINERVA-II rover m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rover (space Exploration)
A rover (or sometimes planetary rover) is a planetary surface exploration device designed to move across the solid surface on a planet or other planetary mass celestial bodies. Some rovers have been designed as land vehicles to transport members of a human spaceflight crew; others have been partially or fully autonomous robots. Rovers are typically created to land on another planet (other than Earth) via a lander (spacecraft), lander-style spacecraft, tasked to collect information about the terrain, and to take crust (geology), crust samples such as dust, soil, rocks, and even liquids. They are essential tools in space exploration. Features Rovers arrive on spacecraft and are used in conditions very distinct from those on the Earth, which makes some demands on their design. Reliability Rovers have to withstand high levels of acceleration, high and low temperatures, pressure, dust, corrosion, cosmic rays, remaining functional without repair for a needed period of time. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photodiode
A photodiode is a light-sensitive semiconductor diode. It produces current when it absorbs photons. The package of a photodiode allows light (or infrared or ultraviolet radiation, or X-rays) to reach the sensitive part of the device. The package may include lenses or optical filters. Devices designed for use specially as a photodiode use a PIN junction rather than a p–n junction, to increase the speed of response. Photodiodes usually have a slower response time as their surface area increases. A photodiode is designed to operate in reverse bias. A solar cell used to generate electric solar power is a large area photodiode. Photodiodes are used in scientific and industrial instruments to measure light intensity, either for its own sake or as a measure of some other property (density of smoke, for example). A photodiode can be used as the receiver of data encoded on an infrared beam, as in household remote controls. Photodiodes can be used to form an optocoupler, allowing tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spacecraft Thermal Control
In spacecraft design, the function of the thermal control system (TCS) is to keep all the spacecraft's component systems within acceptable temperature ranges during all mission phases. It must cope with the external environment, which can vary in a wide range as the spacecraft is exposed to the extreme coldness found in the shadows of deep space or to the intense heat found in the unfiltered direct sunlight of outer space. A TCS must also moderate the internal heat generated by the operation of the spacecraft it serves. A TCS can eject heat passively through the simple and natural infrared radiation of the spacecraft itself, or actively through an externally mounted infrared radiation coil. Thermal control is essential to guarantee the optimal performance and success of the mission because if a component is subjected to temperatures which are too high or too low, it could be damaged or its performance could be severely affected. Thermal control is also necessary to keep specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DC Motor
A DC motor is any of a class of rotary electrical motors that converts direct current (DC) electrical energy into mechanical energy. The most common types rely on the forces produced by induced magnetic fields due to flowing current in the coil. Nearly all types of DC motors have some internal mechanism, either electromechanical or electronic, to periodically change the direction of current in part of the motor. DC motors were the first form of motors widely used, as they could be powered from existing direct-current lighting power distribution systems. A DC motor's speed can be controlled over a wide range, using either a variable supply voltage or by changing the strength of current in its field windings. Small DC motors are used in tools, toys, and appliances. The universal motor, a lightweight brushed motor used for portable power tools and appliances can operate on direct current and alternating current. Larger DC motors are currently used in propulsion of electric vehicle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Aizu
The University of Aizu ( ja, 会津大学, translit=Aizu Daigaku) in Aizuwakamatsu, Japan, is the first university dedicated to computer science engineering in Japan. UoA was ranked 18th (2nd among public universities) and was ranked 7th in the field of computer science in "THE World University Rankings Japan 2022" by Times Higher Education (THE), a British education magazine, released on March 25, 2021. This ranking evaluates universities based on 16 indicators in four areas: educational resources, educational enrichment, educational outcomes, and internationalization, and the University of Aizu was ranked second among public universities. It was ranked 1st in Fostering Entrepreneurship Number of university-launched ventures(Public universities in Japan). The UoA is recognized by many companies and has maintained nearly a 100% of employment rate since its foundation. Description The University of Aizu is in Aizuwakamatsu city in Fukushima prefecture, Japan. The university sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flash ROM
Flash memory is an electronic non-volatile computer memory storage medium that can be electrically erased and reprogrammed. The two main types of flash memory, NOR flash and NAND flash, are named for the NOR and NAND logic gates. Both use the same cell design, consisting of floating gate MOSFETs. They differ at the circuit level depending on whether the state of the bit line or word lines is pulled high or low: in NAND flash, the relationship between the bit line and the word lines resembles a NAND gate; in NOR flash, it resembles a NOR gate. Flash memory, a type of floating-gate memory, was invented at Toshiba in 1980 and is based on EEPROM technology. Toshiba began marketing flash memory in 1987. EPROMs had to be erased completely before they could be rewritten. NAND flash memory, however, may be erased, written, and read in blocks (or pages), which generally are much smaller than the entire device. NOR flash memory allows a single machine word to be written to an erased ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Read-only Memory
Read-only memory (ROM) is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM cannot be electronically modified after the manufacture of the memory device. Read-only memory is useful for storing software that is rarely changed during the life of the system, also known as firmware. Software applications (like video games) for programmable devices can be distributed as plug-in cartridges containing ROM. Strictly speaking, ''read-only memory'' refers to memory that is hard-wired, such as diode matrix or a mask ROM integrated circuit (IC), which cannot be electronically changed after manufacture. Although discrete circuits can be altered in principle, through the addition of bodge wires and/or the removal or replacement of components, ICs cannot. Correction of errors, or updates to the software, require new devices to be manufactured and to replace the installed device. Floating-gate ROM semiconductor memory in the form of erasab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kibibyte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit of memory in many computer architectures. To disambiguate arbitrarily sized bytes from the common 8-bit definition, network protocol documents such as The Internet Protocol () refer to an 8-bit byte as an octet. Those bits in an octet are usually counted with numbering from 0 to 7 or 7 to 0 depending on the bit endianness. The first bit is number 0, making the eighth bit number 7. The size of the byte has historically been hardware-dependent and no definitive standards existed that mandated the size. Sizes from 1 to 48 bits have been used. The six-bit character code was an often-used implementation in early encoding systems, and computers using six-bit and nine-bit bytes were common in the 1960s. These systems often had memory words ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Random-access Memory
Random-access memory (RAM; ) is a form of computer memory that can be read and changed in any order, typically used to store working Data (computing), data and machine code. A Random access, random-access memory device allows data items to be read (computer), read or written in almost the same amount of time irrespective of the physical location of data inside the memory, in contrast with other direct-access data storage media (such as hard disks, CD-RWs, DVD-RWs and the older Magnetic tape data storage, magnetic tapes and drum memory), where the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement. RAM contains multiplexer, multiplexing and demultiplexing circuitry, to connect the data lines to the addressed storage for reading or writing the entry. Usually more than one bit of storage is accessed by the same address, and RAM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mebibyte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit of memory in many computer architectures. To disambiguate arbitrarily sized bytes from the common 8-bit definition, network protocol documents such as The Internet Protocol () refer to an 8-bit byte as an octet. Those bits in an octet are usually counted with numbering from 0 to 7 or 7 to 0 depending on the bit endianness. The first bit is number 0, making the eighth bit number 7. The size of the byte has historically been hardware-dependent and no definitive standards existed that mandated the size. Sizes from 1 to 48 bits have been used. The six-bit character code was an often-used implementation in early encoding systems, and computers using six-bit and nine-bit bytes were common in the 1960s. These systems often had memory words ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SuperH
SuperH (or SH) is a 32-bit reduced instruction set computing (RISC) instruction set architecture (ISA) developed by Hitachi and currently produced by Renesas. It is implemented by microcontrollers and microprocessors for embedded systems. At the time of introduction, SuperH was notable for having fixed-length 16-bit instructions in spite of its 32-bit architecture. This was a novel approach; at the time, RISC processors always used an instruction size that was the same as the internal data width, typically 32 bits. Using smaller instructions had consequences: the register file was smaller and instructions were generally two-operand format. But for the market the SuperH was aimed at, this was a small price to pay for the improved memory and processor cache efficiency. Later versions of the design, starting with SH-5, included both 16- and 32-bit instructions, with the 16-bit versions mapping onto the 32-bit version inside the CPU. This allowed the machine code to continue using ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hitachi
() is a Japanese multinational corporation, multinational Conglomerate (company), conglomerate corporation headquartered in Chiyoda, Tokyo, Japan. It is the parent company of the Hitachi Group (''Hitachi Gurūpu'') and had formed part of the Nissan Group, Nissan ''zaibatsu'' and later DKB Group and Fuyo Group of companies before DKB and Fuji Bank (the core Fuyo Group company) merged into the Mizuho Financial Group. As of 2020, Hitachi conducts business ranging from Information technology, IT, including Artificial intelligence, AI, the Internet of things, Internet of Things, and big data, to infrastructure. Hitachi is listed on the Tokyo Stock Exchange and Nagoya Stock Exchange and its Tokyo listing is a constituent of the Nikkei 225 and TOPIX Core30 indices. It is ranked 38th in the 2012 Fortune Global 500 and 129th in the 2012 Forbes Global 2000. History Hitachi was founded in 1910 by electrical engineer Namihei Odaira (1874–1951) in Ibaraki Prefecture. The company's firs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
