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Sonntag, 2. November 2014 - 18:32 Uhr

Raumfahrt - Indien´s GSLV Mark-III Trägerrakete vor partiellen Testflug im Dezember

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R. S.Kannu, Senior Scientist of Liquid Propulsion Systems Centre of Indian Space Research Organisation near Tirunelveli, explaining the features and functioning of the GSLV Mark-III to school students, at an outreach programme organised by ISRO in Tirupur. File photo: R. Vimal Kumar

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Future workhorse will test unmanned crew module: ISRO chief
GSLV Mark-III, the bigger and better space vehicle that will enable larger national communication satellites to be launched from India, is set for its first partial test flight in the first half of December.
The landmark test flight will lead to a “future workhorse vehicle that will stay with us for many years,” ISRO Chairman K. Radhakrishnan said.
It also tests features of an unmanned crew module that will be flown down from space and recovered from sea.
The second study is part of an ambitious future Human Space Flight proposal that is yet to be approved. The space agency has not attempted a partial test flight before in its rocket development course but Mark-III’s new gas generator cycle technology allows this.
In the crew module test, “the main objective is to look at heating during re-entry and how a vehicle of that size and shape performs in the crucial space phase. The thermal protection systems around the crew module must withstand the [high] temperature.” A failsafe, parachute-aided descent of the crew module is crucial for flying future Indian astronauts into space and getting them back to Earth safely.
Pre-launch activities have begun for Mark-III, Dr. Radhakrishnan said on the sidelines of an engineers’ conclave here. A parachute test was conducted on Thursday and another one would be done in the coming days.
The vehicle stages are being put together and electrical checks are being done at launch site Sriharikota; propulsion systems are being readied at Mahendragiri.
“We should be able to integrate the vehicle [with] the crew module by the end of this month and test the entire system [on ground]," he said.
Mark-III is a totally new vehicle different from the smaller indigenous GSLV Mark-II [II] that is of half its capacity. Its three stages are respectively fuelled by solid, liquid and the upper cryogenic propellants.
For the December flight, “the [solid-fuelled] strap-ons and the liquid core are active but the cryogenic engines will not be ignited. The propellants will be simulated.”
Two years away
Mark-III can have its first full developmental flight — carrying a full satellite of about 3,500 kg – only when the cryogenic stage is qualified; that could take two to three years. ISRO now depends on costly foreign launchers to put its 3-tonne communication satellites into space.
“If a couple of developmental flights succeed, then we should be able to launch from India communication satellites weighing 3.5 tonnes to 4 tonnes and which can carry more transponders and more power... We now have confidence [of realising] the cryogenic engine and stage in that timeframe,” said Dr. Radhakrishnan.
Quelle: The Hindu

Tags: Raumfahrt 

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Sonntag, 2. November 2014 - 17:50 Uhr

Raumfahrt - Virgins SpaceShip Two explodiert - ein Toter

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1.11.2014

Das "SpaceShip Two" sollte Träume wahr machen: Weltraumflüge für Privatpersonen. Nach langen Verzögerungen kündigte der prominente Unternehmer Richard Branson erste Passagierflüge für Frühjahr 2015 an. Nun zerschellte sein Traum in der kalifornischen Wüste.
Das private Raumflugzeug "SpaceShip Two" ist bei einem Testflug im US-Bundesstaat Kalifornien abgestürzt. "Während des Tests erlitt das Gefährt eine ernsthafte Unregelmäßigkeit, die im Verlust des Gefährts resultierte", teilte das Unternehmen Virgin Galactic mit. Nach Polizeiangaben kam einer der beiden Piloten ums Leben, der andere wurde schwer verletzt. Amerikanische TV-Sender zeigten Bilder mehrerer Wrackteile in der Mojave-Wüste.
Der Unfall war der zweite schwere Schlag für die private Raumfahrt innerhalb weniger Tage. Erst am vergangenen Dienstag war der unbemannte US-Raumtransporter "Cygnus" Sekunden nach dem Start in Florida explodiert. Er sollte rund 2,3 Tonnen Nachschub für die Internationale Raumstation ISS ins All bringen.
Andere Treibstoffmischung getestet
Das "SpaceShip Two" hob den Informationen zufolge von einem Flughafen rund 150 Kilometer nördlich von Los Angeles ab. Es wurde zunächst von einem Trägerflugzeug in rund 1,5 Kilometer Höhe gebracht und dann ausgeklinkt. Nur wenig später sei es abgestürzt. Die US-Flugkontrollbehörde FAA teilte mit, kurz nach der Abkoppelung den Kontakt zu dem Raumflugzeug verloren zu haben. Das Trägerflugzeug "WhiteKnightTwo" hingegen sei sicher gelandet, so Virgin Galactic.
Es war der erste Test des Raumgleiters mit Raketenzündung seit Januar. Berichten von Experten zufolge sei diesmal eine andere Treibstoffmischung als zuvor getestet worden. Offizielle Angaben zur Absturzursache machte das UNTERNEHMEN zunächst nicht.
Zukunft des Weltraumtourismus steht in Frage
Das verunglückte Flugzeug basiert auf dem Prototyp "SpaceShip One" und wurde von einer Tochter des US-Rüstungskonzerns Northrop Grumman entwickelt.
Nun steht die Zukunft des Weltraumtourismus in Frage. "Wir werden im nächsten Jahr und wahrscheinlich in den Jahren danach keine kommerziellen FLÜGE für Touristen ins All sehen", glaubt Raumfahrtexperte Marco Caceres von der Beratungsfirma Teal Group. Virgin Galactic sei bislang führend im Bereich des Weltraumtourismus gewesen.
Über 700 Interessierte sicherten sich Tickets
Die rund 18 Meter lange Passagierraumfähre sollte den Planungen zufolge vom kommenden Jahr an Weltraumflüge für Privatpersonen anbieten, die bis in rund 110 Kilometer Höhe über der Erde führen sollten. Die Maschine bot Platz für zwei Piloten und sechs Passagiere. Sie sollten bei ihren REISEN das Gefühl der Schwerelosigkeit erleben können. Die Bullaugen-Fenster des Gefährtes waren deutlich größer als in normalen Passagierflugzeugen.
Hinter dem Projekt steht unter anderem der milliardenschwere britische Unternehmer Richard Branson. Nach seinen Angaben hatten bereits 700 Interessierte Tickets für die FLÜGE ins All gekauft. Darunter sollen auch Stars wie die Hollywood-Schauspieler Tom Hanks und Angelina Jolie sowie der Sänger Justin Bieber sein, wie Medien berichteten.
Quelle:t-online
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Space Tourism Rocket Crash Stirs Mixed Emotions

This image from video by KABC TV Los Angeles shows wreckage of what is believed to be SpaceShipTwo in Southern California's Mojave Desert on Friday, Oct. 31, 2014. A Virgin Galactic space tourism rocket exploded after taking off on a test flight, a witness said Friday. (AP Photo/KABC TV)

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The explosion of Virgin Galactic's passenger rocket ship is stirring up mixed emotions as scientists and others involved in the space industry wait for more details on what happened over the Mojave Desert on Friday.
While several people expressed sadness that one pilot was killed and another was seriously injured, many also said they understand the risks that come with pushing the boundaries that have hampered the burgeoning commercial space travel industry.
The reaction to the crash includes:
— Former NASA top space scientist Alan Stern has seats to fly on Virgin Galactic — and its competitor XCOR aerospace. He isn't rethinking plans to fly in space at all.
"Let's not be Chicken Littles here," said Stern, now a vice president at Southwest Research Institute. "The birth of aviation was also a very dangerous time period."
"All forms of transportation carry risk," he said. "To expect spaceflight could somehow be different is unrealistic on the part of the public or anyone. Secondly to do something very hard, to do something on the frontier, comes with risk."
— Eric Stallmer, the president of the Commercial Spaceflight Federation, offered his sympathies to the families affected by the explosion.
"Today, we are tragically reminded of the tremendous challenges that we face every day in our efforts to push the envelope of human experience and capability in space enterprise and exploration," he said.
Stallmer and Bill Nye, chief executive of the Planetary Society, said the courage of both pilots and the commitment Virgin Galactic has made to space tourism will serve as inspiration as the industry continues to make space travel as safe and reliable as possible.
— Former NASA astronaut Jerry Linenger, who nearly died in a 1997 fire aboard the Russian space station Mir, said that when he first met British billionaire Richard Branson, founder of Virgin Galactic, he told him the first thing he'd have to worry about is liability insurance.
"You will have setbacks," Linenger said he told Branson. "That is a reality."
— In New Mexico, from where Virgin Galactic planned to launch its flights within the next year, hearts were sinking. The New Mexico Spaceport Authority issued a statement saying its thoughts and prayers were with the crew's family members and the team that has been working for years to develop the rocket.
"We will continue to work with and lend our support to Virgin Galactic through this tragedy and in the coming months as we move forward," the authority said.
—The National Space Society said it stands by Virgin Galactic CEO George Whitesides and encouraged the company to press on.
"We expect that the cause of the accident will be found and fixed so that the Virgin Galactic dream of 'opening space to tens of thousands of people' can become a reality," said Mark Hopkins, chairman of the NSS Executive Committee.
—NASA Administrator Charles Bolden also shared his condolences.
"While not a NASA mission, the pain of this tragedy will be felt by all the men and women who have devoted their lives to exploration," he said. "Space flight is incredibly difficult, and we commend the passion of all in the space community who take on risk to push the boundaries of human achievement."
—Wilson da Silva, a journalist, is among the first 100 people to fly once Virgin Galactic begins its commercial flights. While devastated for the pilots and their families, da Silva is still excited about the prospect of going into space.
"While some have in the past grumbled good-naturedly about the years of waiting, we all know Virgin Galactic is doing something new and very difficult, and any delays have been for sound technical and safety reasons," da Silva said. "This is a reminder that what's being attempted here is pioneering and risky."
—Ken Baxter, 65, of Las Vegas, said he was one of those who signed up to make the first flight early next year. He's confident the flight will happen at some point.
"No question about it," he said. "Richard's not a giver-upper and neither am I."
Quelle: abc
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Cause of Fatal Virgin Galactic Crash a Mystery to Designers

The crash of the Virgin Galactic spacecraft that killed one pilot and injured another scattered wreckage across a large area of the Mojave desert, but it also clearly rattled the “small” community of test pilots and technicians in the field.
"Space is hard and today was a tough day," said George Whitesides, CEO of Virgin Galactic. He added, "The future rests in many ways on hard days like this."
Stuart Witt, the CEO of Mojave Air and Space Port, said the death of the pilot was keenly felt.
"When we have a mishap from the test community, we find the test community is very small And we are human and it hurts," Witt said.
The officials confirmed that both people involved in the incident were test pilots from the Virgina Galactic partner, Scaled Composites. The pilots were not identified.
Sheriff Donnie Younblood said, "I flew around the crash site. It’s a large area. The aircraft is in several different pieces."
Virgin founder Richard Branson is expected to arrive in Mojave by Saturday morning. Also due at the site on Saturday is a team from the National Transportation Safety Board. The NTSB announced that they will send a full team of investigators, led by acting chairman Christopher Hart.
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PHOTO: The Virgin Galactic spacecraft breaks up in midair as it flies over the Mojave desert
Witt said the exact cause of the "anomaly" that caused the crash remains unknown.
"From my eyes and my ears, I detected nothing," Witt said.
"I knew [something was wrong] when other things weren't happening. It wasn't cause something happened, it was something’s not happening," he said.
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HOTO: The Virgin Galactic spacecraft breaks up in midair as it flies over the Mojave desert
Whitesides said that a new fuel formulation was being used in this test flight, but said that it had been "proven and tested numerous times on the ground."
The craft dubbed SpaceShipTwo was destroyed after it separated from its mother ship, White Knight Two, the company said.
Kevin Mickey, president of Scale Composites, explained that the mother ship flies the spacecraft to 45,000 feet, "then it’s released. It's a glider in free fall. Then the rocket is lit and you are on your way."
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PHOTO: The Virgin Galactic spacecraft breaks up in midair as it flies over the Mojave desert
Virgin Galactic, part of Branson's group of companies, has announced plans to operate a fleet of SpaceShipTwo vehicles for private sub-orbital flights.
This is the second private space mission to end catastrophically this week.
On Tuesday, an Antares rocket produced by Orbital Sciences exploded seconds after liftoff in Virginia while on a NASA-contracted supply mission to the International Space Station.
"This hasn't been an easy week. It certainly has been a challenge," Witt said. "But where I’m from this is where you find out your true character."
ABC News' Matt Hosford and Jonah Lustig contributed to this report.
Quelle: abc
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Virgin Galactic crash: Inquiry team lands in Mojave
David Willis in the Mojave desert on the final moments of SpaceShipTwo
Continue reading the main story
One pilot died and the other was badly injured when SpaceShipTwo exploded SHORTLY after take-off on Friday.
A National TRANSPORTATION Safety Board team arrived in Mojave on Saturday and was heading to the crash site.
Virgin chief Sir Richard Branson vowed to continue his space tourism "dream" despite the crash.
NTSB investigators flew in to the Mojave Air and Space Port before heading to the desert crash SITE
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The on-site investigation into the crash in the Mojave desert is expected to last SEVERAL days
Speaking at the at the Mojave Air and Space Port, where the craft was being DEVELOPED, Virgin Group founder Sir Richard said: "It is fair to say that all 400 engineers who work here, and I think most people in the world, would love to see the dream living on.
"We owe it to our test pilots to find out what went wrong, and once we find out, if we can overcome it, we will make sure that the dream lives on."
Virgin had hoped to launch commercially in 2015. It has already taken more than 700 FLIGHT bookings at $250,000 (£156,000) each, with Sir Richard pledging to travel on the first FLIGHT.
Eyewitness Ken Brown: "It burned for a time and then just exploded"
Sir Richard said Virgin Galactic and its PARTNERS had "been undertaking a comprehensive testing programme for many years and safety has always been our number one priority".
"We are determined to find out what went wrong and are working with the authorities to get that information," he added.
A team of between 13 and 15 NTSB investigators - including specialists in structures, systems, engines and vehicle performance - arrived in Mojave on Saturday morning and would begin on-SITE work later in the day, NTSB acting chairman Christopher Hart said.
Their work would include detailed examination of all available data, work at the crash site and interviewing witnesses, Mr Hart said.
"This was a test FLIGHT and test FLIGHTS are typically very well documented in terms of data," he added.
'Serious anomaly'
SpaceShipTwo was flying its first test flight for nine months when it crashed shortly after take-off near the town of Bakersfield, California.
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In a statement, the company said SpaceShipTwo experienced "a serious anomaly" after the craft separated from its launcher, an aircraft called WhiteKnightTwo.
WhiteKnightTwo landed safely.
It later emerged that the space craft was burning a new type of of rocket fuel never before used in flight, although officials said it had undergone EXTENSIVE ground testing.
In a blog post on Friday, Sir Richard said everyone involved in the project was "deeply saddened".
"All our thoughts are with the families of everyone affected by this tragic EVENT," he wrote.
Quelle: BBC
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'Tough day' for space travel as Virgin Galactic's spaceship crashes
Quelle: The Los Angeles Times
 
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Update: 2.11.2014 
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CSF Statement on Virgin Galactic and Scaled Composites Test Flight
Washington D.C. – Today, Virgin Galactic and Scaled Composites encountered a tragic in-flight anomaly resulting in the death of the pilot and injuring a second. The Commercial Spaceflight Federation would like to express our deepest sympathies to the families of those affected and offer our wishes for a swift and complete recovery for the injured pilot.
Right now, Virgin Galactic and Scaled Composites are working with the team at Mojave Air & Space Port and local authorities to secure the site and ensure the safety of all those involved in the recovery and investigation. It is far too early to know the details of what happened. CSF will provides updates as they come in.
“Today, we are tragically reminded of the tremendous challenges that we face every day in our efforts to push the envelope of human experience and capability in space enterprise and exploration,” said Commercial Spaceflight Federation President Eric Stallmer. “The precious life that was lost cannot be replaced and will never be forgotten. The courage of both pilots will serve as inspiration for us all to continue to meet the challenges of spaceflight with clear focus and determination in order to make it as safe and reliable as possible.”
About the Commercial Spaceflight Federation
The mission of the Commercial Spaceflight Federation (CSF) is to promote the development of commercial human spaceflight, pursue ever-higher levels of safety, and share best practices and expertise throughout the industry. The Commercial Spaceflight Federation’s member companies, which include commercial spaceflight developers, operators, spaceports, suppliers, and service providers, are creating thousands of high-tech jobs nationwide, working to preserve American leadership in aerospace through technology innovation, and inspiring young people to pursue careers in science and engineering.
Quelle: CSF
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Pilot who parachuted out of exploding Virgin Galactic spaceship is conscious in hospital with shoulder injury and 'talking with doctors and family'
Peter Siebold, who was named today as injured pilot, is 'alert' in hospital
Has shoulder injury and is being treated in California hospital after accident
Siebold ejected from Virgin Galactic spacecraft which exploded yesterday
Co-pilot Michael Alsbury was killed in the disaster over the Mojave Desert 
Siebold, 43, who got his pilot license at just 16, is a married father of two 
He and Alsbury had piloted SpaceShipTwo many times before
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he seriously injured Virgin Galactic astronaut who parachuted out of the space plane that exploded on a test flight yesterday is awake in hospital and able to speak to his family.
Peter Siebold, earlier identified as the sole survivor of the destroyed SpaceShipTwo craft, was today described as 'alert' after suffering serious injuries in the fatal crash. 
Siebold, a 43-year-old father of two, reportedly suffered a serious shoulder injury in the disaster, and is due for surgery soon. But Scaled Composites, Virgin Galactic's partner company, confirmed today he was conscious and communicative. 
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Critical: Peter Siebold (left, getting prepped with Michael Alsbury before the first guide flight in 2010) was critically injured in Friday's explosion
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Best friends: Siebold and Alsbury celebrate after completing their run in 2010, which Richard Branson was on hand to watch
The seasoned pilot lives Tehachapi, California, near the Virgin Galactic spaceport. He was a wife, Traci, and two children.
Michael Alsbury, his co-pilot, was killed when the experimental craft was destroyed at 45,000ft after detaching from another plane which was carrying it over the Mojave Desert in California.
A statement from Scaled Composites today said: 'The Scaled Composites family lost a respected and devoted colleague yesterday, Michael Alsbury, who was the co-pilot for the test flight of SpaceShipTwo.
'Peter Siebold, the Director of Flight Operations at Scaled Composites, was piloting SpaceShipTwo. 
'He is alert and talking with his family and doctors. We remain focused on supporting the families of the two pilots and all of our employees, as well as the agencies investigating the accident.'
The company did not go into detail over his injuries. But Siebold is currently hospitalized with his shoulder injury at Antelope Valley Hospital in Lancaster, California, the LA Times reported. 
Siebold and Alsbury regularly flew the plane as a duo, and had made successful trips as recently as August 28. Their identities were first reported Friday evening by Flying Mag.
Branson has yet to say anything about Siebold, although the Virgin CEO was on hand when he and Alsbury flew the plane's first glide flight in 2010.
Branson had previously claimed he never met Alsbury. 
Siebold, a Scaled Composite pilot like Alsbury, flew his first solo flight and gained his pilot’s license at 16 - the youngest age possible - and went on to teach flight classes at the San Luis Obispo Airport while he was a student at Cal Poly. He completed his degree in 2001.
He was also one of the test pilots for SpaceShipOne, a experimental spaceplane that completed the first manned private spaceflight in 2004.
As a design engineer at its aerospace company Scaled Composites, Siebold was responsible for the simulator, navigation system, and ground control system for the SpaceShipOne project.
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Tragic loss: Alsbury (above) was also a married father of two, and his family was close with the Siebold
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In 2009, he was awarded the Iven C. Kincheloe award - the most prestigious award a test pilot can receive - for his role as chief test pilot on the Model 348 WhiteKnightTwo plane, used to lift the SpaceShipTwo spacecraft to release altitude.
By the time of his award, he had logged about 2,500 hours of flight time in 40 different types of fixed wing aircraft.
Siebold was airlifted to the hospital on Friday, was heading to surgery on Saturday afternoon in California.
Quelle: MO

Tags: Raumfahrt 

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Sonntag, 2. November 2014 - 10:27 Uhr

Raumfahrt - NASA Armstrong feiert 50. Jahrestag des LLRV Erstflug

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NASA Armstrong hosted a colloquium to celebrate the 50th anniversary of the first LLRV flight. Guests included original team members, from left, Wayne Ottinger, Dave Stoddard Glenn Angle, Gene Matranga, Donald Mallick, and Adam Mello.

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Before the Apollo astronauts landed on the moon, they first had to practice on Earth. A colloquium at NASA Armstrong Flight Research Center on Oct. 29 marked the 50th anniversary of the first flight of a most unusual vehicle that was used to train the first humans to visit another world – the Lunar Landing Research Vehicle, or LLRV. Guest speakers included former project manager Gene Matranga, engineer Wayne Ottinger, pilot Donald Mallick, and Rocket Shop supervisor Dave Stoddard. Other original LLRV team members present included Glenn Angle and Adam Mello.
In the early 1960s, NASA studied several techniques for simulating descent to the lunar surface. Electronic simulators and a tethered mockup provided valuable training but only a free-flying vehicle could provide a truly high-fidelity simulation. Hubert Drake at NASA’s Flight Research Center (known today as the Armstrong Flight Research Center) conceived a concept that became the LLRV.
Built of aluminum alloy trusses and shaped like a giant four-legged bedstead, the vehicle simulated a lunar landing profile with the help of a 4,200-pound-thrust turbofan engine mounted vertically in a gimbal. Upon reaching the maximum test altitude, the pilot then throttled back until the jet supported just five-sixths of the vehicle's weight, simulating the moon’s reduced gravity. Two variable-thrust hydrogen peroxide rockets controlled the LLRV's rate of descent and horizontal movement. Sixteen smaller hydrogen peroxide thrusters gave the pilot control in pitch, yaw, and roll.
For the initial flights on Oct. 30, 1964, research pilot Joe Walker flew the LLRV three times for a total of just under 60 seconds, reaching a modest peak altitude of 10 feet. Later flights were shared between Walker; Donald Mallick; the Army's Jack Kleuver; and Joseph Algranti and H.E. "Bud" Ream of NASA’s Manned Spacecraft Center (now the Johnson Space Center) in Houston, Texas.
The first LLRV was shipped to Houston in December 1966, followed a month later by its nearly identical twin. Three slightly larger craft joined the training fleet, and all were re-designated Lunar Landing Training Vehicles. Three of the five were later destroyed in non-fatal accidents. Fittingly, the two surviving vehicles are currently displayed at Armstrong and Johnson.
All prime and backup commanders assigned to Apollo lunar landing missions practiced in the craft and later acknowledged the benefits. Apollo 11 astronaut Neil Armstrong, first human to step onto the moon's surface, said the mission would not have been successful without the quality of simulation that resulted from the LLRV's. Other astronauts echoed these feelings.
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NASA research pilot Joe Walker prepares for a flight in the Lunar Landing Research Vehicle. Eventually, all prime and backup commanders assigned to Apollo lunar landing missions practiced in the unusual craft.
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The ungainly-looking LLRV provided research pilots and astronauts with a highly accurate lunar landing simulation. Though a crucial part of the Apollo training program, it earned the undignified nickname, 'The Flying Bedstead.'
Quelle: NASA

Tags: Raumfahrt 

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Sonntag, 2. November 2014 - 10:14 Uhr

Astronomie - NASA enthüllt Geheimnisse des Interstellaren Raum

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This enormous mosaic of the Milky Way galaxy from NASA's Wide-field Infrared Survey Explorer, or WISE, shows dozens of dense clouds, called nebulae. Many nebulae seen here are places where new stars are forming, creating bubble like structures that can be dozens to hundreds of light-years in size.

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The new Paramount film "Interstellar" imagines a future where astronauts must find a new planet suitable for human life after climate change destroys the Earth's ability to sustain us. Multiple NASA missions are helping avoid this dystopian future by providing critical data necessary to protect Earth. Yet the cosmos beckons us to explore farther from home, expanding human presence deeper into the solar system and beyond. For thousands of years we've wondered if we could find another home among the stars. We're right on the cusp of answering that question.
If you step outside on a very dark night you may be lucky enough to see many of the 2,000 stars visible to the human eye. They're but a fraction of the billions of stars in our galaxy and the innumerable galaxies surrounding us. Multiple NASA missions are helping us extend humanity's senses and capture starlight to help us better understand our place in the universe.
Largely visible light telescopes like Hubble show us the ancient light permeating the cosmos, leading to groundbreaking discoveries like the accelerating expansion of the universe. Through infrared missions like Spitzer, SOFIA and WISE, we've peered deeply through cosmic dust, into stellar nurseries where gases form new stars. With missions like Chandra, Fermi and NuSTAR, we've detected the death throes of massive stars, which can release enormous energy through supernovas and form the exotic phenomenon of black holes. 
Yet it was only in the last few years that we could fully grasp how many other planets there might be beyond our solar system. Some 64 million miles (104 kilometers) from Earth, the Kepler Space Telescope stared at a small window of the sky for four years. As planets passed in front of a star in Kepler's line of view, the spacecraft measured the change in brightness. Kepler was designed to determine the likelihood that other planets orbit stars. Because of the mission, we now know it's possible every star has at least one planet. Solar systems surround us in our galaxy and are strewn throughout the myriad galaxies we see. Though we have not yet found a planet exactly like Earth, the implications of the Kepler findings are staggering—there may very WELL be many worlds much like our own for future generations to explore.
NASA also is developing its next exoplanet mission, the Transiting Exoplanet Survey Satellite (TESS), which will search 200,000 nearby stars for the presence of Earth-size planets.
As of now, the distance between stars is too great for spacecraft to traverse using existing propulsion. Only one spacecraft is poised to leave the solar system in the near future. Voyager 1, launched in 1977, made the historic entry into interstellar space in August of 2012, reaching the region between stars, filled with material ejected by the death of nearby stars millions of years ago. It won't encounter another star for at least 40,000 years.  
The near-term future of exploration should be cause for much excitement, though, as humans and robotic spacecraft pioneer the path Voyager traveled, deeper into our solar system, where extra-terrestrial life may exist, and where humans could one day thrive.
Life as we know it requires water and heat. On our watery planet, we find life teeming at even the most extreme temperatures. Scientists are eager to know if evidence of microbial life exists on other planets and moons within our reach. On Jupiter's moon Europa, for example, there is a temperate ocean caught between a volcanic core and icy surface. Just as life exists in the dark, hot reaches of Earth's ocean, so too could it exist on Europa, waiting to be discovered. NASA is studying a future mission to the watery moon next decade.
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Called the eXtreme Deep Field, or XDF, image from NASA's Hubble Space Telescope contains about 5,500 galaxies. Some span back 13.2 billion years in time -- nearly to the Big Bang, and are the most distant galaxies ever seen.
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Many scientists question if Earth formed with the water it has now. Comets and asteroid impacts early in the planet's history may have brought the water and help transform our atmosphere. Upcoming missions to capture samples of asteroids, like OSIRIS-REx, could reveal the building blocks of life embedded in the rock, which could lead to new insights about the origins of life.
Perhaps the most enticing target to search for evidence of life, however, is Mars. A fleet of spacecraft on the surface and orbiting Mars have revealed the Red Planet once had conditions suitable for life. While the planet's flowing water and atmosphere have significantly diminished, evidence of past life could still be discovered by future exploration. It could even be a home for future human pioneers.
Martian natural resources like water ice embedded in rock could be extracted to create breathable air, drinkable water, and even components for spacecraft propellant. An ability to live off the land will greatly enable multiple human missions to Mars and forever change the history of humankind.
This Journey to Mars begins aboard the International Space Station where astronauts 250 miles above Earth are learning how to live in space for long durations—key knowledge needed for round trips to Mars, which could take 500 days or more. A new generation of U.S. commercial spacecraft and rockets are supplying the space station and will soon launch astronauts once again from U.S. soil. As these 21st century spaceflight innovations open low-Earth Orbit in new ways, NASA is building the capabilities to send humans farther from Earth than even before. In December, we'll conduct the first flight test of the Orion Spacecraft, which will carry astronauts next decade on missions beyond the moon to an asteroid and Mars, launched on the giant Space Launch System rocket. 
Many other missions in the near future will expand the frontier of exploration in our solar system. In 2015, New Horizons will fly by Pluto and see the icy world up close for the first time. In 2016, NASA will launch the InSight mission to Mars and asteroid sample return mission OSIRIS-REx. In 2018, Hubble's successor, the James Webb Space Telescope, will see light from the universe's first stars. In about 2019, we'll launch a robotic spacecraft to capture and redirect an asteroid. In 2020, we'll send a new rover to Mars, to follow in the footsteps of Curiosity, search for ancient Martian life, and pave the way for future human explorers. In 2021, SLS and Orion will launch humans on the first crewed mission of the combined system. In the mid-2020s, astronauts will explore an asteroid redirected to an orbit around the moon, and return home with samples that could hold clues to the origins of the solar system and life on Earth. In doing so, those astronauts will travel farther into the solar system than anyone has ever been.
Quelle: NASA

Tags: Astronomie 

2035 Views

Samstag, 1. November 2014 - 23:20 Uhr

Astronomie - Sonnenfleck-AR2192 durch Nebelbankfilter und SDO

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Spechteln am Wochenende machte mit Sonnenfleck-2192-Beobachtung am Tage durch auflösende Nebelbänke viel Spaß.

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So sieht NASA-Sonde SoHo die aktuellen Sonnenflecken auf der Sonne...

und nachfolgende Aufnahmen vom Beobachten durch Nebelbank als Filter:

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Fotos: @hjkc

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Update:

GIANT SUNSPOT CRACKLING WITH FLARES: AR2192 is the biggest sunspot in nearly 25 years, and it is still growing. The active region now covers 2750 millionths of the solar disk, an area equivalent to more than 16 planet Earths skinned and spread out flat. It is so large that sky watchers are seeing it with the naked eye when the sun is dimmed by low-hanging clouds or, in this case, dense fog:

Barry Freas took the picture on October 26th from Red Hill, Kentucky. "It was a very foggy morning," he says. "AR2192 was remarkable."
Big sunspots tend to produce strong flares, and AR2192 is no exception. It is crackling with magnetic activity. Since the active region appeared on Oct. 19th it has unleashed 5 X-flares and a dozen M-flares. The most intense of these flares have caused HF radio blackouts and other communication disturbances on the dayside of Earth.
Usually, strong flares are accompanied by massive CMEs--billion-ton clouds of electrified gas that billow away from the blast site. So far, however, none of the eruptions from AR2192 has produced a major CME. Without a series of CMEs to hit Earth and rattle our planet's magnetic field, there have been no geomagnetic storms nor any widespread auroras.
Quelle: Spaceweather

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Update: 1.11.2014

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Tracking a Gigantic Sunspot Across the Sun

Super sunspot AR2192 produced 10 significant solar flare while traversing the Earth-side of the sun; six X-class and four above M5-class.
Image Credit: NASA/SDO
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An active region on the sun – an area of intense and complex magnetic fields – rotated into view on Oct. 18, 2014. Labeled AR 12192, it soon grew into the largest such region in 24 years, and fired off 10 sizable solar flares as it traversed across the face of the sun. The region was so large it could be seen without a telescope for those looking at the sun with eclipse glasses, as many did during a partial eclipse of the sun on Oct. 23.
"Despite all the flares, this region did not produce any significant coronal mass ejections," said Alex Young a solar scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. Coronal mass ejections, or CMEs, are giant clouds of solar particles that can affect technology when they reach near-Earth space. "You certainly can have flares without CMEs and vice versa, but most big flares do have CMEs. So we're learning that a big active region doesn't always equal the biggest events."
Such active regions are measured in millionths of a solar hemisphere, where 1 micro-hemisphere, or MH, is about 600,000 square miles. This region topped out at 2,750 MH, making it the 33rd largest region out of approximately 32,000 active regions that have been tracked and measured since 1874. It is the largest sunspot seen since AR 6368, which measured 3,080 MH on Nov. 18, 1990.
The largest five active regions ever observed were between 4,000 and more than 6,000 MH and they all appeared between 1946 and 1951.
On the other hand, the region that produced one of the biggest solar flares of all time on Sep. 1, 1859  – in what's known as the Carrington event – wasn't even one of the top 50 at only 2,300 MH.
During its trip across the front of the sun, AR 12192 produced six X-class flares, which are the largest flares, and four strong M-class flares. M-class flares are one tenth as strong as X-class flares. The number provides more information about its strength. An M2 is twice as intense as an M1, an M3 is three times as intense, etc.
"Having so many similar flares from the same active region will be a nice case study for people who work on predicting solar flares," said Dean Pesnell, project scientist for NASA's Solar Dynamics Observatory at Goddard. "This is important for one day improving the nation's ability to forecast space weather and protect technology and astronauts in space."
The DATES and peak times in EDT of the large solar flares from AR 12192 are as follows:
Oct. 19, 1:01 am:      X1.1
Oct. 21, 9:59 pm:      M8.7
Oct. 22, 10:28 am:    X1.6
Oct. 24, 5:41 pm:      X3.1
Oct. 25, 1:08 pm:      X1.0
Oct. 26, 6:56 am:      X2.0
Oct. 26, 8:34 pm:      M7.1
Oct. 27, 6:09 am:      M6.7
Oct. 27, 10:47 am:    X2.0
Oct. 28, 11:32 pm:    M6.6
AR 12192 rotated onto the far side of the sun on Oct. 30, 2014, however as it evolves, we may see a new version of it rotating back into view in two weeks.
The largest sunspot since November 1990 is seen traveling across the front of the sun in these images from NASA's SDO, captured Oct. 17-Oct 29, 2014.
Image Credit: NASA/SDO
Quelle: NASA



Tags: Astronomie 

1938 Views

Freitag, 31. Oktober 2014 - 08:30 Uhr

Raumfahrt - Progress bringt Plasmakristall-Labor "PK-4" zur Internationalen Raumstation ISS.

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Es gewittert, es blitzt und plötzlich entsteht es - Plasma. Ein ionisiertes Gas, das auf der Erde sonst selten auftritt. Nur der Blick zum Plasmaball Sonne verrät seine natürliche Umgebung, den Weltraum. Es kann auch künstlich hergestellt werden und wird besonders im technischen Bereich genutzt, etwa in Plasmafernsehern oder Leuchtstoffröhren. Künftig sind auch Anwendungen in der Medizin, im Umweltschutz und vielen anderen Bereichen denkbar. Zur Erforschung von Eigenschaften und Verhalten von einem sehr speziellen, dem komplexen Plasma, haben bisher mehr als 30 Kosmonauten und Astronauten Plasmakristall-Experimente im Weltall durchgeführt. Die Forschungsgruppe Komplexe Plasmen des Deutschen Zentrums für Luft- und Raumfahrt (DLR) plant eine neue Experimentreihe: Am 29. Oktober 2014 startete in Baikonur eine Progress-Rakete mit dem Plasmakristall-Labor "PK-4" zur Internationalen Raumstation ISS.
"Seit zwölf Jahren arbeitet unsere Gruppe am PK-4-Projekt zusammen mit unserem russischen Partnerinstitut. Nach dieser langen Vorentwicklungs-, Design-, Fertigungs- und Qualifikationsphase kommt jetzt endlich die lang ersehnte wissenschaftliche Phase. Für unsere Forschungsgruppe und unsere zukünftige Entwicklung wird das ein Meilenstein", so Dr. Hubertus Thomas, Leiter der Forschungsgruppe Komplexe Plasmen am DLR. PK-4 ist ingesamt das dritte Plasmakristall-Labor, welches an Bord der ISS zum Einsatz kommt. Geplant ist ein Betrieb von mindestens vier Jahren.
Grundlegende Forschung
Plasma ist elektrisch neutral geladenes Gas und neben fest, flüssig und gasförmig der vierte Zustand der Materie. Es ist auch der ungeordnetste Zustand. Die Erkenntniss, dass sich im Plasma geordnete Strukturen, sogenannte Plasmakristalle, bilden können, veränderte 1994 das Bild der Physik. Plasmakristalle entstehen, wenn in einem geladenen Gas zusätzlich Staubpartikel oder andere Mikropartikel enthalten sind. Die Besonderheit: Die nur wenige Mikrometer kleinen Plasmateilchen besitzen eine vergleichsweise hohe Masse. Jede Veränderung geschieht verlangsamt - wie in Zeitlupe. So lässt sich sogar die Bewegung einzelner Partikel beobachten. Komplexe Plasmen sind damit ideale Modellsysteme zur Erforschung von dynamischen Vorgängen in der Materie, bei denen die Staubteilchen Atome oder Moleküle repräsentieren. Mit jedem Experiment gewinnen Dr. Hubertus Thomas und seine Kollegen neue und einzigartige Erkenntnisse.
Forschen in der Schwerelosigkeit
Auf der Erde können komplexe Plasmen im Wesentlichen nur auf zweidimensionaler Ebene untersucht werden: Die Partikel breiten sich im Schwerefeld nicht homogen aus, sondern sinken ab und stauchen das System in Richtung der Schwerkraft. Erst in der Schwerelosigkeit wird sichtbar, wie die Plasmateilchen sich im Raum verhalten und sich gegenseitig beeinflussen. Mit der neuen Anlage wollen die Wissenschaftler gezielt der flüssigen Phase von komplexen Plasmen auf den Grund gehen. Im Fokus steht dabei die Erforschung von Selbstorganisation, Turbulenzerscheinungen, die Bestimmung von Grenzen von Nanoflüssigkeiten sowie die Untersuchung des Beginns von kollektiven Effekten in stark gekoppelten Systemen.
Forschungsgruppe Komplexe Plasmen
Die Forschungsgruppe Komplexe Plasmen ist die jüngste Forschungseinheit des DLR. Dabei blickt sie bereits auf rund 20 Jahre Erfahrung zurück, erarbeitet am Max-Planck-Institut für extraterrestrische Physik (MPE). Den Start der Trägerrakete mit der wertvollen Ladung verfolgte das 20-köpfige Team rund um Dr. Hubertus Thomas von ihrer neuen Forschungsheimat aus, in Oberpfaffenhofen. Mit der Eingliederung in das DLR wurde die Fortführung der erfolgreichen Plasmaforschung auf der ISS sichergestellt. Finanziert wird die Forschungsgruppe Komplexe Plasmen zu gleichen Teilen vom Bayerischen Staatsministerium für Wirtschaft und Medien, Energie und Technologie, des DLR-Raumfahrtmanagement im Auftrag des Bundesministeriums für Wirtschaft und Energie und dem DLR.
Über das Projekt
Das PK-4-Labor ist eine europäisch-russische Kooperation, finanziert durch die europäische Weltraumorganisation ESA und die russische Raumfahrtbehörde ROSKOSMOS. Die russische Seite, wissenschaftlich beteiligt über das Joint Institute for High Temperatures (JIHT), ist zuständig für den Transport des Labors, den Transport der Videodaten zurück zur Erde und stellt die Crew-Zeit. Auch die Entwicklung des PK-4-Labors wurde in engem Kontakt zum JIHT durchgeführt. Die experimentelle Hardware ist eine Eigenentwickung der Forschungsgruppe (ehemals MPE) in Zusammenarbeit mit dem MPE und der OHB System AG (vormals Kayser-Threde GmbH), die auch für die Infrastruktur von PK-4 zuständig war. Zusätzliche Finanzierung des Projektes in Deutschland erfolgte  durch das Raumfahrtmanagement DLR und der Max-Planck-Gesellschaft.
Wissenschaftlich beteiligt sind neben dem Kernteam aus Forschungsgruppe und JIHT auch ein europäisches Team (Frankreich, Italien und Schweden) sowie ein internationales Team (Japan und USA). Die Ergebnisse der Plasmakristiall-Experimente auf der ISS erreicht damit die Forschergemeinschaft weltweit.
Quelle: DLR

Tags: Raumfahrt 

1799 Views

Donnerstag, 30. Oktober 2014 - 19:39 Uhr

Astronomie - Ganymed Gespenstische Schatten gibt Jupiter ein Riesenauge

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Here’s Looking at You: Spooky Shadow Gives Jupiter a Giant Eye
This trick that the planet is looking back at you is actually a Hubble treat: An eerie, close-up view of Jupiter, the biggest planet in our solar system. Hubble was monitoring changes in Jupiter’s immense Great Red Spot (GRS) storm on April 21, 2014, when the shadow of the Jovian moon, Ganymede, swept across the center of the storm. This gave the giant planet the uncanny appearance of having a pupil in the center of a 10,000 mile-diameter “eye.” For a moment, Jupiter “stared” back at Hubble like a one-eyed giant Cyclops. Click on the image to view Jupiter from a distance.
Quelle: NASA

Tags: Astronomie 

2144 Views

Donnerstag, 30. Oktober 2014 - 19:30 Uhr

Astronomie - Hubble sieht 'Ghost Light' aus toten Galaxien

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Massive galaxy cluster Abell 2744, nicknamed Pandora's Cluster, takes on a ghostly look where total starlight has been artificially colored blue in this Hubble view.
Image Credit: NASA/ESA/IAC/HFF Team, STScI
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NASA’s Hubble Space Telescope has picked up the faint, ghostly glow of stars ejected from ancient galaxies that were gravitationally ripped apart several billion years ago. The mayhem happened 4 billion light-years away, inside an immense collection of nearly 500 galaxies nicknamed “Pandora’s Cluster,” also known as Abell 2744.
The scattered stars are no longer bound to any one galaxy, and drift freely between galaxies in the cluster. By observing the light from the orphaned stars, Hubble astronomers have assembled forensic evidence that suggests as many as six galaxies were torn to pieces inside the cluster over a stretch of 6 billion years.
Computer modeling of the gravitational dynamics among galaxies in a cluster suggests that galaxies as big as our Milky Way Galaxy are the likely candidates as the source of the stars. The doomed galaxies would have been pulled apart like taffy if they plunged through the center of a galaxy cluster where gravitational tidal forces are strongest. Astronomers have long hypothesized that the light from scattered stars should be detectable after such galaxies are disassembled. However, the predicted “intracluster” glow of stars is very faint and was therefore a challenge to identify. 
“The Hubble data revealing the ghost light are important steps forward in understanding the evolution of galaxy clusters,” said Ignacio Trujillo of The Instituto de Astrofísica de Canarias (IAC), Santa Cruz de Tenerife, Spain. “It is also amazingly beautiful in that we found the telltale glow by utilizing Hubble’s unique capabilities.”
The team estimates that the combined light of about 200 billion outcast stars contributes approximately 10 percent of the cluster’s brightness.
“The results are in good agreement with what has been predicted to happen inside massive galaxy clusters,” said Mireia Montes of the IAC, lead author of the paper published in the Oct. 1 issue of the Astrophysical Journal.
Because these extremely faint stars are brightest at near-infrared wavelengths of light, the team emphasized that this type of observation could only be accomplished with Hubble’s infrared sensitivity to extraordinarily dim light.
Hubble measurements determined that the phantom stars are rich in heavier elements like oxygen, carbon, and nitrogen. This means the scattered stars must be second or third-generation stars enriched with the elements forged in the hearts of the universe’s first-generation stars. Spiral galaxies – like the ones believed to be torn apart -- can sustain ongoing star formation that creates chemically-enriched stars.
Weighing more than 4 trillion solar masses, Abell 2744 is a target in the Frontier Fields program. This ambitious three-year effort teams Hubble and NASA’s other Great Observatories to look at select massive galaxy clusters to help astronomers probe the remote universe. Galaxy clusters are so massive that their gravity deflects light passing through them, magnifying, brightening, and distorting light in a phenomenon called gravitational lensing. Astronomers exploit this property of space to use the clusters as a zoom lens to magnify the images of far-more-distant galaxies that otherwise would be too faint to be seen.
Montes’ team used the Hubble data to probe the environment of the foreground cluster itself. There are five other Frontier Fields clusters in the program, and the team plans to look for the eerie “ghost light” in these clusters, too.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington.
Quelle: NASA

Tags: Astronomie 

2143 Views

Donnerstag, 30. Oktober 2014 - 13:45 Uhr

Science - Antike Gehör Illusionen in prähistorische Kunst reflektiert?

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Here are prehistoric paintings of hoofed animals in a cave with thunderous reverberations located in Bhimbetka, India.

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Some of humankind's earliest and most mysterious artistic achievements -- including prehistoric cave paintings, canyon petroglyphs and megalithic structures such as Stonehenge -- may have been inspired by the behaviors of sound waves being misinterpreted as "supernatural."

During the 168th Meeting of the Acoustical Society of America (ASA), to be held October 27-31, 2014 at the Indianapolis Marriott Downtown Hotel, Steven J. Waller, of Rock Art Acoustics, will describe several ways virtual sound images and absorbers can appear supernatural.
"Ancient mythology explained echoes from the mouths of caves as replies from spirits, so our ancestors may have made cave paintings in response to these echoes and their belief that echo spirits inhabited rocky places such as caves or canyons," explained Waller.
Just as light reflection gives an illusion of seeing yourself duplicated in a mirror, sound waves reflecting off a surface are mathematically identical to sound waves emanating from a virtual sound source behind a reflecting plane such as a large cliff face. "This can result in an auditory illusion of somebody answering you from within the rock," Waller said.
Echoes of clapping can sound similar to hoof beats, as Waller pointed out, while multiple echoes within a cavern can blur together into a thunderous reverberation that mimics the sound of a herd of stampeding hoofed animals.
"Many ancient cultures attributed thunder in the sky to 'hoofed thunder gods,' so it makes sense that the reverberation within the caves was interpreted as thunder and inspired paintings of those same hoofed thunder gods on cave walls," said Waller. "This theory is supported by acoustic measurements, which show statistically significant correspondence between the rock art sites and locations with the strongest sound reflection."
Other acoustical characteristics may have also been misinterpreted by ancient cultures unaware of sound wave theory. Waller noticed a resemblance between an interference pattern and Stonehenge, so he set up an interference pattern in an open field with just two flutes "droning the same note" to explore what it would sound like.
"The quiet regions of destructive sound wave cancellation, in which the high pressure from one flute cancelled the low pressure from the other flute, gave blindfolded subjects the illusion of a giant ring of rocks or 'pillars' casting acoustic shadows," Waller said.
He traveled to England and demonstrated that Stonehenge does indeed radiate acoustic shadows that recreate the same pattern as interference. "My theory that musical interference patterns served as blueprints for megalithic stone circles -- many of which are called Pipers' Stones -- is supported by ancient legends of two magic pipers who enticed maidens to dance in a circle and turned them all into stones," Waller noted.
There are several important implications of Waller's research. Perhaps most significantly, it demonstrates that acoustical phenomena were culturally significant to early humans -- leading to the immediate conclusion that the natural soundscapes of archaeological sites should be preserved in their natural state for further study and greater appreciation.
"Even today, sensory input can be used to manipulate perception and lead to illusions inconsistent with scientific reality, which could have interesting practical applications for virtual reality and special effects in entertainment media," Waller said. "Objectivity is questionable, because a given set of data can be used to support multiple conclusions."
The history of humanity is full of such misinterpretations, such as the visual illusion that the sun moves around the earth. "Sound, which is invisible and has complex properties, can easily lead to auditory illusions of the supernatural," he added. "This, in turn, leads to the more general question: what other illusions are we living under due to other phenomena that we are currently misinterpreting?"
Quelle: Acoustical Society of America (ASA

Tags: Science 

2129 Views

Donnerstag, 30. Oktober 2014 - 13:30 Uhr

Raumfahrt - Fortschritt bei Wirksamkeit der derzeitigen Laserantriebstechnik

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Supersonic laser-propelled rockets: Hybrid approach may help power rockets, launch satellites, push future aircraft past Mach 10
Researchers have described a new system that integrates a laser-ablation propulsion system with the gas blasting nozzles of a spacecraft which can increase the speed of the gas flow out of the system to supersonic speeds while reducing the amount of burned fuel.

The effectiveness of current laser-propulsion techniques is limited by the instability of supersonic gas flow, caused by shock waves that “choke” the inlet of the nozzle, reducing thrust. Those effects can be reduced with the help of laser ablation, redirecting the plasma plume so that it flows close to the interior walls of a supersonic nozzle and significantly improving the overall thrust.

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Scientists and science fiction writers alike have dreamt of aircrafts that are propelled by beams of light rather than conventional fuels. Now, a new method for improving the thrust generated by such laser-propulsion systems may bring them one step closer to practical use.

The method, developed by physicists Yuri Rezunkov of the Institute of Optoelectronic Instrument Engineering, Russia and Alexander Schmidt of the Ioffe Physical Technical Institute in Saint Petersburg, Russia is described today in The Optical Society's (OSA) journal Applied Optics.
Currently, the maximum speed of a spacecraft is limited by the amount of solid or liquid fuel that it can carry. Achieving higher speeds means that more fuel must be burned -- fuel that, inconveniently, has to be carried by the craft and hefted into space. These burdensome loads can be reduced, however, if a laser -- one located at a remote location, and not actually on the spacecraft -- were used to provide additional propulsive force.
A number of systems have been proposed that can produce such laser propulsion. One of the most promising involves a process called laser ablation, in which a pulsed laser beam strikes a surface, heats it up, and burns off material to create what is known as a plasma plume -- a column of charged particles that flow off the surface. The outflowing of that plasma plume -- essentially, exhaust -- generates additional thrust to propel the craft.
In their Applied Optics paper, Rezunkov and Schmidt describe a new system that integrates a laser-ablation propulsion system with the gas blasting nozzles of a spacecraft. Combining the two systems, the researchers found, can increase the speed of the gas flow out of the system to supersonic speeds while reducing the amount of burned fuel.
The researchers show that the effectiveness of current laser-propulsion techniques is limited by factors including the instability of supersonic gases as they flow through the gas nozzle, as well as the production of shock waves that "choke" the inlet of the nozzle, reducing thrust. But those effects can be reduced with the help of a laser-ablation plasma plume that is redirected so that it will flow close to the interior walls of the nozzle. Coupling the ablation jet with supersonic gas flow through the nozzle, they find, significantly improves the overall thrust generated by the nozzle.
"Summarizing the data obtained, we can forecast the application of the supersonic laser propulsion techniques not only for launching small satellites to Earth orbits but also for additional acceleration of supersonic aircrafts to achieve Mach 10 and more," Rezunkov said.
Quelle: ScienceDaily

1937 Views


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