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PSSC-2
PSSC-2, or Pico-Satellite Solar Cell Testbed 2, also known as PSSC-Testbed 2, is a miniaturised satellite which was operated by the United States Air Force as part of a technology demonstration programme. It was the last satellite to be deployed from a Space Shuttle. Overview PSSC-2 was launched aboard on its final mission, STS-135. The launch took place from Kennedy Space Center Launch Complex 39, Launch Complex 39A at the Kennedy Space Center, at 15:29 UTC on 8 July 2011. PSSC-2, along with a deployment mechanism, was carried to orbit in the payload bay of the Shuttle, attached to the right wall behind the Orbiter Docking System. It remained attached during ''Atlantis''' visit to the International Space Station, and was originally scheduled to be deployed at 07:11 UTC on 19 July, the day after undocking. With the extension of the STS-135 mission, undocking, and hence deployment, was delayed by one day. PSSC-2 is the second PSSC satellite, following PSSC-1 which was deployed fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STS-135 Picosat Deployment
STS-135 (ISS assembly sequence, ISS assembly flight ULF7) was the 135th and final mission of the American Space Shuttle Space Shuttle program, program. It used the orbiter ''Space Shuttle Atlantis, Atlantis'' and hardware originally processed for the STS-3xx#STS-335, STS-335 contingency mission, which was not flown. STS-135 launched on July 8, 2011, and landed on July 21, 2011, following a one-day mission extension. The four-person crew was the smallest of any shuttle mission since STS-6 in April 1983. The mission's primary cargo was the Multi-Purpose Logistics Module (MPLM) ''Raffaello MPLM, Raffaello'' and a Lightweight Multi-Purpose Carrier (LMC), which were delivered to the International Space Station (ISS). The flight of ''Raffaello'' marked the only time that ''Atlantis'' carried an MPLM. Although the mission was authorized, it initially had no appropriation in the NASA budget, raising questions about whether the mission would fly. On January 20, 2011, program managers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STS-135
STS-135 ( ISS assembly flight ULF7) was the 135th and final mission of the American Space Shuttle program. It used the orbiter '' Atlantis'' and hardware originally processed for the STS-335 contingency mission, which was not flown. STS-135 launched on July 8, 2011, and landed on July 21, 2011, following a one-day mission extension. The four-person crew was the smallest of any shuttle mission since STS-6 in April 1983. The mission's primary cargo was the Multi-Purpose Logistics Module (MPLM) '' Raffaello'' and a Lightweight Multi-Purpose Carrier (LMC), which were delivered to the International Space Station (ISS). The flight of ''Raffaello'' marked the only time that ''Atlantis'' carried an MPLM. Although the mission was authorized, it initially had no appropriation in the NASA budget, raising questions about whether the mission would fly. On January 20, 2011, program managers changed STS-335 to STS-135 on the flight manifest. This allowed for training and other mission spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STS-126
STS-126 was the one hundred and twenty-fourth NASA Space Shuttle mission, and twenty-second orbital flight of the ''Space Shuttle Endeavour'' (OV-105) to the International Space Station (ISS). The purpose of the mission, referred to as ULF2 by the ISS program, was to deliver equipment and supplies to the station, to service the Integrated Truss Structure, Solar Alpha Rotary Joints (SARJ), and repair the problem in the starboard SARJ that had limited its use since STS-120. STS-126 launched on 15 November 2008 at 00:55:39 UTC from Kennedy Space Center Launch Complex 39A, Launch Pad 39A (LC-39A) at NASA's Kennedy Space Center (KSC) with no delays or issues. ''Endeavour'' successfully docked with the station on 16 November 2008. After spending 15 days, 20 hours, 30 minutes, and 30 seconds docked to the station, during which the crew performed four Extravehicular activity, spacewalks, and transferred cargo, the orbiter undocked on 28 November 2008. Due to poor weather at Kennedy Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solid Rocket Motor
A solid-propellant rocket or solid rocket is a rocket with a rocket engine that uses solid propellants (fuel/oxidizer). The earliest rockets were solid-fuel rockets powered by gunpowder. The inception of gunpowder rockets in warfare can be credited to the ancient Chinese, and in the 13th century, the Mongols played a pivotal role in facilitating their westward adoption. All rockets used some form of solid or powdered propellant until the 20th century, when liquid-propellant rockets offered more efficient and controllable alternatives. Because of their simplicity and reliability, solid rockets are still used today in military armaments worldwide, model rockets, solid rocket boosters and on larger applications. Since solid-fuel rockets can remain in storage for an extended period without much propellant degradation, and since they almost always launch reliably, they have been frequently used in military applications such as missiles. The lower performance of solid propellants (a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonium Perchlorate
Ammonium perchlorate ("AP") is an inorganic compound with the formula . It is a colorless or white solid that is soluble in water. It is a powerful oxidizer. Combined with a fuel, it can be used as a rocket propellant called ammonium perchlorate composite propellant. Its instability has involved it in accidents such as the PEPCON disaster. Production Ammonium perchlorate (AP) is produced by reaction between ammonia and perchloric acid. This process is the main outlet for the industrial production of perchloric acid. The salt also can be produced by salt metathesis reaction of ammonium salts with sodium perchlorate. This process exploits the relatively low solubility of NH4ClO4, which is about 10% of that for sodium perchlorate.Helmut Vogt, Jan Balej, John E. Bennett, Peter Wintzer, Saeed Akbar Sheikh, Patrizio Gallone "Chlorine Oxides and Chlorine Oxygen Acids" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH. AP crystallises as colorless rhombohedra. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adaptive Communication
Adaptive communications can mean any communications system, or portion thereof, that automatically uses feedback information Information is an Abstraction, abstract concept that refers to something which has the power Communication, to inform. At the most fundamental level, it pertains to the Interpretation (philosophy), interpretation (perhaps Interpretation (log ... obtained from the system itself or from the signals carried by the system to modify dynamically one or more of the system operational parameters to improve system performance or to resist degradation. The modification of a system parameter may be discrete, as in hard-switched diversity reception, or may be continuous, as in a predetection combining algorithm. See also * Automatic Link Establishment * Channel use * CALM M5 References Telecommunications techniques {{telecomm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three-axis Stabilisation
Spacecraft attitude control is the process of controlling the orientation of a spacecraft (vehicle or satellite) 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 actuators to apply the torques needed to orient the vehicle to a desired attitude, and algorithms to command the actuators based on the current attitude and specification of a desired attitude. Before and during attitude control can be performed, spacecraft attitude determination must be performed, which requires sensors for absolute or relative measurement. The broader integrated field that studies the combination of sensors, actuators and algorithms is called '' guidance, navigation and control'', which also involves non-attitude concepts, such as position determination and navigation. Motivation A spacecraft's attitude must typically be stabilized and controlled for a variety of reasons. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionosphere
The ionosphere () is the ionized part of the upper atmosphere of Earth, from about to above sea level, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on Earth. Travel through this layer also impacts GPS signals, resulting in effects such as deflection in their path and delay in the arrival of the signal. History of discovery As early as 1839, the German mathematician and physicist Carl Friedrich Gauss postulated that an electrically conducting region of the atmosphere could account for observed variations of Earth's magnetic field. Sixty years later, Guglielmo Marconi received the first trans-Atlantic radio signal on December 12, 1901, in St. John's, Newfoundland (now in Canada) usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Positioning System
The Global Positioning System (GPS) is a satellite-based hyperbolic navigation system owned by the United States Space Force and operated by Mission Delta 31. It is one of the global navigation satellite systems (GNSS) that provide 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 telephone 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. Overview The GPS project was started by the U.S. Department of Defense in 1973. The first prototype spacecraft was launched in 1978 an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occulting
An occultation is an event that occurs when one object is hidden from the observer by another object that passes between them. The term is often used in astronomy, but can also refer to any situation in which an object in the foreground blocks from view (occults) an object in the background. In this general sense, occultation applies to the visual scene observed from low-flying aircraft (or computer-generated imagery) when foreground objects obscure distant objects dynamically, as the scene changes over time. If the closer body does not entirely conceal the farther one, the event is called a ''transit''. Both transit and occultation may be referred to generally as ''occlusion''; and if a shadow is cast onto the observer, it is called an eclipse. The symbol for an occultation, and especially a solar eclipse, is 🝵 (U+1F775 🝵). Occultations by the Moon The term occultation is most frequently used to describe lunar occultations, those relatively frequent occasions when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Air Force
The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its origins to 1 August 1907, as a part of the United States Army Signal Corps, the USAF was established by transfer of personnel from the Army Air Forces with the enactment of the National Security Act of 1947. It is the second youngest branch of the United States Armed Forces and the fourth in United States order of precedence, order of precedence. The United States Air Force articulates its core missions as air supremacy, intelligence, surveillance, target acquisition, and reconnaissance, global integrated intelligence, surveillance and reconnaissance, airlift, rapid global mobility, Strategic bombing, global strike, and command and control. The United States Department of the Air Force, Department of the Air Force, which serves as the USAF's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
