Showing posts with label develop. Show all posts
Showing posts with label develop. Show all posts

Thursday, May 29, 2014

Russia to abandon ISS and develop a new Space Station with China

Russia is developing a national program of manned space explorations which will replace the International Space Station (ISS) program after 2020, the Russian Federal Space Agency, Roscosmos, said Thursday.

"The development of the national strategy of manned spaceflight is underway now."

"Along with the Russian Academy of Sciences and the industrial sector we are preparing a certain concept beyond the ISS," Roscosmos Deputy Chief Sergei Savelyev told reporters at the 18th St. Petersburg International Economic Forum.

China and the European Space Agency (ESA), he added, were seen as the potential partners in the new strategy, but the key role will belong to Russia.

Russian Deputy Prime Minister Dmitry Rogozin, who is in charge of space and defense sectors, said earlier in the week that Moscow had no plans to extend the operation of the ISS beyond 2020, though the United States had proposed to extend ISS cooperation after that year.

On Tuesday, Rogozin also threatened that from June 1 Moscow would shut down 11 U.S. Global Positioning System (GPS) base stations on Russian territory in response to Washington's anti-Russia sanctions and its refusal to plant Russian Glonass ground base stations on U.S. territory.

Meanwhile, Roscosmos plans to resume talks over the placement of Glonass stations in the United States over the next few weeks, Savelyev said.

"I think it will happen in the very near future, over the next two or three weeks. It would still give us a chance to walk away from the unpleasant situation over sanctions and continue cooperation," the Interfax news agency quoted the official as saying.

Thursday, May 8, 2014

Scottish Researchers build acoustic tractor beam

(a) Nonconservative pushing force exerted on an object by a plane wave as a result of strong backscattering. 

(b) Decreasing of the pushing force due to an enhanced forward scattering in a nonparaxial beam. 

(c) The authors used a target designed to maximize the forward scattering of acoustic radiation, leading to a pulling nonconservative force towards the source: an acoustic tractor beam. 

Credit: APS/Alan Stonebraker

A team of researchers with members from the U.K., Scotland and the U.S. has built a functioning acoustic tractor beam in a lab, one that is able to pull objects of centimeter size.

In their paper published in the journal Physical Review Letters, the team describes how they built their device, why it works and to what applications it might be put.

Tractor beams, as we all know are a staple of science fiction, a beam is emitted from a spaceship that can be used to lock on to other objects, such as another space ship, and then used to move that other object in any direction, most interestingly, in the same direction from which the beam is being emitted, pulling it in.

Tractor beams seem counterintuitive as beams of light tend to push objects away, rather than attract them—but, as prior research has shown, optical tractor beams can be created at the nanoparticle level, e.g. optical tweezers.

In this new effort, the research team has extended the abilities of a tractor beam by using one based on acoustics, rather than optics.

Sending a beam (wave) at an object and having it pull the object closer rather than push it can work because of the scattering of the wave that occurs when it collides with the object and if the wave is sent at an angle to the object.

If the scattering and angle are controlled just right, a low pressure zone can be created in front of the object, in effect, pushing it back towards the origin of the beam.

In the lab, the researchers used ultrasonic sound waves in a tank of water.

They put an array of ultrasound emitters at the bottom of the tank and used a hollow isosceles triangular prism as the object to be pulled.

Using an array of emitters allowed for very precisely controlling the wave, which allowed for directing energy onto the outer surface of the object, causing backscattering that led to the frontal low pressure zone, which in turn led to pushing the object back towards the wave source.

An analogy would be squeezing a chocolate chip with your fingers, forcing it to move in whatever direction you choose.

Experimental configuration to demonstrate negative radiation forces with a planar ultrasonic array.

(a) Scaled cross-sectional geometry of the 550 kHz planar matrix array source and hollow, prism-shaped targets suspended above the array. Linear phase gradients applied to the array elements produce wave fronts steered at θ=50.6° towards the array center line.

Active subapertures, forming a hollow core with diameter Δxn, are stepped towards the center line by the array element pitch, with a corresponding lateral (±x) shift in the transmitted local wave fronts and an axial (−z) shift of the intersection with the axis.

(b), (c) Normalised maps of simulated instantaneous pressure field and

(d),(e) measured magnitude of the pressure field produced by the transmitting subapertures illustrated under the field maps. 

Credit: (c) PRL, DOI: 10.1103/PhysRevLett.112.174302

Because of the stipulations required to make it work, applications that could make use of such a tractor beam are clearly limited, though the researchers suggest it might prove useful in some medical situations.

More information: Acoustic Tractor Beam, Phys. Rev. Lett. 112, 174302 – Published 30 April 2014. dx.doi.org/10.1103/PhysRevLett.112.174302

Friday, December 20, 2013

MIT Scientists develop new technique to measure mass of exoplanets

Artistic rendering of a planet's transmission spectrum. 

Credit: CHRISTINE DANILOFF /MIT, JULIEN DE WIT

To date, scientists have confirmed the existence of more than 900 exoplanets circulating outside our solar system.

To determine if any of these far-off worlds are habitable requires knowing an exoplanet's mass—which can help tell scientists whether the planet is made of gas or rock and other life-supporting materials.

But current techniques for estimating exoplanetary mass are limited. Radial velocity is the main method scientists use: tiny wobbles in a star's orbit as it is tugged around by the planet's gravitational force, from which scientists can derive the planet-to-star mass ratio.

Spitzer Space Telescope
For very large, Neptune-sized planets, or smaller Earth-sized planets orbiting very close to bright stars, radial velocity works relatively well.

But the technique is less successful with smaller planets that orbit much farther from their stars, as Earth does.

Now scientists at MIT have developed a new technique for determining the mass of exoplanets, using only their transit signal—dips in light as a planet passes in front of its star.

Julien de Wit
This data has traditionally been used to determine a planet's size and atmospheric properties, but the MIT team has found a way to interpret it such that it also reveals the planet's mass.

"With this method, we realized the planetary mass—a key parameter that, if missing, could have prevented us from assessing the habitability of the first potentially habitable Earth-sized planet in the next decade—will actually be accessible, together with its atmospheric properties," says Julien de Wit, a graduate student in MIT's Department of Earth, Atmospheric and Planetary Sciences.

De Wit is lead author on a paper published today in the journal Science, with co-author Sara Seager, the Class of 1941 Professor of Physics and Planetary Science.


Researchers at MIT explain what exactly an exoplanet or extrasolar planet is, why we study them and how you can detect them.

"The mass affects everything on a planetary level, such as any plate tectonics, its internal cooling and convection, how it generates magnetic fields, and whether gas escapes from its atmosphere," de Wit says.

"If you don't get it, there is a large part of the planet's properties that remains undetermined."

Using large telescopes such as the NASA's Spitzer and Hubble Space Telescopes, scientists have been able to analyze the transmission spectra of newly discovered exoplanets.

A transmission spectrum is generated as a planet passes in front of its star, letting some light through its atmosphere.

By analyzing the wavelengths of light that pass through, scientists can determine a planet's atmospheric properties, such as its temperature and the density of atmospheric molecules. From the total amount of light blocked, they can calculate a planet's size.

More information: "Constraining Exoplanet Mass from Transmission Spectroscopy," by J. de Wit et al. Science, 2013. DOI:10.1126/science.1245450

Tuesday, April 23, 2013

Scientific collaboration to develop affordable High Concentration PhotoVoltaic Thermal (HCPVT) system

Scientists have announced a collaboration to develop an affordable photovoltaic system capable of concentrating, on average, the power of 2,000 suns, with an efficiency that can collect 80 percent of the incoming radiation and convert it to useful energy.

The proposed system can be built anywhere sustainable energy, drinkable water and cool air are in short supply at a cost of three times lower than comparable systems.

A three-year, $2.4 million (2.25 million CHF) grant from the KTISwiss Commission for Technology and Innovation has been awarded to scientists at IBM Research; Airlight Energy, a supplier of solar power technology; ETH Zurich (Professorship of Renewable Energy Carriers) and Interstate University of Applied Sciences Buchs NTB (Institute for Micro- and Nanotechnology MNT) to research and develop an economical High Concentration PhotoVoltaic Thermal (HCPVT) system.

Based on a study by the European Solar Thermal Electricity Association and Greenpeace International it would take only two percent of the Sahara Desert's land area to supply the world's electricity needs.

Unfortunately, current solar technologies on the market today are too expensive and slow to produce, require rare Earth minerals and lack the efficiency to make such massive installations practical.

The prototype HCPVT system uses a large parabolic dish, made from a multitude of mirror facets, which is attached to a tracking system that determines the best angle based on the position of the sun.

Once aligned, the sun's rays reflect off the mirror onto several microchannel-liquid cooled receivers with triple junction photovoltaic chips—each 1x1 centimeter chip can convert 200-250 watts, on average, over a typical eight hour day in a sunny region.

The entire receiver combines hundreds of chips and provides 25 kilowatts of electrical power. The photovoltaic chips are mounted on microstructured layers that pipe liquid coolants within a few tens of micrometers off the chip to absorb the heat and draw it away 10 times more effective than with passive air cooling.

The coolant maintains the chips almost at the same temperature for a solar concentration of 2,000 times and can keep them at safe temperatures up to a solar concentration of 5,000 times.

The direct cooling solution with very small pumping power is inspired by the hierarchical branched blood supply system of the human body and has been already tested by IBM scientists in high performance computers, including Aquasar.

Prof. Ralph Eichler, President of ETH Zurich and Dr. John Kelly, Senior Vice President IBM Research, present Aquasar. 

Photo: Michael Lowry, IBM Research – Zurich

Aquasar is an HPC system developed together by the two institutions using water to directly cool the integrated circuits.

The water with a temperature of about 60o C is used to heat the building of ETH Zurich.

The goal of this research project is to reduce the energy footprint of computing systems: It is assumed that computers use about 5 to 10% of the electricity worldwide.

Aquasar has a computing power of 6 Teraflops and consumes about 20 kilowatt of electricity. Water cooling on the chip may be the big next step to build larger supercomputers and to go to Exaflops (Computer processing speed of one quintillion (10^18) floating point operations per second).

Wednesday, March 27, 2013

Metaflex: Scottish Scientist develop 'Invisibility Cloak'

The material, called "Metaflex" may in future provide a way of manufacturing fabrics that manipulate light.

Metamaterials have already been developed that bend and channel light to render objects invisible at longer wavelengths.

Visible light poses a greater challenge because its short wavelength means the metamaterial atoms have to be very small.

So far such small light-bending atoms have only been produced on flat, hard surfaces unsuitable for use in clothing.

But scientists at the University of St Andrews in Scotland believe they have overcome this problem. They have produced flexible metamaterial "membranes" using a new technique that frees the meta-atoms from the hard surface they are constructed on.

Metaflex can operate at wavelengths of around 620 nanometres, within the visible light region. Stacking the membranes together could produce a flexible "smart fabric" that may provide the basis of an invisibility cloak, the scientists believe.

Other applications could include "superlenses" that are far more efficient than conventional lenses.

Describing their work in the New Journal of Physics, the researchers write: "Arguably, one of the most exciting applications of Metaflex is to fabricate three-dimensional flexible MMs (metamaterials) in the optical range, which can be achieved by stacking several Metaflex membranes on top of one another...

Dr Andrea Di Falco
"These results confirm that it is possible to realise MMs on flexible substrates and operating in the visible regime, which we believe are ideal building blocks for future generations of three-dimensional flexible MMs at optical wavelengths."

Lead scientist Dr Andrea Di Falco said: "Metamaterials give us the ultimate handle on manipulating the behaviour of light."

Sunday, March 10, 2013

ESA's ExoMars: Neptec wins contract to develop cameras

The main challenge in the development of these cameras will be to design them to withstand the extreme environmental conditions that will be experienced on the surface of Mars.

Neptec Design Group has signed a contract with EADS Astrium UK Limited for the design and build of navigation cameras for the ExoMars Rover.

The ExoMars Programme has the goals of understanding the Martian environments and establishing whether life had or could now exist on Mars.

The Programme comprises two Missions: an Orbiter in 2016; and a Rover Mission in 2018.

Contracts with European organisations represent an increasing portion of Neptec's Space Exploration business as the company expands beyond its core business with the NASA and the Canadian Space Agency (CSA).

"We are thrilled to be a part of this exciting journey in exploring the planet Mars," said Mike Kearns, Neptec President of Space Exploration.

"The vision cameras that we are developing will be the eyes of the rover as it explores the surface of Mars." The main challenge in the development of these cameras will be to design them to withstand the extreme environmental conditions that will be experienced on the surface of Mars.

"This ExoMars programme is an example of what can be accomplished when governments and industry work together in the space sector," said Neptec's CEO Iain Christie.

"The contract for these navigation cameras has involved the co-operation of the Canadian Space Agency, and the European Space Agency."

The ExoMars Programme is a European Space Agency Robotic Exploration Mission under the prime contractorship of Thales Alenia Space Italia, with EADS Astrium UK Limited leading the Rover Vehicle developments.