Zee Media Bureau
New Delhi: A probe from one of the most ambitious missions in the history of space will be roused from nearly three years of hibernation to continue its mission of chasing a comet.
"The most important alarm clock in the Solar System" will end the scout Rosetta`s long slumber, gearing it for a historic rendezvous in deep space, the European Space Agency says.
Comets, those clusters of ice and dust believed to be remnants from the very birth of our star system, are one of the least understood nomads of the night sky.
"Unlocking these time capsules, looking at the gas, the dust and particularly the ice they`re made of, provides great clues to the origin of our Solar System and, potentially, even of life," said astrophysicist Mark McCaughrean.
Rosetta was launched in 2004 to keep track of Comet 67P/Churyumov-Gerasimenko as it makes it seven billion kilometres (4.3 billion miles) around the inner Solar System.
"This time capsule has been locked for 4.6 billion years. It`s time to unlock the treasure chest."
Like a game of cosmic billiards, the probe zoomed three times around Earth and once around Mars, using the planets` gravitational pull as a slingshot to gain velocity.
"We had to go around the Sun five times on different orbits to gain speed," said Paolo Ferri, European Space Agency`s head of solar and planetary missions.
By June 2011, the probe reached its intended furthest point from the Sun -- at 800 million km so distant that our star had shrunk to a tepid dot.
While pursuing its path towards the comet, Rosetta at this point closed all its systems for a 31-month energy-saving sleep -- the Sun`s light just too dim to nourish the craft`s two 14-metre (45-feet) solar arrays -- panels so big they could cover a basketball court.
NASA is also a participant in this mission.
"All the instruments aboard Rosetta and the Philae lander are designed to work synergistically," said Sam Gulkis of JPL, the principal investigator for the Microwave Instrument for Rosetta Orbiter. "They will all work together to create the most complete picture of a comet to date, telling us how the comet works, what it is made of, and what it can tell us about the origins of the solar system."
On 20 January, at 1000 GMT, is when its onboard computer is scheduled to end hibernation -- a "wake up, Rosetta!" moment that ESA has turned into a Youtube video competition.
At that point, nerves at mission control in Darmstadt, Germany, will be stretched.
It will take Rosetta nearly six hours to fire up and test all its systems. It is so far away that, provided everything is OK, the "all systems nominal" radio signal will take 45 minutes to reach home.
"The coming months are going to be even more complex," said Ferri.
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.
In November, it will send down a fridge-sized robot laboratory, Philae, designed to harpoon itself to the crumbly comet surface and carry out experiments.
"We want to know everything about the comet -- magnetic field, composition, temperature, everything," said Amalia Ercoli-Finzi, in charge of one of the 10 instruments aboard Philae.
(With Agency inputs)