Chandrayaan 1 update
Chandrayaan-I is now more than half way to the moon with the fourth orbitraising manoeuvre executed flawlessly on Wednesday at 7.38 am. The mission lifted off at Sriharikota on October 22.Director of Isro’s telemetry, tracking and command network (Istrac) S K Shivakumar said during this manoeuvre the spacecraft’s 440 Newton liquid engine was fired for about three minutes resulting in Chandrayaan-I entering a more elliptical orbit. Its apogee (farthest point to earth) lies at 2,67,000 km and the perigee (nearest point to earth) is at 465 km.Chandrayaan-I’s present orbit extends more than half the way to the moon, he said. In this orbit, the spacecraft takes about six days to go round the earth once. Shivakumar said the next firing will be on Monday which will further raise the spacecraft’s altitude to 3,84,000 km. The motor will be fired for 2.5 minutes. “This will be the last earth-bound firing before the spacecraft enters the lunar orbit on November 8,” he said.He said for the lunar orbit insertion (LOI) on November 8, which will take place at 5 pm, the engine will be fired for 800 seconds. Though Shivakumar said all manouvres were equally crucial, others in the Chandrayaan team said the LOI will be the most nerve-wracking. Even a minor deviation in the timing of the engine’s firing can doom the mission.“The ground stations in Thiruvanathapuram, Bangalore, Mauritius, Port Blair and Brunei are monitorning the firing of the spacecraft’s engines especially at the perigee. The process is working flawlessly with one station handing over charge to the other smoothly. It’s like a relay race,” Shivakumar said.He called the flight of the 29-kg moon impact probe from the main spacecraft to the lunar surface either on November 14 or 15 a ballistic descent or an uncontrolled flight. “The exact spot where it will crash land on the moon is being worked out by scientists,” he said.At present, a team of about 100 to 150 officials at Istrac in Bangalore are exclusively dedicated to Chandrayaan operations. “They’re working round-the-clock in shifts and some even have extended shifts in case the need arises,” he said. Once Chandrayaan gets into the routine phase of operations, the number of personnel assigned to the mission will be reduced to about 25, says.
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