JUPITER THE BIGGEST PLANET IN THE SOLAR SYSTEM

Astronomy Jupiter Space

JUPITER THE BIGGEST PLANET IN THE SOLAR SYSTEM

Univers Science 4:01:00 PM Comment

Jupiter

Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a giant planet with a mass one-thousandth that of the Sun, but two and a half times that of all the other planets in the Solar System combined. Jupiter is a gas giant, along with Saturn, with the other two giant planets, Uranus and Neptune, being ice giants. Jupiter was known to astronomers of ancient times.

Our solar system

The Romans named it after their god Jupiter. When viewed from Earth, Jupiter can reach an apparent magnitude of −2.94, bright enough for its reflected light to cast shadows, and making it on average the third-brightest object in the night sky after the Moon and Venus.

(Jupiter the roman god = Zeus the greek) Jupiter  is the king of the gods and the god of sky and thunder  in Ancient Roman religion and mythology

Jupiter is primarily composed of hydrogen with a quarter of its mass being helium, though helium comprises only about a tenth of the number of molecules. It may also have a rocky core of heavier elements, but like the other giant planets, Jupiter lacks a well-defined solid surface. Because of its rapid rotation, the planet's shape is that of an oblate spheroid (it has a slight but noticeable bulge around the equator). The outer atmosphere is visibly segregated into several bands at different latitudes, resulting in turbulence and storms along their interacting boundaries. A prominent result is the Great Red Spot, a giant storm that is known to have existed since at least the 17th century when it was first seen by telescope. Surrounding Jupiter is a faint planetary ring system and a powerful magnetosphere. Jupiter has at least 67 moons, including the four large Galilean moons discovered by Galileo Galilei in 1610. Ganymede, the largest of these, has a diameter greater than that of the planet Mercury.

This cut-away illustrates a model of the interior of Jupiter, with a rocky core overlaid by a deep layer of liquid metallic hydrogen.

Jupiter has been explored on several occasions by robotic spacecraft, most notably during the early Pioneer and Voyager flyby missions and later by the Galileo orbiter. In late February 2007, Jupiter was visited by the New Horizons probe, which used Jupiter's gravity to increase its speed and bend its trajectory en route to Pluto. The latest probe to visit the planet is Juno, which entered into orbit around Jupiter on July 4, 2016. Future targets for exploration in the Jupiter system include the probable ice-covered liquid ocean of its moon Europa.

Formation and migration
Earth and its neighbor planets may have formed from fragments of planets after collisions with Jupiter destroyed those super-Earths near the Sun. As Jupiter came toward the inner Solar System, in what theorists call the Grand Tack Hypothesis, gravitational tugs and pulls occurred causing a series of collisions between the super-Earths as their orbits began to overlap.
Astronomers have discovered nearly 500 planetary systems with multiple planets. Regularly these systems include a few planets with masses several times greater than Earth's (super-Earths), orbiting closer to their star than Mercury is to the Sun, and sometimes also Jupiter-mass gas giants close to their star.
Jupiter moving out of the inner Solar System would have allowed the formation of inner planets, including Earth.

Physical characteristics
Jupiter is composed primarily of gaseous and liquid matter. It is the largest of the four giant planets in the Solar System and hence its largest planet. It has a diameter of 142,984 km (88,846 mi) at its equator. The average density of Jupiter, 1.326 g/cm3, is the second highest of the giant planets, but lower than those of the four terrestrial planets.

Composition
Jupiter's upper atmosphere is composed of about 88–92% hydrogen and 8–12% helium by percent volume of gas molecules. A helium atom has about four times as much mass as a hydrogen atom, so the composition changes when described as the proportion of mass contributed by different atoms. Thus, Jupiter's atmosphere is approximately 75% hydrogen and 24% helium by mass, with the remaining one percent of the mass consisting of other elements. The interior contains denser materials, such that the distribution is roughly 71% hydrogen, 24% helium, and 5% other elements by mass. The atmosphere contains trace amounts of methane, water vapor, ammonia, and silicon-based compounds. There are also traces of carbon, ethane, hydrogen sulfide, neon, oxygen, phosphine, and sulfur. The outermost layer of the atmosphere contains crystals of frozen ammonia. Through infrared and ultraviolet measurements, trace amounts of benzene and other hydrocarbons have also been found.

The atmospheric proportions of hydrogen and helium are close to the theoretical composition of the primordial solar nebula. Neon in the upper atmosphere only consists of 20 parts per million by mass, which is about a tenth as abundant as in the Sun. Helium is also depleted to about 80% of the Sun's helium composition. This depletion is a result of precipitation of these elements into the interior of the planet.

Based on spectroscopy, Saturn is thought to be similar in composition to Jupiter, but the other giant planets Uranus and Neptune have relatively less hydrogen and helium.

Mass and size
Jupiter's mass is 2.5 times that of all the other planets in the Solar System combined—this is so massive that its barycenter with the Sun lies above the Sun's surface at 1.068 solar radii from the Sun's center. Jupiter is much larger than Earth and considerably less dense: its volume is that of about 1,321 Earths, but it is only 318 times as massive. Jupiter's radius is about 1/10 the radius of the Sun, and its mass is 0.001 times the mass of the Sun, so the densities of the two bodies are similar. A "Jupiter mass" (MJ or MJup) is often used as a unit to describe masses of other objects, particularly extrasolar planets and brown dwarfs. So, for example, the extrasolar planet HD 209458 b has a mass of 0.69 MJ, while Kappa Andromedae b has a mass of 12.8 MJ.

mass comparison with earth

Theoretical models indicate that if Jupiter had much more mass than it does at present, it would shrink.[30] For small changes in mass, the radius would not change appreciably, and above about 500 M⊕(⊕:earth mass) (1.6 Jupiter masses) the interior would become so much more compressed under the increased pressure that its volume would decrease despite the increasing amount of matter. As a result, Jupiter is thought to have about as large a diameter as a planet of its composition and evolutionary history can achieve. The process of further shrinkage with increasing mass would continue until appreciable stellar ignition is achieved as in high-mass brown dwarfs having around 50 Jupiter masses.

Although Jupiter would need to be about 75 times as massive to fuse hydrogen and become a star, the smallest red dwarf is only about 30 percent larger in radius than Jupiter. Despite this, Jupiter still radiates more heat than it receives from the Sun; the amount of heat produced inside it is similar to the total solar radiation it receives. This additional heat is generated by the Kelvin–Helmholtz mechanism through contraction. This process causes Jupiter to shrink by about 2 cm each year. When it was first formed, Jupiter was much hotter and was about twice its current diameter.

Internal structure
Jupiter is thought to consist of a dense core with a mixture of elements, a surrounding layer of liquid metallic hydrogen with some helium, and an outer layer predominantly of molecular hydrogen. Beyond this basic outline, there is still considerable uncertainty. The core is often described as rocky, but its detailed composition is unknown, as are the properties of materials at the temperatures and pressures of those depths (see below). In 1997, the existence of the core was suggested by gravitational measurements, indicating a mass of from 12 to 45 times that of Earth, or roughly 4%–14% of the total mass of Jupiter. The presence of a core during at least part of Jupiter's history is suggested by models of planetary formation that require the formation of a rocky or icy core massive enough to collect its bulk of hydrogen and helium from the protosolar nebula. Assuming it did exist, it may have shrunk as convection currents of hot liquid metallic hydrogen mixed with the molten core and carried its contents to higher levels in the planetary interior. A core may now be entirely absent, as gravitational measurements are not yet precise enough to rule that possibility out entirely.

The uncertainty of the models is tied to the error margin in hitherto measured parameters: one of the rotational coefficients (J6) used to describe the planet's gravitational moment, Jupiter's equatorial radius, and its temperature at 1 bar pressure. The Juno mission, which arrived in July 2016, is expected to further constrain the values of these parameters for better models of the core.

The core region is surrounded by dense metallic hydrogen, which extends outward to about 78% of the radius of the planet. Rain-like droplets of helium and neon precipitate downward through this layer, depleting the abundance of these elements in the upper atmosphere.

Above the layer of metallic hydrogen lies a transparent interior atmosphere of hydrogen. At this depth, the pressure and temperature are above hydrogen's critical pressure of 1.2858 MPa and critical temperature of only 32.938 K. In this state, there are no distinct liquid and gas phases—hydrogen is said to be in a supercritical fluid state. It is convenient to treat hydrogen as gas in the upper layer extending downward from the cloud layer to a depth of about 1,000 km, and as liquid in deeper layers. Physically, there is no clear boundary—the gas smoothly becomes hotter and denser as one descends.

The temperature and pressure inside Jupiter increase steadily toward the core, due to the Kelvin–Helmholtz mechanism. At the "surface" pressure level of 10 bars, the temperature is around 340 K (67 °C; 152 °F). At the phase transition region where hydrogen—heated beyond its critical point—becomes metallic, it is calculated the temperature is 10,000 K (9,700 °C; 17,500 °F) and the pressure is 200 GPa. The temperature at the core boundary is estimated to be 36,000 K (35,700 °C; 64,300 °F) and the interior pressure is roughly 3,000–4,500 GPa.

Atmosphere
Jupiter has the largest planetary atmosphere in the Solar System, spanning over 5,000 km (3,000 mi) in altitude. Because Jupiter has no surface, the base of its atmosphere is usually considered to be the point at which atmospheric pressure is equal to 100 kPa (1.0 bar).
Jupiter is perpetually covered with clouds composed of ammonia crystals and possibly ammonium hydrosulfide. The clouds are located in the tropopause and are arranged into bands of different latitudes, known as tropical regions. These are sub-divided into lighter-hued zones and darker belts. The interactions of these conflicting circulation patterns cause storms and turbulence. Wind speeds of 100 m/s (360 km/h) are common in zonal jets. The zones have been observed to vary in width, color and intensity from year to year, but they have remained sufficiently stable for scientists to give them identifying designations.


Source : Wikipedia

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THE HUBBLE SPACE TELESCOPE H.S.T

Astronomy Space Technology

THE HUBBLE SPACE TELESCOPE H.S.T

Univers Science 5:25:00 AM Comment

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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WERNHER VON BRAUN: FROM NAZI TO NASA

Scientists Space Technology

WERNHER VON BRAUN: FROM NAZI TO NASA

Univers Science 5:53:00 AM Comment

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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WERNHER VON BRAUN

Scientists Space

WERNHER VON BRAUN

Univers Science 5:36:00 PM Comment

Wernher Magnus Maximilian Freiherr von Braun (March 23, 1912 – June 16, 1977) was a German, later American, aerospace engineer and space architect credited with inventing the V-2 rocket for Nazi Germany and the Saturn V for the United States. He was one of the leading figures in the development of rocket technology in Nazi Germany, where he was a member of the Nazi Party and the SS. Following World War II, he was moved to the United States, along with about 1,500 other scientists, technicians, and engineers, as part of Operation Paperclip, where he developed the rockets that launched the United States' first space satellite Explorer 1, and the Apollo program manned lunar landings.

Wernher von Braun

In his twenties and early thirties, von Braun worked in Germany's rocket development program, where he helped design and develop the V-2 rocket at Peenemünde during World War II. Following the war, von Braun worked for the United States Army on an intermediate-range ballistic missile (IRBM) program before his group was assimilated into NASA. Under NASA, he served as director of the newly formed Marshall Space Flight Center and as the chief architect of the Saturn V launch vehicle, the superbooster that propelled the Apollo spacecraft to the Moon. According to a NASA source, he is, "without doubt, the greatest rocket scientist in history", as well as the "Father of Rocket Science".[citation needed][6] In 1975, he received the National Medal of Science. He continued insisting on the human mission to Mars throughout his life.


His life
Wernher von Braun was born on 23 March 1912 in the small town of Wirsitz, Posen Province, German Empire (now Wyrzysk, Poland). He was the second of three sons. He belonged to a noble family, inheriting the German title of Freiherr (equivalent to Baron). His father, conservative civil servant Magnus Freiherr von Braun (1878–1972), served as a Minister of Agriculture in the Reich Cabinet during the Weimar Republic. His mother, Emmy von Quistorp (1886–1959), could trace her ancestry through both parents to medieval European royalty and was a descendant of Philip III of France, Valdemar I of Denmark, Robert III of Scotland, and Edward III of England. Von Braun had an older brother, Sigismund, and a younger brother, also named Magnus. After Wernher von Braun's Lutheran confirmation, his mother gave him a telescope, and he developed a passion for astronomy. The family moved to Berlin in 1915 where his father worked at the Ministry of the Interior. Here 12-year-old Wernher von Braun, inspired by speed records established by Max Valier and Fritz von Opel in rocket-propelled cars, caused a major disruption in a crowded street by detonating a toy wagon to which he had attached a number of fireworks. He was taken into custody by the local police until his father came to collect him.

Wernher (center) with his two brothers. 

Wernher von Braun was an accomplished amateur pianist who could play Beethoven and Bach from memory. He learned to play both the cello and the piano at an early age and at one time wanted to become a composer. He took lessons from the composer Paul Hindemith. The few pieces of von Braun’s youthful compositions that exist are reminiscent of Hindemith’s style.

Beginning in 1925, von Braun attended a boarding school at Ettersburg Castle near Weimar, where he did not do well in physics and mathematics. There he acquired a copy of By Rocket into Planetary Space (Die Rakete zu den Planetenräumen, 1923) by rocket pioneer Hermann Oberth. In 1928, his parents moved him to the Hermann-Lietz-Internat (also a residential school) on the East Frisian North Sea island of Spiekeroog. Space travel had always fascinated von Braun, and from then on he applied himself to physics and mathematics to pursue his interest in rocket engineering.

In 1930, he attended the Technische Hochschule Berlin, where he joined the Spaceflight Society (Verein für Raumschiffahrt or "VfR") and assisted Willy Ley in his liquid-fueled rocket motor tests in conjunction with Hermann Oberth. In spring 1932, he graduated from the Technische Hochschule Berlin (now Technical University of Berlin), with a diploma in mechanical engineering. His early exposure to rocketry convinced him that the exploration of space would require far more than applications of the current engineering technology. Wanting to learn more about physics, chemistry, and astronomy, von Braun entered the Friedrich-Wilhelm University of Berlin for post-graduate studies and graduated with a doctorate in physics in 1934. He also studied at ETH Zürich. Although he worked mainly on military rockets in his later years there, space travel remained his primary interest.

In 1930, von Braun attended a presentation given by Auguste Piccard. After the talk the young student approached the famous pioneer of high-altitude balloon flight, and stated to him: "You know, I plan on traveling to the Moon at some time." Piccard is said to have responded with encouraging words.

Working with the Nazis

First rank, from left to right, General Dr Walter Dornberger (partially hidden), General Friedrich Olbricht (with Knight's Cross), Major Heinz Brandt, and Wernher von Braun (in civil garment) at Peenemünde, in March 1941.
In 1933, Von Braun was working on his creative doctorate when the National Socialist German Workers Party (NSDAP, or Nazi Party) came to power in a coalition government in Germany; rocketry almost immediately moved onto the national agenda. An artillery captain, Walter Dornberger, arranged an Ordnance Department research grant for von Braun, who then worked next to Dornberger's existing solid-fuel rocket test site at Kummersdorf. He was awarded a doctorate in physics (aerospace engineering) on July 27, 1934, from the University of Berlin for a thesis entitled "About Combustion Tests"; his doctoral supervisor was Erich Schumann. However, this thesis was only the public part of Von Braun's work. His actual full thesis, Construction, Theoretical, and Experimental Solution to the Problem of the Liquid Propellant Rocket (dated April 16, 1934) was kept classified by the army, and was not published until 1960. By the end of 1934, his group had successfully launched two liquid fuel rockets that rose to heights of 2.2 and 3.5 km (2 mi).

Wernher von Braun with the NAZI party

At the time, Germany was highly interested in American physicist Robert H. Goddard's research. Before 1939, German scientists occasionally contacted Goddard directly with technical questions. Wernher von Braun used Goddard's plans from various journals and incorporated them into the building of the Aggregat (A) series of rockets. The A-4 rocket would become well known as the V-2. In 1963, von Braun reflected on the history of rocketry, and said of Goddard's work: "His rockets ... may have been rather crude by present-day standards, but they blazed the trail and incorporated many features used in our most modern rockets and space vehicles."

Surrender to the Americans
The Soviet Army was about 160 km (99 mi) from Peenemünde in the spring of 1945 when Von Braun assembled his planning staff and asked them to decide how and to whom they should surrender. Afraid of the well-known Soviet cruelty to prisoners of war, von Braun and his staff decided to try to surrender to the Americans. Kammler had ordered relocation of his team to central Germany; however, a conflicting order from an army chief ordered them to join the army and fight. Deciding that Kammler's order was their best bet to defect to the Americans, von Braun fabricated documents and transported 500 of his affiliates to the area around Mittelwerk, where they resumed their work. For fear of their documents being destroyed by the SS, von Braun ordered the blueprints to be hidden in an abandoned mine shaft in the Harz mountain range.
While on an official trip in March, von Braun suffered a complicated fracture of his left arm and shoulder in a car accident after his driver fell asleep at the wheel. His injuries were serious, but he insisted that his arm be set in a cast so he could leave the hospital. Due to this neglect of the injury he had to be hospitalized again a month later where his bones had to be re-broken and re-aligned.
In April, as the Allied forces advanced deeper into Germany, Kammler ordered the engineering team to be moved by train into the town of Oberammergau in the Bavarian Alps where they were closely guarded by the SS with orders to execute the team if they were about to fall into enemy hands. However, Von Braun managed to convince SS Major Kummer to order the dispersion of the group into nearby villages so that they would not be an easy target for U.S. bombers.

Wernher von Braun with americans

President John F. Kennedy and Dr. Wernher von Braun

Von Braun and a large number of the engineering team subsequently made it to Austria. On May 2, 1945, upon finding an American private from the U.S. 44th Infantry Division, Von Braun's brother and fellow rocket engineer, Magnus, approached the soldier on a bicycle, calling out in broken English: "My name is Magnus von Braun. My brother invented the V-2. We want to surrender."
The American high command was well aware of how important their catch was: von Braun had been at the top of the Black List, the code name for the list of German scientists and engineers targeted for immediate interrogation by U.S. military experts.


Source : Wikipedia

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CURIOSITY THE MARS ROBOTIC ROVER

Mars Space Technology

CURIOSITY THE MARS ROBOTIC ROVER

Univers Science 12:51:00 PM Comment

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.


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L.H.C THE LARGE HADRON COLLIDER

Space Technology

L.H.C THE LARGE HADRON COLLIDER

Univers Science 6:04:00 AM Comment

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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