Affichage des articles dont le libellé est Technology. Afficher tous les articles
Affichage des articles dont le libellé est Technology. Afficher tous les articles

8.13.2016

F-15 Twin engine



F-15 
McDonnell Aircraft formalized the concept for the F-15 in 1967 when the company was selected to enter the second phase of the U.S Air Force's FX competition. Competing against Fairchild Hiller and North American Rockwell, McDonnell used lessons learned during the Vietnam War on the changing nature of jet age air-to-air combat, given that the F-4 Phantom II was earning its reputation as a formidable fighter. On Dec. 23, 1969, after more than two years of intensive testing and evaluation, the Air Force awarded McDonnell Douglas the F-15 Advanced Tactical Fighter contract. The McDonnell Douglas team had placed first among the three competitors in all phases of the competition and had the lowest contract price.

F-15
The F-15 is a twin-engine, high-performance, all-weather air superiority fighter known for its incredible acceleration and maneuverability. With a top speed in excess of Mach 2.5 (more than 1,600 mph or 2575 kph), it was the first U.S. fighter with enough thrust to accelerate vertically. The F-15 carries a large complement of missiles — including AIM-9 Sidewinders and AIM-7 Sparrows; the Boeing-built Small Diameter Bomb I, Joint Direct Attack Munition (JDAM) and Laser JDAM weapons; and an internal 20 mm Gatling gun — all vital for modern engagements.

F-15
On June 26, 1972, James S. McDonnell, founder of McDonnell Aircraft, christened the F-15 "Eagle." Test pilot Irv Burrows took the first F-15 Eagle to the air on July 27, 1972, at Edwards Air Force Base in California. Six months later, the Air Force approved the Eagle for full-rate production.
In early 1975, flying out of Grand Forks Air Force Base in North Dakota, an F-15A known as Streak Eagle set many time-to-climb world records. Between Jan. 16 and Feb. 1, 1975, the Streak Eagle broke eight time-to-climb world records. It reached an altitude of 98,425 feet just 3 minutes, 27.8 seconds from brake release at takeoff and coasted to nearly 103,000 feet before descending.
Eagles flown by Israel's air force were the first to face a true adversary in the air. They downed more than 50 Syrian fighters with no losses of their own. In service with the U.S. Air Force, the F-15 Eagle downed MiG fighters during the Balkan conflict and the majority of Iraq's fixed-wing aircraft during Operation Desert Storm.

F-15
To meet the U.S. Air Force requirement for air-to-ground missions, the F-15E Strike Eagle was developed. It made its first flight from St. Louis in December 1986. The Strike Eagle can carry 23,000 pounds of air-to-ground and air-to-air weapons and is equipped with an advanced navigation and an infrared targeting system, protecting the Strike Eagle from enemy defenses. This allows the Strike Eagle to fly at a low altitude while maintaining a high-speed, even during bad weather or at night.

F-15
The F-15 has been produced in single-seat A model and two-seat B versions. The two-seat F-15E Strike Eagle version is a dual-role fighter that can engage both ground and air targets.
F-15C, -D, and -E models participated in Operation Desert Storm in 1991. F-15 downed 32 of 36 U.S. Air Force air-to-air victories and struck Iraqi ground targets. F-15s served in Bosnia in 1994 and downed three Serbian MiG-29 fighters in Operation Allied Force in 1999. They enforced no-fly zones over Iraq in the 1990s. Eagles also hit Afghan targets in Operation Enduring Freedom, and the F-15E version performed air-to-ground missions in Operation Iraqi Freedom.
Boeing has continued to evolve the F-15 with advanced technology, and it is undefeated in air-to-air combat — 101 aerial victories and 0 defeats. Production continues today with advanced models for several international customers.

F-15
In all models, more than 1,500 F-15s have been built. F-15 will be a major player in the U.S. Air Force air superiority and dominance arsenal through the 2040 timeframe using leading-edge technology and capabilities that will keep the Advanced F-15 and its mission systems current.



Source: boeing
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8.08.2016

NIKOLA TESLA : THE BIOGRAPHY



Nikola Tesla contributed to the development of the alternating-current electrical system that's widely used today and discovered the rotating magnetic field (the basis of most AC machinery).

Nikola Tesla aged 34, (in 1890)
Synopsis

Inventor Nikola Tesla was born in July of 1856, in what is now Croatia. He came to the United States in 1884 and briefly worked with Thomas Edison before the two parted ways. He sold several patent rights, including those to his alternating-current machinery, to George Westinghouse. His 1891 invention, the "Tesla coil," is still used in radio technology today. Tesla died in New York City on January 7, 1943.


Early Life

Nikola Tesla was born on July 10, 1856, in what is now Smiljan, Croatia. Tesla's interest in electrical invention was spurred by his mother, Djuka Mandic, who invented small household appliances in her spare time while her son was growing up. Tesla's father, Milutin Tesla, was a priest and a writer, and he pushed for his son to join the priesthood. But Nikola's interests lay squarely in the sciences. After studying at the Realschule, Karlstadt (later renamed the Johann-Rudolph-Glauber Realschule Karlstadt); the Polytechnic Institute in Graz, Austria; and the University of Prague during the 1870s, Tesla moved to Budapest, where for a time he worked at the Central Telephone Exchange. It was while in Budapest that the idea for the induction motor first came to Tesla, but after several years of trying to gain interest in his invention, at age 28 Tesla decided to leave Europe for America.


Famed Inventor

In 1884 Tesla arrived the United States with little more than the clothes on his back and a letter of introduction to famed inventor and business mogul Thomas Edison, whose DC-based electrical works were fast becoming the standard in the country. Edison hired Tesla, and the two men were soon working tirelessly alongside each other, making improvements to Edison's inventions. However, several months later, the two parted ways due to a conflicting business-scientific relationship, attributed by historians to their incredibly different personalities: While Edison was a power figure who focused on marketing and financial success, Tesla was commercially out-of-tune and somewhat vulnerable.

After parting ways with Edison, in 1885 Tesla received funding for the Tesla Electric Light Company and was tasked by his investors to develop improved arc lighting. After successfully doing so, however, Tesla was forced out of the venture and for a time had to work as a manual laborer in order to survive. His luck changed in 1887, when he was able to find interest in his AC electrical system and funding for his new Tesla Electric Company. Setting straight to work, by the end of the year, Tesla had successfully filed several patents for AC-based inventions.   

Nikola Tesla alternating current

 Tesla's AC system eventually caught the attention of American engineer and business man George Westinghouse, who was seeking a solution to supplying the nation with long-distance power. Convinced that Tesla's inventions would help him achieve this, in 1888 he purchased his patents for $60,000 in cash and stock in the Westinghouse Corporation. As interest in an alternating-current system grew, Tesla and Westinghouse were put in direct competition with Thomas Edison, who was intent on selling his direct-current system to the nation. A negative-press campaign was soon waged by Edison, in an attempt to undermine interest in AC power. Tesla, for his part, continued in his work and would patent several more inventions during this period, including the "Tesla coil," which laid the foundation for wireless technologies and is still used in radio technology today.

A multiple exposure picture (one of 68 images created by Century Magazine photographer Dickenson Alley) of Tesla sitting in his Colorado Springs laboratory with his "magnifying transmitter" generating millions of volts. 

Unfortunately for Thomas Edison, the Westinghouse Corporation was chosen to supply the lighting at the 1893 World's Columbian Exposition in Chicago, and Tesla conducted demonstrations of his AC system there. Two years later, in 1895, Tesla designed what was among the first AC hydroelectric power plants in the United States, at Niagara Falls. The following year, it was used to power the city of Buffalo, New York, a feat that was highly publicized throughout the world. With its repeat successes and favorable press, the alternating-current system would quickly become the preeminent power system of the 20th century, and it has remained the worldwide standard ever since.

Spiral Coil of High-Frequency Transformer in New York, 1896

In addition to his AC system and coil, throughout his career, Tesla discovered, designed and developed ideas for a number of other important inventions—most of which were officially patented by other inventors—including dynamos (electrical generators similar to batteries) and the induction motor. He was also a pioneer in the discovery of radar technology, X-ray technology, remote control and the rotating magnetic field—the basis of most AC machinery.  

US Patent 406,968. Dynamo Electric Machine Nikola Tesla - July 16, 1889.


Portable X-ray Machine


The Fall from Grace

Having become obsessed with the wireless transmission of energy, around 1900 Nikola set to work on his boldest project yet: to build a global, wireless communication system—to be transmitted through a large electrical tower—for sharing information and providing free electricity throughout the world. With funding from a group of investors that included financial giant J. P. Morgan, in 1901 Tesla began work on the project in earnest, designing and building a lab with a power plant and a massive transmission tower on a site on Long Island, New York, that became known as Wardenclyffe. 

Nikola Tesla's Wardenclyffe Tower

However, when doubts arose among his investors about the plausibility of Tesla's system and his rival, Guglielmo Marconi—with the financial support of Andrew Carnegie and Thomas Edison—continued to make great advances with his own radio technologies, Tesla had no choice but to abandon the project. The Wardenclyffe staff was laid off in 1906 and by 1915 the site had fallen into foreclosure. Two years later Tesla declared bankruptcy and the tower was dismantled and sold for scrap to help pay the debts he had accrued.



Death and Legacy

After suffering a nervous breakdown, Tesla eventually returned to work, primarily as a consultant. But as time went on, his ideas became progressively more outlandish and impractical. He also grew increasingly eccentric, devoting much of his time to the care of wild pigeons in New York City's parks. He even drew the attention of the FBI with his talk of building a powerful "death beam," which had received some interest from the Soviet Union during World World II. 
Nikola Tesla, who died on January 7, 1943
Poor and reclusive, Nikola Tesla died on January 7, 1943, at the age of 86, in New York City, where he had lived for nearly 60 years. But the legacy of the work he left behind him lives on to this day.

Source: biography


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8.07.2016

THE HUBBLE SPACE TELESCOPE H.S.T

The Hubble Space Telescope (HST) is a space telescope that was launched into low Earth orbit in 1990, and remains in operation. Although not the first space telescope, Hubble is one of the largest and most versatile, and is well known as both a vital research tool and a public relations boon for astronomy. The HST is named after the astronomer Edwin Hubble, and is one of NASA's Great Observatories, along with the Compton Gamma Ray Observatory, the Chandra X-ray Observatory, and the Spitzer Space Telescope.

Hubble Space Telescope over Earth during the STS-109 mission
With a 2.4-meter (7.9 ft) mirror, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared spectra. Hubble's orbit outside the distortion of Earth's atmosphere allows it to take extremely high-resolution images, with substantially lower background light than ground-based telescopes. Hubble has recorded some of the most detailed visible-light images ever, allowing a deep view into space and time. Many Hubble observations have led to breakthroughs in astrophysics, such as accurately determining the rate of expansion of the universe.


One of Hubble's most famous images, "Pillars of Creation" shows stars forming in the Eagle Nebula
The HST was built by the United States space agency NASA, with contributions from the European Space Agency. The Space Telescope Science Institute (STScI) selects Hubble's targets and processes the resulting data, while the Goddard Space Flight Center controls the spacecraft.
Space telescopes were proposed as early as 1923. Hubble was funded in the 1970s, with a proposed launch in 1983, but the project was beset by technical delays, budget problems, and the Challenger disaster (1986). When finally launched in 1990, Hubble's main mirror was found to have been ground incorrectly, compromising the telescope's capabilities. The optics were corrected to their intended quality by a servicing mission in 1993.
Hubble is the only telescope designed to be serviced in space by astronauts. After launch by Space Shuttle Discovery in 1990, four subsequent Space Shuttle missions repaired, upgraded, and replaced systems on the telescope. A fifth mission was canceled on safety grounds following the Columbia disaster (2003). However, after spirited public discussion, NASA administrator Mike Griffin approved one final servicing mission, completed in 2009. The telescope is operating as of 2016, and could last until 2030–2040. Its scientific successor, the James Webb Space Telescope (JWST), is scheduled for launch in 2018.

The Hubble Space Telescope (HST) was put into orbit from the Space Shuttle Discovery

Quest for funding
The continuing success of the OAO program encouraged increasingly strong consensus within the astronomical community that the LST should be a major goal. In 1970, NASA established two committees, one to plan the engineering side of the space telescope project, and the other to determine the scientific goals of the mission. Once these had been established, the next hurdle for NASA was to obtain funding for the instrument, which would be far more costly than any Earth-based telescope. The U.S. Congress questioned many aspects of the proposed budget for the telescope and forced cuts in the budget for the planning stages, which at the time consisted of very detailed studies of potential instruments and hardware for the telescope. In 1974, public spending cuts led to Congress deleting all funding for the telescope project.
In response to this, a nationwide lobbying effort was coordinated among astronomers. Many astronomers met congressmen and senators in person, and large scale letter-writing campaigns were organized. The National Academy of Sciences published a report emphasizing the need for a space telescope, and eventually the Senate agreed to half of the budget that had originally been approved by Congress.

Grinding of Hubble's primary mirror at Perkin-Elmer, March 1979

The funding issues led to something of a reduction in the scale of the project, with the proposed mirror diameter reduced from 3 m to 2.4 m, both to cut costs  and to allow a more compact and effective configuration for the telescope hardware. A proposed precursor 1.5 m space telescope to test the systems to be used on the main satellite was dropped, and budgetary concerns also prompted collaboration with the European Space Agency. ESA agreed to provide funding and supply one of the first generation instruments for the telescope, as well as the solar cells that would power it, and staff to work on the telescope in the United States, in return for European astronomers being guaranteed at least 15% of the observing time on the telescope. Congress eventually approved funding of US$36 million for 1978, and the design of the LST began in earnest, aiming for a launch date of 1983. In 1983 the telescope was named after Edwin Hubble, who made one of the greatest scientific breakthroughs of the 20th century when he discovered that the universe is expanding.

Snow Angel S106 Nebula - Hubble Space Telescope



Source Wikipedia


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8.06.2016

WERNHER VON BRAUN: FROM NAZI TO NASA

On Thursday, September 20, 1945, Wernher von Braun arrived at Fort Strong. The small military site on the northern tip of Boston Harbour's Long Island was the processing point for Project Paperclip, the government programme under which hundreds of German scientists were brought into America. Von Braun filled out his paperwork that day as the inventor of the Nazi V-2 rocket, a member of the Nazi party, and a member of the SS who could be linked to the deaths of thousands of concentration camp prisoners. Two and a half decades later on Wednesday, July 16, 1969, von Braun stood in the firing room at Kennedy Spaceflight Centre and watched another of his rockets, the Saturn V, take the Apollo 11 crew to the Moon.


Wernher von Braun

Wernher von Braun


That he was responsible for both the deadly Nazi V-2 and NASA's majestic Saturn V makes Wernher von Braun a controversial historical figure. Some hold that his participation in the Nazi war effort necessitates classifying him as a villain. But while his actions during the Second World War were monstrous, he wasn't motivated by some inherent evil or personal belief in Nazi ideology. Von Braun was motivated by his childhood obsession with spaceflight, a somewhat uncritical patriotism, and a naive grasp of the ramifications of his actions in creating one of the War's deadliest weapons. How can we treat someone who brought technological triumph to two nations, in one case as a purveyor of death and destruction and in the other a bringer of wonder and inspiration?

The von Brauns
Wernher von Braun's lineage can be traced back to the Junkers, a social class of nobles that dominated the Prussian military officer corps, the landowning elite, and offices of civil service in the 19th and early 20th centuries.

The young Wernher von Braun 

High social standing was inherited or acquired through marriage, a legacy that typically gave Junkers a narrow and self-interested world view. Von Braun's father Magnus was a civil servant, a career that ensured the family had a certain quality of life. Raised in this privileged environment with a sense of his Junker heritage shaped von Braun at an early age into a proud and sometimes arrogant young man.
Wernher von Braun's love affair with space, which was at odds with his upbringing, began when his mother Emmy gave him a telescope for his thirteenth birthday. Looking up at the Moon and the stars, he was seized with a desire to travel into space; launching rockets and landing spacecraft, men, and possibly himself on the Moon became his life's goal. He devoured books about space travel and worked out mission plans of his own.
This obsession with spaceflight took a toll on his academics, as von Braun only applied himself to the subjects that would help him launch rockets. He excelled beyond his professors in maths and physics, eventually teaching classes and tutoring his peers. His grades in other courses, meanwhile, were largely satisfactory. Nevertheless, he was skipped ahead halfway through the twelfth grade to graduate high school a year early.

Rocketry, opportunity, and the Second World War
It was around this time that von Braun got his first hands-on experience with rockets as a member of the Verein fur Raumschiffahrt (VfR), an amateur rocket society. The VfR's activities caught the German Army's attention, and when a group of officers went to watch a launch in the spring of 1932, it was von Braun who stood out. Army Ordnance officer Walter Dornberger saw promise in the young engineer and offered him the opportunity to develop his rockets and explore their possible military applications on the Army's dime. Von Braun accepted Dornberger's offer and began his doctoral work in physics and engineering at the University of Berlin later that year.
In 1933, Adolf Hitler came to power. Still deeply engaged in his doctoral work, von Braun was only partially aware of the nationwide changes brought about by this new leadership. He was only 21 and by his own admission (albeit later in life) apolitical and somewhat disinterested in the world around him. He was patriotic, but rockets were his main concern.
Von Braun finished his dissertation in 1934. Titled "Design, Theoretical and Experimental Contributions to the Problem of the Liquid Fuel Rocket", its contents were deemed so important to the future of Germany's military that it was hidden under a new title, "Regarding Combustion Experiments", and transferred to the Army Ordnance's custody. Von Braun was just 22. Not long after, he began working for the Army on a variety of rocket programmes, among them the ballistic missile the Nazi Propaganda Ministry would eventually call Vergeltungswaffe-Zwei, Vengeance Weapon 2 or V-2.

Vergeltungswaffe-Zwei The V-2 Rocket

A cutaway drawing of a German V2 rocket

The Army increased funding for the V-2 programme throughout the 1930s. By the time the War broke out in 1939, von Braun was running a sizable operation at a dedicated rocket facility at Peenemunde. Sitting on the northern German island of Usedom, Peenemunde afforded von Braun's team the space to build, test, and launch their rockets harmlessly into the Baltic Sea.
But the V-2s that were launched towards London beginning in 1944 weren't built at Peenemunde. These rockets were built in underground factories near the central German town of Nordhausen - most famously at Mittelwerk, where construction was done by prisoners from the nearby Dora-Mittelbau concentration camp. Over 60,000 prisoners lived, worked, and died in the damp underground tunnels at Mittelwerk. Some succumbed to disease and malnutrition. Some were worked to death. Others were hanged publicly in group executions. The death rate rose so high that crematoriums became a necessity.
Von Braun visited Mittelwerk at least once; he was given a tour of the facility by SS guards in late 1943 when prisoners were still excavating tunnels. But just how this and any subsequent trips affected the young rocketeer is open to speculation. There are no records of von Braun planning or overseeing operations at Mittelwerk, even from a distance. It's possible that his boyhood disinterest in politics helped him either ignore or repress what he knew about Mittelwerk, or perhaps he was able to justify the deplorable conditions in his rockets' factory as a necessity of war. Years later, in America, von Braun called the V-2 his contribution to Germany's wartime arsenal. It was what any citizen was expected to do.
During his tenure developing the V-2, von Braun joined the Nazi party and became a member of the SS.

 Von Braun SS membership

He also held on to his dream of landing men on the Moon. One night in early March of 1944, he drank too much at a party and spoke too freely in what he thought was just casual conversation. He told fellow party goers that he foresaw the war ending badly for Germany and added that all he'd ever wanted to do with his rockets was launch them into space. It was an admission akin to treason, which was a crime punishable by death. Von Braun was arrested weeks later, and while he was never incarcerated, it was his first indication that he wouldn't be safe in his home country when the war ended.
Von Braun was attracted by the opportunities America promised and suspected that the US military would support his continued research in rocketry. He had already decided that he wanted to surrender to and build rockets for America when he heard that Hitler was dead on May 1, 1945. Hiding with his fellow rocket engineers in Bavaria at the time, von Braun elected an emissary from the group, his younger brother Magnus, to go, find and surrender to American soldiers. Magnus did. By nightfall on May 2, Wernher von Braun was in the hands of American soldiers and within months the US government made him the offer he'd hoped for: military funding to develop an Americanised version of the V-2.

Finding fame in America
After working in relative obscurity in New Mexico for four years, von Braun and other former Peenemunders brought overseas under Project Paperclip were moved to the US Army's Redstone Arsenal in Huntsville, Alabama.

A group of 104 rocket scientists (aerospace engineers) at Fort Bliss, Texas


On March 22, 1952, von Braun introduced the American public to his vision of space exploration in the pages of Collier's Magazine. In a series of articles published over two years, he described how men would live and work in huge doughnut-shaped orbital space stations before setting off on missions to the Moon. He imagined spacecraft launching and gliding back to Earth daily. And he described, in detail, the rockets he would build to launch such missions. Americans met the man behind this compelling future on March 9, 1955 when von Braun appeared in the first episode of Walt Disney's Tomorrowland TV series. Viewers saw von Braun's vision come to life with stunning animation.
Von Braun brought the same vision to NASA when the agency absorbed his rocket group in 1960. Throughout the decade, he was pictured shaking hands with presidents, smiling with astronauts, and posing in front of the massive rockets that would launch them into space. And while NASA's path to the Moon ultimately deviated from von Braun's vision, he nevertheless achieved his boyhood dream in 1969.

Apollo Saturn V Rocket

Wernher von Braun dwarfed by the F-1 engines of the Saturn V


Whatever celebrity von Braun achieve in America, it couldn't erase his Nazi past. But in the same way he covered or ignored his association with Mittelwerk, American leaders and administrators suppressed or deliberately misrepresented his past and emphasised his contributions to the nation's space programme and space exploration generally. He wasn't ostracised as an ex-Nazi; he was celebrated as the creator of the Saturn V.

Wernher von Braun dwarfed by the F-1 engines of the Saturn V


JFK with Wernher Von Braun at Cape Canaveral, 1963


Times of war
The circumstances surrounding von Braun's two greatest rocket triumphs were very different. The V-2 was built by prison labour and launched as an offensive weapon while the Saturn V was built by American aviation companies and launched with manned spacecraft to the Moon. But there's nevertheless a strong parallel: both rockets were built and launched in times of war. In both cases, von Braun followed the money and developed the technology he could to defeat an enemy, Allied soldiers in Europe and the Soviet Union in space. In neither case did he undertake his work for strong ideological reasons. He had no apparent moral quandary or crisis of conscience aligning himself with the Nazi party in the 1930s, nor did he labour over the decision to turn his back on his homeland and immigrate to America in 1945. The constant thread running through von Braun's life during both wars is his fixation on spaceflight.
The legacy von Braun has left behind will always be split between those who classify him as a villain and those who classify him as a visionary. Both might be true. He certainly exploited horrifying means to pursue his goals, but was unquestionably one of the most influential rocket engineers and spaceflight visionaries of the 20th century.

Source: Al Jazeera
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8.05.2016

CURIOSITY THE MARS ROBOTIC ROVER

Curiosity is a car-sized robotic rover exploring Gale Crater on Mars as part of NASA's Mars Science Laboratory mission (MSL). As of August 5, 2016, Curiosity has been on Mars for 1422 sols (1460 total days) since landing on August 6, 2012.


The Rover Curiosity
 Curiosity was launched from Cape Canaveral on November 26, 2011, at 15:02 UTC aboard the MSL spacecraft and landed on Aeolis Palus in Gale Crater on Mars on August 6, 2012, 05:17 UTC. The Bradbury Landing site was less than 2.4 km (1.5 mi) from the center of the rover's touchdown target after a 563,000,000 km (350,000,000 mi) journey.
The rover's goals include: investigation of the Martian climate and geology; assessment of whether the selected field site inside Gale Crater has ever offered environmental conditions favorable for microbial life, including investigation of the role of water; and planetary habitability studies in preparation for future human exploration.
Curiosity's design will serve as the basis for the planned Mars 2020 rover. In December 2012, Curiosity's two-year mission was extended indefinitely.

Goals and objectives
As established by the Mars Exploration Program, the main scientific goals of the MSL mission are to help determine whether Mars could ever have supported life, as well as determining the role of water, and to study the climate and geology of Mars. The mission will also help prepare for human exploration. To contribute to these goals, MSL has eight main scientific objectives:

Biological

  • Determine the nature and inventory of organic carbon compounds
  • Investigate the chemical building blocks of life (carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur)
  • Identify features that may represent the effects of biological processes (biosignatures and biomolecules)

Geological and geochemical

  • Investigate the chemical, isotopic, and mineralogical composition of the Martian surface and near-surface geological materials
  • Interpret the processes that have formed and modified rocks and soils

Planetary process

  • Assess long-timescale (i.e., 4-billion-year) Martian atmospheric evolution processes
  • Determine present state, distribution, and cycling of water and carbon dioxide

Surface radiation

  • Characterize the broad spectrum of surface radiation, including galactic and cosmic radiation, solar proton events and secondary neutrons. As part of its exploration, it also measured the radiation exposure in the interior of the spacecraft as it traveled to Mars, and it is continuing radiation measurements as it explores the surface of Mars. This data would be important for a future manned mission.

About one year into the surface mission, and having assessed that ancient Mars could have been hospitable to microbial life, the MSL mission objectives evolved to developing predictive models for the preservation process of organic compounds and biomolecules; a branch of paleontology called taphonomy.


Martian rover Curiosity using ChemCam

Specifications
Dimensions: Curiosity has a mass of 899 kg (1,982 lb) including 80 kg (180 lb) of scientific instruments. The rover is 2.9 m (9.5 ft) long by 2.7 m (8.9 ft) wide by 2.2 m (7.2 ft) in height.
Power source: Curiosity is powered by a radioisotope thermoelectric generator (RTG), like the successful Viking 1 and Viking 2 Mars landers in 1976.


Curiosity rover showing the radioisotope thermoelectric generator that supplies electrical power and heat to the rover

Radioisotope power systems (RPSs) are generators that produce electricity from the decay of radioactive isotopes, such as plutonium-238, which is a non-fissile isotope of plutonium. Heat given off by the decay of this isotope is converted into electric voltage by thermocouples, providing constant power during all seasons and through the day and night. Waste heat can be used via pipes to warm systems, freeing electrical power for the operation of the vehicle and instruments. Curiosity's RTG is fueled by 4.8 kg (11 lb) of plutonium-238 dioxide supplied by the U.S. Department of Energy.

Heat rejection system:
The temperatures at the landing site can vary from −127 to 40 °C (−197 to 104 °F); therefore, the thermal system will warm the rover for most of the Martian year. The thermal system will do so in several ways: passively, through the dissipation to internal components; by electrical heaters strategically placed on key components; and by using the rover heat rejection system (HRS). It uses fluid pumped through 60 m (200 ft) of tubing in the rover body so that sensitive components are kept at optimal temperatures. The fluid loop serves the additional purpose of rejecting heat when the rover has become too warm, and it can also gather waste heat from the power source by pumping fluid through two heat exchangers that are mounted alongside the RTG. The HRS also has the ability to cool components if necessary.
Computers: The two identical on-board rover computers, called Rover Computer Element (RCE) contain radiation hardened memory to tolerate the extreme radiation from space and to safeguard against power-off cycles. Each computer's memory includes 256 kB of EEPROM, 256 MB of DRAM, and 2 GB of flash memory. For comparison, the Mars Exploration Rovers used 3 MB of EEPROM, 128 MB of DRAM, and 256 MB of flash memory.


Source : Wikipedia
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8.03.2016

L.H.C THE LARGE HADRON COLLIDER


The Large Hadron Collider (LHC) 


The Large Hadron Collider (LHC) is the world’s largest and most powerful particle accelerator. It first started up on 10 September 2008, and remains the latest addition to CERN’s accelerator complex. The LHC consists of a 27-kilometre ring of superconducting magnets with a number of accelerating structures to boost the energy of the particles along the way.



Virtual map of L.H.C








Inside the accelerator, two high-energy particle beams travel at close to the speed of light before they are made to collide. The beams travel in opposite directions in separate beam pipes – two tubes kept at ultrahigh vacuum. They are guided around the accelerator ring by a strong magnetic field maintained by superconducting electromagnets. The electromagnets are built from coils of special electric cable that operates in a superconducting state, efficiently conducting electricity without resistance or loss of energy. This requires chilling the magnets to ‑271.3°C – a temperature colder than outer space. For this reason, much of the accelerator is connected to a distribution system of liquid helium, which cools the magnets, as well as to other supply services.




Thousands of magnets of different varieties and sizes are used to direct the beams around the accelerator. These include 1232 dipole magnets 15 metres in length which bend the beams, and 392 quadrupole magnets, each 5–7 metres long, which focus the beams. Just prior to collision, another type of magnet is used to "squeeze" the particles closer together to increase the chances of collisions. The particles are so tiny that the task of making them collide is akin to firing two needles 10 kilometres apart with such precision that they meet halfway.

L.H.C Control center

L.H.C Control center


All the controls for the accelerator, its services and technical infrastructure are housed under one roof at the CERN Control Centre. From here, the beams inside the LHC are made to collide at four locations around the accelerator ring, corresponding to the positions of four particle detectors – ATLAS, CMS, ALICE and LHCb.


Source CERN
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