India's Ambitious MARS Mission hits a major snag

India's mission to Mars has hit a snag, after a planned engine burn failed to raise the spacecraft's orbit around Earth by the intended amount.

The problem occurred during a manoeuvre designed to boost the craft's maximum distance from 71,623km to 100,000km.

A problem with the liquid fuel thruster caused the 1,350kg vehicle to fall short of the mark.

But the head of the Indian Space Research Organisation (Isro) said the spacecraft remained "healthy".

As a solution, the Mars Orbiter Mission (MOM) - known informally as Mangalyaan, or Mars-craft - will be commanded to execute an additional thruster firing at 05:00 IST on Tuesday (23:30 GMT on Monday) to make up for the shortfall.

However, independent experts cont acted by the BBC said they were puzzled by Isro's working hypothesis for the failure.

Instead of flying directly to Mars, the probe is scheduled to orbit Earth until the end of the month, building up the necessary velocity to break free from our planet's gravitational pull.

This was the fourth in a series of five engine burns known as "midnight manoeuvres" because several constraints require that they are carried out in the early hours of the morning.

Speaking to Pallava Bagla, science editor at Indian broadcasting network NDTV, Isro's chairman K Radhakrishnan said: "The spacecraft is healthy and it encountered a problem when a specific redundancy test was being conducted and it failed to reach the desired velocity it was to achieve."

In that redundancy test, two coils in the liquid engine were supposed to be energised simultaneously.

"When you are going so far away, if one thing fails, you want to have a standby option. Everything is almost doubled up on the satellite, which is why they were not able to carry so much scientific equipment," Mr Bagla explained.