Chandrayaan enters final orbit

Chandrayaan-I’s smooth voyage continued as the satellite successfully entered its final circular orbit only 100 km from the moon’s surface at 6.35 pm, triggering another round of back-patting among scientists and engineers in the mission control room at Isro’s telemetry, tracking and command network (Istrac) at Bangalore. After the heart-stopping entry of the satellite into the lunar orbit last Saturday, Chandrayaan is now prepared for the next most eagerly awaited event of the voyage—the launching of the 29-kg Moon Impact Probe (MIP) on the evening of November 14 with the Tricolour. It is tentatively scheduled to crashland in the Malapert crater on the moon’s south pole. The dramatic event coincides with Children’s Day, perhaps an attempt to excite the younger generations’ interest in space sciences. MIP team leader Ashok Kumar said once the probe is released, it will travel at a velocity of 1.6 km per second and slam into the moon’s surface about 25 minutes later. “During the flight, the video camera, altimeter and a spectrometer will operate, transmitting data to the main spacecraft,” he said. About an hour after the manoeuvre, project director Mylaswamy Annadurai and Istrac chief S K Shivakumar said the spacecraft with its 11 scientific instruments is coursing in the northsouth direction across the lunar poles at an altitude of 100 km above the moon’s surface. “It is known as the circular polar mission experimental orbit,” Shivakumar said, adding the experiments would be activated soon. In this orbit, Chandrayaan takes about two hours to go around the moon. Annadurai said the 440 Newton liquid engine of the spacecraft was fired for 58 seconds which reduced the velocity of the spacecraft by 32 metres per second to enable it to enter its final orbit. “On Thursday, we will closely monitor the performance of the spacecraft in this orbit,’’ he said.