BANGALORE: The Mars Orbiter spacecraft of the Indian Space Research Organisation (ISRO) moved closer to its home on Monday, as ISRO woke up its liquid engine from slumber and slowed down the spacecraft marginally. This is in preparation for the final manoeuvres on Wednesday morning, which will slow it further and place it in Martian orbit by 8 am.A successful set of manoeuvres will make ISRO the world’s only organisation to reach Mars in its first attempt. Monday’s operation was crucial as the Liquid Apogee Motor (LAM) was lying idle since December 1 last year. Although ISRO had tested the engine on the ground, a 10-month journey through the cold interplanetary space was a new experience for its engineers, and events there are unpredictable. The mission has so far gone like clockwork, with each manoeuvre executed with precision, thereby raising expectations for the rest of the mission.A faultless operation means that ISRO will save fuel and make the spacecraft last longer. If the LAM does not fire, it will have to use eight smaller thrusters to slow the spacecraft enough for capture by the red planet. But these thrusters are not as efficient as the main liquid engine, and so the spacecraft will spend more fuel on slowing down.The spacecraft will then be substantially higher than originally planned, thereby forcing a review of the scientific objectives of the mission. Monday’s firing, although only for 3.98 seconds, made sure the spacecraft approached the planet at the right altitude for maximum efficiency in operation.It will approach Mars on Wednesday at a velocity of just over 5 km per second, which will be slowed down to about 4.3 km per second after the LAM fires for 24 minutes starting 7.17 am. The news of each event — there is a series of them starting at 6.56 am — will reach the earth 12.5 minutes later.The first set of pictures will arrive in the afternoon. At an average distance of 224 million kilometres, Mars is so far away that a perfect mission to the planet is very difficult. Many of the Mars mission failures happened in the 1960s and 1970s, when scientists had not mastered some essential technologies.Failures happened even in the 1990s, after NASA had flown many successful missions. A Russian rocket to the planet never left the earth in 2011. This is why scientists can take nothing for granted while travelling to Mars. Which is also why India is close to a truly historic moment.