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WORLD> Europe
Billion-dollar European probe set for asteroid encounter
(Agencies)
Updated: 2008-09-05 09:25

At the closest point, expected at 1858 GMT on Friday, the craft will flash past Steins at a distance of 800 kms (500 miles) and with a speed of 8.6 kms (5.2 miles) per second, or 30,720 kph (19,200 mph).

Rosetta is due to carry out a second asteroid flyby, skimming past a 100-km (62-mile) behemoth called 21 Lutetia in July 2010.

Costing a billion euros (US$1.45 billion), Rosetta is the most ambitious mission ever undertaken by ESA.

The project was approved in 1993 and launched in 2004 from ESA's base at Kourou, French Guiana.

Since then, the spacecraft has looped twice around the Earth and once around Mars, using planetary gravity as a slingshot to help it build up speed.

A third gravitational "assist" by Earth is due in November 2009.

If all goes well, Rosetta will meet up with Churyumov-Gerasimenko in May 2014 and then send down a lander, known as Philae, that will anchor to the comet's surface and analyse samples in a tiny onboard lab.

Friday's flyby of asteroid Steins coincides by accident with another big date for ESA, when its truck-sized robot freighter, Jules Verne, is scheduled to detach from the orbital International Space Station (ISS) after a five-month maiden mission.

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