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Privately-funded Solar Sail Prepared For Launch

In a parallel universe, a NASA-sponsored experimental solar sail—the largest ever built—would be launching into space next month along with the solar wind-monitoring DSCOVR spacecraft. That won’t happen in this universe: NASA cancelled the Sunjammer launch last year due to scheduling concerns, and it’s not clear when, or even if, the sail will get another opportunity to fly.

But there is a bright spot on the near horizon for solar sail tests. The space advocacy organization The Planetary Society today announced that a date has been set for the first flight of its LightSail spacecraft. The 30-centimeter-long CubeSatan increasingly popular class of small spacecraftis set to take off from Cape Canaveral Air Force Station in May as a secondary payload on an Atlas V rocket.

Solar sails are propelled by the momentum that photons impart when they bounce off a reflective surface. This method of propulsion can provide slow but steady acceleration to high speeds, which could cut down on the cost and mass of interplanetary missions. With the assistance of a powerful laser beam, the same technique might be used to propel spacecraft to interstellar mission speeds.

Solar sails “will ultimately eventually take a lot of missions a long, long way,” Planetary Society CEO Bill Nye told the New York Times. He said that this spacecraft—and a second one set to launch next year—together cost less than US $4 million to build. 

This first LightSail, integrated and tested by the Pasadena, Calif.–based Ecliptic Enterprises, will spend a month or so in orbit before it unfurls Mylar sheets along 4-meter-long booms to create a 32-square-meter sail. The first flight will be a shakedown mission to test sail deployment and other aspects of the spacecraft. But the sailing will have to wait; the spacecraft will be carried to a fairly low orbit where it will experience significant drag from the atmosphere. The second spacecraft, slated to launch in 2016 on a SpaceX Falcon Heavy rocket, will reach a higher orbit where solar pressure can be used to maneuver.

Other spacecraft have used radiation pressure to adjust their orbits, and solar sails have already had a few successful missions. In 2010, the Japan’s space agency JAXA launched a solar sail called IKAROS (short for Interplanetary Kite-craft Accelerated by Radiation Of the Sun) on a mission past Venus. And in 2011, NASA successfully unfurled NanoSail-D, also a compact CubeSat, in low-Earth orbit.

The new Planetary Society mission comes some 10 years after its first solar sail spacecraft, Cosmos 1, fell to Earth after a rocket failure. 

The Planetary Society's Jason Davis writes that the team has been sharing data with NASA teams that are working on additional solar-sail-bearing CubeSat missions. The space agency aims to launch at least two such missions (not all payloads have been selected yet) on the maiden voyage of the new heavy-lift Space Launch System, which could happen as early as 2018. One of the spacecraft, Lunar Flashlight, will use its solar sail to maneuver and to reflect light onto the moon's south pole.

Entanglement On a Chip

Quantum entanglement is a phenomenon where particles act in sync, even if they are at separate ends of the universe. Links of this type are so delicate that, if anyone tried to eavesdrop on a message sent using a stream of entangled particles, the disturbance would immediately be obvious. This has led to extraordinarily secure quantum cryptography that can instantly detect any spying.

But if this phenomenon is to be used to keep cellphone conversations private or make sure that no one can sniff out your banking password, scientists have to first generate entangled photons using electronics that can fit onto a microchip. However, until now, entangled photon emitters could only be scaled down to millimeters in size, too large for on-chip applications by several orders of magnitude. In addition, such emitters required much more power than is practical for putting them on, say, a cellular handset.

Now researchers at the University of Pavia in Italy say they have developed a device that can generate a continuous supply of entangled photons and is small enough to fit on a microchip. The scientists detailed their findings on 26 January in the online edition of the journal Optica.

The key component of the device is a "micro-ring resonator," a 20-micrometer-diameter ring etched into a silicon wafer. The ring is 500 nanometers wide and 220 nanometers high. When a laser beam is directed along an optical fiber and into the device, the photons race around the ring and can become entangled. “The key to this result is the ability to confine light and matter in the same microscopic place for as long as possible to force their interaction,” Daniele Bajoni, a physicist at the University of Pavia in Italy who is a member of the research team, told IEEE Spectrum.

The device can generate 10 million entangled pairs of photons per second, and requires less than a milliwatt of power—thousands of times less than was needed by previous entangled photon emitters. The researchers employ lasers with a wavelength of 1,550 nanometers, which is often used in telecommunications. They suggest their device could be readily incorporated into existing silicon chip technologies.

Bajoni and his colleagues now aim to integrate this device onto microchips. “I would like to caution the lay reader that we are not going to see a quantum version of the Internet, in which you can send quantum-encrypted e-mails, anytime soon,” Bajoni said. “It is probable that the first applications will be point-to-point exchanges of information. For instance, one can think of quantum ATM machines where bank clients can exchange quantum cryptography keys to be used for home banking.”

MIT's Planning Algorithms are Like Siri, Except Creative and Helpful

People have trouble with realistic planning. By “people,” I mean humans in general, particularly those of us who have jobs and families and hobbies and all that other stuff that makes life variable and complicated. We can’t do it all, but we try anyway, and it frequently involves failures of varying levels of catastrophe. While there are plenty of interactive tools to assist us with scheduling, they mostly just do what we say, whether or not it makes sense. MIT engineers are trying to inject some sense into personal planning. They are trying to make a better version of Apple’s Siri virtual assistant by factoring in risks and probabilities of success, and offering alternatives, even if those alternatives bend the rules a little bit.

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The Germanium-Tin Laser: Answer to the On-Chip Data Bottleneck?

Photonics engineers dream about using light to zap data between processor cores on multicore CPU chips. By replacing copper wires, such optical interconnects could make chips much faster and more power efficient. The holy-grail for optical on-chip communication is a laser made of silicon.

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2014 U.S. Venture Funding Was Highest Since Dot-Com Boom

2014 was the biggest year for venture capital since the peak of the dot-coom boom in 2000. Venture capitalists poured US $48.3 billion across 4,356 deals with U.S. startups last year, according to a new report by PricewaterhouseCoopers and the National Venture Capital Association. That’s 61 percent higher than the $30 billion startups got from investors in 2013 and twice the $20.4 billion invested in 2009.

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Lost Beagle 2 Robot Found Intact on Mars After a Decade

A decade-long search for a lost Martian robot has finally discovered the UK-led mission’s fate. The Beagle 2 Mars Lander apparently made it down to the red planet in one piece but failed to fully deploy properly in order to make contact with mission controllers on Earth.

The discovery of the lost robot brings some measure of closure to UK and European Space Agency team members after Beagle 2’s silence following its Christmas Day descent to the red planet in 2003. But the partial deployment of  just two or three of Beagle 2’s four solar panels likely blocked the robot’s RF antenna and made it impossible for mission controllers to send a signal to revive the mission remotely.

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Obesity-Fighting Implant Approved by FDA

A medical device company in Minnesota has had a big win. It can now sell its weight-loss implant in the heaviest country on the planet. In the Lancet’s list of nations with the most obese people, the United States came out on top with 13 percent of the world’s 671 million. Now Enteromedics, the Minneapolis company, can offer those considering gastric-bypass surger—or similar drastic measures—a less radical alternative.

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Google Glass: Not Dead, Just Resting

Google Glass looks like its poised to become the latest inductee into the Hall of Technological Hubris.

The Hall is for those products that were introduced, with great fanfare, as things that could alter the daily lives of millions, but which either died completely or found only a niche existence. (Think of the Segway, the Microsoft SPOT watch, and the Apple Newton.)

As announced yesterday—almost as a sidenote—in a post on Google+, Google is ending its Explorer program on 19 January. That program allowed anyone to buy the current “beta” version of Glass for US $1,500. While Google promises new versions of the wearable computer are in the works, no hints have been given as to when these might be available or what form they might take.

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