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Advanced Communications Technology Satellite
STS-51 was a NASA Space Shuttle ''Discovery'' mission that launched the Advanced Communications Technology Satellite (ACTS) in September 1993. The flight also featured the deployment and retrieval of the SPAS-ORFEUS satellite and its IMAX camera, which captured spectacular footage of ''Discovery'' in space. A spacewalk was also performed during the mission to evaluate tools and techniques for the STS-61 Hubble Space Telescope (HST) servicing mission later that year. STS-51 was the first shuttle mission to fly a Global Positioning System (GPS) receiver, a Trimble TANS Quadrex. It was mounted in an overhead window where limited field of view (FoV) and signal attenuation from the glass severely impacted receiver performance. Full triple-redundant 3-string GPS would not happen until 14 years later with STS-118 in 2007. Crew Launch Preparations STS-51 was notable for having been scrubbed three times on the launchpad, each time after the crew had boarded the spacecraft: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Transportation System
The Space Transportation System (STS), also known internally to NASA as the Integrated Program Plan (IPP), was a proposed system of reusable crewed space vehicles envisioned in 1969 to support extended operations beyond the Apollo program. (NASA appropriated the name for its Space Shuttle Program, the only component of the proposal to survive Congressional funding approval). The purpose of the system was two-fold: to reduce the cost of spaceflight by replacing the current method of launching capsules on expendable rockets with reusable spacecraft; and to support ambitious follow-on programs including permanent orbiting space stations around Earth and the Moon, and a human landing mission to Mars. In February 1969, President Richard Nixon appointed a Space Task Group headed by Vice President Spiro Agnew to recommend human space projects beyond Apollo. The group responded in September with the outline of the STS, and three different program levels of effort culminating with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Shuttle Program
The Space Shuttle program was the fourth human spaceflight program carried out by the U.S. National Aeronautics and Space Administration (NASA), which accomplished routine transportation for Earth-to-orbit crew and cargo from 1981 to 2011. Its official name, Space Transportation System (STS), was taken from a 1969 plan for Space Transportation System, a system of reusable spacecraft of which it was the only item funded for development. It flew 135 missions and carried 355 astronauts from 16 countries, many on multiple trips. The Space Shuttle—composed of an Space Shuttle orbiter, orbiter launched with two reusable Space Shuttle Solid Rocket Booster, solid rocket boosters and a disposable Space Shuttle external tank, external fuel tank—carried up to eight astronauts and up to of Payload (air and space craft), payload into low Earth orbit (LEO). When its mission was complete, the orbiter would atmospheric reentry, reenter the Earth's atmosphere and land like a glider (aircr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1993 S51 Liftoff
File:1993 Events Collage.png, From left, clockwise: The Oslo I Accord is signed in an attempt to resolve the Israeli–Palestinian conflict; The Russian White House is shelled during the 1993 Russian constitutional crisis; Czechoslovakia is peacefully dissolved into the Czech Republic and Slovakia; In the United States, the ATF besieges a compound belonging to David Koresh and the Branch Davidians in a search for illegal weapons, which ends in the building being set alight and killing most inside; Eritrea gains independence; A major snow storm passes over the United States and Canada, leading to over 300 fatalities; Drug lord and narcoterrorist Pablo Escobar is killed by Colombian special forces; Ramzi Yousef and other Islamic terrorists detonate a truck bomb in the subterranean garage of the North Tower of the World Trade Center in the United States., 300x300px, thumb rect 0 0 200 200 Oslo I Accord rect 200 0 400 200 1993 Russian constitutional crisis rect 400 0 600 200 Dissolu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STS-118
STS-118 was a Space Shuttle mission to the International Space Station (ISS) flown by the orbiter '' Endeavour''. STS-118 lifted off on 8 August 2007 from launch pad 39A at Kennedy Space Center (KSC), Florida and landed at the Shuttle Landing Facility at KSC on 21 August 2007. This was the first flight of ''Endeavour'' since STS-113 in November 2002, which was also the last successful shuttle flight before STS-107 which culminated in the loss of '' Columbia'' when it disintegrated during reentry. STS-118 pilot Charles Hobaugh had been the entry team CAPCOM for STS-107. ''Columbia'' had originally been selected for this flight, for what would have been its 29th mission, and its first and likely only visit to the ISS, mainly due to its heavier weight. The mission is also referred to as ISS-13A.1 by the ISS program. The mission added two more components to the ISS and brought supplies for its crew. During and after the mission, the media focused heavily on a small puncture in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redundancy (engineering)
In engineering, redundancy is the intentional duplication of critical components or functions of a system with the goal of increasing reliability of the system, usually in the form of a backup or fail-safe, or to improve actual system performance, such as in the case of GNSS receivers, or multi-threaded computer processing. In many safety-critical systems, such as fly-by-wire and hydraulic systems in aircraft, some parts of the control system may be triplicated, which is formally termed triple modular redundancy (TMR). An error in one component may then be out-voted by the other two. In a triply redundant system, the system has three sub components, all three of which must fail before the system fails. Since each one rarely fails, and the sub components are expected to fail independently, the probability of all three failing is calculated to be extraordinarily small; it is often outweighed by other risk factors, such as human error. Redundancy may also be known by the terms "m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Attenuation
In physics, attenuation (in some contexts, extinction) is the gradual loss of flux intensity through a medium. For instance, dark glasses attenuate sunlight, lead attenuates X-rays, and water and air attenuate both light and sound at variable attenuation rates. Hearing protectors help reduce acoustic flux from flowing into the ears. This phenomenon is called acoustic attenuation and is measured in decibels (dBs). In electrical engineering and telecommunications, attenuation affects the propagation of waves and signals in electrical circuits, in optical fibers, and in air. Electrical attenuators and optical attenuators are commonly manufactured components in this field. Background In many cases, attenuation is an exponential function of the path length through the medium. In optics and in chemical spectroscopy, this is known as the Beer–Lambert law. In engineering, attenuation is usually measured in units of decibels per unit length of medium (dB/cm, dB/km, etc.) and is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field Of View
The field of view (FoV) is the extent of the observable world that is seen at any given moment. In the case of optical instruments or sensors it is a solid angle through which a detector is sensitive to electromagnetic radiation. Humans and animals In the context of human and primate vision, the term "field of view" is typically only used in the sense of a restriction to what is visible by external apparatus, like when wearing spectacles or virtual reality goggles. Note that eye movements are allowed in the definition but do not change the field of view when understood this way. If the analogy of the eye's retina working as a sensor is drawn upon, the corresponding concept in human (and much of animal vision) is the visual field. It is defined as "the number of degrees of visual angle during stable fixation of the eyes".Strasburger, Hans; Pöppel, Ernst (2002). Visual Field. In G. Adelman & B.H. Smith (Eds): ''Encyclopedia of Neuroscience''; 3rd edition, on CD-ROM. El ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimble Inc
Trimble Inc. is an American software, hardware, and services technology company. Trimble supports global industries in building & construction, agriculture, geospatial, natural resources and utilities, governments, transportation and others. Trimble also does hardware development of global navigation satellite system (GNSS) receivers, scanners, laser rangefinders, unmanned aerial vehicles (UAVs), inertial navigation systems and software processing tools. History Trimble Navigation was founded in November 1978 by Charles Trimble and two partners from Hewlett Packard. It initially operated above a movie theatre in Los Altos, California. By the end of 2016, the company had 8,388 employees, with more than half of employees in locations outside the United States. The company's acquisitions include Telog Instruments, Pocket Mobile AB, @Road, Cengea Solutions Inc., Datacom Software Research, Spectra Precision Group, Tripod Data Systems, Advanced Public Safety, Inc., ALK Technologies, A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Positioning System
The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite systems (GNSS) that provides geolocation and time information to a GPS receiver anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. It does not require the user to transmit any data, and operates independently of any telephonic or Internet reception, though these technologies can enhance the usefulness of the GPS positioning information. It provides critical positioning capabilities to military, civil, and commercial users around the world. Although the United States government created, controls and maintains the GPS system, it is freely accessible to anyone with a GPS receiver. The GPS project was started by the U.S. Department of Defense in 1973. The first prototype spacecraft was lau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble Space Telescope
The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versatile, renowned both as a vital research tool and as a public relations boon for astronomy. The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA's Great Observatories. The Space Telescope Science Institute (STScI) selects Hubble's targets and processes the resulting data, while the Goddard Space Flight Center (GSFC) controls the spacecraft. Hubble features a mirror, and its five main instruments observe in the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. Hubble's orbit outside the distortion of Earth's atmosphere allows it to capture extremely high-resolution images with substantially lower background light than ground-based telescopes. It has recorded some of the most detaile ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STS-61
STS-61 was the first NASA Hubble Space Telescope servicing mission, and the fifth flight of the Space Shuttle ''Endeavour''. The mission launched on 2 December 1993 from Kennedy Space Center (KSC) in Florida. The mission restored the spaceborne observatory's vision (marred by spherical aberration in its mirror) with the installation of a new main camera and a corrective optics package (COSTAR). This correction occurred more than three and a half years after the Hubble was launched aboard STS-31 in April 1990. The flight also brought instrument upgrades and new solar arrays to the telescope. With its very heavy workload, the STS-61 mission was one of the most complex in the Shuttle's history. It lasted almost 11 days, and crew members made five spacewalks (extravehicular activities (EVAs)), an all-time record; even the re-positioning of Intelsat VI on STS-49 in May 1992 required only four. The flight plan allowed for two additional EVAs, which could have raised the total nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extravehicular Activity
Extravehicular activity (EVA) is any activity done by an astronaut in outer space outside a spacecraft. In the absence of a breathable Earthlike atmosphere, the astronaut is completely reliant on a space suit for environmental support. EVA includes ''spacewalks'' and lunar or planetary surface exploration (commonly known from 1969 to 1972 as ''moonwalks''). In a stand-up EVA (SEVA), an astronaut stands through an open hatch but does not fully leave the spacecraft. EVA has been conducted by the Soviet Union/Russia, the United States, Canada, the European Space Agency and China. On March 18, 1965, Alexei Leonov became the first human to perform a spacewalk, exiting the Voskhod 2 capsule for 12 minutes and 9 seconds. On July 20, 1969, Neil Armstrong became the first human to perform a moonwalk, outside his lunar lander on Apollo 11 for 2 hours and 31 minutes. On the last three Moon missions, astronauts also performed deep-space EVAs on the return to Earth, to retrieve film ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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