Comet-chasing probe Rosetta wakes up, signals Earth

[Buster's Uncle]

Comet-chasing probe wakes up, signals Earth
Associated Press
By FRANK JORDANS  2 hours ago



FILE - This undated image provided by the European Space Agency ESA shows an artist's impression of the Philae lander. Scientists at the European Space Agency are expecting their comet-chasing probe Rosetta to wake from almost three years of hibernation at 11 a.m. Monday Jan. 20, 2014 (1000 GMT; 5 a.m. EST) and phone home to say all is well. (AP Photo/ESA ATG medialab , Astrium E, Viktor, File)



BERLIN (AP) — Waking up after almost three years of hibernation, a comet-chasing spacecraft sent its first signal back to Earth on Monday, prompting cheers from scientists who hope to use it to land the first space lander onto a comet.

The European Space Agency received the all-clear message from its Rosetta spacecraft at 7:18 p.m. (1818 GMT; 1:18 p.m. EST) — a message that had to travel some 800 million kilometers (500 million miles).

In keeping with the agency's effort to turn the tense wait for a signal into a social media event, the probe triggered a series of "Hello World!" tweets in different languages.

Dormant systems on the unmanned spacecraft were switched back on in preparation for the final stage of its decade-long mission to rendezvous with the comet named 67P/Churyumov-Gerasimenko. Systems had been powered down in 2011 to conserve energy, leaving scientists in the dark about the probe's fate until now.

Because of the time it took Rosetta to wake up, and the long distance between the spacecraft and Earth, the earliest possible hour for a signal to arrive was 6:30 p.m.

"I think it's been the longest hour of my life," said Andrea Accomazzo, the spacecraft's operations manager at ESA's mission control room in Darmstadt, Germany. "Now we have it back."



FILE - This image provided by the European Space Agency ESA shows an artist’s impression of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko. The image is not to scale; the Rosetta spacecraft measures 32 m across including the solar arrays, while the comet nucleus is thought to be about 4 km wide. Scientists at the European Space Agency are expecting their comet-chasing probe Rosetta to wake from almost three years of hibernation at 11 a.m. Monday Jan. 20, 2014 (1000 GMT; 5 a.m. EST) and phone home to say all is well. (AP Photo/ESA, C.Carreau, File)


Scientists will now take control of Rosetta again, a procedure slowed by the 45 minutes it takes a signal to travel to or from the spacecraft, he said.

The wake-up call is one of the final milestones for Rosetta before it makes its rendezvous with comet 67P in the summer. The probe will then fly a series of complicated maneuvers to observe the comet — a lump of rock and ice about four kilometers (2.5 miles) in diameter — before dropping a lander called Philae onto its icy surface in November.

The lander will dig up samples and analyze them with its instruments.

Although the spacecraft was launched almost a decade ago, the instruments aboard Rosetta and the Philae lander are still considered cutting edge, said Joel Parker of the Southwest Research Institute in Boulder, Colorado. The institute developed a specialized camera called ALICE that can detect different chemicals in the comet.

Rosetta is named after a block of stone that allowed archeologists to decipher ancient Egyptian hieroglyphs. Scientists hope the space mission will help them understand the composition of comets and thereby discover more about the origins and evolution of our solar system.



FILE - In this photo provided by the European Space Agency, ESA, Monday Jan. 20, 2014 technicians celebrate after receiving the Rosetta wake up signal in the control room of ESA in Darmstadt, Germany. Waking up after almost three years of hibernation, a comet-chasing spacecraft sent its first signal back to Earth on Monday, prompting cheers from scientists who hope to use it to achieve the first landing on a comet.The European Space Agency received the all-clear message from its Rosetta spacecraft at 7:18 p.m. (1818 GMT; 1:18 p.m. EST) _ a message that had to travel some 800 million kilometers (500 million miles). (AP Photo/ESA, Juergen Mai, File)


Comets are regarded as flying time capsules because they are essentially unchanged for the last 4.6 billion years. Scientists have speculated that comets may be responsible for the water found on some planets. And like asteroids, comets also pose a theoretical threat to life on Earth.

"Over the millennia, comets have actually affected our evolution," said Paolo Ferri, head of mission operations at the European Space Agency. "There are many theories about comets hitting the Earth and causing global catastrophes. So understanding comets is also important to see in the future what could be done to defend the Earth from comets."

The mission is different from NASA's Deep Impact, a spacecraft that fired a projectile into a comet in 2005 so scientists could study the resulting plume of matter. NASA also managed to land a probe on an asteroid in 2001, but comets are much more volatile places because they constantly release dust and gas that can harm a spacecraft.

NASA is planning another space rock mission between 2019 and 2021. The agency is looking into sending a robotic spaceship to lasso a small asteroid and haul it close to the moon, where spacewalking astronauts would explore it.

____

http://www.esa.int/rosetta

https://www.twitter.com/ESA_Rosetta



A scientist of European space agency ESA stands at an airworthy copy of space probe 'Rosetta' in the ESA control center in Darmstadt, Germany, Monday, Jan. 20, 2014. Scientists at the European Space Agency are expecting their comet-chasing probe Rosetta to wake from almost three years of hibernation at 11 a.m. Monday Jan. 20, 2014 (1000 GMT; 5 a.m. EST) and phone home to say all is well. The scientists are facing an agonizing wait of several hours until the first signal reaches Earth. (AP Photo/dpa, Daniel Reinhardt)



A scientist of European space agency ESA stands at an airworthy copy of space probe 'Rosetta' in the ESA control center in Darmstadt, Germany, Monday, Jan. 20, 2014. Scientists at the European Space Agency are expecting their comet-chasing probe Rosetta to wake from almost three years of hibernation at 11 a.m. Monday Jan. 20, 2014 (1000 GMT; 5 a.m. EST) and phone home to say all is well. The scientists are facing an agonizing wait of several hours until the first signal reaches Earth. (AP Photo/dpa, Daniel Reinhardt)


http://news.yahoo.com/comet-chasing-probe-wakes-signals-earth-202352375.html

[Buster's Uncle]

Rosetta Spacecraft Waking Up for Final Leg of Comet Journey
SPACE.com
by Charles Q. Choi, Astrobiology Magazine Contributor  13 hours ago



An artist's impression of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko



Editor's Note: The comet-chasing Rosetta spacecraft successfully woke up Monday (Jan. 20) for its encounter with Comet 67P/Churyumov–Gerasimenko later this year. Read our full wrap story here: Sleeping Rosetta Spacecraft Wakes Up for Historic Comet Rendezvous and Landing

Rosetta, the first spacecraft built to orbit a comet and land a probe on these icy nomads, is now waking up after more than two years of slumber, and videos filmed as part of an international competition will help greet the spacecraft after it awakens.

Comets are some of the most primitive building blocks of the solar system, with many dating to soon after its formation. Comets also likely helped seed Earth with water and other ingredients of life. By analyzing the composition of the comet, the European Space Agency's Rosetta spacecraft will help scientists learn more about the role comets have played in the evolution of the solar system and life on Earth.

You can watch the Rosetta comet probe wake-up webcast live here, courtesy of the European Space Agency. The webcast began at 4:15 a.m. EST (0915 GMT) and will run through 1:30 p.m. EST (1830 GMT).

TheRosetta spacecraft launched from Europe's spaceport in French Guiana in 2004. It has since traveled around the sun five times, reaching a distance of about 500 million miles (800 million kilometers) away from the sun.

The mission's final destination is the mysterious Comet 67P/Churyumov–Gerasimenko, which Rosetta is scheduled to reach in August. A comet is made of a solid nucleus or core surrounded by a gaseous envelope known as a coma and trailing a large tail. Rosetta will become the first spacecraft to orbit the nucleus of a comet, and in November, it will be the first to land a probe, named Philae, on a comet's surface. It will also be the first mission to escort a comet as it travels around the sun.

For the coldest leg of Rosetta's mission, as it traveled out toward the orbit of Jupiter, the spacecraft was placed into hibernation in order to help it save energy. After 31 months of sleep, researchers are now waking Rosetta up, with its internal alarm clock set for 5 a.m. EST (1000 GMT) on Jan. 20. Once the spacecraft has warmed itself up, it should reestablish communication with Earth several hours later.

To celebrate the spacecraft's waking, ESA initiated the "Wake Up Rosetta" campaign, inviting people worldwide to upload video clips of them shouting "Wake up, Rosetta!" to Rosetta's Facebook page. As of Jan. 15, there were more than 70 entries.

"Some are cute, some are short, some are long. All are entertaining," said Daniel Scuka, who works on the social media team of ESA's European Space Operations Center at Darmstadt, Germany. "We are really impressed and pleasantly surprised with the creativity and effort that we've seen. Several submissions include full costumes and scenes with singing and dancing, and folks are ensuring their dogs, cats and kids are well-represented."

Videos have not only been submitted by individuals, but also families, schools and groups of friends. A number of videos have been stop-motion or full-digital animations. Submissions have been received from around the world. A number of astronauts have sent videos as well.

One submission even came from NASA's Jet Propulsion Laboratory to promote the contest to U.S. audiences, Scuka said.

"We're quite pleased to see the inter-agency cooperation — this highlights the fact that Rosetta really is a cooperative mission that would not be as successful if it were just ESA alone," said ESA spokesman Markus Bauer.

Visitors to Rosetta's Facebook page can vote on their favorite videos. The top 10 videos will be transmitted from Earth into space with 20,000 watts of power in February via one of ESA's deep-space tracking stations, and those who made them will receive gift bags. Two winning entries will also be invited to ESA's control center in Darmstadt, Germany for an event celebrating the first landing on a comet.

Although Rosetta will not rendezvous with the comet until August, the spacecraft is set to wake up on January to give researchers enough time to completely test the spacecraft and make it ready for arrival.

"There is a lot to prepare for rendezvousing and landing on the comet," said ESA cometary scientist Gerhard Schwehm. "First we have to switch on and check that all 11 instrument packages on the orbiter and 10 on lander are working. Then we need time to track the comet so we can prepare our rendezvous maneuvers."

The researchers also want to study the comet as Rosetta approaches it in case certain parts of the comet are active. When a comet orbits near the sun, it gives off fountains of gas that could be obstacles for Rosetta or its probe Philae.

"We'd want to avoid getting too close to those!" Schwehm said. "Choosing a landing site for Philae will also take careful consideration, and then we have to finalize the commands to deliver the lander to the surface based on that selection. We certainly have plenty to do before we arrive at the comet in August."

During Rosetta's 31 months of hibernation, most of the spacecraft's systems were shut down, except for the onboard "alarm clock" and several heaters set to periodically turn on and off to make sure Rosetta did not freeze up completely. When the probe wakes up, it will switch on its star trackers to determine its orientation and eventually point at Earth, transmitting a signal to let the world know that it has reawakened, said Rosetta spacecraft operations manager Andrea Accomazzo.

The Wake Up Rosetta competition will accept entries until 5:30 p.m. Greenwich Mean Time on January 20, and the winners will be announced on January 24. The contest is open to all, but prizes can only be won by citizens and permanent members of European Union countries, the United States, and ESA member and cooperating states.

ESA also invites people to join the Wake Up Rosetta campaign via Twitter and shout #WakeUpRosetta at @ESA_Rosetta. The agency especially wants to see shouts on Jan. 20, between 10 a.m. and 5:30 p.m. Greenwich Mean Time.


http://news.yahoo.com/rosetta-spacecraft-waking-final-leg-comet-journey-102229296.html

[Buster's Uncle]

Rosetta Satellite Wakes Up To Catch a Comet
By ABC News
2 hours ago






ABC News' Gina Sunseri reports:

How to catch a comet: First, set your alarm clock to wake up after a two-and-a-half year nap, then reboot your computer and check your odometer. You are now 500 million miles from where you started.

Rosetta is the European Space Agency's daring mission to catch up to comet 67P Churyumov-Gerasimenko after 10 years of hurtling through space (including the two-and-a-half year nap) to rendezvous with a comet speeding through space at 24,600 mph. Scientists put Rosetta into a planned hibernation 957 days ago to save resources so the spacecraft-probe would have enough power to complete its mission, leaving just a computer and a few heaters to keep it warm.

Rosetta @ESA_Rosetta has been auto-tweeting "still sleeping" for its 5,000 followers for the past two-and-a-half years.

In order to wake up the dormant satellite, ESA's Mission Control sent a very special wake-up song to Rosetta .

Jet Propulsion Laboratory scientist Claudia Alexander explained to ABC News what the satellite does following the signal: "When Rosetta wakes up, it will take a look around, we will be recommissioning the spacecraft, which is like rebooting your computer. It takes a while to spin and come up to speed again, weeks actually, while we are double-checking each instrument."

Rosetta launched March 4, 2004, using the gravitational pull of Earth and Mars as a slingshot to get into the proper comet-chasing orbit.

When it gets close in June, it will prepare to launch a probe named Philae to land on the comet, where it will drill into the icy surface and send back unprecedented data and photos.

Rosetta will release the impact probe Philae on July 3 but we won't know until July 4 when NASA's JPL will confirm impact and send back the first images from the probe if it is successful.

This is the first time any space-faring nation will land on a comet, and Alexander said she is excited about what we will learn. "To hang out in the neighborhood of a comet as it orbits will change what we know about comets," she said.


http://news.yahoo.com/blogs/abc-blogs/wake-rosetta-catch-comet-212010800--abc-news-topstories.html

[Buster's Uncle]

Sleeping Rosetta Spacecraft Wakes Up for Historic Comet Rendezvous and Landing
SPACE.com
by Mike Wall, Senior Writer  5 hours ago



An artist's impression of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko



A European probe awoke from a deep sleep Monday (Jan. 20) to gear up for an unprecedented comet rendezvous and landing this year that will cap a 10-year voyage across the solar system.

After two and a half years in hibernation, the European Space Agency's Rosetta spacecraft emerged from its slumber while cruising nearly 418 million miles (673 million kilometers) from the sun. The wakeup call, which was due to begin at 5 a.m. EST (1000 GMT), took hours as Rosetta switched on heaters to warm itself after its long night in the cold depths of space.

"We made it!" Andrea Accomazzo, Rosetta's spacecraft operations manager, shouted in exultation in a webcast. "We can definitely see a signal from Rosetta!"


Wake up, Rosetta!

The first signal from Rosetta was received by NASA's Deep Space Network at 1:18 p.m. EST (1818 GMT) and relayed to ESA's Space Operations Center in Darmstadt, Germany, which erupted in cheers and applause as the signal was confirmed.



Rosetta mission scientists cheer as the comet-chasing probe's first signal after awaking


Rosetta's first message home via Twitter: "Hello, world!"

The signal came after 18 minutes of tense silence as Rosetta's mission team awaited word from the spacecraft.

"We have our comet-chaser back," said Alvaro Giménez, ESA's Director of Science and Robotic Exploration, in a statement. "With Rosetta, we will take comet exploration to a new level."

Rosetta's wakeup process took several hours as the spacecraft activated heaters and beamed a message back home. The solar-powered spacecraft had slept since mid-2011, when it sailed out near the orbit of Jupiter — 501 million miles (800 million km) from Earth — where there was not enough sunlight to power its systems. Monday's wakeup success sets the stage for what promises to be a historic spaceflight event.

"This was one alarm clock not to hit snooze on, and after a tense day we are absolutely delighted to have our spacecraft awake and back online," Rosetta mission manager Fred Jansen said in a statement. ESA officials also held a public "Wake Up, Rosetta!" video contest to encourage the public to get involved with the mission.



The wake-up signal from the European Space Agency's Rosetta spacecraft can be seen in this photo


Once Rosetta shakes the sleep out of its eyes, the solar-powered spacecraft will begin final preparations to rendezvous with its target — Comet 67P/Churyumov-Gerasimenko — in May, and then enter orbit around the icy body in August. If all goes well, Rosetta will release a piggyback probe toland on the comet in November.

"We shall be on and around the comet to see how it is 'living' for more than one year, " ESA Director General Jean-Jacques Dordain said during a live webcast Monday. "It's risky, because nobody has done that before, but this is the price to pay to learn about the origin of the solar system and perhaps more of the origin of life."


Landing on a comet

From orbit, Rosetta will start scouting out potential places on 67P/Churyumov-Gerasimenko's surface to deliver a 220-lb (100 kilograms) lander named Philae. A final site is expected to be chosen in October, and the touchdown will follow a month later, ESA officials say.

When the time comes, Philae will be ejected from the Rosetta mothership and spiral down toward the 2.4-mile-wide (3.9 km) comet's core. When it reaches the surface, Philae will fire a harpoon to anchor itself and counter the rebounding force of its touchdown.



This image shows the 4-kilometer wide Comet 67P/Churyumov–Gerasimenko - the target of the Rosetta


No probe has ever landed on a comet before, so success is far from assured. But if all goes well, Philae will study 67P/Churyumov-Gerasimenko up close with its 10 science instruments, using a drill to snag samples up to 8 inches (20 centimeters) beneath the comet's surface.

"All other comet missions have been flybys, capturing fleeting moments in the life of these icy treasure chests," said Matt Taylor, ESA's Rosetta project scientist. “With Rosetta, we will track the evolution of a comet on a daily basis and for over a year, giving us a unique insight into a comet’s behavior and ultimately helping us to decipher their role in the formation of the solar system."


A comet, up close and personal

Philae should also return some otherworldly views of Comet 67P/Churyumov-Gerasimenko, which is currently in a sun-approaching phase of its 6.45-year-long orbit, researchers said.

"On the lander, there's a camera that can look straight down like you’re standing up and looking at the ground. Then there's a panoramic camera that can look out and see a picture of the horizon," mission co-investigator Michael Combi of the University of Michigan said in a statement. "It’ll be fun to see what this landscape looks like. It’ll be like standing on a comet."

Meanwhile, the Rosetta orbiter will be studying the comet from above with its 11 science instruments. The orbiter and lander will continue their observations through December 2015, yielding a detailed look at 67P/Churyumov-Gerasimenko's structure and composition, and how the icy object changes as it moves around the sun. NASA has contributed three of the science instruments riding on Rosetta, as well as components of others, with several U.S. researchers participating on the mission's science team.

"We are going to be in the cometary catbird seat on this one," NASA's Rosetta project scientist Claudia Alexander at the agency's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. "To have an extended presence in the neighborhood of a comet as it goes through so many changes should change our perspective on what it is to be a comet."

Currently, Rosetta is about 5.6 million miles (9 million km) from Comet 67P/Churyumov-Gerasimenko. By May, it should have closed that gap to about 1.2 million miles (2 million km), ESA officials have said.

Rosetta's journey to 67P/Churyumov-Gerasimenko has been long and circuitous. The spacecraft blasted off in March 2004 and has completed four speed-boosting planetary flybys, three of Earth and one of Mars.

Rosetta also flew by and imaged two asteroids — 2867 Steins in September 2008 and 21 Lutetia in July 2010 — before entering hibernation mode in June 2011, when it neared the orbit of Jupiter, the coldest and most distant part of its path around the sun.


http://news.yahoo.com/sleeping-rosetta-spacecraft-wakes-historic-comet-rendezvous-landing-192224888.html

[Buster's Uncle]

'Sleeping beauty' comet probe awakens from slumber
AFP
2 hours ago



A file handout picture released by the European Space Agency (ESA) shows an artist's impression of the ESA probe Rosetta with Mars in the background



Paris (AFP) - The European probe Rosetta woke up Monday after a 31-month hibernation in a nearly decade-old quest to explore a comet, the European Space Agency (ESA) announced.

"Hello, world!" ESA said on Twitter, mimicking the signal sent back from deep space by the billion-dollar unmanned craft.

The agency described Rosetta as a "sleeping beauty" that had emerged from a long sleep.

"It was a fairy-tale ending to a tense chapter," it said.

Europe's most ambitious space mission, the craft was launched in 2004 on a trek of seven billion kilometres (4.3 billion miles) around the inner Solar System.

Its goal is to meet up in August with a comet, 67P/Churyumov-Gerasimenko, and in November send down a lander to carry out experiments on the icy wanderer.

Comets are clusters of ice and dust which are believed to be remnants from the very birth of our star system.

Analysing this primeval stuff should unlock secrets of how the Solar System formed -- and possibly how life on Earth was kickstarted.

Rosetta was placed in hibernation in June 2011 as it was so far from the Sun that light was too dim to power its solar array.



Graphic fact file on the European probe Rosetta and its mission (AFP Photo/)


Scientists on Monday had to wait more than eight hours before getting the precious signal, sent home from a distance of more than 800 million km (500 million miles), to confirm that it had woken up.

Nerves were strained at mission control in Darmstadt, Germany, until the all-is-well message showed up as a spike in a radio wave, prompting cheers and backslapping.

“This was one alarm clock not to hit snooze on, and after a tense day we are absolutely delighted to have our spacecraft awake and back online,” said Fred Jansen, ESA’s Rosetta mission manager.


Unprecedented mission

After further health tests, Rosetta will progressively carry out braking and steering manoeuvres designed to get it on track with Comet "C-G."

In August, the craft will be inserted into an orbit just 25 kilometres (15 miles) above the comet, using 11 cameras, radar, microwave, infrared and other sensors to scan its surface.

The craft carries a 100-kilo (220-pound) fridge-sized robot laboratory, Philae, designed to harpoon itself to the "dirty snowball" surface and carry out experiments, riding piggyback as the comet loops around the Sun.

The comet will be at its closest to the Sun on August 13, 2015, at about 185 million kms (115 million miles).

Over the last quarter-century, 11 unmanned spacecraft have been sent on missions to comets, most of them flybys.

Successes include the US Stardust probe, which brought home dusty grains snatched from a comet's wake, and Europe's Giotto, which ventured to within 200 km (120 miles) of a comet's surface.

But if Rosetta succeeds, it would outshine them all in terms of its sampling size, proximity and duration.

“All other comet missions have been flybys, capturing fleeting moments in the life of these icy treasure chests,” said project scientist Matt Taylor.

"With Rosetta, we will track the evolution of a comet on a daily basis and for over a year, giving us a unique insight into a comet’s behaviour and ultimately helping us to decipher their role in the formation of the Solar System.”

Alvaro Gimenez Canete, ESA's director of science and robotic exploration, referred to the carved stone that in the early 19th century unlocked Egyptian hieroglyphics and revealed the life of the Pharaohs.

"Rosetta and the comet 67/P may become the Rosetta Stone for planetary science," he said.

Thomas Reiter, ESA's director of human spaceflight and operations, described the Rosetta venture as "one of the superlatives".

"It's truly unique and in William Shakespeare's words, 'stuff dreams are made of.'"


http://news.yahoo.com/alarm-call-set-wake-comet-probe-114645648.html

[Buster's Uncle]

Scientists hope comet-chaser spacecraft wakes up
Associated Press
By FRANK JORDANS  13 hours ago



FILE - This image provided by the European Space Agency ESA shows an artist’s impression of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko. The image is not to scale; the Rosetta spacecraft measures 32 m across including the solar arrays, while the comet nucleus is thought to be about 4 km wide. Scientists at the European Space Agency are expecting their comet-chasing probe Rosetta to wake from almost three years of hibernation at 11 a.m. Monday Jan. 20, 2014 (1000 GMT; 5 a.m. EST) and phone home to say all is well. (AP Photo/ESA, C.Carreau, File)



BERLIN (AP) — Europe's Rosetta probe is due to wake up from years of hibernation Monday, but scientists face an agonizing wait of several hours until the first signal reaches Earth and they can celebrate a new milestone in their unprecedented mission to land a spacecraft on a comet.

Dormant systems on the unmanned spacecraft were scheduled to switch back on at 11 a.m. (1000 GMT; 5 a.m. EST) in preparation for the final stage of its decade-long mission to rendezvous with comet 67P/Churyumov-Gerasimenko. They had been powered down in 2011 to conserve energy, leaving scientists in the dark about the probe's fate until now.

"We don't know the status of the spacecraft," said Paolo Ferri, head of mission operations at the European Space Agency. "There is a possibility that we're not going to hear anything. Two-and-a-half years are a long time. We're talking about sophisticated electronics and mechanics. We've taken all possible precautions for this not to happen but of course we cannot exclude that problems may have happened."

Scientists will bridge the time between Rosetta's alarm going off and the first signal traveling the 800 million kilometers (500 million miles) back to Earth by holding a social media competition. Space enthusiasts are being asked to compose and perform songs to "wake up Rosetta," with the top entries being beamed to the spacecraft and the winner invited to witness the landing from ESA's mission control room.

The agency says the earliest it might receive the probe's all-clear call is about 6.30 p.m. (1730 GMT; 12:30 p.m. EST). If no signal is received by Tuesday, scientists will try to manually restart the probe from the ground.

Rosetta is named after a block of stone that allowed archeologists to decipher ancient Egyptian hieroglyphs. Scientists hope the probe's findings will help them understand the composition of comets and thereby discover more about the origins and evolution of our solar system.





Comets are regarded as flying time capsules because they are essentially unchanged for 4.6 billion years. Scientists have speculated that comets — which are essentially giant, dirty snowballs — may be responsible for the water found on some planets. And like asteroids, comets also pose a theoretical threat to life on Earth.

"Over the millennia comets have actually affected our evolution," said Ferri. "There are many theories about comets hitting the Earth and causing global catastrophes. So understanding comets is also important to see in the future what could be done to defend the Earth from comets."

If all goes as planned, Rosetta will reach 67P in the coming months and fly a series of complicated maneuvers to observe the comet — a lump of rock and ice about four kilometers (2.5 miles) in diameter — before dropping a lander onto its icy surface in November.

The Philae lander will dig up samples and analyze them with its on-board instruments.

The probe and its lander will keep sending back data until their batteries die or the debris streaming off the comet irreparably damages their sensitive instruments.





The mission is different from NASA's Deep Impact probe that fired a projectile into a comet in 2005 so scientists could study the resulting plume of matter. NASA also managed to land a probe on an asteroid in 2001, but comets are much more volatile places because they constantly release dust and gas that can harm a spacecraft.

NASA is planning another space rock mission between 2019 and 2021. The agency is looking into sending a robotic spaceship to lasso a small asteroid and haul it close to the moon, where spacewalking astronauts would explore it.

____

http://www.esa.int/rosetta

https://www.facebook.com/RosettaMission


http://news.yahoo.com/scientists-hope-comet-chaser-spacecraft-wakes-052207567.html

[Buster's Uncle]

Comet-Chasing Spacecraft Sends First Signal in 31 Months
By Alex Morales  Jan 20, 2014 1:55 PM ET



Rosetta is box-shaped with a pair of 14-meter solar panels, giving it a total span of 32 meters (105 feet).   Source: ESA/AFP via Getty Images



The comet-chasing Rosetta spacecraft sent its first signal back to Earth after a 31-month hibernation on its decade-long mission into deep space.

Scientists at the European Space Agency’s mission control in Darmstadt, Germany, jumped up and cheered when the signal registered at about 7:20 p.m. local time, according to a webcast of the proceedings. It came during the agency’s predicted 1-hour window and more than 8 hours after the craft’s alarm clock woke it up from a hibernation period far in space.

“We made it!” Rosetta Spacecraft Operations Manager Andrea Accomazzo said on the webcast. “The signal from Rosetta is up there, you can see it on the screen. It’s a big success for everybody.”

The Rosetta mission is the first attempt to orbit and land a probe on a comet, and researchers hope to glean more about the role of comets in the evolution of the solar system. Made from dirty ice, dust and gas, they are considered building blocks that likely helped seed Earth with water and possibly even life. Its target is the Churyumov-Gerasimenko comet, which it’s due to reach in August.

After receiving the alarm call, the craft began a 6-hour wakeup procedure that included switching on some heaters to warm the units that control the direction it points, ESA’s head of mission operations, Paolo Ferri, said earlier today in an interview. Then the instruments had to halt the rotation of the craft, point an antenna to Earth and transmit a signal.

NASA’s monitoring station in Goldstone, California, was used to pick up the signal.


Airbus Project

Rosetta’s scientists will now test all of its subsystems and activate each of the craft’s scientific instruments in turn between now and April, according to Ferri. In May, they’ll begin to slow the craft down to a pace of a few meters per second from 1 kilometer per second, he said.

“Then we will be starting the final approach, and in August we can basically say we are in orbit around the comet,” Ferri said. “That’s when we start our phase of detailed characterization of the comet and we take pictures and we measure the gravity potential.”

Astrium, now part of Airbus Defence and Space, was the main contractor for the spacecraft launched on March 2, 2004. After reaching the Churyumov-Gerasimenko comet, Rosetta is then scheduled to orbit until the end of 2015, placing its lander, called Philae, on the icy mass, this November after identifying a suitable site. Rosetta has 11 packages of scientific instruments, and Philae 10.


Two Harpoons

“The mission is staying around the comet, studying it and seeing its evolution as it gets closer to the sun,” said Ferri.

When the lander is in place, it will shoot two harpoons into the comet to anchor it. The main craft will be “flying over the landing site, collecting signals, storing them on board and periodically pointing the antenna to Earth to send them back,” he said.

While Philae would be the first probe to touch down on a comet and beam data back, ESA’s first deep-space mission, Giotto, was sent to investigate Halley’s Comet in 1986. The U.S. National Aeronautics and Space Administration has also launched two missions to study comets in the past 20 years.


NASA’s Work

In 2005, NASA fired a projectile from its Deep Impact spacecraft into the comet Tempel 1. It monitored the ejected material using two instruments on the main craft, and the projectile beamed data back until nearly the point of impact.

In early 2006, the agency’s Stardust spacecraft returned samples to Earth that were collected during a seven-year round trip to the comet Wild 2. The mission had used a tray of silica gel to trap particles flying off the comet.

ESA’s Giotto in 1986 passed near the nucleus of Halley’s comet, capturing images of the nucleus and discovering the first evidence of organic material in a comet. In 1992, the same craft passed near a second comet, Grigg-Skjellerup.

Rosetta is currently about 670 million kilometers (416 million miles) from the sun and more than 800 million kilometers from earth, according to ESA. Its planned hibernation began in June 2011 because it was too far from the sun for its solar panels to generate sufficient energy. Since then, only the computer and some heaters have been active to ensure the craft didn’t freeze.

“For mission control, not having the signal of the spacecraft is the worst thing that you can have,” Ferri said. “When we have a signal, we know what is the status. Even if there are problems with the spacecraft we can intervene. Even though it was planned, 2 1/2 years without contact is very bad.”

Rosetta is box-shaped with a pair of 14-meter solar panels, giving it a total span of 32 meters (105 feet). The craft is named after the Rosetta Stone, a slab of basalt inscribed in different languages that helped historians to decipher Egyptian hieroglyphics.

The Churyumov-Gerasimenko comet orbits the sun every 6.6 years at a distance that ranges from 186 million kilometers to 857 million kilometers. Discovered in 1969, the comet has a nucleus estimated to be four kilometers in diameter. The Paris-based European Space Agency was formed in 1973 and has 20 member countries, including the U.K., Germany and France.


http://www.bloomberg.com/news/2014-01-20/comet-chasing-rosetta-spacecraft-gets-wakeup-call.html?cmpid=yhoo

[Geo]

Must look up what kind of energy source  the probe uses. I assume its still too far out for any significant solar power accumulation.