The Indian Space Research Organisation on Monday said it will fire India’s second mission to the moon Chandrayaan-2’s liquid engine on Tuesday to put the spacecraft in an orbit around the moon, PTI reported.

“It’s tomorrow morning [tentatively between 8.30 am and 9.30 am],” ISRO chairman K Sivan told the news agency. “It’s challenging,” he added.

ISRO said this operation will be followed by four orbit manoeuvres to make the spacecraft enter into its final orbit passing over the lunar poles, at a distance of about 100 km from moon’s surface. The lander, called Vikram, will separate from the orbiter on September 2, the agency added.

Two orbit manoeuvres will be performed on the lander before it lands on the lunar south polar region on September 7. Chandrayaan-2 had entered the Lunar Transfer Trajectory on August 14.

The spacecraft is being monitored from the Mission Operations Complex at ISRO Telemetry, Tracking and Command Network in Bengaluru with support from Indian Deep Space Network antennas at Byalalu, near the city.

Chandrayaan-2 was put into orbit on July 22 on board the Geosynchronous Satellite Launch Vehicle Mark III-M1, which lifted off from the Satish Dhawan Space Centre in Sriharikota in Andhra Pradesh. The space agency had said the spacecraft would reach the moon on August 20.

If the mission is successful, India will become the fourth country to achieve a soft landing on the moon after the United States, Russia and China. A successful landing would make Chandrayaan-2 the first lunar probe on the south polar region of the moon.

Also read: What does Chandrayaan-2 hope to accomplish?