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Raumfahrt - NASA CubeSat Initiative hilft beim Testen von Sonnensegel Technologie im All

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21.05.2015

With help from NASA, a small research satellite to test technology for in-space solar propulsion launched into space Wednesday aboard an Atlas V rocket from Cape Canaveral Air Force Station, Florida, as part of the agency’s CubeSat Launch Initiative.
The Atlas V sent the U.S. Air Force’s X-37B space plane on its fourth mission, which also is carrying NASA’s Materials Exposure and Technology Innovation in Space (METIS) investigation that will expose about 100 different materials samples to the space environment for more than 200 days.
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LightSail team members Alex Diaz and Riki Munakata prepare the spacecraft for a sail deployment test.
Credits: The Planetary Society
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The Planetary Society’s LightSail satellite is a technology demonstration for using solar propulsion on CubeSats, a class of research spacecraft called nanosatellites. Using the momentum transferred from solar photons as they strike a large, thin, reflective sail would allow a spacecraft to accelerate continuously using only the sun’s energy. NASA is considering the use of solar sails on future exploration mission secondary payloads, and data from this mission will advance understanding of this form of propulsion.
This first LightSail mission specifically is designed to test the spacecraft’s critical systems, including the deployment sequence for the Mylar solar sail, which measures 32 square meters (344 square feet). The Planetary Society is planning a second, full solar sailing demonstration flight for 2016.
NASA selected LightSail as part of the agency’s CubeSat Launch Initiative, which provides opportunities for small satellites to fly as auxiliary payloads on planned missions. It was assigned to a launch as part of as the 11th installment of the Educational Launch of Nanosatellite (ELaNa) mission.
The upper stage of the Atlas V included the National Reconnaissance Office’s third auxiliary mission to launch CubeSats. The Ultra Lightweight Technology and Research Auxiliary Satellite (ULTRASat) carried 10 CubeSats -- including LightSail -- from five organizations. It was made possible through agreements between NASA, the Air Force’s Space and Missile Systems Center and the National Reconnaissance Office to work together on CubeSat integration and launch opportunities.
The cube-shaped satellites measure about four inches on each side, have a volume of about one quart and weigh less than three pounds each. LightSail consists of three CubeSats bundled together. Individual CubeSat research projects may address science, exploration, technology development or education. During the next month, the LightSail team will receive data from the satellite in space. As part of its agreement with NASA, the Planetary Society will provide the agency a report on outcomes and scientific findings.
Since its inception in 2010, the CubeSat Launch Initiative has selected 110 CubeSats primarily from educational and government institutions around the United States. NASA will announce the next call for proposals in August 2015.
Quelle: NASA
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Update: 21.00 MESZ
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LightSail Sends First Data Back to Earth
Topics: pretty pictures, mission status, LightSail
The Planetary Society’s LightSail spacecraft is sending home telemetry data following a Wednesday commute to orbit aboard a United Launch Alliance Atlas V rocket. Deployment from the Centaur upper stage occurred at 1:05 p.m. EDT (17:05 p.m. UTC), and LightSail crossed into range of its Cal Poly San Luis Obispo ground station at 2:20 p.m. EDT (18:20 UTC). With the LightSail team on console, The Planetary Society staff gathered in Cocoa Beach, Florida to listen in as the first signals were received from space.
Shortly after the ground pass began, Cal Poly detected LightSail’s automated radio chirps. 
Quelle: The Planetary Society
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Update: 31.05.2015
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'It's Alive!' LightSail Solar Sail Reboots Itself After Orbital Glitch
After eight days of uneasy silence, the LightSail solar sail experiment rebooted itself to recover from a software glitch in orbit, the Planetary Society said Saturday.
"Our LightSail called home!" Bill Nye the Science Guy, who's the nonprofit society's CEO, reported in a news release emailed to reporters. "It's alive!"
The LightSail nanosatellite is about the size of a loaf of bread, but there's a 344-square-foot sail of ultra-thin reflective plastic folded inside. It was launched on May 20 as one of the secondary payloads accompanying the U.S. Air Force's X-37B space plane into orbit. Just a couple of days after launch, the spacecraft stopped transmitting data. Mission managers figured out that a software glitch had filled its onboard memory with needless information, causing a computer crash.
Engineers had to wait for the automatic reboot, which may have been triggered by a stray cosmic ray.
"We were ready for three more weeks of anxiety," Nye said. "In this meantime, the team has coded a software patch ready to upload. After we are confident in the data packets regarding our orbit, we will make decisions about uploading the patch and deploying our sails — and we'll make that decision very soon."
Nye said the mission "has been a roller coaster for us down here on Earth, all the while our capable little spacecraft has been on orbit going about its business."
The primary goal of this test flight is to practice the sail deployment procedure. A higher-altitude LightSail test, scheduled for next year, will provide an opportunity to steer a spacecraft by reflecting photons of light from the sun at various angles.
The technology was tested previously by Japan's Ikaros solar sail in 2010 and NASA's Nanosail-D spacecraft in 2011. The Planetary Society hopes that its LightSail project will lead to even more ambitious sun-powered space voyages. Eventually, solar sails could conceivably be used to propel spacecraft to the outer reaches of the solar system and beyond.
Quelle: NBC-News
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Update: 11.06.2015
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LightSail Spacecraft Snaps Solar Sail Selfie in Space (Photo)

The Planetary Society’s LightSail cubesat captured this image of its deployed solar sails in Earth orbit on June 8, 2015.
Credit: The Planetary Society
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The Planetary Society's tiny LightSail spacecraft has sent a photo of its deployed solar sail down to Earth, confirming that the cubesat's shakeout flight has been a complete success.
The outlook wasn't always sunny for LightSail solar sail. The cubesat — whose mission is funded by members and supporters of The Planetary Society, a California-based nonprofit — overcame two troubling orbital incidents before unfurling its sail on Sunday (June 7).
"I'm very proud to say that our LightSail test mission was a success," Planetary Society CEO and former TV "Science Guy" Bill Nye said in a statement today (June 10). "We saw again that space is hard. It's a test flight, and sure enough, our little spacecraft tested us."
LightSail launched to low Earth orbit May 20 aboard the same rocket that lofted the U.S. Air Force's robotic X-37B space plane on its fourth mystery mission. The cubesat was tasked with proving the viability of some key components of solar-sailing technology, which allows spacecraft to harness the momentum imparted by photons streaming from the sun.
"Solar sailing is worth doing, because it has the potential to democratize space," Nye said during a news conference today.
"It will allow small organizations — or organizations that don't want to allocate too much money to a space mission — to build a small solar sail, deploy it the way we deployed ours and go to almost any destination in the solar system," Nye added. "If you have time, you can get there, because you never run out of fuel. The sun shines all the time."
On this first flight, mission managers wanted to see how LightSail's core systems work — especially the gear designed to deploy its 344-square-foot (32 square meters) solar sail. The overall goal was to pave the way for a true orbital solar-sailing trial by another LightSail cubesat, which is due to launch next year.
But LightSail went dark on May 22, felled by a software glitch. The spacecraft didn't communicate with Earth again until a week later, when it was apparently rebooted after a fast-moving charged particle struck its electronics board.
The drama wasn't over, however. LightSail went silent again on June 3, shortly after deploying its solar panels. This maneuver resulted in a voltage bump that caused the spacecraft's batteries to go offline, mission team members said.
"It took about two or three days for the battery system to juggle the new power levels and go through all the eclipses and sunlight periods and eventually stabilize," said Rex Ridenoure, CEO and president of California-based Ecliptic Enterprises Corp., LightSail's integrating contractor for testing and flight readiness.
"Eventually, they did stabilize, and everything was working great," Ridenoure said of the batteries. "All that perturbation really caused some concern, but it really wasn't an anomaly; it was as designed, and it looks like it's working well now."
LightSail bounced back Friday (June 5), and the spacecraft's handlers soon commanded it to unfurl its sail. The first few attempts failed, but LightSail finally complied on Sunday. Then, on Tuesday (June 9), mission team members received the final pieces of an image taken by LightSail that confirmed the successful sail deployment.
"That was quite a thrill," said LightSail project manager Doug Stetson. "This has really been a roller-coaster ride of emotions — a lot of sleepless nights for the operations and engineering team."
LightSail's days in space are numbered; it launched to a relatively low orbit, and atmospheric drag is already pulling the cubesat down. The spacecraft will probably burn up in Earth's atmosphere on Saturday or Sunday (June 13 or June 14), Stetson said.
Skywatchers may be able to catch a glimpse of LightSail before this happens; The Planetary Society provides viewing tips here.
LightSail is not the first craft to deploy a solar sail away from Earth; Japan's Ikaros probe unfurled a much larger sail in deep space in 2010, and NASA's NanoSail-D cubesat deployed one in Earth orbit in January 2011. Such missions are helping lay the foundation for greater leaps to come, Nye said.
"Right now, there really isn't much of a limit on what you can do in the solar system" with solar sails, he said. "This LightSail test flight is the first small step on that long journey."
Quelle: SC
 

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