Europe's Comet-Chasing Spacecraft Gets Big Wake-Up Call Monday

[Steve williams]

by Mike Wall, Senior Writer | SPACE.com

A European spacecraft will emerge from 2.5-year hibernation Monday (Jan. 20) to begin preparing for a long-awaited encounter with a comet in May.
The European Space Agency's Rosetta probe is scheduled to wake up at 5 a.m. EST (1000 GMT) Monday after sleeping in deep space for the past 957 days. The first signal from a newly alert Rosetta is expected to arrive here on Earth no earlier than 12:30 p.m. EST (1730 GMT) Monday, ESA officials said.

The Rosetta spacecraft blasted off in March 2004 on a mission to chase down and rendezvous with Comet 67P/Churyumov-Gerasimenko more than a decade later.
To date, the probe has completed four speed-boosting planetary flybys — three of Earth and one of Mars — on its circuitous journey to the comet, which measures about 2.4 miles (4 kilometers) across. Rosetta also zoomed past and imaged two asteroids (2867 Steins in September 2008 and 21 Lutetia in July 2010) before entering hibernation mode in June 2011.

Monday's wakeup initiates the final leg of Rosetta's long trek. The probe will meet up with 67P/Churyumov-Gerasimenko in May, just inside the orbit of Jupiter, and study the comet as it gets closer and closer to the sun.
But that's not all. In November 2014, the Rosetta mission will drop a 220-lb (100 kilograms) lander called Philae onto the surface of 67P/Churyumov-Gerasimenko to get an up-close look at the composition and structure of the comet's nucleus. Philae will drill more than 8 inches (20 centimeters) into the comet, collecting samples for analysis by the lander's onboard laboratory.

The groundbreaking Rosetta mission should reveal new insights about comets and the solar system's early days, ESA officials say.
"Comets are considered the primitive building blocks of the solar system, and likely helped 'seed' the Earth with water, and maybe even life. By studying the nature of the comet’s dust and gas, Rosetta will help scientists learn more about the role of comets in the evolution of the solar system," ESA officials write in a Rosetta mission description.

"Rosetta will be the first mission ever to orbit a comet’s nucleus and land a probe on its surface," they add. "It will also be the first spacecraft to fly alongside a comet as it heads towards the inner solar system, watching how a frozen comet is transformed by the warmth of the sun."
The main Rosetta spacecraft and the Philae lander will continue studying the comet until December 2015, when the mission is slated to end.

 

[MadFloyd]

Wow, that's pretty fascinating.

 

[treitz3]

Let's hope there are no glitches with waking up and initiating systems again. We'll find out on Monday whether or not systems are a go. Thanks for sharing, Steve.

Tom

 

[Steve williams]

Comet-chasing probe wakes up, signals Earth

By FRANK JORDANS | Associated Press

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."
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.

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.

 

[MadFloyd]

It still boggles my mind that we can actually communicate with anything that far away.