NASA Messenger extends its mission life using Helium

Now orbiting the planet Mercury after over ten years in space, NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft is still functioning better than expected.

Its mission will soon come to an end though, it's running out of fuel and is scheduled to crash into the planet in March.

However, mission control have come up with a novel plan that will use the helium used to pressurize the unmanned probe's engine to give it another month of life.

According to the MESSENGER team, fuel is usually the last problem that a robotic exploration team worry about because there are so many other things that can go wrong long before it runs out.

That being said, the fuel is the single most important consumable aboard an orbiter mission because it not only allows the spacecraft to maintain the correct attitude and keep its antennae pointed at Earth, it also lets it use the main engine to boost its orbit against atmospheric drag, which decays the orbit.

The upshot is that when the propellant runs out, the spacecraft starts to tumble and spirals in to burn up in the atmosphere or, in MESSENGER's case, crash into the surface at hypersonic speed.



So normally when the fuel runs out, that's it, but NASA reasoned that MESSENGER's liquid-fuel rocket engine design meant there was still a bit of thrust left even after all the propellant was expended.

The MESSENGER's engine is pressure fed, which means that it uses helium from a separate tank to push the fuel and oxidizer into the engine's combustion chamber.

Since the helium needs to work against the force of the rocket's combustion, it's under considerable pressure, and when the fuel is gone, there will be some helium left in the pressure tank.

The idea is to use the helium as a cold propellant. In other word's where the rocket engine gets its thrust by burning fuel, the helium pushes the spacecraft by simple gas pressure like a toy balloon when the open neck is let go.

Unfortunately, this is the first time a pressurant has been as an improvised thruster and MESSENGER's engine is a bit more complicated than a balloon.

According to MESSENGER Mission Systems Engineer Dan O’Shaughnessy, of the Johns Hopkins University Applied Physics Laboratory (APL), the pressure in the helium tank isn't much compared to a firing engine.

In addition, the gas passes through a number of reduction valves and nozzles that have to be taken into account, and helium is the second lightest of gases, so it doesn't provide much in the way of thrust.

If these problems can be overcome, NASA estimates that it will give MESSENGER another month of active life before impact on Mercury. MESSENGER's current closest approach to Mercury is 25 km (15 mi).

If a scheduled course correction using the helium is successful, this will rise to 80 km (50 mi). This will allow the orbiter to carry out additional low altitude observations, including collecting a new set of high-resolution images.

"During the additional period of operations, up to four weeks, MESSENGER will measure variations in Mercury’s internal magnetic field at shorter horizontal scales than ever before, scales comparable to the anticipated periapsis altitude between 7 km (4 mi) and 15 km (9 mi) above the planetary surface," says APL’s Haje Korth, the instrument scientist for the spacecraft's magnetometer.

"Combining these observations with those obtained earlier in the mission at slightly higher altitudes will allow the depths of the sources of these variations to be determined. In addition, observations by MESSENGER’s Neutron Spectrometer at the lowest altitudes of the mission will allow water ice deposits to be spatially resolved within individual impact craters at high northern latitudes."

Built and operated by John Hopkins University for NASA, the MESSENGER spacecraft was launched from Cape Canaveral on August 3, 2004 as the first mission aimed to place an orbiter around the innermost planet Mercury. 

Scientists concerned over the future of satellite-based research

Landsat 8 captured fine details of the lava flowing in Iceland between the Bardarbunga and Askja volcanoes.

Credit: NASA, NOAA.

The U.S. has more than 30 civilian, Earth-observing satellites circling the planet, providing scientists with a torrent of crucial environmental and climate information.

More satellites are on deck to launch in the next few years, but, according to an article in Chemical & Engineering News (C&EN), the weekly news magazine of the American Chemical Society, scientists have registered serious concerns over the lack of a long-term, cohesive vision for the scientific missions.

Jyllian Kemsley, a senior editor at C&EN, reports that satellites are marvels of technology.

From their orbits up to thousands of miles above the planet's surface, they collect Earthly measurements and beam down to scientists information they can't get any other way.

The satellites map cloud cover; they track snow and ice cover; they measure atmospheric carbon dioxide, a potent greenhouse gas; they detect chemical reactions in the atmosphere; they help meteorologists make weather predictions.

Future launches will undoubtedly add to the treasure trove of scientific data.

But some scientists say that despite the state-of-the-art sensors the satellites are equipped with, a short-sighted vision for the future, may cause the resulting science to suffer.

They say that the division between two agencies leading the way, NASA, which operates under a "first and best" vision, and the National Oceanic & Atmospheric Administration (NOAA), which takes the longer view, has created a "valley of death."

This gap hinders the use of NASA's research instruments for NOAA's desired sustained monitoring, which is critical to understanding complex systems of atmospheric chemistry and climate.

More information: Observing Earth - cen.acs.org/articles/92/i36/Observing-Earth.html

Dyson 360 EYE Robotic Vacuum Cleaner - A system with vision

Dyson after numerous years of work has released its first robot vacuum cleaner. The Dyson 360 Eye took 16 years but Dyson's engineers think the time has come, entering a market where, as Dyson sees it, the entry will outshine others.

The company pointed out the problem with existing robots is that they have poor suction and don't navigate properly.

They would not be alone in seeing the need for robot cleaners to come closer to the performance of conventional models.



Dan Costa, editor in chief of PCMag, said "We've been testing robot vacuum cleaners at PCMag for years," and, overall, have found them to be pretty good but he also commented that they just aren't quite as good as traditional vacuums.

Dyson is attempting to change that impression of vacuum robots with its product's features.

First off, there is the high speed digital motor. They developed their own digital motor, and it enables them to generate greater suction than any conventional machine.

Another key feature is the 360-degree camera mounted on the top, which will constantly scan the room for obstacles.

The vision system lets the Dyson robot see where it is, where it has been and where it has yet to clean.

Gizmag said, "The cleaner's camera images at up to 30 frames per second to provide an accurate visualization of its surrounding environment. Dyson says the device is accurate to within millimeters."



Margaret Rhodes in Wired detailed how the camera functions. The Eye hinges on a 360-degree camera that views the room at a 45-degree angle and takes pictures; those photos become a live map of the room.

"The Eye undocks itself from a charging station affixed to the wall, near the floor. The robot triangulates its position in the room, finds the center, and starts spiraling outward. Once it has vacuumed 10 square feet, it relocates to clean a new patch."

"Infrared sensors keep the Eye aware of pets or thin table legs, but the bulk of the vacuum's spatial smarts come from the real-time map of the room."

This is a big change from robots that just change direction when bumping into something, said PCMag's Costa.



Next on the feature list, Dyson engineers designed Radial Root Cyclone technology which generates high centrifugal forces to capture particles as small as pollen and mould. The clear bin is made from tough polycarbonate.

A smartphone Link app lets the owner start, pause and schedule cleanings.

The company said It enables the owner to view maps of cleaning progress when not at home, activates a two-year guarantee, automatically downloads software updates and provides access to troubleshooting guides.

The price is not yet set; the Dyson 360 Eye, will be available in Japan next year before going worldwide.

NASA Stereo: Phaethon confirmed as rock comet

The Sun-grazing asteroid, Phaethon, has betrayed its true nature by showing a comet-like tail of dust particles blown backwards by radiation pressure from the Sun.

Unlike a comet, however, Phaethon's tail doesn't arise through the vaporization of an icy nucleus.

During its closest approach to the Sun, researchers believe that Phaethon becomes so hot that rocks on the surface crack and crumble to dust under the extreme heat.

David Jewitt

The findings will be presented by David Jewitt on Tuesday 10 September at the European Planetary Science Congress (EPSC) 2013 in London.

Most meteor showers arise when the Earth ploughs through streams of debris released from comets in the inner solar system.

The Geminids, which grace the night sky annually in December, are one of the best known and most spectacular of the dozens of meteor showers.

However, astronomers have known for 30 years that the Geminids are not caused by a comet but by a 5 km diameter asteroid called (3200) Phaethon.

Until recently, though, and much to their puzzlement, astronomer's attempts to catch Phaethon in the act of throwing out particles all ended in failure.

The tide began to turn in 2010 when Jewitt and colleague, Jing Li, found Phaethon to be anomalously bright when closest to the Sun.

The key to success was their use of NASA's STEREO Sun-observing spacecraft. Phaethon at perihelion appears only 8 degrees (16 solar diameters) from the sun, making observations with normal telescopes impossible.

Now, in further STEREO observations from 2009 and 2012, Jewitt, Li and Jessica Agarwal have spotted a comet-like tail extending from Phaethon.

"The tail gives incontrovertible evidence that Phaethon ejects dust," said Jewitt. 'That still leaves the question: why? Comets do it because they contain ice that vaporizes in the heat of the Sun, creating a wind that blows embedded dust particles from the nucleus. Phaethon's closest approach to the Sun is just 14 per cent of the average Earth-Sun distance (1AU). That means that Phaethon will reach temperatures over 700 degrees Celsius – far too hot for ice to survive."

Seeing Things That Aren’t There? Charles Bonnet Syndrome

One woman saw a fully dressed Royal Canadian mountie in her living room. Another saw the same red brick building in every part of town, as well as in the country. One man saw monkeys with red hats and blue coats playing in his yard.

They were all experiencing Charles Bonnet (“bo-nay”) Syndrome.

“Do you ever see something you know is not there, but it looks real?” It’s a question that Lylas G. Mogk, M.D., and Raman Deol, O.D., of the Henry Ford Center for Vision Rehabilitation and Research in metropolitan Detroit, always ask their low-vision patients.

Low vision that cannot be improved through corrective lenses or surgery can be the result of macular degeneration, glaucoma, diabetes, stroke, or other causes.

Some of their patients respond that they see purple flowers everywhere, even in winter. Others see animals, people, buildings, or geometric, quilt-like patterns. They rarely share their experience with their families, for fear of being misunderstood. Some wonder whether the visions suggest early dementia.

In 1789, Swiss naturalist Charles Bonnet described the visions of his father-in-law, who had low vision and saw people, animals and other objects that he knew were not real.

Bonnet himself experienced phantom visions later in his life, similar to those of his father-in-law. Bonnet’s discovery went largely unnoticed for 150 years until the 1930s, when doctors rediscovered his files and named the syndrome after him.

The frequently undiagnosed Charles Bonnet Syndrome is very common, affecting 20 – 30 percent of those with low vision. Some may experience it for a few months, others for several years.

The images can occur daily or only occasionally, with the same image appearing to the same person. There is no cure, but most people are not bothered by the images, and many find them interesting or amusing, especially once they understand it’s just their eyes playing tricks on them.

Although the cause is not known, the images can be compared to the “phantom pain” that can be felt by people who have had a limb amputated.

The nerves that were connected to the missing limb still send signals to the brain. In our visual system, the nerves no longer receiving visual messages can cause the brain to “see” realistic images, while recognizing they are not real.

Many physicians are not yet aware of Charles Bonnet Syndrome, and may mistake it for psychotic hallucinations. Patients with the syndrome have been misdiagnosed and prescribed anti-psychotic medications.

To identify Charles Bonnet Syndrome, ophthalmologists use these criteria:
• The person has low vision.
• The images occur when the person is conscious, with open eyes.
• The person recognizes the images are not real.
• The same image appears repeatedly, superimposed on the real world. For example, the person sees a room normally, but the wall appears to have flowers on it and only that same image of flowers recurs to that same person.
• Images are only visual; they may move, but there are no sounds or smells. It’s like seeing a picture, or watching a silent movie.
• Images are common, familiar objects. They may be amusing or mildly annoying, but not frightening.
People with low vision who believe they may be experiencing Charles Bonnet Syndrome should discuss it with their ophthalmologist.

Sea urchins see with their entire body

Many animals have eyes that are incredibly complex – others manage without. Researchers at the University of Gothenburg have shown that sea urchins see with their entire body despite having no eyes at all.

The study has been published in the scientific journal Proceedings of the National Academy of Sciences (PNAS).

Most animals react to light and have developed a very sophisticated way of seeing complex images so that they can function in their surroundings.

Good examples include insects’ compound eyes and the human eye. Charles Darwin and other evolutionary biologists were bewildered by the eye’s complexity and wondered how this kind of structure could have evolved through natural selection.

But some creatures, such as sea urchins, can react to light even though they do not have eyes. Previous studies of sea urchins have shown that they have a large number of genes linked to the development of the retina, which is the light-sensitive tissue in the human eye.

This means that sea urchins have several genes that are coded for a widely occurring eye protein, opsin.

“It was this discovery that underpinned our research,” says Sam Dupont from the University of Gothenburg’s Department of Marine Ecology, one of the researchers behind the study and co-authors of the article.

“We wanted to see where the opsin was located in sea urchins so that we could find the sensory light structures, or photoreceptors. We quite simply wanted to know where the sea urchin sees from.”

The research group behind the study showed that the photoreceptors seem to be located on the tip and base of the tube feet that are found all over the sea urchin’s body and are used to move.

“We argue that the entire adult sea urchin can act as a huge compound eye, and that the shadow that is cast by the animal’s opaque skeleton over the light-sensitive cells can give it directional vision,” says Dupont.

Lockhead Martin's Supersonic Vision

Image: This artist's rendering shows an advanced concept design of an environmentally friendly supersonic airframe and propulsion system. Credit: Lockheed Martin Corporation

NASA has awarded an 18-month, $1.96 million study contract to a team led by Lockheed Martin Corporation to generate environmentally friendly supersonic airframe and propulsion concepts and develop technology maturation plans to make those concepts a reality.

Goals of the team—which includes GE Global Research, Purdue University, and Wyle Laboratories—are to produce a future Next Generation Air Transportation System system-level solution, conduct extensive teaming, and leverage past experience and methodology to provide an integrated advanced vehicle concept operational in the 2030-2035 timeframe.

The team will use analytical and design tools to assess performance parameters to find synergistic combinations of technologies and concepts for aerodynamic, structural, aero-servo-propulso-elastics, boom, airport noise, emissions and fuels.

Results of the study will include an optimized supersonic vision vehicle, identification of the highest-value enabling technologies to make that vehicle a reality, and technology roadmaps that lay out an industry-wide path to maturing necessary technologies.

The intention is to devise a revolutionary concept that has the ability to showcase green technologies, which would be an exciting vision that promotes understanding of future supersonic travel.

Third Eye Retroscope (TER) - Improves Colonscope vision and Polyp Detection

Two new studies show an increase in polyp detection rates using the Third Eye Retroscope (TER), a retrograde viewing device, during colonoscopy.

The first study found that TER added to standard colonoscopy detected 13.2 percent more polyps than colonoscopy alone, including 11 percent additional adenomas (precancerous polyps).

A second study examined endoscopist experience using TER and its impact on polyp detection rates, concluding that polyp detection rates improved significantly with TER.

The studies appear in the March issue of GIE: Gastrointestinal Endoscopy, the monthly peer-reviewed scientific journal of the American Society for Gastrointestinal Endoscopy (ASGE).

Colonoscopy is recommended as the primary screening method for colorectal cancer and is the final common pathway for all other recommended screening tests.

It is considered the "gold standard" for colorectal cancer screening because of the ability to diagnose and remove polyps (growths in the colon) before they become cancer.

During a colonoscopy, the endoscopist uses a thin, flexible tube (colonoscope) fitted with a miniature camera and light source. This device is connected to a video monitor that the endoscopist watches while performing the test.

Various miniaturised tools can be inserted through the colonoscope to obtain samples (biopsies) of the colon and to perform maneuvers to diagnose or treat conditions.

The Third Eye Retroscope is a disposable catheter imaging device that is inserted through the instrument channel of a standard colonoscope to provide a retrograde view of the colon during the withdrawal phase of a colonoscopy.

After the colonoscope has been advanced to the cecum, the TER is inserted through the instrument channel. As it emerges from the distal tip of the colonoscope, the TER automatically bends 180 degrees to form a J shape so that its sensor and integrated light source are directed back toward the tip of the colonoscope.

The device is then withdrawn together with the colonoscope, providing a continuous retrograde view to complement the forward view of the colonoscope. Previous studies showed that TER can increase detection rates for adenomas and other polyps.

"A retrograde-viewing device improves detection of adenomas in the colon: a prospective efficacy evaluation"

To read the full article click here

NASA WiSE Vision: The Magnificent and Beautiful Andromeda Galaxy

The immense Andromeda galaxy, also known as Messier 31 or simply M31, is captured in full in this new image from NASA's Wide-field Infrared Survey Explorer, or WISE. The mosaic covers an area equivalent to more than 100 full moons, or five degrees across the sky.

WISE used all four of its infrared detectors to capture this picture (3.4- and 4.6-micron light is colored blue; 12-micron light is green; and 22-micron light is red). Blue highlights mature stars, while yellow and red show dust heated by newborn, massive stars.

Andromeda is the closest large galaxy to our Milky Way galaxy, and is located 2.5 million light-years from our sun. It is close enough for telescopes to spy the details of its ringed arms of new stars and hazy blue backbone of older stars.

Also seen in the mosaic are two satellite galaxies, known as M32, located just a bit above Andromeda to the left of center, and the fuzzy blue M110, located below the center of the great spiral arms. These satellites are the largest of several that are gravitationally bound to Andromeda.

The Andromeda galaxy is larger than our Milky Way and contains more stars, but the Milky Way is thought to perhaps have more mass due to its larger proportion of a mysterious substance called dark matter.

Both galaxies belong to our so-called Local Group, a collection of more than 50 galaxies, most of which are tiny dwarf systems. In its quest to map the whole sky, WISE will capture the entire Local Group.

Image credit: NASA/JPL-Caltech/UCLA

'Superman' vision penetrates opaque glass

It's not quite X-ray vision, but a way has been found to transmit simple images through opaque objects using ordinary light – physicists projected an image through glass covered in thick paint.

Some things we consider opaque – "not able to be seen through", in the New Oxford Dictionary of English definition – are slightly translucent, meaning some light does in fact make it through. However, it is scattered so much by bouncing around such materials' lattice of atoms that physicists thought it was beyond practical use for seeing what is on the other side of the object.

A 2007 experiment that managed to focus light through eggshells and a human tooth demonstrated that might not be so. Now the first simple images have been transmitted through an opaque object and reconstructed on the far side, by physicist Sylvain Gigan and colleagues at École Supérieure de Physique et de Chimie Industrielles in Paris, France.

Read the full article here...

Gene therapy cures colour-blind monkeys - health - New Scientist

Gene therapy cures colour-blind monkeys - health - 16 September 2009 - New Scientist

Two colour-blind monkeys nicknamed Dalton and Sam have been "cured" through gene therapy.

The breakthrough could be a prelude to new gene treatments for human vision disorders that currently result in blindness. And because the treated monkeys were "middle aged", it challenges the assumption that gene therapies cannot work in adults because their brain connections are too set in their ways to change beneficially.

A human gene injected into the monkeys' eyes enabled them for the first time to produce Clong-wavelength opsin" the pigment sensitive to red and green light. "That gave them a retina like that of a normal person with full colour vision," says Jay Neitz at the University of Washington in Seattle.

The team used squirrel monkeys because the males are known to be colour-blind, whereas females have full colour vision. Males do have a full set of colour-sensing "cone" cells in their eyes, but they only make pigments for detecting blue and yellow light, making them blind to red and green.

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NASA Climate monitoring site: Eyes on the Earth 3D