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Mars Base

Phobos-Grunt's Mysterious Thruster Activation: A Function of Safe Mode or Just Good Luck? - 0 views

www.universetoday.com/...of-safe-mode-or-just-good-luck

scibyte22 Phobos-Grunt

shared by Mars Base on 17 Nov 11 - No Cached
  • Phobos-Grunt probe is still stuck in orbit
  • periodically the spacecraft experiences a mysterious slight boost in its orbit
  • The activation of the spacecraft’s thrusters – the small engines that are designed to steer the craft and make small adjustments  – was an obvious answer.
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  • the probe “Corrects her orbit” every now and then.
  • Does this mean that the probe knows where she is? Probably not.
  • If Grunt’s safe mode includes a program that fires thrusters every so often to keep the craft from entering the atmosphere in the event of a malfunction just after reaching low Earth orbit
  • continues to occur, we can expect that the predicted date of atmospheric entry will be moved back again, just as it was moved from late December/early November to mid-January after the first orbital correction episode
  • it could buy more time for controllers to establish communication –although Roscosmos has stated that December is the limit for correcting the problem
Mars Base

Venerable Voyager 2 Spacecraft Gets a Tune-up 14 billion Kilometers From Earth - 0 views

www.universetoday.com/...-billion-kilometers-from-earth

scibyte23

shared by Mars Base on 17 Nov 11 - No Cached
  • engineers at JPL sent commands across 14 billion kilometers (9 billion miles) out to Voyager 2
  • enabling it to switch to the backup set of thrusters that controls the roll of the spacecraft
  • This will reduce the amount of power that the 34-year-old probe needs to operate,
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  • hopefully — the power to operate for at least another decade
  • The move was a little risky
  • backup roll thrusters were previously unused
  • been idle and out in the harsh environment of space for 32 years
  • Voyager 2 will save about 11.8 watts of electric power by turning off the heater that kept the hydrazine fuel to the primary thrusters warm
  • Voyager 1 and 2 are each equipped with six sets, or pairs, of thrusters to control the pitch, yaw and roll motions of the spacecraft. With this latest command, both spacecraft are now using all three sets of their backup thrusters
  • The primary roll thrusters now turned off fired more than 318,000 times. Voyager 1 changed to the backup for this same component after 353,000 pulses in 2004
  • energy generated by Voyager 2′s Plutonium 238 nuclear power source continues to decline, and is now down to about 270 watts from the 470 watts being produced when the spacecraft launched in 1977
  • at the rate of decay, the Voyager spacecraft won’t have sufficient electric power to its instruments sometime by the mid-2020′s.
  • Using solar power for a spacecraft traveling beyond Jupiter is impractical
  • This latest tune-up will hopefully get Voyager 2 a little farther while she’s still able to communicate with Earth
Mars Base

Jupiter Moon's Buried Lakes Evoke Antarctica | Jupiter Moon Europa | Subsurface Lakes P... - 0 views

www.space.com/arth-antarctica-analogues.html

scibyte22 Europa

shared by Mars Base on 17 Nov 11 - No Cached
  • Patches of broken ice unique to the moon have puzzled scientists for over a decade
  • Some have argued they are signs of a subterranean ocean breaking through, while others believe that the crust is too thick for the water to pierce
  • studies of ice formations in Antarctica and Iceland have provided clues to the creation of these puzzling features
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  • , a combination of these elements could very well be at work on Jupiter's moon
  • "It looks like crushed ice,
  • In Iceland, volcanoes lay beneath the ice. Their heat melts the base of glaciers and ice sheets, causing the surface to buckle in on itself and allowing stress fractures to form
  • there's no evidence for volcanoes on Europa, and the makeup of the ice is likely different from Earth'
  • irregular areas contain domes and iceberglike blocks that no theoretical models have been able to replicate
  • "On Earth, it is the volcano [melting the ice]," Schmidt said. "On Europa, it is the warm ice plume coming up from below."
  • estimated that it contained as much water as all of the North America's Great Lakes combined, about 1.5 miles (3 kilometers) beneath the surface.
  • One such lake
  • several liquid lakes are likely to exist near the surface today
  • The material cycled into the ocean via these lakes may make Europa's ocean even more habitable than previously imagined
  • The lakes may even be habitats themselves
Mars Base

Pristine reptile fossil holds new information about aquatic adaptations - 0 views

www.physorg.com/...ne-reptile-fossil-aquatic.html

scibyte22

shared by Mars Base on 17 Nov 11 - No Cached
  • Extinct animals hide their secrets well, but an exceptionally well-preserved fossil of an aquatic reptile, with traces of soft tissue present, is providing scientists a new window into the behavior of these ancient swimmers
  • from the mosasaur family, a group of reptiles that lived between 65 and 98 million years ago
  • found in Western Kansas, and was submerged under a shallow sea at the time of the mosasaur's existence.
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  • analysis of mosasaur locomotion had been limited by a lack of soft tissue fossils, which was crucial for the scientists to truly understand the degree of aquatic adaptation that the creature had achieved
  • new findings, which include scales and skin impressions, suggest that the mosasaur was able to minimize its frictional drag in the water.
  • features suggest that it held the front of its body somewhat rigid during swimming, leading it to depend on the rear of its body and tail for propulsion
Mars Base

Ultrathin flexible brain implant offers unique look at seizures - 0 views

medicalxpress.com/...ible-brain-implant-unique.html

scibyte21

shared by Mars Base on 14 Nov 11 - No Cached
  • Researchers funded by the National Institutes of Health have developed a flexible brain implant that could one day be used to treat epileptic seizures
  • a type of electrode array that conforms to the brain's surface – to take an unprecedented look at the brain activity underlying seizures
  • Someday, these flexible arrays could be used to pinpoint where seizures start in the brain and perhaps to shut them down
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  • These flexible electrode arrays could significantly expand surgical options for patients with drug-resistant epilepsy
  • In an animal model, the researchers saw spiral waves of brain activity not previously observed during a seizure
  • Similar waves are known to ripple through cardiac muscle during a type of life-threatening heart rhythm called ventricular fibrillation.
  • A stimulating electrode array might one day be designed to suppress seizure activity, working like a pacemaker for the brain
  • The brain contains billions of interconnected neurons that normally transmit electrical pulses
  • During a seizure, these pulses occur in abnormal, synchronized, rapid-fire bursts that can cause convulsions, loss of consciousness and other symptoms
  • is made of a pliable material that is only about one quarter the thickness of a human hair
  • It contains 720 silicon nanomembrane transistors in a multiplexed 360-channel array, which allow for minimal wiring and dense packing of the electrodes
  • The flexibility of the array allows it to conform to the brain's complex shape, even reaching into grooves that are inaccessible to conventional arrays
  • the array could be rolled into a tube and delivered into the brain through a small hole rather than by opening the skull
  • The researchers tested the flexible array on cats. Although mice and rats are used for most neuroscience research, cats have larger brains that are anatomically more like the human brain, with simplified folds and grooves
Mars Base

Exceptional Memory Linked To Bulked-up Parts Of Brain - Science News - 0 views

www.sciencenews.org/...ed_to_bulked-up_parts_of_brain

scibyte21

shared by Mars Base on 14 Nov 11 - No Cached
  • some real-life people can remember every day of their lives in detail
  • Those superrememberers have more bulk in certain parts of their brains, possibly explaining the remarkable ability to recall minutiae from decades ago
  • brain region involved in such incredible recall has been implicated in obsessive-compulsive disorder
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  • OCD and superior memory might have a common architecture in the brain
  • Scientists have long studied people with memory deficits, but there haven’t been many studies on people with exceptional memories
  • 11 people who scored off the charts for autobiographical memory. These people could effortlessly remember, for instance, what they were doing on November 2, 1989, and could also tell you that it was a Thursday
  • Using brain scans, researchers found that people with supermemories had larger brain regions associated with memory
  • a brain structure called the lentiform nucleus, a cone-shaped mass in the core of the brain, was bigger in people with exceptional memories
  • This brain area has been linked to obsessive-compulsive disorder
  • The subjects haven’t been clinically evaluated for OCD, but LePort says that there are some similarities
  • The ability to organize their memories by dates seems to relieve anxiety
  • These people could encode information more effectively, or have a better system of retrieving it, or both
  • Though no genetic tests have been performed, some of the volunteers have reported that family members share extraordinary powers of recall
  • The volunteers are now keeping detailed diaries, so that the scientists can test whether particular kinds of memories are better suited to recollection. People might be better at remembering emotional memories, for instance
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