As part of the study, the principles used by the sidewinders to gracefully climb sand dunes were tested using a modular snake robot developed at Carnegie Mellon. Before the study, the snake robot could use one component of sidewinding motion to move across level ground, but was unable to climb the inclined sand trackway the real snakes could readily ascend. In a real-world application -- an archaeological mission in Red Sea caves -- sandy inclines were especially challenging to the robot.

However, when the robot was programmed with the unique wave motion discovered in the sidewinders, it was able to climb slopes that had previously been unattainable. The research was funded by the National Science Foundation, the Army Research Office, and the Army Research Laboratory.

"Our initial idea was to use the robot as a physical model to learn what the snakes experienced," said Daniel Goldman, an associate professor in Georgia Tech's School of Physics. "By studying the animal and the physical model simultaneously, we learned important general principles that allowed us to not only understand the animal, but also to improve the robot."

The detailed study showed that both horizontal and vertical motion had to be understood and then replicated on the snake-like robot for it to be useful on sloping sand.

"Think of the motion as an elliptical cylinder enveloped by a revolving tread, similar to that of a tank," said Howie Choset, a Carnegie Mellon professor of robotics. "As the tread circulates around the cylinder, it is constantly placing itself down in front of the direction of motion and picking itself up in the back. The snake lifts some body segments while others remain on the ground, and as the slope increases, the cross section of the cylinder flattens."

At Zoo Atlanta, the researchers observed several sidewinders as they moved in a large enclosure containing sand from the Arizona desert where the snakes live. The enclosure could be raised to create different angles in the sand, and air could be blown into the chamber from below, smoothing the sand after each snake was studied. Motion of the snakes was recorded using high-speed video cameras which helped the researchers understand how the animals were moving their bodies.

"We realized that the sidewinder snakes use a template for climbing on sand, two orthogonal waves that they can control independently," said Hamid Marvi, a postdoctoral fellow at Carnegie Mellon who conducted the experiments while he was a graduate student in the laboratory of David Hu, an associate professor in Georgia Tech's School of Mechanical Engineering. "We used the snake robot to systematically study the failure modes in sidewinding. We learned there are three different failure regimes, which we can avoid by carefully adjusting the aspect ratio of the two waves, thus controlling the area of the body in contact with the sand."

Limbless animals like snakes can readily move through a broad range of surfaces, making them attractive to robot designers.

"The snake is one of the most versatile of all land animals, and we want to capture what they can do," said Ross Hatton, an assistant professor of mechanical engineering at Oregon State University who has studied the mathematical complexities of snake motion, and how they might be applied to robots. "The desert sidewinder is really extraordinary, with perhaps the fastest and most efficient natural motion we've ever observed for a snake."

Many people dislike snakes, but in this study, the venomous animals were easy study subjects who provided knowledge that may one day benefit humans, noted Joe Mendelson, director of research at Zoo Atlanta.

"If a robot gets stuck in the sand, that's a problem, especially if that sand happens to be on another planet," he said. "Sidewinders never get stuck in the sand, so they are helping us create robots that can avoid getting stuck in the sand. These venomous snakes are offering something to humanity."

The modular snake robot used in this study was specifically designed to pass horizontal and vertical waves through its body to move in three-dimensional spaces. The robot is two inches in diameter and 37 inches long; its body consists of 16 joints, each joint arranged perpendicular to the previous one. That allows it to assume a number of configurations and to move using a variety of gaits -- some similar to those of a biological snake.

"This type of robot often is described as biologically inspired, but too often the inspiration doesn't extend beyond a casual observation of the biological system," Choset said. "In this study, we got biology and robotics, mediated by physics, to work together in a way not previously seen."

Choset's robots appear well suited for urban search-and-rescue operations in which robots need to make their way through the rubble of collapsed structures, as well as archaeological explorations. Able to readily move through pipes, the robots also have been tested to evaluate their potential for inspecting nuclear power plants from the inside out.

For Goldman's team, the work builds on earlier research studying how turtle hatchlings, crabs, sandfish lizards, and other animals move about on complex surfaces such as sand, leaves, and loose material. The team tests what it learns from the animals on robots, often gaining additional insights into how the animals move.

"We are interested in how animals move on different types of granular and complex surfaces," Goldman said. "The idea of moving on flowing materials like sand can be useful in a broad sense. This is one of the nicest examples of collaboration between biology and robotics."

In addition to those already mentioned, co-authors included Chaohui Gong and Matthew Travers from Carnegie Mellon University; and Nick Gravish and Henry Astley from Georgia Tech.

Humans and robots working together

What is unique about SHERPA is the cooperation between humans and robots, each with their own qualities, in order to achieve a common goal: saving lives. The emphasis with robots is on their autonomy, cognitive capacities, strategy for cooperation and in the interaction with their human colleagues'. Together, humans and robots will form rescue teams that the Italian organization of rescue workers has stationed in the Alps.

The Twente robotic arm

On behalf of the University of Twente (UT), Raffaella Carloni and other members of the Robotics and Mechatronics group (CTIT institute) and the LEO Centre for Service Robotics are working on the mechanical design, the control mechanism and realizing the robotic arm. This arm is being developed and constructed in Twente and will be mounted onto the ground robot. Furthermore, the UT is focussing on technological support of the interaction between humans and robots. The robotic arm is capable of grasping the Unmanned Aerial Vehicle (UAV), i.e., the flying robot, while it is airborne and placing it on the charger for the ground robot. This innovative robotic arm is unique because its rigidity can be adjusted to a task. In addition, the arm is more resilient to shocks and vibrations than the current generation of robotic arms.

Sensors on humans

In order to provide a rescue worker who is operating the airborne robot with the best possible technological support, he or she will be equipped with sensors and portable technology. This too is, in part, a 'task of' the UT. The enormous advantage of this approach is that a rescue worker has optimum perception and can respond adequately to a possible calamity situation without actually having to be present at the site of the calamity. The Sensors measure the robot's dynamic movements, such as position, speed and resistance. Because of the robot's cognitive algorithms, the robot and human can jointly seek victims and determine their actions in order to save human lives.

Petter Ögren, Associate Professor at the Center for Autonomous Systems (CAS) at Stockholm's KTH Royal Institute of Technology, says the technique would allow a more natural interaction with the robot than currently in use when the so-called unmanned ground vehicles (UGV) are sent into burning or collapsed buildings and other places too dangerous for human responders.

"The idea is to reduce the mental strain on the operator, so they can focus on the environment they are dealing with," he says.

With free look control, an operator interacts with a remote controlled robot in much the same way they would with an avatar in role-playing or first-person shooter games such as Call of Duty.

But emergency response is no game. Time is precious and it's critical for those controlling the robots to quickly attain what responders call "situational awareness" -- the understanding of the environment and what is happening in it. Situational awareness enables an operator to maintain a mental picture of their environment. In a burning house, the operator keeps track of in which room the robot has been, and when it's time to go upstairs to search the next floor.

While the current standard, "tank control" is more straightforward to implement, it takes more concentration to use. The camera movements and the robot's body movements are each directed by different levers that are linked to different pieces of hardware, says Ögren. In other words, they are controlled independently of each other.

But with free look control, the commanded direction of motion of the robot is always interpreted relative to the view of the camera. So if the robot is looking to the right, the forward control lever will move the robot toward the direction in which it is looking. The operator will not have to take the orientation of the robot into account, which is the case when using tank control.

The robot is also able to easily move perpendicular to its direction of view, a technique gamer's call "strafing," which is a quite natural thing to do when conducting tasks such as searching an environment for victims.

Ögren says that in tests that the team conducted with a fire brigade in Pisa, Italy, 12 out of 16 users preferred free look control. One of the tests included searching an indoor industrial environment for two minutes, trying to find as many markers as possible.

"Using tank control, the average was 4.5 markers per user. Using free look control, they found an average of 6," he says.

The research was conducted within the framework of the EU project, Long-Term Human-Robot Teaming for Robot-Assisted Disaster Response (TRADR), which is included in the Seventh Framework Programme, FP7. In addition to CAS at KTH, researchers from Germany, Switzerland, Netherlands and Italy are involved in the project.

"Fermi's Gamma-ray Burst Monitor (GBM) has captured the same evidence from smaller and much more frequent eruptions called bursts, opening up the potential for a wealth of new data to help us understand how neutron stars are put together," said Anna Watts, an astrophysicist at the University of Amsterdam in the Netherlands and co-author of a new study about the burst storm. "It turns out that Fermi's GBM is the perfect tool for this work."

Neutron stars are the densest, most magnetic and fastest-spinning objects in the universe that scientists can observe directly. Each one is the crushed core of a massive star that ran out of fuel, collapsed under its own weight, and exploded as a supernova. A neutron star packs the equivalent mass of half-a-million Earths into a sphere about 12 miles across, roughly the length of Manhattan Island in New York City.

While typical neutron stars possess magnetic fields trillions of times stronger than Earth's, the eruptive activity observed from magnetars requires fields 1,000 times stronger still. To date, astronomers have confirmed only 23 magnetars.

Because a neutron star's solid crust is locked to its intense magnetic field, a disruption of one immediately affects the other. A fracture in the crust will lead to a reshuffling of the magnetic field, or a sudden reorganization of the magnetic field may instead crack the surface. Either way, the changes trigger a sudden release of stored energy via powerful bursts that vibrate the crust, a motion that becomes imprinted on the burst's gamma-ray and X-ray signals.

It takes an incredible amount of energy to convulse a neutron star. The closest comparison on Earth is the 9.5-magnitude Chilean earthquake of 1960, which ranks as the most powerful ever recorded on the standard scale used by seismologists. On that scale, said Watts, a starquake associated with a magnetar giant flare would reach magnitude 23.

The 2009 burst storm came from SGR J1550−5418, an object discovered by NASA's Einstein Observatory, which operated from 1978 to 1981. Located about 15,000 light-years away in the constellation Norma, the magnetar was quiet until October 2008, when it entered a period of eruptive activity that ended in April 2009. At times, the object produced hundreds of bursts in as little as 20 minutes, and the most intense explosions emitted more total energy than the sun does in 20 years. High-energy instruments on many spacecraft, including NASA's Swift and Rossi X-ray Timing Explorer, detected hundreds of gamma-ray and X-ray blasts.

Speaking at the Fifth Fermi International Symposium in Nagoya, Japan, on Oct. 21, Watts said the new study examined 263 individual bursts detected by Fermi's GBM and confirms vibrations in the frequency ranges previously seen in giant flares. "We think these are likely twisting oscillations of the star where the crust and the core, bound by the super-strong magnetic field, are vibrating together," she explained. "We also found, in a single burst, an oscillation at a frequency never seen before and which we still do not understand."

A key element of the research is a new analysis technique developed by University of Amsterdam researcher Daniela Huppenkothen. Normally scientists search for oscillations in high-energy data by looking for variations aligned to a particular frequency. Such methods are best suited for finding a strong signal with little competition rather than a faint signal immersed in a bright and rapidly changing environment, such as a burst.

Huppenkothen likens the problem to detecting ripples from a stone tossed into a quiet pond. "Now imagine you're in the middle of the North Atlantic during a storm, searching for those ripples amidst huge waves in a churning sea," she explained. "Our old methods really weren't appropriate for this, but I have in effect developed a way of accounting for the rough sea so we can find ripples even in stormy conditions."

A paper describing the research, which was led by Huppenkothen, appeared in the June 1 edition of The Astrophysical Journal.

While there are many efforts to describe the interiors of neutron stars, scientists lack enough observational detail to choose between differing models. Neutron stars reach densities far beyond the reach of laboratories and their interiors may exceed the density of an atomic nucleus by as much as 10 times. Knowing more about how bursts shake up these stars will give theorists an important new window into understanding their internal structure.

Earth's protective ozone layer is well on track to recovery in the next few decades thanks to concerted international action against ozone depleting substances, according to a new assessment by 300 scientists.Assessment of Ozone Depletion 2014, is being published by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO), and is the first comprehensive update in four years.

• Under full compliance with the Montreal Protocol, the ozone layer is expected to recover to 1980 benchmark levels- the time before significant ozone layer depletion- before the middle of the century in mid-latitudes and the Arctic, and somewhat later in the Antarctic.

• The Montreal Protocol and associated agreements have led to decreases in the atmospheric abundance of gases, such as CFCs (chlorofluorocarbons) and halons, once used in products such as refrigerators, spray cans, insulation foam and fire suppression.

• Total column ozone declined over most of the globe during the 1980s and early 1990s. It has remained relatively unchanged since 2000, but there are recent indications of its future recovery.

• The Antarctic ozone hole continues to occur each spring and it is expected to continue occurring for the better part of this century given that ozone depleting substances persist in the atmosphere, even though their emissions have ceased.

• The Arctic stratosphere in winter/spring 2011 was particularly cold, which led to large ozone depletion as expected under these conditions.

• The Montreal Protocol has made large contributions toward reducing global greenhouse gas emissions. In 1987, ozone-depleting substances contributed about 10 gigatonnes CO2-equivalent emissions per year. The Montreal Protocol has now reduced these emissions by more than 90 per cent. This decrease is about five times larger than the annual emissions reduction target for the first commitment period (2008-2012) of the Kyoto Protocol on climate change.

• Hydrofluorocarbons (HFCs) do not harm the ozone layer but many of them are potent greenhouse gases. They currently contribute about 0.5 gigatonnes of CO2-equivalent emissions per year. These emissions are growing at a rate of about 7 per cent per year. Left unabated, they can be expected to contribute very significantly to climate change in the next decades.

• Replacements of the current mix of high-GWP HFCs with alternative compounds with low GWPs or not-in-kind technologies would limit this potential problem.

• Ozone depletion has contributed to cooling of the lower stratosphere and this is very likely the dominant cause of observed changes in Southern Hemisphere summertime circulation over recent decades, with associated impacts on surface temperature, precipitation, and the oceans.

• In the Northern Hemisphere, where the ozone depletion is smaller, there is no strong link between stratospheric ozone depletion and tropospheric climate.

• What happens to the ozone layer in the second half of the 21st century will largely depend on concentrations of CO2, methane and nitrous oxide -- the three main long-lived greenhouse gases in the atmosphere. Overall, CO2 and methane tend to increase global ozone levels. By contrast, nitrous oxide, a by-product of food production, is both a powerful greenhouse gas and an ozone depleting gas, and is likely to become more important in future ozone depletion.