The chip at the core of the Sprite
microsatellite is smaller than a dime.
What’s the News: Imagine a cloud of tiny satellites, each no larger than a postage stamp, sailing like dust on solar winds through a planet’s atmosphere and sending radio signals home, with no need for fuel. When a small patch of real estate opened up on an International Space Station experiment, researchers jumped at the chance to test the durability of such tiny “satellites on a chip,” which they hope to eventually deploy in atmospheres like Saturn’s, and three of the miniature objects are being delivered to the Space Station by Endeavor on its final flight (which was just scrubbed for today). They will allow researchers to see how well such microsatellites hold up to radiation and other rigors of space.
Good news, solar sail enthusiasts: the NASA experimental spacecraft that was feared to be a dud sprang into life last week.
NanoSail-D was launched aboard a small satellite in December; once the satellite was in orbit the engineers back on Earth ordered the cargo door opened, and waited for NanoSail-D to pop out as planned. But the solar sail craft remained stubbornly inside the cargo bay. As weeks passed with no action, NASA’s hopes for the craft sunk.
But last Wednesday, NASA announced that NanoSail-D had spontaneously emerged.
“We knew that the door opened and it was possible that NanoSail-D could eject on its own,” Mark Boudreaux, FASTSAT project manager at the Marshall Center, said in a press release. “What a pleasant surprise this morning when our flight operations team confirmed that NanoSail-D is now a free flyer.” [CNN]
NanoSail-D, phone home.
On December 6, NASA launched its Fast, Affordable, Science and Technology Satellite (FASTSAT), which, among other cargo, carried the test craft NanoSail-D. No bigger than a breadbox, NanoSail-D was supposed to blast free from FASTSAT and spend three days floating free before spreading a 100-square-foot solar sail—what would be NASA’s first successful solar sail project. But while all signs initially indicated the 8-pound box succeeded in ejecting from the satellite, now NASA is not so sure. The agency is having trouble communicating with NanoSail-D, and its whereabouts are unknown.
“We have not been able to locate or make contact with NanoSail-D,” says Kim Newton of NASA’s Marshall Space Flight Center in Huntsville, Alabama. The sail was scheduled to unfurl on 9 December, but NASA reports that the deployment of the sail cannot be confirmed, and it is not clear whether the sail was successfully ejected into space. [New Scientist]
This summer, Japan’s golden solar sail unfurled in space, becoming the first successful mission to sail on the physical pressure of the sun’s radiation. Its success led dreamers like Planetary Society director Bill Nye to envision a future of machines pushed forward by the pressure of lasers to explore the cosmos. And now, down here on Earth, researchers say they have demonstrated one of the key principles needed to realize such a vision: a “lightfoil” that uses light to create lift.
The lightfoil described in Nature Photonics is only micrometers in scale, but lead researcher Grover Swartzlander argues that it shows scientists can create and control optical lift. It operates on the property of refraction–how glass bends light.
Optical lift is different from the aerodynamic lift created by an airfoil. A plane flies because air flowing more slowly under its wing exerts more pressure than the faster-moving air flowing above. But in a lightfoil, the lift is created inside the object as the beam shines through. The shape of the transparent lightfoil causes light to be refracted differently depending on where it goes through, which causes a corresponding bending of the beam’s momentum that creates lift. [Science News]
This neat trick could potentially be used to steer a spacecraft, the researchers say.
When Ikaros unfurled, it unfurled like a spinning top blossoming into a pinwheel. Out in space earlier this month, the center piece of Japan’s solar sail was rotating quickly when it began to extend the arms that had been wrapped up inside. As they stretched out into a stiff X shape, like the stakes that hold a kite taut, the craft slowed to a gentler rotation (a consequence of conservation of angular momentum, like the way a figure skater’s spin slows down when she extends her arms). The JAXA scientists then could let Ikaros stretch the shining sail into a square that spanned 66 feet diagonally.
In Brooklyn this week, solar sail enthusiasts gathered for an international symposium. Last night Osamu Mori of the Ikaros team (seen above with a mock-up) was the toast of the party, and a group of experts joined him to celebrate and look forward to a bevy of new explorations. The roster included Planetary Society current director Louis Friedman and director-to-be Bill Nye, NASA’s Les Johnson, Malcolm McDowell of the University of Strathclyde in Scotland, and Roman Kezerashvili of the host New York City College of Technology.
“I feel like they deserve a ticker-tape parade here in New York City,” Friedman said, “rather than just showing up for a scientific conference.”
Ikaros hasn’t flown too close to the sun. It’s flown just close enough to ride the light.
Japan’s space agency JAXA confirmed on Friday that its solar sail project, Ikaros, achieved another of its goals: The sun’s photons pushed against the sail and accelerated the craft.
The effect stems from the cumulative push of light photons striking the solar sail. When measured together, it adds up to a small continuous thrust that does not require fuel use by the Ikaros craft. JAXA engineers used Doppler radar measurements of the Ikaros craft to determine that sunlight is pressing on the probe’s solar sail with a force of about 1.12 millinewtons (0.0002 pounds of force) [MSNBC].
Japan launched Ikaros in May and unfurled the sail in June. Now, JAXA scientists say, “with this confirmation, the IKAROS was proved to generate the biggest acceleration through photon during interplanetary flight in history.” Coming soon: A controlled flight in which the researchers turn the sail toward or away from the sun to control Ikaros’ velocity.
80beats: Today In Space: Japanese Craft Spreads a Solar Sail
80beats: Japan’s Venus-Bound Probe Will Hunt Volcanoes And Study Violent Storms
DISCOVER: Japan Stakes Its Claim in Space, on the Hayabusa mission
South Korea’s attempt to jump into the space race met with disaster today. A little more than two minutes after takeoff today, the nation’s Naro rocket exploded. It had been carrying a satellite, and South Korea was vying to become the tenth country to put a satellite in orbit with rockets assembled at home.
South Korea has invested more than 500 billion won (400 million dollars) and much national pride in the 140-ton Naro-1. The liquid-fuelled first stage of the rocket was made in Russia, while the second stage was built domestically, as was the satellite [AFP].
In Japan, meanwhile, happier news: Last month its space agency, JAXA, launched a batch of new missions into space that included its solar sail project, called Ikaros. Today it unfurled the sail, seen above in the blinding light of the sun.
After separating from Akatsuki [a separate probe going on to Venus], Ikaros began unfolding four panels that, when fully unfurled, should look like a square kite measuring 66 feet (20 meters) along its diagonal. Pictures sent back by a camera mounted on the spacecraft’s hub show the extension of four booms holding the panels, plus the unfurling of sail material. This is the “primary deployment” of the sail. During the secondary stage of deployment, the sail is stretched out to its full extent [MSNBC].
Atmospheric Tag Team
Akatsuki, the Venus climate probe, will arrive at the second planet from the sun in December. There it will team up with the European Space Agency’s Venus Express probe, using five cameras to peer down into the turbulent atmosphere and study Venus‘ maniacal meteorology.
One of the main goals is to understand the “super-rotation” of the Venus atmosphere, where violent winds drive storms and clouds at speeds of more than 220 mph (360 kilometers per hour), 60 times faster than the planet itself rotates [MSNBC].
The Venus Express’ own findings since it reached the planet in 2006 have bolstered the idea that Venus was once alive with plate tectonics, oceans, and continents—that is, it was once much more Earth-like than its current, sweaty incarnation. In fact, Venus may still be active.
It’s alive! It’s alive! (Maybe.)
On May 18, the Japan Aerospace Exploration Agency (JAXA) says, it will launch into space a “solar yacht” called Ikaros—the Interplanetary Kite-craft Accelerated by Radiation of the Sun (named, of course, in honor of Icarus in Greek mythology). JAXA plans to control the path of Ikaros by changing the angle at which sunlight particles bounce off the silver-coloured sail [AFP].
Actually, the solar sail is a dual-purpose system, taking advantage of both the pressure and the energy of sunlight. The sail, which is less than the thickness of a human hair and 66 feet in diagonal distance, will catch the actual force of sunlight for propulsion as a sailboat’s sail catches the wind. But the solar sail is also covered in thin-film solar cells to generate electricity. And if you can make electricity, you can use it to ionize gas and emit it at high pressure, which is the propulsion systems most satellites use.
Potential velocity using a solar sailor has been theorized to be extremely high. “Eventually you’ll have these missions lasting many years, reaching speeds approaching 100,000 mph, getting out of the solar system in five years instead of 25 years,” said Louis D. Frieman, the Executive Director of the Planetary Society [Clean Technica]. The society has toyed around with its own solar sail.
For now, though, JAXA has a six-month test mission planned for Ikaros. If it works, they want to send a solar sail-powered mission to Jupiter and then the Trojan asteroids. That voyage would employ both the force of the sun and ion propulsion, and the Japanese are brimming with confidence: “Unlike the mythical Icarus, this Ikaros will not crash,” Yuichi Tsuda, an assistant professor at JAXA, said today [BusinessWeek].
80beats: Japan’s Damaged Asteroid Probe Could Limp Back to Earth in June
80beats: Spacecraft That Sails on Sunshine Aims For Lift-Off in 2010, on the Planetary Society’s own attempts at a solar sail.
DISCOVER: Japan Stakes Its Claim in Space
DISCOVER: One Giant Step for a Small, Crowded Country, on Japan’s moon aspirations
DISCOVER: Japan Sets Sail in Space
It was a fitting tribute to Carl Sagan’s imagination, optimism, and starry-eyed wonder. On Monday, which would have been Sagan’s 75th birthday, the Planetary Society announced that it is pushing ahead with a plan for experimental spacecraft that will ride on sunbeams, powered by solar sails. The first small craft will be sent into orbit in 2010, if all goes well, and will be followed by two others, which may venture farther. Sagan was a founder of the Planetary Society and a big booster of solar sail plans.
Solar sail technology, which has not yet been tested in space, relies on the tiny impacts created by the light particles streaming from the sun as they hit a reflective surface. The force on a solar sail is gentle, if not feeble, but unlike a rocket, which fires for a few minutes at most, it is constant. Over days and years a big enough sail, say a mile on a side, could reach speeds of hundreds of thousands of miles an hour, fast enough to traverse the solar system in 5 years. Riding the beam from a powerful laser, a sail could even make the journey to another star system in 100 years, that is to say, a human lifespan [The New York Times].
The spacecraft that is scheduled for orbit in 2010, the LightSail-1, has been made possible by an anonymous donation to the Planetary Society. The recent donation reinvigorates the Society’s solar sail hopes, which were dashed in 2005 when the Russian Volna rocket carrying its first solar sail prototype, Cosmos 1, failed to reach orbit…. In addition to the Cosmos 1 disappointment, NASA’s NanoSail-D attempt was lost in the third failed flight of SpaceX’s Falcon 1 rocket in 2008 [SPACE.com].
80beats: Millionaire’s Private Rocket Fails to Reach Orbit on Third Try
80beats: Solar Sail Experiment Planned for Earth Orbit
Image: The Planetary Society