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Sonntag, 17. Juli 2016 - 21:15 Uhr

Luftfahrt-History - 1998: Spotlight on Dryden Flight Research Center

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In March 1994, Dryden Flight Research Center became a full-fledged field center. As a result of attaining center status, Dryden’s Technology Transfer and Commer- cialization (T2) office was officially created in May 1995. The T2 office is now part of the “PACE” group, which consists of Public Affairs, Commercialization, Education, and History.
As NASA’s primary installation for flight research over the last fifty years, Dryden projects have led to major advancements in the design and capabilities of many civilian and military aircraft. The T2 staff work closely with a variety of clients, from large aircraft companies to small business owners from the start, to ensure that the technologies tested and developed at the center can be directly integrated by its customers.
The T2 staff developed their own guidelines and work closely with the researchers and engineers at the center to capture Dryden’s unique innovations. Aeronau- tics research at the center results in technical papers, the essence of which are captured in NASA’s TechTracS database. The T2 staff also work in tandem with the Research Engineering, Projects and Facilities directorates to determine which innovations should be protected by patents.
In addition, the staff work closely with contracting managers’ technical representatives to determine what technologies have been developed as a result of contracts, grants, and Small Business Innovation Research (SBIR) contracts. This cooperation resulted in many new patents and a faster transfer of new technologies to U.S. industry. To facilitate new technology reporting, the T2 staff encourage the companies to write articles for NASA Tech Briefs, and follow up with press releases to help launch the companies’ new innovations.
Striving to meet the aggressive goals set forth by Administrator Dan Goldin in NASA’s Strategic Vision, the following projects and partnerships provide an overview of Dryden’s role in meeting NASA’s goals. This roadmap for the future is outlined and best illustrated by the “Aeronautics and Space Transportation Technology: Three Pillars for Success.”
Pillar One: Global Civil Aviation
To preserve the nation’s economic health and the welfare of the traveling public, the first pillar focuses on safety, environmental compatibility, and affordable air travel. Dryden’s first goal is to reduce the aircraft accident rate by a factor of five within ten years and by a factor of ten within twenty years. To meet the challenge, current
innovations and programs include the patented Propul- sion-Controlled Aircraft, the Structural Health Monitor- ing System on Systems Research Aircraft for X-33, and the Lidar Clear Air Turbulence Measurement, developed under an SBIR contract by Coherent Technologies.
The innovative work of reducing emissions of future aircraft by a factor of three within ten years, and five within twenty years, is ongoing. In addition, a new family of remotely-piloted vehicles (RPVs) that fly slower, higher, and longer are being developed. These long-duration, high-altitude RPVs could be used in upper-atmosphere science missions to help collect, identify, and monitor environmental data to assess global change. They could also carry telecommunications equipment to high altitudes, serving much like satellites for a fraction of the cost of putting traditional satellites in space.
The Environmental Research Aircraft and Sensor Technology (ERAST) partnership has yielded significant technological advancements to meet the second goal of the first pillar—environmental compatibility. Besides Dryden, three other NASA research centers (Ames, Langley, and Lewis), along with The Association for Unmanned Vehicle Systems International, American Technology Initiatives Inc., Thermo Mechanical Systems Inc., and several universities are included as partners. The major industry partners are listed below in parentheses, after the names of the unpiloted aircraft, which are products of the ERAST partnership.
• Pathfinder (AeroVironment Inc.) is a proof-of- concept vehicle for two more prototype solar- powered aircraft that have the ability to study the upper atmosphere without disturbing it. Remote monitoring of storm developments, forests, and crop damage are also benefits.
• Apex (Advanced Soaring Concepts, Inc.) is used to validate high-altitude testbed aircraft design methodologies by measuring airfoil characteristics at low Reynolds numbers and high subsonic
Mach numbers in a low-turbulence environment. • Perseus B (Aurora Flight Sciences Corp.) involves
test engine concepts, lightweight structures, science payload integration, and fault tolerant flight control systems.
• Altus (General Atomics Aeronautical System Inc.) verifies technologies that lead to a long-duration, high-altitude vehicle that could carry science payloads.
• Demonstrator-2 (Scaled Composites Inc.) centers on over-the-horizon communication capabilities, lightweight structures, science payload integration, engine development, and flight control systems.
The second goal is to reduce the perceived noise levels of future aircraft by a factor of two from today’s subsonic aircraft within ten years, and by a factor of four within twenty years. Dryden is currently flying the SR-71 aircraft, on loan from the U.S. Air Force, to study sonic 
boom propagation. Data from the SR-71 high speed research program will be used to aid designers of future supersonic/ hypersonic aircraft and propulsion systems, including a high speed civil transport.
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The final goal is affordable air travel. While maintaining safety, Dryden strives to triple the aviation system throughout, in all weather conditions within ten years. Reducing the cost of air travel by twenty-five percent within ten years and by fifty percent within twenty years, is being accomplished by Orbital Sciences’ patented Adaptive Performance Optimization, Electro Hydrostatic Actuator, the Fiber Optic Position Measurement Network, and the Smart Actuator, which reduces wire weight by sixty percent and detects its own internal failures; thereby reducing maintenance costs.
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Pillar Two: Revolutionary Technology Leaps
NASA’s objective outlined in the second pillar is to explore high-risk technology areas that can revolutionize air travel and create new markets for U.S. industry. The technology challenges for NASA include: eliminating the barriers to affordable supersonic travel, expanding general aviation, and accelerating the application of technology advances.
The first technology goal is to reduce the travel time to the Far East and Europe by fifty percent within twenty years, and to do so at today’s subsonic ticket prices. To break the barriers to high speed travel, Dryden has imitated several programs including the TU-1 44LL Initiative.
The Russian TU-144LL supersonic transport is being used as a flight research test vehicle to conduct experi- ments which will enhance the development of advanced technology necessary to build the next generation high speed civil transport. The purpose of the program is threefold: develop and transfer supersonic airliner technology directly to U.S. aircraft industry under NASA sponsorship; establish a working relationship between U.S. and former Russian aircraft manufacturers at 
programmatic and technical levels; and acquire flight research data and existing operational experience to narrow the margin of European supersonic transport experience gained from the Concorde.
Dryden is also dedicated to providing next-genera- tion design tools and experimental aircraft to increase design confidence and cut the development cycle in half. This goal is being accomplished through several programs including: the Hyper-X program, which will demonstrate hypersonic propulsion technologies; the X-36 Tailless Fighter Agility Research Aircraft, a remotely-piloted jet designed to fly without traditional tail surfaces aimed at improving the maneuverability and survivability of future fighter aircraft; and the Linear Aerospike SR-71 Experi- ment (LASRE), designed to gather data on the aerospike’s exhaust plume as it travels through the transonic region of flight (just below to just above Mach 1).
Pillar Three: Access to Space
Finally, low-cost space access is essential to unleash- ing the commercial potential of space and greatly expand- ing space research and integration. NASA’s primary space transportation technology role is to develop and demon- strate pre-competitive, next-generation technology that will enable the commercial launch industry to develop full-scale, highly competitive, and reliable space launchers.
Dryden is pushing ahead with two programs with objectives to meet the goal of this last pillar. First, in partnership with Lockheed-Martin in the X-33 program, Dryden aims to reduce the payload cost to low-Earth orbit by an order of magnitude, from $10,000 per pound within ten years. Second, in partnership with Kelly Aerospace, the Eclipse program goal is to reduce the payload cost to low-Earth orbit by an additional order of magnitude, from thousands to hundreds of dollars per pound, by the year 2020.
The flight research programs initiated at Dryden help move the U.S. aircraft industry closer to achieving its goals. And everyday the efforts of the Technology Transfer and Commercialization office take Dryden Flight Research Center one step closer to realizing its vision statement: “The world leader in flight research for discovery, technology development, and technology transfer for U.S. aeronautics and space preeminence.”
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Quelle: Technology Transfer and Commercialization / NASA

Tags: Luftfahrt 

1315 Views

Sonntag, 17. Juli 2016 - 20:15 Uhr

Luftfahrt-History - 1996: Dryden Flight Research Center

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Some of the nation's greatest advances in aviation have been staged at Hugh L. Dryden Flight Research Center. It is the home of aircraft that
push the envelope of aerodynamic theory, along with research pilot skill, nerve, and courage.
Dryden is located at Edwards, California, in the Mojave Desert, some 80 miles north of Los Angeles. Enjoying nearly perfect weather for flight research, this NASA facility sits at the southern end of a 260-mile high-altitude high-speed supersoniccorridor (there are three high-speed corridors altogether). Situated adjacent to Rogers Dry Lake, a 44-square mile natural surface for landing, Dryden is in an isolated area free of population density.
Dryden has data catalogued from years of flying experimental aircraft, such as the Bell X-1-the first aircraft to break the sound barrier on October 14, 1947. The X-1 program provided the National Advisory Committee for Aeronautics (NACA), NASA's predeces- sor, an ability to master the effects of transonic speeds and the stability and control of aircraft flying in that regime.
Since the late 1940s, Dryden has acquired a unique and highly specialized capability for conducting flight research programs. Its research organization, consisting of pilots, engineers, technicians and mechanics is unmatched anywhere in the world.
The open skies, land and resources at Dryden proved their usefulness to the space effort in a large way. The Mach-6 X-15 program researched and developed various technologies that were implemented in the U.S. Mercury, Gemini and Apollo spacecraft. The X- 15 provided the pioneeringwork needed to design a craft to go into space, then return to a horizontal landing on Earth. Along with the X-15, lifting body research done at Dryden in the 1960s helped pave the way for today's Space Shuttle.
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In September 1996, Dryden celebrated its 50th anniversary of contributing to the nation's aerospace capabilities. This expertisewas clearly in evidence in 1973 as the first flight of the X-24B took place. The X- 24B was successor to the wingless lifting bodies that were flown in a joint USAF-NASA research program to demonstrate a pilot's ability to maneuver and safely land a vehicle with a shape designed for reentry from space flight.
Like its wingless lifting body predecessors-the
M-2, HL-10 and the X-24A that had flown at Dryden-the X-24B made use of a B-52 for air launch above the dry lake bed. Released at 40,000 feet, the X- 24B glided to a desert touchdown a scant four minutes later. Flown from August 1973 to November 1975, the X-24B proved invaluable in shaping the Space Shuttle program.
An F-8 Crusader first flown at Dryden in 1972 inaugurated in 1973 the first tests of Digital Fly-By- Wire (DFBW), a concept that utilizes an electronic flight control system coupled with a digital computer. The research aircraft tested DFBW as a replacement for conventional mechanical flight controls. Well over 200 flights of the F-8 Crusader were carried out in a DFBW program that lasted 13years-considered one of the most significant and successfd aeronautical programs in NASA history. Fly-by-wire flight control technology, made possible in large measure by the F-8 Crusader tests, was later applied in creating the Space Shuttle flight control system.
The center's primary study tools are research aircraft. But ground based facilities play a significant role in Dryden research. These key facilities include a high temperature and loads calibration laboratory to test complete aircraft and structural components under the combined effects of loads and heat, a highly developed aircraft flight instrumentation capability and a flight systems laboratory with a diversified capability for avionics system development.
Other assets of Dryden include a flow visualization facility that permits examinations of how air courses around test models or small components, a data analysis facility for processing of flight research data and a remotely piloted research vehicles facility.
Dryden participated in the five free-flight Approach and Landing Tests of the Space Shuttle Enterprise staged in 1977 and continues to support Shuttle orbiter landings if diverted by bad weather from the Kennedy Space Center in Florida. If a shuttle does land in California, the vehicle is then ferried back to the launch site atop a 747 aircraft.
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Clearly in evidence at Dryden is the match of the center's past prestige with the necessary technical competence to tackle the aeronautical challenges of the day. In this regard is the speciallyinstrumented FIA-18, used to investigatehigh angle of attack, or high alpha, flight. Today's high performance jet aircraft can fly in the high alpha flight regime, but not necessarily efficiently.The center's research created a data base for aircraft designers to accurately predict high alpha airflow aircraft control and performance. High alpha technology may result in better control and maneuverability and enhanced safety in future high performance aircraft.
Another high alpha program at Dryden featured the thrust-vectored X-31. An international test organization managed by the Advanced Research Projects Agency (ARPA) conducted flight tests to obtain data for next generation high performance aircraft. In addition to NASA and ARPA, program participants included the U.S. Navy, U.S. Air Force, Rockwell Aerospace, Deutsche Aerospace, and the Federal Republic of Germany.
In 1993 and 1995, a Propulsion Controlled Aircraft (PCA) system underwent successful tests at Dryden. A PCA system provides a pilot with a computerized system to land an aircraft with only engine controls in the event of a catastrophichydraulic system failure. Once consid- ered an impossible feat by many engineers, automatic PCA landings of two McDonnell Douglas aircraft, an F- 15 fighter and an MD-11 airliner, were accomplished.
The EnvironmentalResearch Aircraft and Sensor Technology program at Dryden is attempting to develop remotely controlled aircraft capable of sustained, slow flight at high altitudes to gather currently unavailable information about our atmosphere. For example, Pathfinder is a solar-powered, ultra light research aircraft developed by AeroVironment Corporation. The vehicle will test very high-altitude and extremely long-duration flight for periods of up to several weeks or months. Key areas of development include solar cell, battery and electric motor technology; flight operations techniques and procedures; structures; flight environment simulation; and science mission demonstration.
For the past half century, Dryden Flight Research Center has been at the forefront of flight research; a place where people can be engaged in examining and resolving the great aeronautical and astronautical challenges of our time. By pushing the experimental envelope, be it speed, altitude, control, or other bound- aries, Dryden research has strengthened the U.S. position as a world-class leader in aeronautics.
Quelle: Aerospace Research and Development / NASA

Tags: Luftfahrt 

1339 Views

Sonntag, 17. Juli 2016 - 17:00 Uhr

Raumfahrt - ISRO plant Supersonic Combustion Ramjet (SCRAMJET)-Modell-Testflug

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17.07.2016

ISRO soon to test-fly scramjet engine model
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The Indian Space research Organisation (ISRO) is slated to test fly this month a small model of what is called a ‘scramjet’ engine that could one day help to put satellites and other systems to space.
Scientists are quietly keeping their fingers crossed about it. This half-metre, 45-kg model could later grow to power a future dream Indian rocket of two stages (compared to three and four stages at present); a rocket that launches satellites and systems super efficiently at much lower costs than now.
Reliable
The scramjet bid is a move towards faster, cheaper, better rockets; if it works, an eventual launch vehicle using a scramjet engine can be very reliable compared to conventional rocket systems that use liquid or cryogenic systems, said a propulsion scientist who did not want to be named.
In March 2010, the ISRO tested a passive scramjet engine module on a customised sounding (experimental) rocket, named Advanced Technology Vehicle (ATV-D01).
The specialty of the ‘scramjet’ engine is that it ‘inhales’ air from the atmosphere and uses its oxygen to burn. In turn it pushes the vehicle and helps to release the satellite in it to space. Regular launchers now carry liquid oxygen or an oxidiser to fire the engine.
In the upcoming experiment — or demonstration — of the air breathing technology, a small model of a scramjet engine is flown on the experimental ATV to a certain distance in space and ignited. The ISRO expects to sustain the engine for five seconds this time.
K.Sivan, Director of Vikram Sarabhai Space Centre (VSSC) which is the lead centre for launcher activities, had earlier told The Hindu that sustaining the engine burn for even this tiny duration is extremely challenging.
Quelle: The Hindu
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Jan 10, 2006
ISRO Achieves Breakthrough in Supersonic Combustion Technology
As part of the Advanced technology initiative in the area of Air- Breathing propulsion, the Vikram Sarabhai Space Centre of ISRO at Thiruvananthapuram, has successfully carried out the design, development, characterisation and realisation of the Supersonic Combustion Ramjet (SCRAMJET). Through a series of ground tests, a stable supersonic combustion has been demonstrated for nearly 7 seconds with an inlet Mach number of 6 (i.e., six times the speed of sound).
As such technologies are in a very nascent stage of development the world over, ISRO considers this achievement as a major technology breakthrough in Air- Breathing propulsion. Other than USA, which has recently carried out in-flight demonstration of supersonic combustion for a short duration, work related to supersonic combustor designs in other countries like Japan, China, Russia, Australia , Europe and others are either in their initial or ground testing phase.
Currently, the space transportation systems are expendable in nature and use the conventional chemical rocket systems for their propulsion. The cost per kg of payload of such expendable systems is quite high, and is in the range of $12,000 to $15,000 per kg. If we have to make the access to space more affordable, this cost needs to be brought down by an order of magnitude to something like $500 - $1000 per kg. This will require a two pronged approach (a) the systems are made recoverable and reusable (b) adopt more efficient propulsion systems like Air- Breathing rockets.
Air- Breathing rocket systems are the ones which use the atmospheric oxygen from their surroundings and burn it with the stored on- board fuel for producing the forward thrust in contrast to the conventional chemical rocket systems which carry both the oxygen and the fuel on-board. As a result, the Air-Breathing systems become much lighter and more efficient leading to reduced overall costs. As the Air- Breathing systems have the capability to operate only during the atmospheric phase of flight, they always have to be adopted along with the conventional chemical rockets, for meeting the final orbital velocity requirements.
A good example of Air-Breathing engines is the Turbojet engines used in aircrafts; however, they have limitations in operating only up to a maximum of Mach number 3. To travel beyond these Mach number regimes, SCRAMJET propulsion is the only viable option. The development of SCRAMJET system is quite complex and it involves a number of technological challenges, especially the ones related to the mixing of very high speed air (velocity around 1.5 km/s) with fuel, achieving stable ignition and flame holding in addition to ensuring efficient combustion, within the practical length of the combustor.
In the coming years, ISRO is planning to flight test an integrated SCRAMJET propulsion system comprising of air-intake, combustor and nozzle, by using a cost effective two stage RH-560 sounding rocket. Development of such a high technology system will come in a big way towards meeting the futuristic space transportation needs of our country.
Quelle:ISRO
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Dec 27, 2006
Indian Space Programme - Major Events During 2006
The Indian space programme continued to make forays in the development of new technologies during the year 2006 with the successful ground testing of indigenous cryogenic stage for GSLV, good progress made in the GSLV-Mk III project and demonstration of Supersonic Combustion Ramjet (SCRAMJET). The Commercial activities picked up momentum with the winning of two contracts for building communication satellites for European customers jointly with EADS, France. Space exploration mission got further fillip with Chandrayaan-1 mission making substantial progress and ISRO agreeing to carry two US-NASA instruments on board the spacecraft in addition to its own five primary instruments and three instruments of European Space Agency and one from Bulgaria. As an important strategy for establishing an indigenous and independent satellite navigation system, the government approved in May 2006, the establishment of Indian Regional Navigational Satellite System (IRNSS).
Space applications continued to expand reaching the benefits of space technology to a wider cross section of the society. The EDUSAT network has expanded to 33 nodes connecting about 10.000 classrooms. ISRO's satellite based telemedicine network has expanded to connect 182 hospitals - 148 remote and rural hospitals including those in J & K, NE region and Andaman and Nicobar Islands and 34 super specialty hospitals in major cities. So far, 130 Village Resource Centres (VRCs) have been established to facilitate access to spatial information on important aspects like land use/land cover, soil and ground water prospects and enable the farmers in taking important decisions based on their query.
The year 2006 also saw a setback when GSLV-F02 mission did not succeed. However, the space programme continued to look towards even more challenging missions and the studies conducted by ISRO for a manned space mission were discussed by scientists in November 2006. Some of the important events during 2005 are as follows:
 
 January, 2006: ISRO Achieves Breakthrough in Supersonic Combustion Technology: As part of advanced technology initiatives, ISRO demonstrated Supersonic Combustion Ramjet (SCRAMJET) through a series of ground tests achieving a stable supersonic combustion for nearly 7 seconds with an inlet Mach number of 6 (i.e., six times the speed of sound).
 
February 2006: Contract Won to Build Communication Satellites for European Customers: Antrix/ISRO and EADS Astrium, Paris, Memorandum of Agreement, signed in June 2005 to jointly address the commercial market for communications satellites, achieved the first success with the award of W2M satellite contract by Eutelsat Communications. One more contract was won during the year under this MOA to build Highly Adoptable Satellite, HYLAS, for Avanti Screen Media. The satellites will be built by ISRO while EADS, Astrium, will build the communication payloads.
 
May 9, 2006: ISRO-NASA MOU on Chandrayaan-1: ISRO and National Aeronautics and Space Administration (NASA) of USA signed Memoranda of Understanding (MOU) according to which India will include two US Scientific instruments on board Chandrayaan-1. These are in addition to three instruments from European Space Agency and one from Bulgaria. The primary Indian scientific instruments on board Chandrayaan-1 include: Terrain Mapping Camera (TMC), Hyper Spectral Imager (HySI), High-Energy X-ray spectrometer (HEX), Lunar Laser Ranging Instrument (LLRI) and Moon Impact Probe (MIP). Chandrayaan-1 is India's first mission to moon, planned in early 2008.
 
May 2006: Government Approves Establishment of Indian Regional Navigational Satellite System (IRNSS): The Government approved the establishment of an "Indian Regional Navigational Satellite System (IRNSS)" with a constellation of seven satellites to be realised over 6-7 years to provide navigation and timing services over the Indian subcontinent. The satellites are to be launched using Indian launch vehicles. IRNSS is an important component of the Indian strategy for establishing an indigenous and independent satellite navigation system.  
 
July 10, 2006: GSLV- F02/ INSAT 4C Mission: The launch of GSLV- F02, carrying the communication satellite, INSAT- 4C, took place from Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota. However, at around 45 sec into flight, the vehicle started deviating significantly from its nominal flight path resulting in the vehicle experiencing severe aerodynamic loads and its subsequent breakup at about 65 sec. A Failure Analysis Committee (FAC), constituted to review the reasons for the failure concluded that the primary cause for the failure was the sudden loss of thrust in one out of the four liquid propellant strap-on stages (S4) immediately after lift-off resulting from the malfunctioning of a propellant regulator. FAC concluded that the design of GSLV is robust and recommended implementation of strict control on fabrication, inspection and acceptance procedures.
 
October 28, 2006. Testing of Indigenous Cryogenic Stage: ISRO achieved a major milestone in the development of indigenous Cryogenic Upper Stage for GSLV when the stage was tested for duration of 50 sec. The indigenous cryogenic stage is planned to be flight tested in GSLV- D3 mission in 2007-08.  
 
November 7, 2006. Scientists Discuss Indian Manned Space Mission: About 80 senior scientists from across the country discussed the studies conducted by ISRO related to Indian Manned Space Mission at Bangalore. The scientists were unanimous in suggesting that the time is appropriate for India to undertake a manned mission.
Quelle: ISRO
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IDN TAKE: THE GREAT SCRAMJET SCRAM
MONDAY, NOVEMBER 16, 2015 BY INDIANDEFENSE NEWS
Bidding for their rightful place among the world’s majors, two of the country’s premier agencies are in the advanced stages of proving SCRAMJET (Supersonic Combustion Ramjet) technology to meet India's strategic needs. The Indian double has caught global attention in the hypersonic race for cheap and cost effective launch technology.
While the Indian Space Research Organisation (ISRO) is working on the Reusable Launch Vehicle - Test Demonstrator (RLV-TD) for launching satellites, the Defence Research and Development Organisation (DRDO) is dreaming about a Hypersonic Technology Demonstrator Vehicle (HSTDV) to carry a range of weapons faster and farther.
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ISRO has already carried out a seven-second experimental combustion of a test engine. There’s a remarkable design difference between the RLV and the HSTDV. ISRO’s hypersonic plane, being built at the Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram, is a winged body while the HSTDV is a sleeker structure. The only common architecture, perhaps, is the air intake scoop at the front through which atmospheric air will be sucked in before oxygen is separated from it to oxidize the onboard fuel.
This is how the SCRAMJET bypasses the need to carry an oxidiser on board. In a conventional rocket, the fuel and oxidiser are stored separately and burnt in a regulated combustion of eight grams of oxygen to one gram of fuel. But in the SCRAMJET, oxygen is isolated from the air, compressed and introduced to a stream of fuel.
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To ensure that sufficient oxygen is ingested for a self-sustaining flight, the SCRAMJET must get to supersonic speeds before going ahead with its designated mission of launching a satellite for ISRO or delivering a warhead for DRDO.
This speed is achieved by coupling the SCRAMJET to a conventional rocket during the initial phase of the flight. "We will mount the RLV prototype on a sounding rocket (S9). The rocket will speed it up to Mach 5 before the body is allowed to surf and suck air for onboard combustion. This process fires the SCRAMJET and propels the payload to the desired orbit at speeds between Mach 8 and 10.
The DRDO plans to use a core-alone Agni stage (S1). The capsule containing the HSTDV will ride on Agni to stratospheric heights. After the first stage separates, the capsule shifts to a horizontal alignment and opens up to allow the HSTD to skim the atmosphere and breathe air.
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But like space rockets, ICBMs are a very costly chemical proposition. The hyperplane can fly in at fast speeds, fire the missile or launch the warhead and return. The reusability will reduce our costs significantly. Cost figures in ISRO’s calculus as well. The cost of launching a satellite using conventional rockets like the PSLV or GSLV is $25,000 to $28,000 per kg. The SCRAMJET can reduce it to $500. This will make any nation with such a technology a launch destination.
One great attraction is that the RLV can be brought back and reused. The conventional rocket is expendable. Each stage burns out as the payload soars. But the RLV will come back after its mission. ISRO will land the RLV on the sea using parachutes. But a project to facilitate its landing like an unmanned aircraft is on the anvil. DRDO also plans to land it like an aircraft. This technology is being experimented with. It can be integrated with the HSTDV.
Another frontier that SCRAMJET research has opened up is advanced metallurgy as the craft moves at great speeds, breaks off from the atmosphere and re-enters, weathering high temperatures and atmospheric friction. There are several new alloys being developed. Apart from their use in SCRAMJET vehicles, this research will impact the whole gamut of strategic metallurgy.
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India is experimenting with silica-carbon-silica and nickel-based alloys to cover the SCRAMJET. Both alloys have high thermal resistance. A prototype using these alloys has been subjected to wind tunnel tests to gauge their strength against the vagaries of the atmosphere and beyond.
United States and China have been successful with SCRAMJET engines but the irony is they are yet to design materials which can withstand the heat generated from an object travelling at such high speeds. In a high speed aircraft, air friction cause extreme heating of the leading edge and temperature could be very high (Mach 5 generates 1,000 degree Celsius). Sadly, there is no technology available curently which can withstand such extreme heat. ISRO & DRDO are struggling very hard to crack this metallurgy.
The Indian Institute of Science (IISc) will play a key role in simulating the speeds and conducting tests in its newly commissioned hypersonic wind tunnel. This facility can test any object that will fly in space. The funding for the project is from the Defence Research and Development Laboratory, Hyderabad.
The 0.5 metre tunnel, which was commissioned in April 2014 is the second largest facility in the country; the largest is at the Vikram Sarabhai Space Centre of ISRO in Trivendrum.
It is but natural for anyone to wonder why two Indian agencies are developing the same technology in parallel, with so much, except the sophisticated nature of the end-use, in common. ISRO insiders blame it on the absence of a pro-active culture within DRDO’s portals; the latter finds fault with ISRO’s big brother attitude.
“It’s the typical Indian defence story,” says one former top gun of ISRO. “In a way, it’s a blessing in disguise. Whoever proves it first will attract global attention. With the country inching closer to the concept of aerospace strategic forces, there will be a lot of give and take once the technology is proved indigenously,” he adds.
HSTDV would give us a lead in hypersonic vehicle design, SCRAMJET, material technology and how to manage environment which is peculiar to hypersonic flying engines. HSTDV will be the equivalent of NASA's X43 and a huge achievement for our scientists once it's ready for use by the armed forces. And the SCRAMJET will place India in a league of nations that includes the US, Japan, China, Russia, Australia and Europe where this nascent technology is the latest scientific fad. (Adapted from ISRO, Indian Express, DRDO Newsletters & other Internet Sources)
Quelle: INDIANDEFENSE NEWS

Tags: Raumfahrt 

1246 Views

Sonntag, 17. Juli 2016 - 10:45 Uhr

Astronomie - 7-Meter ALMA-Antenne- On the move

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Otto — one of two 22-wheeled ALMA transporters — repositions one of the twelve 7-metre ALMA antennae atop the Chajnantor Plateau in this scene from the Atacama Desert in northern Chile.

Quelle: ESO


Tags: Astronomie 

1214 Views

Sonntag, 17. Juli 2016 - 10:00 Uhr

Raumfahrt - ALLtag auf ISS: Erde-Blick

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Quelle: NASA-LIVE-Frams


Tags: Raumfahrt 

1293 Views

Samstag, 16. Juli 2016 - 22:30 Uhr

Luftfahrt-History - 1947: P-84 Thunderjet

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Aus dem CENAP-Archiv:

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Quelle: CENAP-Archiv


Tags: Luftfahrt 

1217 Views

Samstag, 16. Juli 2016 - 20:30 Uhr

Raumfahrt - ESA-Sonde Rosetta/Philae auf Komet 67P/Churyumov-Gerasimenko - Update-48

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8.04.2016

THE COLOUR-CHANGING COMET

Comet 67P/Churyumov-Gerasimenko was seen changing colour and brightness by Rosetta’s Visible and InfraRed Thermal Imaging Spectrometer, VIRTIS, as more water-ice was exposed near its surface as it moved close to the Sun between August and November 2014.
In the three-month study period the comet moved from about 542 million km to 438 million km from the Sun, and the spacecraft-to-comet distance varied from about 100 km to 10 km, resulting in a range of illumination conditions and viewing geometries.
In general, the darkest portions of the comet, containing dry dust made out of a mixture of minerals and organics, reflect light at redder wavelengths, while active regions and the occasional ice-rich exposure is bluer.
The VIRTIS study shows that even in the first three months of study at the comet, global average changes are noticeable, with an overall trend of the comet becoming brighter and more water-ice-rich. This is particularly notable in the Imhotep region, which becomes overall bluer over time.
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Rosetta’s comet has been seen changing colour and brightness in front of the ESA orbiter’s eyes, as the Sun’s heat strips away the older surface to reveal fresher material.
Rosetta’s Visible and InfraRed Thermal Imaging Spectrometer, VIRTIS, began to detect these changes in the sunlit parts of Comet 67P/Churyumov–Gerasimenko – mostly the northern hemisphere and equatorial regions – in the months immediately following the spacecraft’s arrival in August 2014.
A new paper, published in the journal Icarus, reports on the early findings of this study, up to November 2014, during which time Rosetta was operating between 100 km to within 10 km of the comet nucleus. At the same time, the comet itself moved along its orbit closer to the Sun, from about 542 million km to 438 million km.
VIRTIS monitored the changes in light reflected from the surface over a wide range of visible and infrared wavelengths, as an indicator of subtle changes in the composition of the comet’s outermost layer. 
When it arrived, Rosetta found an extremely dark body, reflecting about 6% of the visible light falling on it. This is because the majority of the surface is covered with a layer of dark, dry, dust made out of mixture of minerals and organics.
Some surfaces are slightly brighter, some slightly darker, indicating differences in composition. Most of the surface is slightly reddened by organic-rich material, while the occasional ice-rich material shows up as somewhat bluer.
Even when Rosetta first rendezvoused with the comet far from the Sun, ices hidden below the surface were being gently warmed, sublimating into gas, and escaping, lifting some of the surface dust away and contributing to the comet’s coma and tail.
VIRTIS shows that as the ‘old’ dust layers were slowly ejected, fresher material was gradually exposed. This new surface was both more reflective, making the comet brighter, and richer in ice, resulting in bluer measurements.
On average, the comet’s brightness changed by about 34%. In the Imhotep region, it increased from 6.4% to 9.7% over the three months of observations.
“The overall trend seems to be that there is an increasing water-ice abundance in the comet’s surface layers that results in a change in the observed spectral signatures. In that respect, it’s like the comet is changing colour in front of our eyes,” says Gianrico Filacchione, lead author of the study.
“This evolution is a direct consequence of the activity occurring on and immediately beneath the comet’s surface. The partial removal of the dust layer caused by the start of gaseous activity is the probable cause of the increasing abundance of water ice at the surface.”
“The surface properties are really dynamic, changing with the distance from the Sun and with the levels of comet activity,” adds Fabrizio Capaccioni, VIRTIS principal investigator.
“We’ve started analysing the subsequent datasets and can already see that the trend continues in the observations made beyond November 2014.”
“The evolution of surface properties with activity has never been observed by a cometary mission before and is a major science objective of the Rosetta mission,” says Matt Taylor, ESA’s Rosetta Project Scientist.
“It is great to see science papers being published directly addressing this topic and we’re looking forward to seeing how things have changed over the entire mission.”
Quelle: ESA
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Update: 9.04.2016
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SwRI-led team identifies clathrate ices in comet 67P
Studying comets provides clues to the early history of our solar system
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San Antonio -- For decades, scientists have agreed that comets are mostly water ice, but what kind of ice -- amorphous or crystalline -- is still up for debate. Looking at data obtained by ESA's Rosetta spacecraft in the atmosphere, or coma, around comet 67P/Churyumov-Gerasimenko, scientists at Southwest Research Institute (SwRI) are seeing evidence of a crystalline form of ice called clathrates.
"The structure and phase of the ice is important because it tells us a lot about how and where the comet may have formed," says Dr. Adrienn Luspay-Kuti, a research scientist in SwRI's Space Science and Engineering Division. She is the lead author of a paper titled "The presence of clathrates in comet 67P/Churyumov-Gerasimenko" published in the April 8 issue of the journal Science Advances. "If the building blocks of 67P were predominantly crystalline ices and clathrates, then 67P likely agglomerated from chunks of ice closer to the Sun. The protosolar nebula closer to the Sun experienced higher temperatures and more turbulence where crystalline ices could form as the nebula cooled. More pristine amorphous ices likely dominated the colder outskirts of the rotating disk of dust and gas that surrounds the core of a developing solar system."
Amorphous water ice efficiently traps large amounts of volatile compounds, which are released simultaneously upon warming. Water clathrates are crystalline structures containing gas molecules. The volatiles locked inside the water actually create the stable clathrate structure. These structures release gases at characteristic temperatures, dependent on the gas-phase volatile locked inside the clathrate. Luspay-Kuti led an international team of cometary experts that interpreted Rosetta spacecraft data, and found that the observed outgassing pattern indicates the nucleus of 67P contains clathrates.
"Without direct sampling of the nucleus interior, evaluating the composition of the coma provides the best clues about the ice structure and, as a result, the possible origin of cometary nuclei," said Luspay-Kuti. "Thought to closely reflect the composition of the building blocks of our solar system, comets carry important information about the prevalent conditions in the solar nebula before and after planet formation. These small icy bodies help us understand the big picture."
The multi-institute team of cometary scientists analyzed mass spectrometer data from the southern region of 67P from September to October 2014, before equinox. 67P is a Jupiter family comet thought to originate from the Kuiper Belt. Scientists are comparing these new data with data from the flyby of Hartley 2 -- considered cometary kin in family and origin to 67P -- and finding correlations. If these comets formed closer to the Sun than originally thought, these data could help refine solar system formation models.
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This research was supported by NASA's Jet Propulsion Laboratory, Cornell University, the French National Research Agency, Centre National d'Études Spatiales, and the James Webb Space Telescope project. Rosetta is an ESA mission with contributions from its member states and NASA. Airbus Defense and Space built the Rosetta spacecraft. JPL manages the U.S. contribution of the Rosetta mission for NASA's Science Mission Directorate in Washington, D.C., under a contract with the California Institute of Technology.
Quelle: AAAS
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COMETWATCH 4 APRIL
This week Rosetta has been moving back towards Comet 67P/Churyumov-Gerasimenko again following its far excursion in the anti-sunward direction to study the wider coma, tail and plasma environment.
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Rosetta NAVCAM image of Comet 67P/C-G taken on 4 April 2016 from a distance of 338 km. The image scale is 28.8 m/pixel and the image measures 29.5 km across. Credits: ESA/Rosetta/NavCam – CC BY-SA IGO 3.0
The spacecraft reached ~1000 km on 30 March and is now less than 100 km again. Today’s CometWatch image was taken on the inbound leg of the journey, on 4 April, from a distance of 338 km.
Even at this distance, a number of the comet’s regions can be picked out: notably the flat surface of Khepry to the top right of the large lobe with Aker ‘below’ and Babi to the left in this orientation. On the small lobe, Hatmehit is in shadow to the lower right with parts of Bastet and Ma’at above and to the left.
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OSIRIS narrow-angle camera image taken on 29 March 2016, when Rosetta was 820 km from Comet 67P/Churyumov–Gerasimenko. The scale is 14.9 m/pixel. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
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Earlier this week we also saw views from the far excursion through Rosetta’s OSIRIS narrow- and wide-angle cameras, from distances of 820 km on the outward journey (above), and 442.3 km on the return journey (right), respectively.
The spacecraft continues to approach the comet and over the weekend it is set to carry out a zero phase flyby at around 30 km altitude.
The original NAVCAM image is provided below:
ESA_Rosetta_NAVCAM_20160404
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COMETWATCH 10 APRIL
After a far excursion to explore the tail of Comet 67P/Churyumov-Gerasimenko, Rosetta is now back to closer distances from the comet nucleus. This week's CometWatch image was obtained with Rosetta's NAVCAM at 01:39 UTC on 10 April 2016, 31.4 km away.
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Enhanced NAVCAM image of Comet 67P/C-G taken on 10 April 2016, 31.4 km from the comet nucleus. The scale is 2.7 m/pixel and the image measures 2.7 km across. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
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Enhanced NAVCAM image of Comet 67P/C-G taken on 10 April 2016, 31.4 km from the comet nucleus. The scale is 2.7 m/pixel and the image measures 2.7 km across. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
On the night between 9 and 10 April 2016, the spacecraft performed a special flyby, 30 km from the nucleus and with a phase angle very close to zero degrees.
The phase angle is measured between the direction of the sunlight illuminating the nucleus and that of the light reflected by the nucleus and caught by Rosetta. A near-zero phase angle means that these two directions are very close to one another, which happens when the spacecraft is flying exactly between the Sun and the comet.
In this configuration, Rosetta could see the sunlight hitting the nucleus at right angles, and therefore observed very little shadows on the surface.
The CometWatch image was taken shortly after the closest approach on this flyby, at a phase angle of 11.7 degrees.
The image shows mostly the small comet lobe and 'neck' region, with the smooth and bouldered terrains of Hapi, along the comet's neck, visible in the top right corner. A hint of the large lobe can also be seen in the top right corner.
Moving towards the lower left, portions of the rough Hathor region are visible, as well as parts of Ma'at farther on the left. The linear and almost parallel features visible on the right, instead, are part of Bastet.
The three-dimensional aspect of the nucleus and of its characteristic surface features is almost lost in this low phase-angle view, due to the scarcity of shadows. This is even more evident in the image captured by Rosetta’s OSIRIS wide-angle camera at 00:57 UTC on 10 April, about one hour before the NAVCAM view, at a phase angle of 0.9 degrees.
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OSIRIS wide-angle camera image taken on 10 April 2016, when Rosetta was 29.3 km from Comet 67P/Churyumov–Gerasimenko. The scale is 2.86 m/pixel. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
In this image, the large lobe is in the foreground and the small lobe in the background, on the left. The view on the large lobe is dominated by the flat landscape of the Imhotep region, with Khepry on its lower left, Aten on the upper left and Ash on the upper right.
Parts of Imhotep, Khepry and Ash are also featured in this OSIRIS narrow-angle camera image, taken somewhat earlier, at 00:10 UTC on 10 April, at a phase angle of two degrees.
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OSIRIS narrow-angle camera image taken on 10 April 2016, when Rosetta was 30.1 km from Comet 67P/Churyumov–Gerasimenko. The scale is 0.55 m/pixel. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
With hardly any shadows cast on the surface, the morphological differences between the three regions do not markedly appear. However, we can still recognise the smooth terrains of Imhotep in the right half of the image, while the cliff in the upper left corner is part of Ash and the rougher areas at the centre and towards the lower left belong to Khepry.
The original NAVCAM image is provided below.
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Quelle: ESA
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Update: 1.07.2016
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Rosetta comet probe given termination date
The Rosetta probe will be crash-landed on Comet 67P on Friday 30 September, the European Space Agency has confirmed.
The manoeuvre, which is expected to destroy the satellite, will bring to an end two years of investigations at the 4km-wide icy dirt-ball.
Flight controllers plan to have the cameras taking and relaying pictures during the final descent.
Sensors that "sniff" the chemical environment will also be switched on.
All other instruments will likely be off.
Flight dynamics experts have still to work out the fine details, but Rosetta will be put into a tight ellipse around the comet and commanded to drop its periapsis (lowest pass) progressively. A final burn will then put the satellite on a collision course with the duck-shaped object.
Mission managers have previously talked about bringing Rosetta down in a place dubbed "Agilkia" - the location originally chosen to land its surface robot, Philae, in November 2014.
In the event, Philae bounced a kilometre away, but Agilkia's relatively flat terrain is an attractive option still, although other targets are being studied.
Having swept around the Sun last August, Comet 67P is currently on a trajectory that is taking it away from the inner Solar System towards the orbit of Jupiter.
Today, the probe is nearly half a billion km from the Sun.
This means the amount of light falling on Rosetta's solar panels is gradually diminishing; and, as a consequence, it has less power day by day to run its instruments and sub-systems.
Engineers would soon have to put the satellite into hibernation mode if they wanted to use it long term - during 67P's next encounter with the Sun in a few years' time.
But having already spent 12 years in space, battling huge temperature swings and damaging radiation, not to mention a much-reduced fuel load - there is little confidence Rosetta will still be operable so far into the future.
The crash-landing on the other hand offers the opportunity to get some very close-in science to complement the more distant remote sensing it has been doing.
Controllers will try to maintain contact with the satellite for as long as possible during the final descent.
Much will depend on how well Rosetta copes with the dusty environment around the comet.
Recent months have seen several occasions when the probe's navigation equipment, which tracks the stars to define a position in space, has got confused in the maelstrom of particles emanating from 67P's surface.
This has tripped the satellite into a "safe mode" that shuts down all non-essential operations, including instrument observations.
Rosetta will need to be commanded not to do this in the minutes before impact.
Crash-landing has become a common way to end the missions of planetary probes.
Most have been very high-velocity impacts, but a few, like the one Rosetta will attempt, have been walking-pace touchdowns.
In 2001, the US space agency's Near Shoemaker probe put down on the asteroid Eros so gently that it continued to work for a further two weeks at the surface before engineers eventually determined to terminate communications.
This will not be the case with Rosetta, however. Controllers are expected to program an auto shutoff, which will be triggered at the moment the satellite hits 67P.
Even if by chance its antenna were to survive the crush, Rosetta will not be calling home.
Quelle: BBC
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Update: 17.45 MESZ
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Rosetta wird ihre Mission am 30. September 2016 mit einer kontrollierten Landung auf die Oberfläche ihres Kometen abschließen.
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Die Mission erreicht aufgrund der immer größeren Entfernung des Raumfahrzeugs von der Sonne und Erde ihr Ende. Die Sonde bewegt sich in Richtung Jupiterorbit. Daher nimmt die für den Betrieb des Raumfahrzeugs und der Instrumente erforderliche Sonnenenergie aber auch die verfügbare Bandbreite zur Übermittlung der Wissenschaftsdaten zur Erde stetig ab.
In Verbindung mit dem steigenden Alter des Raumfahrzeugs sowie der Nutzlast, die mehr als 12 Jahre lang die harschen Umweltbedingungen im Weltraum überdauert haben – nicht nur die letzten beiden Jahre in der Nähe eines staubigen Kometen –, bedeutet dies, dass Rosetta das Ende ihres “natürlichen Lebens” erreicht.
Im Unterschied zu 2011, als Rosetta für die am weitesten entfernte Etappe ihrer Reise über 31 Monate lang in eine Art Winterschlaf versetzt wurde, fliegt sie dieses Mal Seite an Seite mit dem Kometen. Die größte Entfernung des Kometen 67P/Tschurjumov-Gerassimenko von der Sonne (mehr als 850 Millionen km) ist so weit, wie Rosetta nie zuvor gereist ist. Leider steht an diesem entlegensten Punkt der Reise nicht mehr genügend Energie zur Verfügung, um Rosetta Heizungen zu betreiben und so für ein Überleben der Sonde zu sorgen.
Statt sich der Gefahr einer weitaus längeren Überwinterung auszusetzen, die die Sonde vermutlich nicht überstehen würde, und nach Beratungen mit dem Wissenschaftsteam von Rosetta im Jahr 2014, wurde beschlossen, dass Rosetta ihrem Landemodul Philae auf die Kometenoberfläche folgt.
Die letzten Stunden des Abstiegs bieten Rosetta die einmalige Möglichkeit, zahlreiche Messwerte zu erfassen, unter anderem auch extrem hochauflösende Bilder. Solche Nahaufnahmen, die nur bei diesem glorreichen Abschluss der Mission zu machen sind, setzen den wissenschaftlichen Erkenntnissen der Sonde zweifelsfrei die Krone auf.
Die Kommunikation mit dem Orbiter wird jedoch bei Erreichen der Kometenoberfläche enden, wenn er seinen Betrieb einstellt. 
“Wir werden versuchen, noch so viele Untersuchungen wie möglich herauszuziehen, bevor uns die Sonnenenergie ausgeht”, erzählt Matt Taylor, Rosetta Projektwissenschaftler der ESA. “Der 30. September markiert das Ende des Betriebs der Raumsonde, jedoch auch den Beginn der Phase, in der sich die Teams voll und ganz auf die Wissenschaft fokussieren. Deswegen wurde die Rosetta Mission gestartet und es liegen einige Jahre Arbeit vor uns, bis wir all ihre Daten sorgfältig ausgewertet haben.”
Das Kontrollteam von Rosetta wird die Flugbahn im August, vor dem großen Finale, so anpassen, dass sie eine Reihe elliptischer Orbits fliegt und sich dabei langsam dem Kometen annähert.
“Die Planung dieser Phase ist tatsächlich wesentlich komplexer als es bei der Landung von Philae der Fall war”, meint Sylvain Lodiot, Rosetta Spacecraft Operations Manager bei der ESA. “Die letzten sechs Wochen werden ganz besonders spannend, weil wir dann exzentrische Orbits um den Kometen fliegen – und das ist in vielerlei Hinsicht wesentlich riskanter als der eigentliche Abstieg.
“Je näher wir dem Kometen kommen, desto stärker wirkt sich seine ungleichmäßige Schwerkraft aus, weswegen wir die Flugbahn intensiver kontrollieren müssen. Dafür sind zahlreiche Manöver erforderlich – unsere Planungszyklen werden dann sehr viel kurzfristiger ausgeführt.”
An den letzten Tagen der Mission wird eine letzte Flugbahnänderung in etwa 20 km Abstand vom Kometen, circa 12 Stunden vor dem Aufsetzen, eine Reihe von Manövern abschließen und die Raumsonde auf ihren letzten Weg hinunter zum Kometen bringen.
Wo Rosetta landen soll, wird weiterhin diskutiert, da das Operationsteam und die Wissenschaftler die verschiedenen Parameter mit zahlreichen unterschiedlichen Flugbahnen abstimmen müssen. 
Generell wird jedoch erwartet, dass die Landung mit etwa 50 cm/s erfolgen soll, das ist etwa halb so schnell, wie die Landegeschwindigkeit von Philae im November 2014.
Die an den Tagen davor hochgeladenen Befehle stellen automatisch sicher, dass sowohl die Transmitter als auch alle Einheiten und Instrumente zur Fluglage und Kontrolle des Orbits mit der Landung ausgeschaltet werden, um die Entsorgungsanforderungen für Raumfahrzeuge zu erfüllen.
In jedem Fall wird die Hochleistungsantenne von Rosetta nach der Landung nicht mehr auf die Erde gerichtet sein, wodurch eine Kommunikation praktisch unmöglich wird.
Zwischenzeitlich laufen die Forschungen weiter, wie sonst auch, obwohl zahlreiche Risiken vorprogrammiert sind. Vergangenen Monat verbrachte das Raumfahrzeug einige Zeit in einem ‘sicheren Modus’, als es nur 5 km vom Kometen entfernt war und Staub das Navigationssystem beeinträchtigte. Rosetta hat sich dann wieder erholt, aber das Missionsteam kann nicht ausschließen, dass ein solcher Zustand zum Ende der Mission hin erneut auftritt.
“Obwohl wir unsere Arbeit bestmöglich erledigen, damit Rosetta bis dahin unversehrt bleibt, wissen wir aufgrund unserer Erfahrungen aus den vergangenen zwei Jahren beim Kometen, dass vieles nicht so läuft, wie geplant und – wie immer – müssen wir auf das Unerwartete vorbereitet sein”, räumt Patrick Martin ein, Rosetta-Missionsleiter bei der ESA.
“Dies ist die ultimative Herausforderung für unsere Teams und für unser Raumfahrzeug, und ein sehr passendes Ende für die unglaubliche und erfolgreiche Rosetta Mission.”
Quelle: ESA
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Update: 5.07.2016
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ID NAC_2016-07-03T11.09.52.166Z_ID10_1397549001_F22
Date taken 2016-07-03T11:11:19.201 (UTC)
Camera Narrow Angle Camera
Filter FFocus_Vis (-) / Orange (649 nm)
Exposure time 0.114 s
Pixel resolution 0.16 m/px at 67P/CG
Processing level Raw
Distance Rosetta ↔ 67P/CG 9.115 km
Distance 67P/CG ↔ Sun 497355104 km 3.324614 AU
Distance Rosetta ↔ Earth 523909280 km 3.502117 AU
Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Quelle: ESA
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Update: 16.07.2016
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COMETWATCH 25 JUNE
This week's CometWatch image was taken with Rosetta's NAVCAM on 25 June 2016, when the spacecraft was 16.7 km from the nucleus of Comet 67P/Churyumov-Gerasimenko.
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Enhanced NAVCAM image of Comet 67P/C-G taken on 25 June 2016, 16.7 km from the nucleus. The scale is 1.4 m/pixel and the image measures 1.5 km across. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
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The image shows a portion of the large comet lobe, with the neck region and a hint of the small lobe on the upper right.
Dominated by the smooth terrains of Anubis, on the large lobe, this scene reveals the many boulders scattered across this region, as well as a number of surface features visible in the dust cover. A similar view of this area, taken from a comparable distance but different perspective, was featured in CometWatch 1 May.
In the central left portion of the image, towards the upper edge of the nucleus, some elevated, shadow-casting structures mark the boundary between Anubis and Seth. Parts of the more complex Atum region are visible in the bottom part of the image, exhibiting a number of linear features especially towards the lower right corner, close to the boundary with the neighbouring Geb region.
On the upper right, along the neck, the smooth region of Hapi, covered in dust and plenty of boulders, guides the eye towards the rougher Anuket, partly cast in shadow.
Another image, taken on the same day with Rosetta's OSIRIS narrow-angle camera, shows a detailed view of an entirely different portion of the large comet lobe, at the meeting point between the regions of Khepry (upper left), Imhotep (right) and Bes (bottom).
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OSIRIS narrow-angle camera image taken on 25 June 2016, when Rosetta was 17.9 km from Comet 67P/C-G. The scale is 0.31 m/pixel and the image measures about 630 m. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
The original NAVCAM image is provided below.
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COMETWATCH 30 JUNE
Today's CometWatch entry, also featured as ESA Space Science Image of the Week, is an image of Comet 67P/Churyumov-Gerasimenko taken with Rosetta's navigation camera (NAVCAM) on 30 June 2016, from a distance of 25.8 km.
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Enhanced NAVCAM image of Comet 67P/C-G taken on 30 June 2016, 25.8 km from the nucleus. The scale is 2.2 m/pixel and the image measures 2.3 km across. The faint vertical striping effect is an image artifact. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
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Depicted in the lower right part of the image is the region Hathor, a very intriguing portion of the small comet lobe, where the head declines steeply towards the neck and body of the comet.
This view shows a good fraction of the 900-m high cliff that forms Hathor, with marked linear features crossing the region from left to right. Perpendicular to these, additional streaks and even small terraces can be seen. Beyond the cliff of Hathor, on the right, are hints of the Ma'at region.
In the upper right corner, smoother patches of the large comet lobe are visible, covered in dust and boulders. The large lobe casts its shadow on the comet's neck, which separates the two lobes and is hidden from view in this image.
Meanwhile, Rosetta's OSIRIS wide-angle camera obtained this stunning image of a different portion of the comet on 2 July, when the spacecraft was 14.5 km from the nucleus.
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OSIRIS wide-angle camera image taken on 2 July 2016, when Rosetta was 14.5 km from Comet 67P/C-G. The scale is 1.38 m/pixel and the image measures about 2.8 km. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
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The image shows most of the large comet lobe, with the Khonsu, Atum and Anubis regions well in sight, from left to right, and hints of Seth towards the right edge. In the lower right corner, the smooth region of Hapi is visible, on the neck, leading towards the rougher Anuket.
Another striking image, featuring smooth-covered terrains in the Babi region, on the large comet lobe, was taken with the OSIRIS narrow-angle camera on 3 July, when Rosetta was about 11 km from the nucleus.
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OSIRIS narrow-angle camera image taken on 3 July 2016, when Rosetta was 11.2 km from Comet 67P/C-G. The scale is 0.20 m/pixel and the image measures about 410 m. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
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Currently, Rosetta is on a 27 km x 9 km elliptical orbit around the nucleus; this weekend, it will move to a less eccentric, 9 km x 10 km orbit, ahead of entering the end-of-mission orbit. The mission will continue its close-up investigation of the comet environment until the grand finale, a controlled descent of the spacecraft to the surface of the comet on 30 September.
The original NAVCAM image is provided below.
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Quelle: ESA
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COMETWATCH 9 JULY
This week's CometWatch image was taken with Rosetta's NAVCAM on 9 July 2016, when the spacecraft was 11.7 km from the nucleus of Comet 67P/Churyumov-Gerasimenko.
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Enhanced NAVCAM image of Comet 67P/C-G taken on 9 July 2016, 11.7 km from the nucleus. The scale is 1 m/pixel and the image measures about 1 km. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
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This close-up view shows a portion of the Khonsu region on the larger of the two comet lobes. Khonsu is part of the southern hemisphere of 67P/C-G.
The image reveals a variety of fractured and smooth terrains, with a great number of boulders of all sizes, including several large ones. It also includes a three-layered structure with a balancing boulder on top, which was also portrayed in previous images, for example the NAVCAM view featured as CometWatch 13 June, which shows the same region but from a broader perspective.
Meanwhile, a view of Comet 67P/C-G from Rosetta's OSIRIS wide-angle camera was published on the OSIRIS Image of the Day website earlier this week.
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OSIRIS wide-angle camera image taken on 4 July 2016, when Rosetta was 13.3 km from Comet 67P/C-G. The scale is 1.28 m/pixel and the image measures 2.6 km. To preserve the correct orientation of the comet, the image has been flipped horizontally with respect to the one originally published on the OSIRIS Image of the Day website. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
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The image, taken on 4 July from a distance of 13.3 km, shows a large portion of the large comet lobe, highlighting the circular features of the Seth and Ash regions and with hints of the complex terrains of Atum towards the right.
In the top left part of the frame, on the comet's neck, the dust covered landscape of Hapi is portrayed just below the slopes of the rougher Anuket region, while the cliffs of Hathor are cast in shadow on the left.
A similar and somewhat complementing view, also taken with the OSIRIS wide-angle camera but on 11 July, some 15 km from the nucleus, was published earlier today.
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OSIRIS wide-angle camera image taken on 11 July 2016, when Rosetta was 14.9 km from Comet 67P/C-G. The scale is 1.38 m/pixel and the image measures 2.8 km. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
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On the small lobe, in the top part of the image, are portions of Serqet (left) and Ma'at (right), while on the large lobe, in the lower left part of the frame, are views of Seth and Ash. In the central part of the image, the regions on and close to the neck – Hapi, Hathor and Anuket – are cast in dark shadows.
Another view, taken with the OSIRIS narrow-angle camera on 10 July from a distance of 9.5 km, provides a detailed view of a different portion of the large comet lobe, with sights of the Khepry and Aker regions.
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OSIRIS narrow-angle camera image taken on 10 July 2016, when Rosetta was 9.5 km from Comet 67P/C-G. The scale is 0.31 m/pixel and the image measures about 630 m. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
The original NAVCAM image is provided below.
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Quelle: ESA

Tags: Raumfahrt 

2373 Views

Samstag, 16. Juli 2016 - 11:40 Uhr

Luftfahrt - NUCLEAR-POWERED SUPERSONIC AIRLINER CONCEPT

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THIS NUCLEAR-POWERED SUPERSONIC AIRLINER CONCEPT IS A BEAUTIFUL DREAM
AS IMPROBABLE AS IT IS WONDERFUL
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Skies are big and empty. What is stopping us from filling them with massive, supersonic, nuclear-powered jetliners?
Well, other than physics, regulations, a lack of market need, and common sense — almost nothing!
Oscar Viñals in a conceptual artist freed from such constraints, and his vision of a supersonic, nuclear-powered airliner is exists as a sort of beautiful, high-tech dream.
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The "FF" Flash Falcon design is based in a deep study of today’s and upcoming technologies and future theoretical advances. This airplane's design is the last one of a trilogy (Sky Whale, Progress Eagle & Flash Falcon) about how the future airliners could be. This airplane would belong to an hypothetical generation that would be equipped with a technology based on Fusion Energy (the future GREEN ENERGY), which today can only be found under development, but in the next fifteen years it could become a feasible reality, capable to generate great amounts of Electric Energy without the use of "contaminant" materials.
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Viñals has no shortage of optimism, and expects planes like this to take the skies in the 2030s.
An earlier Viñals concept, the Progress Eagle proposed a similarly massive aircraft, powered by rows and rows of solar panels on its wings and back.
For the Flash Falcon, Viñals imagines it flying as fast as Mach 3 at altitudes of up to 60,000 feet. The full schematics include engine designs and a special “sonic boom eraser system”, designed to make the superfast behemoth quiet, too.
It is extremely unlikely any aircraft designed like this will ever fly. But it’s a beautiful, big dream of what a futuristic aircraft could possibly be. Keep dreaming as big as the sky, Viñals.
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Quelle: PS

Tags: Luftfahrt 

1290 Views

Samstag, 16. Juli 2016 - 10:15 Uhr

Raumfahrt - NASA sucht Vorschläge zur Nutzung des zukünftigen Raumstation Docking-Port

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Michael Suffredini of Axiom Space showed July 14 this concept of a commercial module his company is considering for use on the International Space Station that could later serve as part of a standalone commercial space station. Credit: Axiom Space
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SAN DIEGO — As two companies move forward with plans to develop commercial modules for use on the International Space Station as precursors to independent space stations, NASA is soliciting concepts for use of a space station docking port.
NASA issued a request for information (RFI) July 1 about how “limited availability, unique International Space Station capabilities” could be used to support economic development in low Earth orbit. “This RFI is being used to determine private market interest in using unique ISS capabilities that have limited availability in order to advance economic development in LEO,” the document states.
That request specifically mentions future use of the aft docking port on the Node 3, or Tranquility, module. That port is currently occupied by the Bigelow Expandable Activity Module (BEAM), installed on the station earlier this year for a two-year test. It would thus be available for use by other modules as soon as 2018, when the BEAM is removed from the station.
Bill Gerstenmaier, NASA associate administrator for human exploration and operations, mentioned the RFI at a July 13 hearing of the Senate Commerce Committee’s space subcommittee, saying NASA was seeking input for how industry could use the port and how the agency could work with companies to gain access to it.
“We essentially have one of the ports on the space station that we’re going to make available to the private sector to go utilize how they want,” he said. NASA would provide power and life support for that module in addition to the docking port itself, he said, while the company using the port would purchase cargo and crew transportation services from the private companies that provide similar services for NASA.
“We asked them for ideas of how they would use this port,” Gerstenmaier said of the RFI. “It will be exciting to see what the private sector tells us in this response. How can they use this unique asset?”
Gerstenmaier suggested that a company might seek to install their own module at that port as a precursor for an independent station once the ISS is retired. “And then at some point, when the station’s life is exceeded, they could undock from the station and be the basis for the next private sector station,” he said.
At least two companies have expressed an interest in placing a private module on the ISS as a precursor to a full-fledged commercial space station. In April, Bigelow Aerospace announced it was in discussions with NASA about installing one of its B330 modules on the ISS as soon as 2020.
Robert Bigelow, president of Bigelow Aerospace, did not specifically mention that proposal during a panel session at the International Space Station Research and Development Conference here July 14. He did state that the company was on schedule to have two B330 modules ready for launch by 2020. “Things are looking very good so far,” he said.
Bigelow said after the panel session that Bigelow was still in discussions with NASA about installing a B330 on the station. “We have made a formal proposal to do that,” he said. “We would be really excited to do that with NASA, and we gave them a tremendous deal.” He said, though, that he was not certain if Bigelow Aerospace planned to respond to the NASA RFI.
In June, Michael Suffredini, the former NASA ISS program manager who is now president of the commercial space division of Stinger Ghaffarian Technologies (SGT), announced the formation of a new venture, Axiom Space, to develop commercial space station modules. An initial module could be installed on the station as a precursor to a standalone station.
Speaking on the same panel as Bigelow, Suffredini showed an illustration of one concept for company’s proposed first module. That module, he said, would be sized to be as large as possible while still able to fit within existing launch vehicles and their payload fairings so it can go to the ISS on a single launch.
That module would be undocked at the end of the ISS’ life to form the core of a commercial space station, he said. “In our vision, the idea is that you have to build a station that can evolve as the market grows,” he said, confirming after his talk that his company planned to submit a response to the NASA RFI.
That evolutionary approach is essential, he said, since he believed that while long-term projections for market demand were promising, there wasn’t enough business now for a standalone commercial station. “Near term, however, we still have a long way to go.”
Quelle: SN

Tags: Raumfahrt 

1195 Views

Samstag, 16. Juli 2016 - 10:00 Uhr

Astronomie - Mysteriöses Rauschen von Pulsaren lässt auf Begleiter schließen

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Objects that closely orbit pulsars may distort their radio signals
NASA/Caltech
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Two strange celestial bodies might have the clingiest friends in the cosmos. If the spinning neutron stars B1859+07 and B0919+06 are orbited by very dense objects once every few minutes – closer than any known pair in the universe – it could explain a strange repeating pattern distorting their radio signals.
Pulsars, the dense, spinning corpses of stars that have died in a supernova, normally emit radio pulses like clockwork – though sometimes their pace can shift. But in the 1990s, Joanna Rankin at the University of Vermont in Burlington noticed another pattern she calls a “swoosh”: pulses from an object called B0919+06 started to arrive sooner than expected, and then, minutes later, the signal drifted back to normal.
Rankin says she initially thought it was an instrumental effect that originated inside the telescope. But when another pulsar started to show swooshes, she became curious about what caused the gradual shift and documented the phenomenon in a paper.
Now, a study led by Rankin’s student Haley Wahl offers the team’s best guess, after further observations that show swooshes sometimes repeat. Without an alternative explanation, Wahl thinks the periodic pattern could result from companion objects orbiting the pulsars at close range.
No ordinary object
These unseen neighbours, if they exist, would orbit the pulsars at the breakneck pace of once every few minutes – a shorter orbital period than any known pair of objects in the universe, says Rankin. By passing through the pulsar’s magnetic field at a sizeable fraction of the speed of light, these companions could be creating the swoosh pattern by disrupting the radio signal we see.
The companion must be something special, because most ordinary objects would be ripped to shreds by the pulsar’s gravity. “It has to be something incredibly dense to stay together,” says Rankin. “Even a rock of normal material couldn’t do anything but turn into dust.”
A small black hole could work, she says. But the most likely candidate would be a hunk of white dwarf matter, given that white dwarfs are already known to orbit neutron stars with periods as short as a few hours. The system could be at a later stage of its evolution, in which a white dwarf-neutron star pair is circling towards an inevitable collision with the pulsar.
The theory is still preliminary, Rankin says: “The whole idea of satellites this close to a pulsar is sufficiently wild that we say it’s the last resort.”
Still, pulsars with fragments of white dwarf around them should be out there, says Maura McLaughlin at West Virginia University in Morgantown. The trouble is that the proposed companions are small and faint, and thus hard to see. “It’s extremely hard to prove that a companion like that exists,” says McLaughlin.
Rankin’s team hopes that this paper will inspire others to work out a more complete physical model for the swooshes, allowing them to then ask for telescope time to check out these pulsars in more detail.
Quelle: NewScientist

Tags: Astronomie 

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