While Isro has lost contact with the Vikram lander and Pragyaan rover, the Chandrayaan-2 orbiter remains safe in its orbit around the Moon (Reuters image)

An inexplicable flip that turned the Chandrayaan-2 lander upside down moments before it was to land on the Moon may explain what happened last Saturday, when the Indian Space Research Organisation lost all contact with the Vikram lander.

Data and readings from the Vikram lander's descent on to the lunar surface, gathered by the India Today Magazine, offer an exclusive glimpse into how the Chandrayaan-2 lander lost contact with Earth during its attempt to land on the Moon.

In the early hours of September 7, the Chandrayaan-2 lander began its descent on to the lunar surface. The descent was to last around 15 minutes and initially everything seemed to be going according to plan.

Around 11 minutes after Vikram began its descent, things went haywire.

At that point, Vikram was supposed to rotate slightly so that its cameras could map the lunar surface for a suitable landing site.

During this crucial movement, Vikram unexpectedly and inexplicably performed a somersault.

For a brief moment the Chandrayaan-2 lander was upside down over the lunar surface.

What this meant was that the reverse thrust-producing engines, which were slowing Vikram down, faced the sky for some time. And so, instead of slowing the craft down, the engines actually pushed the Vikram lander down towards the lunar surface.

This was clearly visible in the final readings sent by Vikram -- at 11 minutes and 28 seconds after beginning its descent, Vikram's vertical velocity (the speed with which it was descending on to the Moon) was 42.9 metres per second. A minute and a half later, the speed dramatically increased to 58.9 metres per second.

It was right after this that Vikram went silent and stopped communicating. It still has not gotten back in touch.

For more on the Chandrayaan-2 mission and what went wrong with Vikram, read this deep dive by India Today Group Editorial Director Raj Chengappa, published in this week's issue of India Today Magazine.

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WHAT NOW?

It's been nearly a week since the Indian Space Research Organisation lost contact with the Chandrayaan-2 lander. Since then, Isro, which continues to remain tight-lipped over the matter, has been making constant efforts to re-establish communication with the spacecraft.

A day after losing contact with Vikram, Isro said it had been able to locate the Chandrayaan-2 lander on the Moon. However, communication with the lander remains elusive.

Next week, a lunar orbiter operated by the United States' National Aeronautics and Space Administration (Nasa) is set to fly over the area where Vikram is located. The orbiter is expected to take pictures and offer clues to Vikram's fate.

Meanwhile, the Chandrayaan-2 orbiter remains safe in its orbit around the Moon. In fact, it was the Chandrayaan-2 orbiter that, on Sunday, managed to locate Vikram on the lunar surface.

The orbiter's mission life has been extended from one year to seven years, due fuel savings made during the trip to the Moon. Over the course of its mission life, the Chandrayaan-2 orbiter will perform several experiments, including one to estimate the quantity of iced water on the Moon.