Chandryaan-I, India’s first unmanned moon probe has successfully entered moon’s orbit today. Chandrayaan-I, which was launched on 22 November 2008 has completed one of the most difficult steps called “Lunar Orbit Insertion” or LOI to enter the moon’s gravitational field. LOI started at around 1700 HRS (IST). Earlier, the spacecraft completed five orbit raising manouevres to raise the apogee (farthest point of the orbit) to about 3,80,000 kms.

“The liquid apogee motor on board the spacecraft was fired for about 805 seconds to put Chandrayaan-1 into an elliptical orbit with 7,500 km aposelene (farthest from moon) and 500 km pericelene (nearest to moon),” ISRO director S. Satish told IANS.

This step is very critical in any mission. Nearly 30% of US and USSR’s mission have failed at this very step i.e. LOI, and ISRO has achieved this without any glitch. With that India’s first lunar mission has also been declared successful.

The probe which is travelling around moon at an height of 500 kms will have its orbit gradually lowered to 100 kms in the coming 2-4 days and then ISRO will attempt to send the “impactor probe” to the moon to place Indian flag on its surface.