7 November 2013
Last updated at 15:05
After a successful launch on Tuesday, India’s Mars spacecraft has carried out the first of six crucial engine firings in Earth orbit.
The probe performed the firing with its liquid fuel thruster at 19:47 GMT on Wednesday (Thursday 1:17 IST).
The aim is to gradually build up the necessary velocity to break free from our planet’s gravitational pull.
If the firings succeed, the spacecraft will travel for 300 days, ready for entering Mars orbit in 2014.
K. Radhakrishnan, head of the Indian Space Research Organisation (Isro), told the Times of India that the spacecraft was in “excellent health”.
After lift-off, the Mars Orbiter Mission (MOM) was placed into an elliptical parking orbit around Earth with a perigee (the point in the orbit closest to Earth) of 248.4 km and an apogee (the point farthest away) of 23,550 km.
The six major thruster firings are designed to manoeuvre the MOM into a so-called hyperbolic trajectory so that the probe escapes the Earth’s sphere of influence.
After a 10-month journey, the probe will arrive at Mars on 24 September next year. The engine will be fired again to slow down the spacecraft, enabling it to be captured by the planet’s gravity and place it into Martian orbit.
Four further manoeuvres between 8 and 16 November will raise the craft’s apogee to 192,000km.
“It’s going to be a large sequence of events,” said Mr Radhakrishnan.
On 1 December, the engine will be fired again for its “trans-Martian injection”, sending the craft on its way to the Red Planet.
This week, Prof Andrew Coates, from University College London’s Mullard Space Science Laboratory, told BBC News that the planned mechanics for getting to Mars were on a sound footing, and that the probe stood a good chance as long as its engines fired correctly.
But any delay in these operations would require precious extra fuel to be used to catch up with the desired path to Mars.
India’s PSLV rocket – the second choice for the mission after a beefier launcher failed – was not powerful enough to send the MOM on a direct flight to Mars.
So engineers opted for a method of travel called a Hohmann Transfer Orbit to propel the spacecraft from Earth to Mars with the least amount of fuel possible.
At a cost of about $72m (£45m), the MOM is extremely cheap by the standards of planetary missions.
Even so, some commentators have questioned whether India should be spending its millions on a planetary mission when a significant part of its population are in poverty and figures for childhood malnutrition are some of the highest in the world.