NACA and NASA Cheap MLB Jerseys Wholesale , Part IX Technology Articles | July 28, 2017 Galileo probe ??????????? Galileo was an unmanned spacecraft sent by NASA to study the planet Jupiter and its moons. Named after the astronomer and Renaissance pioneer Galileo Galilei, it was launche...
Galileo probe
??????????? Galileo was an unmanned spacecraft sent by NASA to study the planet Jupiter and its moons. Named after the astronomer and Renaissance pioneer Galileo Galilei, it was launched on October 18, 1989 by the Space Shuttle Atlantis on the STS-34 mission. It arrived at Jupiter on December 7, 1995, a little more than six years later Cheap MLB Jerseys , via gravitational assist flybys of Venus and Earth.
Despite antenna problems, Galileo conducted the first asteroid flyby near 951 Gaspra, discovered the first asteroid moon Dactyl around the asteroid 243 Ida, was the first spacecraft to orbit Jupiter, and launched the first probe into Jupiter's atmosphere.
The spacecraft measured the atmospheric composition of Jupiter and directly observed ammonia clouds, which seem to be created by an outflow from the lower depths of Jupiter's atmosphere. Galileo also registered Io's volcanism and the plasma interactions between its and Jupiter's atmospheres. Other studies gave support for the popular theory of liquid oceans under the icy surface of Europa. There was also indications of similar liquid-saltwater layers under the surfaces of Ganymede and Callisto, while Ganymede was shown to possess a magnetic field. New evidence was also found for the existence of exospheres around Europa Cheap Jerseys Online , Ganymede, and Callisto.
It was furthermore discovered that Jupiter's faint ring system is formed by dust from impacts on the four small inner moons. The extent and structure of Jupiter's magnetosphere was also mapped.
Galileo also provided the only direct observation of comet Shoemaker-Levy 9's impact into the atmosphere of Jupiter in 1994.
On September 21, 2003, after 14 years in space and 8 years of service in the Jovian system, Galileo's mission was terminated by sending the orbiter into Jupiter's atmosphere at a speed of nearly 50 kilometres per second to avoid any chance of it contaminating local moons with bacteria from Earth. Of particular concern was the ice-crusted moon Europa, which, thanks to Galileo Cheap Jerseys Free Shipping , scientists now suspect harbors a saltwater ocean beneath its surface.
??????????? Galileo's launch had been significantly delayed by the hiatus in Space Shuttle launches that occurred after the Challenger space shuttle disaster. New safety protocols introduced as a result of the disaster forced Galileo to use a lower-powered upper stage booster rocket, instead of a Centaur booster rocket, to send it from Earth orbit to Jupiter. Several gravitational slingshots, called "VEEGA"s or Venus Earth Earth Gravity Assist maneuvers, provided the additional velocity required to reach its destination: Venus was flown by on February 10, 1990, and Earth twice Cheap Jerseys From China , on December 8, 1990, and again on December 8, 1992. Along the way, Galileo performed close observation of the asteroids 951 Gaspra (October 29, 1991) and 243 Ida (August 28, 1993) Cheap Jerseys China , and discovered Ida's moon Dactyl. In 1994, Galileo was perfectly positioned to watch the fragments of comet Shoemaker-Levy 9 crash into Jupiter. Terrestrial telescopes had to wait to see the impact sites as they rotated into view.
Galileo's prime mission was a two-year study of the Jovian system. The spacecraft traveled around Jupiter in elongated ellipses, each orbit lasting about two months. The differing distances from Jupiter afforded by these orbits allowed Galileo to sample different parts of the planet's extensive magnetosphere. The orbits were designed for close-up flybys of Jupiter's largest moons. Once Galileo's prime mission was concluded, an extended mission followed, starting on December 7, 1997; the spacecraft made a number of daring close flybys of Jupiter's moons Europa and Io. The closest approach was 180 km (112 mi) on October 15, 2001. The radiation environment near Io in particular was very unhealthy for Galileo's systems Cheap Jerseys Wholesale , and so these flybys were saved for the extended mission when loss of the spacecraft would be more acceptable.
Galileo's cameras were deactivated on January 17, 2002, after they had sustained irreparable radiation damage. NASA engineers were able to recover the damaged tape recorder electronics, and Galileo continued to return scientific data until it was deorbited in 2003, performing one last scientific experiment —a measurement of the moon Amalthea's mass as the spacecraft swung by it.
The Jet Propulsion Laboratory built the Galileo spacecraft and managed the Galileo mission for NASA. Germany supplied the propulsion module. NASA's Ames Research Center managed the probe, which was built by Hughes Aircraft Company.
At launch, the orbiter and probe together had a mass of 2 Cheap Jerseys ,564 kilograms (5,653 pounds) and stood seven metres tall. One section of the spacecraft rotated at 3 rpm, keeping Galileo stable and holding six instruments that gathered data from many different directions, including the fields and particles instruments. The other section of the spacecraft was an antenna, and data were periodically transmitted to it. Back on the ground,the mission operations team used software containing 650,000 lines of programming code in the orbit sequence design process; 1 Wholesale Authentic MLB Jerseys ,615,000 lines in the telemetry interpretation; and 550,000 lines of code in navigation.
The CDH was actively redundant, with two parallel strings running at all times. It was composed of multiplexers (MUX), high-level modules (HLM), low-level modules (LLM), power converters (PC) Wholesale MLB Jerseys , bulk memory (BUM), data management subsystem bulk memory (DBUM), timing chains (TC), phase lock loops (PLL), Golay coders (GC), and hardware command decodes (HCD).
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