India's first unmanned spacecraft Chandrayaan-1 entered the lunar orbit on Saturday after Indian Space Research Organisation scientists successfully carried out a highly complex and tricky manoeuvre crossing another historic milestone in the country's space programme.
    
ISRO scientists at the Mission Control Centre near Bengaluru [Images] fired the spacecraft's liquid engine at 1651 hours for a
duration of 817 seconds in a hit or miss Lunar Orbit Insertion operation in the maiden moon mission, 18 days
after it was launched from Sriharikota spaceport.
     
"For the first time in the history of India, an Indian-made satellite is circulating the Moon [Images]", a jubilant ISRO chairman G Madhavan Nair told PTI shortly after the home-grown satellite broke away from the Earth's gravitational field for the first time and reached the moon. India becomes the sixth country to put a satellite in lunar orbit.
      
The engine was fired when the spacecraft passed at a distance of about 500 km from the moon to reduce its velocity
to enable lunar gravity to capture it into an intended orbit around the moon.
      
The spacecraft is now orbiting the moon in an elliptical orbit that passes over the polar regions of the moon. The nearest point of this orbit (perilune) lies at a distance of about 504 kms from the moon's surface, while the farthest poin(apolune) lies at about 7,502 km.
     
A relieved  Nair said today's operation was the "most crucial moment" in the mission."We have done it," he declared.
"For the last 20 minutes, almost all our hearts were at a standstill," Nair said immediately after the the challenging manoeuvre was carried out.

"Nobody else in the world perhaps would have got such a precise lunar orbit as India did in the first attempt," Nair said.