Pages

December 29, 2014

KC-46A tanker program makes first test flight

The KC-46A tanker program makes its first flight (Photo: Boeing)

The KC-46A tanker program makes its first flight (Photo: Boeing)

Boeing and the US Air force have announced the successful first test flight of the KC-46A tanker program. Set to replace the Air Force's aging fleet of KC-135 Stratotankers, the KC-46A is designed to act primarily as an airborne refueling tanker that is compatible with all US, allied, and coalition aircraft capable of in-flight refueling, but can also carry passengers and cargo, or act as a medivac airplane.

As part of the KC-46A test program, Boeing is building two 767-2Cs for testing as freighters (after which they will be fitted with in-flight refueling and other military systems systems) and two KC-46As built fully equipped to complete the FAA and military certifications.

In today's test, one of the Boeing 767-2C commercial cargo aircraft lifted off from Paine field in Everett, flew for 3 h and 32 min, and then landed at Boeing Field in Seattle.

Based on the 767 airframe and incorporating the cockpit avionics from the Large Boeing 787, the aircraft's versatility is further boosted by the fact that it's equipped with countermeasures that allow it to fly in medium-threat environments.

Powered by two Pratt & Whitney PW4062 turbofan engines, the KC-46A carries a crew of three, including the refueling boom operator, and has permanent seating for 15 passengers, though it can be reconfigured to hold 114 passengers, 18 pallets, or 58 patients. It has a fly-by wire refueling boom and can lift off with more fuel from shorter runways than the KC-135. According to Boeing, it has a cruising speed of Mach 0.80 (530 mph, 851 km/h), and a range of 6,385 nmi (12,200 km).

The first 18 of 179 KC-46As are scheduled for delivery in 2017.

post from sitemap

December 28, 2014

Northrop Grumman MQ-8C Fire Scout makes first destroyer flight

The MQ-8C Fire Scout hovering over the flight deck of USS Jason Dunham (Photo: Northrop Gr...

The MQ-8C Fire Scout hovering over the flight deck of USS Jason Dunham (Photo: Northrop Grumman)

A helicopter landing on the flightdeck of a destroyer is hardly news – unless it's the US Navy's latest Unmanned Aerial Vehicle. Northrop Grumman's MQ-8C Fire Scout became the first unmanned helicopter to operate from a US destroyer on December 16. Under guidance of the ship's ground control station, the MQ-8C made 22 takeoffs and 22 precision landings on the guided missile destroyer USS Jason Dunham (DDG 109) off the coast of Virginia.

The MQ-8C has already completed a year of land-based testing since its first flight from Naval Base Ventura County in California on October 31, 2013. Based on the Bell 407 airframe, the MQ-8C uses an improved version of the autonomous avionics from the smaller MQ-8B, and is powered by a Rolls-Royce 250-C47E.

Designed as a dynamic, multi-purpose unmanned helicopter, the Navy has 28 on order. When delivered, each will have a range of 150 nmi (170 mi, 280 km) an endurance of 12 hours, and will be able to carry a 318 kg (701 lb). The helicopter is intended for unmanned resupply missions, support for special forces, and other missions requiring a longer on-station presence.

The MQ-8C Fire Scout on the deck of USS Jason Dunham (DDG 109) (Photo: Northrop Grumman)

"These dynamic interface tests are an essential part in clearing the operational envelope of the system and are proving the system's ability to operate off any air-capable ship," says George Vardoulakis, vice president for medium range tactical systems, Northrop Grumman Aerospace System. "We are on track to validate all of the critical performance parameters of this Navy asset and ready the system for deployment and operational use."

The video below shows the MQ-8C undergoing sea trials.

post from sitemap

MESSENGER uses helium for last minute reprieve

Artist's concept of the MESSENGER orbiter (Image: NASA)

Artist's concept of the MESSENGER orbiter (Image: NASA)

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. It wasn't until March 18, 2011 that it went into orbit around its target because matching orbits with Mercury required an elaborate series of flybys of Earth, twice of Venus, and three times of Mercury before it obtained the proper trajectory. After completing its year-long mission to study Mercury's surface and exosphere, the orbiter was then placed on two extended missions; the second of which is now scheduled to end in April.

post from sitemap

December 27, 2014

Moto Hint review: The future of Bluetooth headsets ... almost

Gizmag reviews Motorola's attempt at reinventing the Bluetooth headset, the Moto Hint (Ima...

Gizmag reviews Motorola's attempt at reinventing the Bluetooth headset, the Moto Hint (Image credit: Eric Mack/Gizmag.com)

When we visited Motorola's Chicago headquarters in September, one of the most intriguing new gadgets wasn't quite ready for the press to try out. But now we've been able to spend some quality time with Moto Hint, the company's next generation Bluetooth earbud. Though it's a step in the right direction compared to the wonky things some of us stick in our ears, there's still some room for improvement.

Unlike most Bluetooth headsets that make your ear look like a miniature satellite dish, the majority of the Moto Hint fits snugly but comfortably inside your head. It resembles something like an oddly shaped hearing aid: it's visible, but doesn't have the cyborg aesthetic that most headsets add to your cranium.

Ironically, the Hint does grant its wearer more cyborg-like powers than the average Bluetooth ear dongle, at least when paired with a Moto X or Droid Turbo. On Motorola's flagship phones, the Hint basically acts as an extension of the Moto Voice feature, which allows a user to control the phone from across a room using voice commands.

The Hint essentially acts as a remote ear for those phones and is always listening for their user defined trigger phrase, which then tells the phone that the next thing you say will be a search or executable command. It can also push incoming calls, select notifications and other kinds of audio to your ear, even when your phone is in the next room.

If you're in an environment where you don't want to address your unseen phone by some silly name, you can also tap the outward-facing capacitive touch area of the headset to get your phone's attention to start listening for commands. If you're using the Moto Hint with a late model Android phone or iPhone, a touch will summon Google Now or Siri, respectively.

Hint works best with Moto Voice (Image credit: Eric Mack/Gizmag.com)

Concierge in your ear

The things you can do with a Moto Hint in your ear and a connected Moto Voice device within range are limited only by what Google Now and the Moto software can understand, which seems to expand monthly if not weekly. Using only voice, we were able to do currency conversions, send and receive texts, calls and emails, manage calendar events, get weather reports, translate "oatmeal" into a handful of different languages, navigate to the veterinarian, and play a little old school Cypress Hill via Spotify, among many other potential functions – all without having the paired phone in the same room.

As long as you remain conscious that you're wearing a Moto Hint, it can become easy to go a little crazy with it, asking it for help with every mundane thought or query that comes into your head. There's a good chance this will quickly irritate any companions you might be with, as it did my wife and daughter at our breakfast table, who both rolled their eyes when I asked the digital bug in my ear how to say oatmeal in Portuguese.

It is surprisingly easy to forget that you're wearing a Hint, as it is as comfortable and lightweight as any ear-worn consumer device we've tested. We tried a number of headsets, earbuds and helmet insert devices while wearing a ski helmet for winter sports, and the Hint is the best yet for getting through an entire day on the mountain. We found it even more comfortable than elaborate helmet-mounted systems designed specifically for active sports use.

Hinting at serious design chops

The Hint is also a leap forward in design in terms of being able to take it with you and still have normal social interactions that don't leave people joking about your robot ear minutes later. Yes, it's smaller and less ostentatious or geeky than most headsets. You can even choose from different premium materials for the touch area including leather, bamboo and walnut. But the smartest new feature here is an infrared proximity sensor that detects when it's in your ear and automatically connects when you put it in. By the same token, it automatically disconnects and hands off any calls or other audio in progress to your phone relatively seamlessly when you pull it out of your ear.

Moto Hint comes in a variety of styles (Image credit: Motorola)

This is pretty much perfect for how I wear a Bluetooth headset, and I'm the biggest fan of Bluetooth audio devices that I know. But I still tend to pull my headset out of my ear to have a face-to-face conversation with someone or if I need to focus on another external source of sound. I love being able to just pull the Hint out in a quick, subtle motion and know that I'm not missing any part of what I was just hearing, and without fiddling with any switches, buttons or long presses.

The final thing that we love about the Moto Hint is its nifty little carrying case/charger/battery pack that is another of those neat little ways that Motorola shows off how good it has become at design. When you plug in the case, you're charging both the Hint in its cradle and an extra rechargeable battery in the case itself. With a fully charged case, which can be slipped on a key ring via the plastic loop that lights up when charging is happening, you can juice up your Hint at least two more times while on the go.

This brings us to a shorter but still significant list of gripes that we have about the Moto Hint.

The key ring loop lights up when charging (Image credit: Eric Mack/Gizmag.com)

Hinting at areas in need of improvement

First off, let's address why that cool carrying case has a battery in it in the first place. It's because the battery in such a tiny headset is correspondingly tiny and only lasts for about three hours worth of listening, be it to music, podcasts, audiobooks or whatever. Motorola deserves a lot of credit here for designing a case that goes a long way towards solving this shortcoming, but it means you basically need to remember to bring a charged case with you everywhere you go, and if you lose it, your US$150 headset is now worthless.

Yes, you read that right, too. The Hint costs $150, which is more than you'll pay for a Moto X to connect to it (with a new carrier contract, at least) and makes it one of the more expensive earbuds on the market, but without the same sound quality you'll get from most other high-end headsets.

That would be our third complaint about the Hint: its volume is often either too low or inconsistent. Walking through city traffic or working in a loud environment, you can easily miss a notification, even with the volume on your phone (the Hint does not have its own volume controls) turned up to 100 percent. Beyond the volume issue, sound quality is adequate, but we get better fidelity on headsets that cost a third of the Hint's retail price.

Sometimes the Hint itself can also have problems hearing, but strangely the issue is not with background noise in the user's environment, it's with the sounds coming from the Hint itself. When listening to music via the headset, it often seems to be unable to hear our attempts to give it new commands. We'll say the trigger phrase over and over with no response, then remember that we can just as easily get the Hint to pay attention by tapping it with a finger ... only to find that it also is less responsive while music is streaming from it. Eventually a forceful enough tap will get it to listen to our desperate attempts to ask directions to the nearest Starbucks.

Oh, and one final little complaint: The Moto software does not seem to be aware that Google tries to force most Android users to use its Hangouts app for texting, so if you've integrated your text messages into hangouts, you won't automatically have new texts read to you via the Hint. To hear the message, you'll have to say your trigger phrase or tap the Hint and then ask it to "read notifications." It's a minor hassle, but one that it seems should be easy to fix with a software update.

Hint retails for $149 (Image credit: Eric Mack/Gizmag.com)

Conclusion

I'm a huge Bluetooth fan and an admitted cyborg constantly listening to books, podcasts or music in my ear while working, walking, exercising or sometimes even when trying to fall asleep. It kind of blows my mind that it isn't more socially acceptable to have one of these things in your ear, even as it's increasingly acceptable to thoroughly disconnect from the society around you by focusing your full attention on screens of all sizes at all times.

The Moto Hint seems like it could be a big step towards building the bridge to that future of more seamless, hands- and eyes-free utilitarian connection that looks cool in movies like "Her" but that many people continue to resist.

Perhaps it's a good thing that we aren't all ready for this vision of the future just yet, because if the Moto Hint is going to lead the wave of wearable devices that brings it into the mainstream, it's going to need a few upgrades and improvements before it's ready for primetime itself.

post from sitemap

Recapture system limits mercury exposure from gold purification

The MCS costs about US$500

The MCS costs about US$500

According to the World Gold Council, about 195,300 tons (177,200 tonnes) of gold have been dug out of the ground in all of human history. Countless lives have been lost obtaining the rare metal, and in the developing world, which currently accounts for 20 percent of the world's gold production, small-scale mining and smelting under primitive conditions poses a major health hazard. To help alleviate this, a team from Argonne National Laboratory and the US Environmental Protection Agency (EPA) are developing a prototype mercury capture system (MCS) to reduce heavy metal pollution.

A common method used by small miners in South America and other places is mercury extraction, which exploits the ability of mercury to "dissolve" gold and form an amalgam. This way, particles of gold can be separated from crushed ore and floated away. When the mercury is boiled away, the gold remains behind. This process is now outmoded in the mainstream mining industry, where it's been superseded by cyanide and other methods that are cheaper, more effective, less expensive, and much safer, but is still in common use in the developing world.

The use of mercury is more than a theoretical hazard. The removal of the mercury in smelting the gold is often incomplete, so when goldsmiths melt gold in their city shops, more mercury is released. Worse, the protections against airborne mercury are notoriously poor with only five percent of gold shops in Brazil having any mercury control systems. Usually, the shops have little more than extraction hoods that empty directly into the open air, and Argonne says that Peruvian shops have no protection at all. Not surprisingly, the mercury levels in and around gold shops in the developing world generally exceed safe levels.

Exploded view of the MCS

The upshot of this is that these small operations account for 700 tons (635 tonnes) of airborne mercury being released each year. The heavy metal falls back to earth, where it is inhaled, is picked up on exposed food on market stalls, and washes away into streams, where it enters the food chain. Its this latter problem that drew the attention of the EPA, because it can get into food exports, which eventually reach US tables, as well as airborne aerosols that can drift into US water systems.

Argonne and the EPA's answer is the prototype MCS, which consists of a converted steel drum that condenses and recaptures the mercury vapor with 80 percent effectiveness. An Argonne/EPA team worked with locals in the Amazon region to refine the design of the MCS and to build prototypes, which cost about US$500 each. These were then installed in several gold shops along with fume hoods and exhaust chimneys.

A fume hood for collecting airborne mercury

The prototype is made of a 55-gallon drum fitted with a circulating fan, baffles for collecting the mercury, and a piping system to collect and remove the liquid metal. The over-large hood, the drum, and the baffles provide the mercury vapor plenty of time to condense, which is the key to the device's efficiency. The team says that the MCS is affordable and can be retrofitted to existing shop hood ventilation systems.

"We wanted to design a system to address the significant mercury exposure affecting both the shops and the homes that purify gold," says Argonne environmental systems engineer Margaret MacDonell. "Many people have been burning mercury for decades because that is the way their grandparents or neighbors did it. We helped develop a better way of thinking about the process."

The video below explains the MCS project.

post from sitemap