Indian space agency says $140m module has reached distance of 100km from moon’s surface and is set to land on Saturday.

The landing module of India‘s unmanned moon mission separated successfully from the orbiter on Monday in the run-up to its planned touchdown on the moon’s south polar region this weekend, the country’s space agency said.

All the systems of the orbiter and the lander are “healthy,” the Indian Space Research Organisation said in a statement.

Monday’s manoeuvre removed the lander from the orbiter’s top, where it had been sitting since the mission took off from southern India on July 22.

The module has reached a distance of about 100km from the moon’s surface, the space agency said.

It will attempt India’s first moon landing on a relatively flat surface on Saturday to study previously discovered water deposits.

The roughly $140m mission is known as Chandrayaan-2, the Sanskrit word for “moon craft.”

Chandrayaan-1 orbited the moon in 2008 and helped confirm the presence of water.

Space agency Chairman K Sivan has said that landing on the lunar surface involves a lot of technical complexities – an event he described as “15 terrifying minutes.”

If India does manage the landing, it will be only the fourth country to do so after the United States, Russia and China.

India plans to send humans into space by 2022.