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Friday, January 25, 2008
Thursday, December 27, 2007
Every researcher knows the best plans can go horribly pear-shaped. Just think of the ill-fated Beagle 2 spacecraft that went missing on its way down to the surface of Mars just four years ago. What exactly went wrong is still unclear, but a mechanical fault with the landing parachute is the chief suspect. And remember the Mars Climate Orbiter, which smacked into the Red Planet's surface when it was meant to maintain an orbit of 140 kilometres? It turned out that the main contractor, Lockheed Martin, had used imperial rather than metric units as specified by NASA in the design of its navigation system. Not all such accidents make headlines, however, so we've rounded up five of the most shocking, surprising or downright silly that may have slipped under your radar. You can tell us about others here.
Memory scramble
THEY say ballooning is the least stressful way to fly. Indeed, a balloon seemed the perfect platform from which the $10 million BLAST telescope, funded by NASA, the Canadian Space Agency and the UK's Particle Physics and Astronomy Research Council, could take far-infrared snaps of star formations.
For 12 days running up to 2 January 2007, it collected valuable data as it floated 40 kilometres above Antarctica. As it descended, the gondola released the huge balloon and deployed its landing chutes as planned. But the electronics that should have released the parachutes on touchdown failed. Antarctic winds inflated them like giant spinnakers, turning the cargo into a wind-powered sled.
"It was moving as fast as I could run," recalls project leader Mark Devlin, who was following the fate of the 180-kilogram telescope and its support computers from his home in the US. "It was absolutely sickening." The support plane could only watch as the gondola bounced across the ice, strewing pieces of equipment as it went. It finally came to rest 24 hours later, when it wedged in a crevasse 200 kilometres from its landing site.
Devlin was emailed a picture of the scene, which he scrutinised for any sign of the hard drives bearing the only copy of the mission's data. "NASA paints everything white," he says, so his search was initially in vain. Fortunately, a pilot tracking the furrow gouged by the gondola spotted the package. The damaged drives eventually yielded their irreplaceable data, but the telescope was a write-off. Devlin is now fund-raising for a similar mission, with tougher electronics and one other change: "I'm thinking fluorescent orange," he muses.
The trouble with rockets
ROCKET science has a deserved reputation for being tough, so it should be no surprise that things can get a little bumpy when designing and testing a launcher. Just ask Elon Musk, the millionaire founder of PayPal and rocket company SpaceX.
His first rocket, Falcon 1, was scheduled to lift off from the Pacific atoll Kwajalein in November 2005, at which point the problems began. First, unplanned engine tests used up more liquid oxygen (LOX) fuel than expected, then the LOX generator broke down. A shipment of fuel was ordered from Hawaii, but the tanker sprang a leak and arrived only one-fifth full. There was just enough to launch, but a valve was left open during the final preparations allowing more fuel to waste away, so the launch had to be cancelled.
A fresh shipment of LOX arrived a month later but disaster struck again. High winds hit the atoll, and to be on the safe side, engineers decided to drain the fuel from the rocket. A faulty pressure valve caused a vacuum to form inside the main fuel tank, sucking in its soft sides like a crushed beer can.
After three months of repairs, by March 2006 Falcon 1 was ready to go. Seconds after launch, however, the main engine sprang a fuel leak, leaving a trail of flame in the rocket's wake as it spiralled off course and crashed within sight of the disappointed engineers. An investigation pinpointed the cause: a corroded fuel-line nut was to blame.
A year later, with the rocket rebuilt from scratch, Falcon 1 finally took off without a hitch. It managed 5 minutes of smooth flight. But a bump as the first and second stages separated confused a control system, causing it to enter an uncontrolled roll, which triggered a premature shutdown of the second-stage boosters. Falcon 1 did reach space, but not with the velocity needed to secure orbit.
Its next outing is scheduled for January 2008, when it will carry the cremated remains of 125 people, including actor James Doohan - Star Trek's Scotty. Let's hope he gets a fitting send-off.
Goodbye yellow submarine
THE submarine Autosub 2's mission might sound simple enough: film the rich diversity of species living under the permanent ice of the Antarctic. Yet exploring 15 kilometres under the Fimbulisen ice shelf had to be done autonomously, so the 7-metre sub's creators at Southampton University, UK, installed an artificially intelligent guidance system.
In 2003, Autosub 2 was sent on its maiden voyage under sea ice and completed the test mission successfully. Repeat missions in 2004 boosted the researchers' confidence and so they prepared for the big one: to explore under the permanent ice. The next year they went for it.
All looked good until five hours after launch. The £1.5 million yellow submarine called home using an acoustic distress beacon. Somehow it had lost its way, and had become wedged deep under the permanent ice.
Researchers on the support ship were stunned - there was nothing they could do to help it. "I remember it taking a while to believe the sub was gone," says Miles Pebody, a robotics engineer who worked on Autosub 2. "It would have been great to send another vehicle under to find it - but it was too dangerous."
The research ship returned for a final farewell five days later. Autosub 2 had not budged. It kept sending its distress call until its 5500 D-cell batteries went flat.
Recovering the sub could reveal what went wrong, but its icy tomb makes that practically impossible. A report last year guessed that a hardware fault had probably cut the power, triggering a decision to surface prematurely, while the sub was still under the ice.
Back to the future
IN FEBRUARY 2007, 12 F-22 Raptors, the US air force's new stealth fighters, left Hickam Air Force Base in Hawaii, bound for Okinawa, Japan, on the high-tech planes' first overseas outing. Things went smoothly until they reached the 180th meridian - otherwise known as the International Date Line.
Some of the pilots suddenly found themselves without any navigation aids. With nothing to tell them their compass heading or even whether they were level or not, it was as if the pilots had been instantaneously transported from the cockpit of the world's most advanced aircraft into one dating from the first world war.
Fortunately the skies were clear, so the squadron did an about-face and was able to follow its in-flight refuelling tankers back to Hickam.
The error was diagnosed as a problem with a "partial line of code" that had pitched the planes' computers into an infinite loop of trying and failing to calculate their position while dealing with an unexpected date. A fix was issued, and three weeks later the planes made their trip to Japan without a hitch.
"Reliance on electronics has changed the flight-test process," says Donald Shepperd, once head of the US Air National Guard. "It used to be tails falling off, now it's typos that ground a fighter."
A matter of perspective
IT'S REASSURING to know that an engineering screw-up doesn't always get you into trouble. It can sometimes even dig you out of it, as astronomers found out at the Canada-France-Hawaii telescope on Mauna Kea, Hawaii.
In early 2003, researchers began observing the skies using the telescope, equipped with a new digital camera - the biggest in the world at the time. The CFHT was fitted with four precision lenses so the camera could capture crisp images of vast areas of sky.
The results were disappointing. The images were sharp in the centre, but far more blurred than expected at the sides. Various tests failed to find a problem, much less a solution, so astronomers pressed ahead with a five-year survey using the camera, until May 2004, when a steering committee said the image quality was jeopardising the project.
A laborious investigation followed, with engineers dismantling the optics and reassembling them daily, but finding no answer. Then one day, an engineer mistakenly replaced one of the four lenses back-to-front. The images improved spectacularly.
"The next observations were just 'Wow!'," says Christian Veillet, the observatory's director. "The image quality was just what it should have been."
To this day, no one understands why the back-to-front lens works so well, or why it didn't work when it was oriented as planned. "That has been frustrating, but it would be a waste of resources to investigate, so we decided to just forget about it," says Veillet. "Now the science that is coming out is exquisite."
Memory scramble
THEY say ballooning is the least stressful way to fly. Indeed, a balloon seemed the perfect platform from which the $10 million BLAST telescope, funded by NASA, the Canadian Space Agency and the UK's Particle Physics and Astronomy Research Council, could take far-infrared snaps of star formations.
For 12 days running up to 2 January 2007, it collected valuable data as it floated 40 kilometres above Antarctica. As it descended, the gondola released the huge balloon and deployed its landing chutes as planned. But the electronics that should have released the parachutes on touchdown failed. Antarctic winds inflated them like giant spinnakers, turning the cargo into a wind-powered sled.
"It was moving as fast as I could run," recalls project leader Mark Devlin, who was following the fate of the 180-kilogram telescope and its support computers from his home in the US. "It was absolutely sickening." The support plane could only watch as the gondola bounced across the ice, strewing pieces of equipment as it went. It finally came to rest 24 hours later, when it wedged in a crevasse 200 kilometres from its landing site.
Devlin was emailed a picture of the scene, which he scrutinised for any sign of the hard drives bearing the only copy of the mission's data. "NASA paints everything white," he says, so his search was initially in vain. Fortunately, a pilot tracking the furrow gouged by the gondola spotted the package. The damaged drives eventually yielded their irreplaceable data, but the telescope was a write-off. Devlin is now fund-raising for a similar mission, with tougher electronics and one other change: "I'm thinking fluorescent orange," he muses.
The trouble with rockets
ROCKET science has a deserved reputation for being tough, so it should be no surprise that things can get a little bumpy when designing and testing a launcher. Just ask Elon Musk, the millionaire founder of PayPal and rocket company SpaceX.
His first rocket, Falcon 1, was scheduled to lift off from the Pacific atoll Kwajalein in November 2005, at which point the problems began. First, unplanned engine tests used up more liquid oxygen (LOX) fuel than expected, then the LOX generator broke down. A shipment of fuel was ordered from Hawaii, but the tanker sprang a leak and arrived only one-fifth full. There was just enough to launch, but a valve was left open during the final preparations allowing more fuel to waste away, so the launch had to be cancelled.
A fresh shipment of LOX arrived a month later but disaster struck again. High winds hit the atoll, and to be on the safe side, engineers decided to drain the fuel from the rocket. A faulty pressure valve caused a vacuum to form inside the main fuel tank, sucking in its soft sides like a crushed beer can.
After three months of repairs, by March 2006 Falcon 1 was ready to go. Seconds after launch, however, the main engine sprang a fuel leak, leaving a trail of flame in the rocket's wake as it spiralled off course and crashed within sight of the disappointed engineers. An investigation pinpointed the cause: a corroded fuel-line nut was to blame.
A year later, with the rocket rebuilt from scratch, Falcon 1 finally took off without a hitch. It managed 5 minutes of smooth flight. But a bump as the first and second stages separated confused a control system, causing it to enter an uncontrolled roll, which triggered a premature shutdown of the second-stage boosters. Falcon 1 did reach space, but not with the velocity needed to secure orbit.
Its next outing is scheduled for January 2008, when it will carry the cremated remains of 125 people, including actor James Doohan - Star Trek's Scotty. Let's hope he gets a fitting send-off.
Goodbye yellow submarine
THE submarine Autosub 2's mission might sound simple enough: film the rich diversity of species living under the permanent ice of the Antarctic. Yet exploring 15 kilometres under the Fimbulisen ice shelf had to be done autonomously, so the 7-metre sub's creators at Southampton University, UK, installed an artificially intelligent guidance system.
In 2003, Autosub 2 was sent on its maiden voyage under sea ice and completed the test mission successfully. Repeat missions in 2004 boosted the researchers' confidence and so they prepared for the big one: to explore under the permanent ice. The next year they went for it.
All looked good until five hours after launch. The £1.5 million yellow submarine called home using an acoustic distress beacon. Somehow it had lost its way, and had become wedged deep under the permanent ice.
Researchers on the support ship were stunned - there was nothing they could do to help it. "I remember it taking a while to believe the sub was gone," says Miles Pebody, a robotics engineer who worked on Autosub 2. "It would have been great to send another vehicle under to find it - but it was too dangerous."
The research ship returned for a final farewell five days later. Autosub 2 had not budged. It kept sending its distress call until its 5500 D-cell batteries went flat.
Recovering the sub could reveal what went wrong, but its icy tomb makes that practically impossible. A report last year guessed that a hardware fault had probably cut the power, triggering a decision to surface prematurely, while the sub was still under the ice.
Back to the future
IN FEBRUARY 2007, 12 F-22 Raptors, the US air force's new stealth fighters, left Hickam Air Force Base in Hawaii, bound for Okinawa, Japan, on the high-tech planes' first overseas outing. Things went smoothly until they reached the 180th meridian - otherwise known as the International Date Line.
Some of the pilots suddenly found themselves without any navigation aids. With nothing to tell them their compass heading or even whether they were level or not, it was as if the pilots had been instantaneously transported from the cockpit of the world's most advanced aircraft into one dating from the first world war.
Fortunately the skies were clear, so the squadron did an about-face and was able to follow its in-flight refuelling tankers back to Hickam.
The error was diagnosed as a problem with a "partial line of code" that had pitched the planes' computers into an infinite loop of trying and failing to calculate their position while dealing with an unexpected date. A fix was issued, and three weeks later the planes made their trip to Japan without a hitch.
"Reliance on electronics has changed the flight-test process," says Donald Shepperd, once head of the US Air National Guard. "It used to be tails falling off, now it's typos that ground a fighter."
A matter of perspective
IT'S REASSURING to know that an engineering screw-up doesn't always get you into trouble. It can sometimes even dig you out of it, as astronomers found out at the Canada-France-Hawaii telescope on Mauna Kea, Hawaii.
In early 2003, researchers began observing the skies using the telescope, equipped with a new digital camera - the biggest in the world at the time. The CFHT was fitted with four precision lenses so the camera could capture crisp images of vast areas of sky.
The results were disappointing. The images were sharp in the centre, but far more blurred than expected at the sides. Various tests failed to find a problem, much less a solution, so astronomers pressed ahead with a five-year survey using the camera, until May 2004, when a steering committee said the image quality was jeopardising the project.
A laborious investigation followed, with engineers dismantling the optics and reassembling them daily, but finding no answer. Then one day, an engineer mistakenly replaced one of the four lenses back-to-front. The images improved spectacularly.
"The next observations were just 'Wow!'," says Christian Veillet, the observatory's director. "The image quality was just what it should have been."
To this day, no one understands why the back-to-front lens works so well, or why it didn't work when it was oriented as planned. "That has been frustrating, but it would be a waste of resources to investigate, so we decided to just forget about it," says Veillet. "Now the science that is coming out is exquisite."
Tuesday, July 24, 2007
WATERY CARS
Forget cars fuelled by alcohol and vegetable oil. Before long, you might be able to run your car with nothing more than water in its fuel tank. It would be the ultimate zero-emissions vehicle.
While water, plain old H2O, is not at first sight an obvious power source, it has a key virtue: it is an abundant source of hydrogen, the element widely touted as the green fuel of the future. If that hydrogen could be liberated on demand, it would overcome many of the obstacles that till now have prevented the dream of a hydrogen-powered car becoming reality. Producing hydrogen by conventional industrial means is expensive, inefficient and often polluting. Then there are the problems of storing and transporting hydrogen. The pressure tanks required to hold usable quantities of the fuel are heavy and cumbersome, which restricts the car's performance and range.
Tareq Abu-Hamed, now at the University of Minnesota, and colleagues at the Weizmann Institute of Science in Rehovot, Israel, have devised a scheme that gets round these problems. By reacting water with the element boron, their system produces hydrogen that can be burnt in an internal combustion engine or fed to a fuel cell to generate electricity. "The aim is to produce the hydrogen on-board at a rate matching the demand of the car engine," says Abu-Hamed. "We want to use the boron to save transporting and storing the hydrogen." The only by-product is boron oxide, which can be removed from the car, turned back into boron, and used again. What's more, Abu-Hamed envisages doing this in a solar-powered plant that is completely emission-free.
Simple chemistry
The team calculates that a car would have to carry just 18 kilograms of boron and 45 litres of water to produce 5 kilograms of hydrogen, which has the same energy content as a 40-litre tank of conventional fuel. An Israeli company has begun designing a prototype engine that works in the same way, and the Japanese company Samsung has built a prototype scooter based on a similar idea.
The hydrogen-on-demand approach is based on some simple high-school chemistry. Elements like sodium and potassium are well known for their violent reactions with water, tearing hydrogen from its stable union with oxygen. Boron does the same, but at a more manageable pace. It requires no special containment, and atom for atom it's a light material. When all the boron is used up, the boron oxide that remains can be reprocessed and recycled.
Abu-Hamed and his team are not the first to investigate hydrogen-on-demand vehicles. The car giant DaimlerChrysler built a concept vehicle called Natrium (after the Latin word for sodium, from which the element's Na symbol is drawn), which used slightly more sophisticated chemistry to generate its hydrogen. Instead of pure water as the source of the gas, it used a solution of the hydrogen-heavy compound sodium borohydride. When passed over a precious-metal catalyst such as ruthenium, the compound reacts with water to liberate hydrogen that can be fed to a fuel cell. It was enough to give the Natrium a top speed of 130 kilometres per hour and a respectable range of 500 kilometres, but DaimlerChrysler axed the project in 2003 because of difficulties in providing the necessary infrastructure to support the car in an efficient, environmentally friendly way.
Engineuity, an Israeli start-up company run by Amnon Yogev, a former Weizmann Institute scientist, is working on a similar strategy, but using the reaction between aluminium wire and water to generate hydrogen. In Engineuity's design, the tip of the metal wire is ignited and dipped into water to begin splitting the water molecules. The liberated hydrogen is piped into the engine alongside the resulting steam, where it is mixed with air and burnt. Engineuity is looking for investors to pay for a prototype, and claims it will be able to commercialise its idea "in a few years' time". The US company PowerBall Technologies envisages a hydrogen-on-demand engine containing plastic balls filled with sodium hydride powder that are split to dump the contents into water, where it reacts to produce hydrogen.
Abu-Hamed says the generation of hydrogen for his team's engine would be regulated by controlling the flow of water into a series of tanks containing powdered boron. To kick-start the reaction, the water has to be supplied as vapour heated to several hundred degrees, so the car will still require some start-up power, possibly from a battery. Once the engine is running, the heat generated by the highly exothermic oxidation reaction between boron and water could be used to warm the incoming water, Abu-Hamed says. Alternatively, small amounts of hydrogen could be diverted from the engine and stored for use as the start-up fuel. Water produced when the hydrogen is burnt in an internal combustion engine or reacted in a fuel cell could be captured and cycled back to the vehicle's tank, making the whole on-board system truly zero-emission.
Hydrogen-on-demand, whether from water or another source, could address two of the big problems still holding back the wider use of hydrogen as a vehicle fuel: how to store the flammable gas, and how to transport it safely. Today's hydrogen-fuelled cars rely on stocks of gas produced in centralised plants and distributed via refuelling stations in either liquefied or compressed form. Neither is ideal. The liquefaction process eats up to 40 per cent of the energy content of the stored hydrogen, while the energy density of the gas, even when compressed, is so low it is hard to see how it can ever be used to fuel a normal car.
"Hydrogen-on-demand does not need costly infrastructure and makes cars safer"
Hydrogen-on-demand would not only remove the need for costly hydrogen pipelines and distribution infrastructure, it would also make hydrogen vehicles safer. "The theoretical advantage of on-board generation is that you don't have to muck about with hydrogen storage," says Mike Millikin, who monitors developments in alternative fuels for the Green Car Congress website. A car that doesn't need to carry tanks of flammable, volatile liquid or compressed gas would be much less vulnerable in an accident. "It also potentially offsets the requirements for building up a massive hydrogen production and distribution infrastructure," Millikin says.
There is a potentially polluting step that has to be tackled. "You'll need an infrastructure to produce and distribute whatever the key elements of the generation system might be," Millikin warns. While Abu-Hamed's scheme still requires a distribution network and reprocessing plant, he has devised an ingenious plan that will allow the spent boron oxide to be converted back to metallic boron in a pollution-free process that uses only solar energy (see Diagram). Heating the oxide with magnesium powder recovers the boron, leaving magnesium oxide as a by-product. The magnesium oxide can then be recycled by first reacting it with chlorine gas to produce magnesium chloride, from which the magnesium metal and chlorine can then be recovered by electrolysis.
Solar source
The energy to drive these processes would ultimately come from the sun. The team calculates that a system of mirrors could concentrate enough sunlight to produce electricity from solar cells with an efficiency of 35 per cent. Overall, they say, their system could convert solar energy into work by the car's engine with an efficiency of 11 per cent, similar to today's petrol engines.
Experts are sceptical that we'll be seeing cars running on water any time soon. "It's not the kind of thing you're going to see appearing in a car in five or even ten years' time," says Jim Skea, research director at the UK Energy Research Centre in London. For example, DaimlerChrysler is now focusing its efforts on cars running on compressed hydrogen because filling stations that supply it already exist in some places.
Proponents of cars that run on water are banking that long term the idea will win out. Engineuity's Yogev claims the running costs will be comparable to those of today's petrol engines and expects to have a prototype built within three years.
My other car runs on water? Don't bet against it.
WOW CARS !!!!!!!!!!!
Cleaner, smarter automobiles are the theme for the 2005 Tokyo Motor Show in Japan, although high performance and downright wacky concept vehicles have also been revealed.
Many of the designs on display at the show will never be made commercially available. However, the event provides insight into the importance many car manufacturers place on certain nascent technologies.
With a handful of hybrid gasoline-electric and fuel-cell powered cars already on the market in the Japan and elsewhere, manufacturers sought to promote even more radical reduced-emission designs.
Building on the popularity of the Prius gasoline-electric hybrid, Toyota demonstrated the Fine-X, a fuel-cell car with wheels that can be independently controlled, enabling it to rotate on the spot. The Fine-X also features wing-like doors that open upwards providing access to the front and back seats simultaneously.
Go to work in an egg
An even more unusual parking trick was revealed by Nissan Motor's Pivo concept car. This vehicles egg-shaped cabin can swivel 360°, allowing the driver to turn backwards into forwards at the flick of a switch. Central to this idea is drive-by-wire technology – controlling the car electronically, rather than mechanically.
"With the Pivo concept, we want to demonstrate the myriad possibilities that drive-by-wire could achieve," designer Masato Inoue said at a preview event in September.
Researchers from Tokyo's Keio University also displayed an eight-wheeled electricity-powered sedan capable of a top speed of 370 kilometres (230 miles) per hour and 0-100 kph (60 mph) in 4.2 seconds. The fastest non-racing electric car ever made, it was constructed in cooperation with the Japanese government and several automobile companies.
Multi-hybrid
Japanese company Mazda revealed a multi-hybrid design – the Premacy Hydrogen RE – a van that can use gasoline, a hydrogen fuel cell or electricity. In addition, the company also took the wraps off a hydrogen-powered version of its RX-8 sports car.
Yamaha also unveiled several reduced-emission two-wheeled designs, including an electricity-powered motorcycle and a hybrid gasoline-electric scooter.
The Deinonychus motorcycle has electric motors in both wheels, which can also be adjusted to provide several possible riding positions. The Gen-Ryu hybrid scooter comes with a 600cc engine as well as distance warning system, a rear-view video display and a navigation system that gives the rider verbal prompts.
Among non-Japanese companies at the show, Mercedes-Benz unveiled the F600 Hygenius, a fuel-cell-powered people transporter that generates enough surplus electricity to power laptop computers, DVD players and other entertainment gizmos in the back. And Volkswagen demonstrated the EcoRacer, a diesel sports car with a 1.5 litre, 136-horse-power turbo engine capable of 111 km (69.2 miles) to the gallon.
Mean machines
But for those who want their cars to be meaner rather than cleaner, Audi showed off the S8 saloon. The sedate-looking car features a Lamborghini engine capable of 445 brake horse power and 0-100 kph in 5 seconds flat. When it goes on sale in Germany in 2006, the car's top speed will be electronically limited to 250 kph (155 mph).
More outlandish designs at the show include the MINI Tokyo Concept, which features tea-making facilities built into the back half of the chassis.
And finally, Honda demonstrated a car for drivers who really care about their pet. The snub-nosed WOW car is designed for hardcore dog lovers, and features special pooch compartments and floors designed for easy cleaning.
Monday, July 9, 2007
AIR FILTERS
The air filters in ordinary vacuum cleaners clog with dust and fluff and need frequent cleaning. Now Bosch and Siemens in Munich, Germany, are automating this dirty and annoying job (WO 2004/100750 and 753).
Their new filter is made from a sheet of porous ceramic with an electric heating coil attached to one side and a small loudspeaker clamped to the other. From time to time the coil warms the filter to break down large particles of dirt, while the speaker blasts it with ultrasound to shake the particles out.
Their new filter is made from a sheet of porous ceramic with an electric heating coil attached to one side and a small loudspeaker clamped to the other. From time to time the coil warms the filter to break down large particles of dirt, while the speaker blasts it with ultrasound to shake the particles out.
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