Showing posts with label Aero. Show all posts
Showing posts with label Aero. Show all posts

Russia launches 'largest telescope ever made'

To look at the Russian RadioAstron spacecraft, which launched from Kazakhstan this Monday, it doesn't seem particularly record-breaking. Its 10-meter (33-foot) antenna is certainly no match for those on earthbound radio telescopes, which can be up to 300 meters (984 feet) across. Once in orbit, however, its signal will join forces with those from ground-based telescopes to form one giant virtual telescope. Using a process known as interferometry, they will form the equivalent of a single radio telescope dish that at over 350,000 kilometers (217,480 miles) across is almost 30 times wider than the Earth. Although it's not actually one physical object, it is nonetheless being heralded as the largest telescope ever created.



Interferometry itself is nothing new, having been around since the 1960s. Very basically speaking, it involves combining the output of two or more geographically-separated telescopes to obtain one image with a resolution higher than either telescope could achieve on its own.
While radio telescopes have been sent into space for this purpose before, the plan is for RadioAstron's oval-shaped orbit to take it up to ten times farther than any of those other spacecraft have traveled, at 10,000 to 390,000 kilometers (6,214 to 242,335 miles) from Earth. Working with telescopes in locations such as West Virginia, Germany and Puerto Rico, it should be able to capture details at 10,000 times the resolution of the Hubble Space Telescope.
Plans for its use include the observation of a huge black hole at the center of a nearby galaxy, M87.
Although already launched, it will still be a few months before the spacecraft reaches the starting point of its orbit, and then goes through a check-out period with its ground control team at Russia's Lebedev Physical Institute Astro Space Center. Once it starts receiving and transmitting data ... well, there will be a lot of it. It's estimated that RadioAstron will be taking in up to 144 megabits per second, which will be continuously relayed to the ground.
So far, however, there is only one 22-meter (72-foot) dish set up to receive that data, near Moscow. This means that much of the data will simply be lost. It is hoped that throughout RadioAstron's five-year mission, more receiving stations can be set up.
Source: Gizmag via New Scientist

D-Dalus - an entirely new genre of aircraft arrives



Austrian research company IAT21 has presented a new type of aircraft at the Paris Air Show which has the potential to become aviation's first disruptive technology since the jet engine.



The D-Dalus (a play on Daedalus from Greek mythology) is neither fixed wing or rotor craft and uses four, mechanically-linked, contra-rotating cylindrical turbines, each running at the same 2200 rpm, for its propulsion.
The key to the D-Dalus' extreme maneuverability is the facility to alter the angle of the blades (using servos) to vector the forces, meaning that the thrust can be delivered in your choice of 360 degrees around any of the three axes. Hence D-Dalus can launch vertically, hover perfectly still and move in any direction, and that's just the start of the story.
Like most cars and aircraft these days, it sounds very complex but it's all controlled by computer algorithms, so it's simple joystick control for the user, and far less exacting than a helicopter to fly.
Existing rotary wing aircraft offer VTOL capabilities but have vulnerabilities which make them unsuitable for many applications. They are challenged in bad weather, at long ranges, at high speed and in operating to and from lurching platforms, such as boats in rough weather.
By contrast, D-Dalus is particularly suited for such conditions and can thrust upwards and hence "glue down" on landing, which it can also do on a moving vehicle. Indeed, landing on a moving vehicle is one of the D-Dalus' many party tricks, and it's a natural for landing on watercraft. Not surprisingly, since it initially broke cover at the Royal Aeronautical Society conference a few days ago, it has already attracted a lot of interest from military quarters.

The D-Dalus is also near-silent, and has the dynamic stability to enter buildings and handle rough weather with ease - things which existing rotorcraft simply cannot achieve. The aircraft also has a sense-and-avoid system which, in conjunction with its complete lack of vulnerable external parts (such as rotors), means it can hover in very close proximity to vertical rock faces and walls, making it suitable for search-and-rescue operations, as a surveillance drone with hover-and-stare capabilities and as a proactive tool for urban battlefield situational awareness.
The lack of vulnerable external moving parts will give a small D-Dalus-type drone the ability to fly into buildings through windows, and its unique capabilities also offer 360 degree vision, another aspect lacking in traditional rotor craft which have blind spots due to the rotors, and nowhere near the same maneuverability as the D-Dalus.
IAT21 forsees many applications based on these key new criteria - apart from being able to enter and search buildings, it could conceivably remove radioactive contamination or explosives, extract casualties, or hold and direct water hoses for fire fighters.
As it can lift heavy loads, and becomes even more efficient in doing so as it scales upwards in size, it is also envisaged as a platform for loading and unloading ships when cranes are not available.
The D-Dalus is also so simple mechanically that it needs little maintenance and requires no more maintenance expertise than an auto mechanic. It should be noted that all VTOL aircraft capable of carrying large payloads are complex and very costly to maintain.
Currently, tests are being conducted using a 120 bhp KTM engine and turbines around five feet long - and the capability of lifting a payload of 70 kg. More tests are planned over the coming weeks. IAT21 is now also working with Cranfield University in the U.K. on a larger, more powerful motor, a new hull shape for the craft, and advanced guidance and control systems.
The forces on the blade pivots are understandably huge, and in initial testing it was found that all available bearings failed, so inventor Meinhard Schwaiger, who already has more than 150 patents to his name, knuckled down and invented (and patented) his own, near-frictionless swivel-bearing to cope with the stresses.
The D-Dalus is constructed of carbon fiber, and appears to be scalable for a range of potential applications including maritime search and rescue, freight transport, operating alongside and within buildings during fires - the long term hopes for the platform include a passenger version for public transit.

Solar plane's first international flight a success


Solar Impulse during flight tests earlier this year / Image: Solar Impulse

Solar Impulse has successfully completed its first international flight. After spending most of last week on standby waiting for favorable weather conditions, the Swiss solar powered aircraft made the run from Payerne to Brussels on Friday May 13 in a flight that lasted 12 hours 59 minutes. Hats-off to the Solar Impulse team!

Solar Impulse is an astonishing feat of engineering. It has a wingspan of over 200 feet (61 m) yet it weighs only 1600 kg (3,527 lb) and carries almost 12,000 solar cells which supply all of the energy required to keep it aloft.
The plane has actually flown for a longer duration than Friday's 12 hours 59 minute flight, setting a mark of more than 26 hours in an overnight flight last summer. The achievement of its first international flight is as much about the logistics of civil aviation as it is about performance. Solar Impulse is a slow moving aircraft – during the latest flight it flew at around 31 mph (50 km/h) – and this makes for some unique challenges when it comes to flight planning as Solar Impulse Air Traffic Control manager Niklaus Gerber explains on the Solar Impulse Blog:
"HB-SIA is an obstacle for civil and military aviation because it is not very mobile, and rather inflexible. It is slow (31 mph/50 km/h) and does not really show up on radar (you see it as a point that hardly moves). Now, alongside it, there are aircraft that are traveling at between 400 and 900 km/h. So the other aircraft are the ones that have to make adjustments to avoid it. But this scenario is theoretical because we have done everything to avoid it in planning the flight. Usually, the separation distance between aircraft is 300 meters (984 ft) vertically and 8 kilometers (5 miles) when flying at the same height. In the case of Solar Impulse, our margin of safety is much greater. And an aircraft that passes above it needs to be at least 900 meters (2,953 ft) higher, due to the turbulence it creates which descends for about 5 minutes at a rate of 150 meters (492 ft) per minute before dissipating."
Successfully negotiating these constraints in the flight from Switzerland to Belgium is therefore a big milestone in the build up towards the planned round-the-world journey.

A new future for aviation?

The project founded by Bertrand Piccard and AndrĂ© Borschberg (who was at the controls during the first international flight) is not geared towards producing a commercial product but instead aims to demonstrate just how much can be achieved with renewable technology. Even without the round the world trip that the team plans to undertake in 2013, it's arguable that the achievements of the past year which began with the aircraft's maiden flight in April 2010 have already gone a long way to proving the point. We could well be looking back on this period as a "Wright brothers moment" in the history of aviation.
In the flight from Payerne to Brussels, Solar Impulse covered around 390 miles (628 km) using no fuel. A rough calculation tells us that a Boeing 747 would have used around 2,000 gallons (7,570 L) of fuel to make the same trip.* Of course it's not much of a comparison when you consider that a commercial airliner can carry hundreds of people, but one can't help but think that the seeds of a new era are being sewn. Solar Impulse is powered by 4 x 10 horsepower electric engines, the Wright Brothers had 12 horsepower at their disposal when they flew at Kitty Hawk in 1903. Food for thought.
Watch the majestic landing at Brussels in the Solar Impulse video below:
* A 747-400 that flies 3,500 statute miles (5,630 km) and carries 126,000 pounds (56,700 kg) of fuel will consume an average of five gallons (19 L) per mile (Boeing.com).