NASA spacecraft becomes first to enter Mercury orbit

 Washington: A NASA spacecraft, after over six years of space travel, has become the first to enter the orbit of Mercury, the agency said Friday.

The Messenger spacecraft began the orbit insertion manoeuvre at 0045 GMT Friday, RIA Novosti reported.

"NASA's Messenger spacecraft successfully achieved orbit around Mercury. This marks the first time a spacecraft has accomplished this engineering and scientific milestone at our solar system's innermost planet," the NASA website said. It took the spacecraft more than six years to enter the orbit of Mercury, the least explored planet of the solar system.

To reach its destination point, the spacecraft, launched in 2004, covered over 7.8 billion km. It followed a route through the inner solar system, which included one fly-by of Earth, two fly-bys of Venus, and three fly-bys of Mercury.

Engineers will check how the spacecraft's systems are sustaining in Mercury's harsh thermal environment, and equipment will be turned on March 23. The scientific mission will begin April 4.

Mercury is the smallest and the densest planet among the four terrestrial planets, including Venus, Earth and Mars. Before the Messenger mission, only 45 percent of Mercury's surface had been photographed by a spacecraft. The previous mission was Mariner-10, launched in the 1970s.